Congenital & Acquired Heart Defects. Cindi Mockel RN, MSN, PHN, FNP

Transcription

1 Congenital & Acquired Heart Defects Cindi Mockel RN, MSN, PHN, FNP

2 Review Of The Heart and Circulation: Fetal Circulation Oxygenated blood in the umbilical vein travels through the fetal liver through ductus venosus into the inferior vena cava Small amount of blood travels into the hepatic circulation to provide O2 and nutrients to the hepatic tissue Inferior vena cava empties to the right atrium then through the foramen ovale into the left atrium Oxygenated blood travels through the left ventricle into the aorta feeding the coronary arteries and the brain two most oxygenneedy organ system Blood returning from the upper body enters the superior vena cava into the right atrium and drains to the right ventricle and ejected into the pulmonary artery Resistance in the pulmonary circulation is very high because of collapsed fluid filled lung. Most of blood flow through the ductus arteriosus to the descending aorta to be distributed to the lower body organ systems and tissues and returns to the placenta for gas exchange.

3 Transitional and Neonatal Circulation With neonate s first breath, gas exchange is transferred from placenta to the lungs Fetal shunts (ductus venosus, ductus arteriosus, foramen ovale) close in response to pressure changes in the systemic and pulmonary circulation and increased blood oxygen content.

4 Overview of Normal Circulation At the start of each heartbeat, blood returning from the body and the lungs fills the heart's two upper chambers. The mitral and tricuspid valves are located at the bottom of these chambers. As the blood builds up in the upper chambers, these valves open to allow blood to flow into the lower chambers of your heart. After a brief delay, as the lower chambers begin to contract, the mitral and tricuspid valves shut tightly. This stops blood from flowing backward. As the lower chambers contract, they pump blood through the pulmonary and aortic valves. The pulmonary valve opens to allow blood to flow from the right lower chamber into the pulmonary artery. This artery carries blood to the lungs to get oxygen. At the same time, the aortic valve opens to allow blood to flow from the left lower chamber into the aorta. This aorta carries oxygenrich blood to the body. As the contraction ends, the pulmonary and aortic valves shut tightly. This stops blood from flowing backward into the lower chambers.

5 Overview of Heart Valves Tricuspid Valve (R AV Valve)- between the (R) Atrium and (R) Ventricle. Has 3 leaflets and 3 papillary muscles. They are connected to the papillary muscles by the chordae tendinae, which are in the right ventricle. Pulmonic Valve (Semilunar)- between the R ventricle and the Pulmonary Artery and has 3 cusps. Opens in ventricular systole when the pressure in the right ventricle rises above the pressure in the pulmonary artery. At the end of ventricular systole, when the pressure in the right ventricle falls rapidly, the pressure in the pulmonary artery will close the pulmonic valve.

6 Heart Valves (cont.) Mitral Valve between the L atrium (LA) and L Ventricle (LV). Has 2 leaflets. Opens to pressure from LA allowing blood to flow into the LV during LA systole (contraction) At the end of ventricular diastole, the bicuspid valve shuts, and prevents backflow as the ventricle begins its systolic phase. Aortic Valve between the LV and the Aorta. Has 3 leaflets. Because the ventricle is a pump, it must have both an inflow valve and an outflow valve. The aortic valve is on the left side of the heart and is the outflow valve. The aortic valve opens to allow blood to leave the LV and closes to prevent backflow of blood from aorta as it pumps out to the body.

7 Heart Sounds Heard on Auscultation Sound S1 (first heart sound) S2 (Second heart sound) S3 (Third Heart Sound) S4 (Fourth Heart Sound) Cause Closure of tricuspid and mitral valves w/ beginning of ventricular contraction. Closure of pulmonary and aortic valves with beginning of atrial contraction (diastole) Rapid ventricular filling Abnormal filling of ventricles

8 P wave: ECG deflection representing atrial depolarization. Atrial repolarization occurs during ventricular depolarization and is obscured. QRS wave: ECG deflection representing ventricular depolarization. T wave: ECG defection representing ventricular repolarization. Basic ECG

9 Disorders with Increased Pulmonary Blood Flow

10 Patent Foramen Ovale Patent Foramen Ovale (PFO) is an anatomical interatrial communication with potential for right-to-left shunt. allows a continuation of the atrial shunting of blood.

11 Atrial Septal Defects (ASD) 1 - atrial septal defect The shunt or abnormal flow is from left atrium to right atrium as indicated by the shaded red arrow.

12 Types of ASD s Ostium Primum Ostium Secundum Sinus Venosus Common atrium

13 ASD Pathophysiology A group of common (1% of cardiac) congenital anomalies defects occurring in a number of different forms and more often in females. Abnormal opening between the atria Four Types: differ in location in the atria Altered Hemodynamics Lower right ventricular compliance compared with left ventricular compliance leads to left-to-right shunting at the atrial level though the ASD Effect enlarged right atrium and ventricle and increased pulmonary blood flow

14 ASD Cont. Manifestations Many young and older children asymptomatic Fatigue and dyspnea Palpitation Acyanotic Systolic Murmur- ejection, medium pitch best 2 nd L IC space (murmur heard not because of shunt but increased blood flow through PV). Diastolic murmur (large shunts) Poor appetite Complications: RA & RV dilatation = RV dysfunction. CHF, Atrial dysrhythmias, paradoxical embolism, pulmonary vascular obstructive disease from pulmonary overcirculation. Therapeutic Management Spontaneous closure can occur in the 1 st year of life for small ASD many don t need tx Medical management: Diuretics and digoxin Antidysrhythmias Prophylactic antibiotics Surgical Intervention Surgical closure using suture or a pericardial or prosthetic patch Open heart surgery; Mediastinal incision.

15 Ventricular Septal Defect (VSD) The shunt or abnormal flow is from left ventricle to right ventricle as indicated by the shaded red arrow.

16 VSD Pathophysiology Abnormal opening between the right and left ventricles May vary in size from minuscule hole to complete absence of the septum, resulting in common ventricle Most common cardiac lesion often accompanied by other cardiac defect Altered Hemodynamics Pulmonary vascular circulation receives increased pulmonary blood flow Continuous high systemic pressure causes pulmonary hypertension which over time can lead to pulmonary vascular disease

17 VSD Continued Manifestation Asymptomatic at birth and children with small lesions Symptomatic moderated to large lesion Acyanotic Murmur (loud, harsh, pansytolic LSB 3 rd -4 th ICS Poor feeding and failure to thrive Complication: Eisenmenger s Syndrome uncorrected VSD reverses from left-to-right shunting to right-to-left shunting causing deoxygenated blood to mix with oxygenated blood resulting in decreased oxygen supply for the body Therapeutic management Spontaneous closure approximately 60% Medical Management CHF digoxin, diuretics, ACE inhibitor (reduce afterload) Increase caloric intake Prevent respiratory infection Surgical Intervention Suture or insertion of Prosthetic or Pericardial Patch For multiple VSD pulmonary artery banding (decreases pulmonary blood flow reducing risk for pulmonary artery disease

18 Patent Ductus Arteriosus (PDA) The shunt or abnormal flow is from aorta to pulmonary artery as indicated by the shaded red arrow.

19 PDA Pathophysiology PDA is caused by failure of the fetal ductus arteriosus to close completely Stimuli for closure are increased oxygen levels in the blood when infants begins to breath and decrease in prostaglandin level after birth Normal closure within hrs after birth (functional closure) and degenerates to a ligament (anatomic closure) within first week. Altered Hemodynamics Oxygenated blood from the aorta returns through the PDA to the pulmonary arteries (leftto-right shunting) to the lungs and onto the left atrium and left ventricle Effect increased workload on the left side of the heart and increased pulmonary blood flow Child s body receives insufficient amount of oxygenated blood

20 PDA cont Manifestation Many are Asymptomatic Continuous murmur (machinery) heard throughout systole and diastole) upper LSB or under cllavicle. Thrill Widened pulse pressure Bounding pulse Enlarge left ventricle Tachypnea Poor feeding Weight gain Frequent respiratory tract infection Diaphoresis Complications: CHF, pulmonary congestion, pulmonary infection, endocarditis, and aneurysm Therapeutic Management Prevent exposure to respiratory illnesses Caloric density increased to improve weight gain Frequent rest periods and position to optimize respiratory effort Medical Management: Diuretic and digoxin to control CHF Indomethacin (Indocin) prostaglandin inhibitor that promotes ductal constriction Interventional Cardiac Catheterization coil is placed that promotes embolization (occlusion) Surgical Management: perform through a left thoracotomy - ductus is ligated (circumferential sutures) or divided (surgically cut and the ends oversewn)

21 Atrioventricular Canal Defect 1 - atrial septal defect 2 - abnormal tricuspid valve 3 - abnormal mitral valve 4 - ventricular septal defect The shunt or abnormal flow is from left atrium to right atrium, left ventricle to right ventricle (as indicated by the shaded red arrows). Tricuspid and mitral valve regurgitation occurs as a result of the abnormal tricuspid and mitral valves. (AV Canal)

22 AV Canal Pathophysiology Atrioventricular (AV) canal defect is a large hole in the center of the heart. The defect is situated where the septal wall between the upper chambers (atria) joins the septal wall between the lower chambers (ventricles). In addition, the tricuspid and mitral valves (the atrioventricular valves), which normally separate the heart's upper and lower chambers, are not formed as individual valves. Instead, one large valve bridges the defect. Associated w/ Trisomy 21. Altered Hemodynamics There are two types of AV canal defects; partial and complete. The partial form involves only the two upper chambers of the heart. The complete form allows blood to travel freely among all four chambers of the heart. Both types allow extra blood to circulate to the lungs. Ensuing problems overwork the heart and cause it to enlarge. If left untreated, atrioventricular canal defect may cause congestive heart failure and high blood pressure in the lungs (pulmonary hypertension).

23 AV Canal Manifestations Difficulty breathing (dyspnea) Lack of appetite Poor weight gain Bluish discoloration of the lips and skin (cyanosis) Some develop CHF which includes; Fatigue and weakness Persistent cough or wheezing with white or pink blood-tinged phlegm Swelling (edema) in the legs, ankles and feet Swelling of the abdomen (ascites) Sudden weight gain from fluid retention Decreased alertness Irregular or rapid heartbeat Therapeutic Management Medical management Many children will eventually need to take medications to help the heart and lungs work better, due to strain from the extra blood passing through the septal defects. Medications that may be prescribed include the following: Digoxin Diuretics. ACE (angiotensin-converting enzyme) inhibitors High Calorie Formula/ MBM Tube Feedings Surgical management The goal is to repair the septal openings and repair the valves before the lungs become damaged from too much blood flow and pressure. The atrial and ventricular septal defects are often closed with a pericardial patch The valve repair technique will differ according to the abnormality.

24 Disorders with Obstruction to Blood Flow

25 Pulmonic Stenosis 1 - narrowed pulmonary valve blood flow patterns are normal but blood flow through the pulmonary artery is reduced as indicated by the broken white arrows.

26 Pulmonic Stenosis (PS) Pathophysiology With pulmonary stenosis, problems with the pulmonary valve make it harder for the leaflets to open and permit blood to flow forward from the right ventricle to the lungs. In children, these problems can include: a valve that only has one or two leaflets instead of three. a valve that has leaflets that are partially fused together. a valve that has thick leaflets that do not open all the way. Altered Hemodynamics The area around the pulmonary valve can become blocked or the blood vessel beyond the valve can become narrowed, causing the right ventricle to have to pump harder to get blood past the blockage to the pulmonary artery. If the stenosis is severe, there will be a lack of blood flow to the lungs and the baby can become cyanotic. The condition requires treatment when the pressure in the right ventricle is high.

27 Pulmonic Stenosis Manifestation Murmur- systolic ejection, grade IV or V cresendodecrescendo, LUSB may radiate to suprsternal notch, thrill may be present. 2 nd Sound may be widely split due to late closure of PV. heavy or rapid breathing shortness of breath fatigue rapid heart rate swelling in the feet, ankles, face, eyelids, and/or abdomen fewer wet diapers or trips to the bathroom Therapeutic management Balloon dilation or valvuloplasty - in a cardiac catheterization The catheter is placed in the narrowed valve, the balloon is inflated to stretch the area open. Valvotomy - surgical release of adhesions that are preventing the valve leaflets from opening properly. cardiac/ps.html

28 Aortic Stenosis (Valvular) 1 - narrowed aortic valve flow patterns are normal but blood flow to the aorta is reduced as indicated by the broken white arrows.

29 Aortic Stenosis Pathophysiology May be present in varying degrees, classified according to how much obstruction to blood flow is present. Problems with the aortic valve make it harder for the leaflets to open and permit blood to flow forward from the left ventricle to the aorta. In children, these problems can include a valve that: only has two leaflets instead of three (bicuspid aortic valve). has leaflets that are partially fused together. has thick leaflets that do not open all the way. area above or below the valve is narrowed (supravalvar or subvalvar). althlibrary/cardiac/as.html Altered Hemodynamics Mild AS may not cause any symptoms. Several problems may occur, however, when aortic stenosis is moderate to severe; The LV has to work harder to try to move blood through the tight aortic valve. Eventually, the LV is no longer able to handle the extra workload, and it fails to pump blood to the body efficiently. There is a higher than average chance that the aorta may become dilated (enlarged). This can increase the risk of an aneurysm or dissection of the aorta. There is a increased chance of developing bacterial endocarditis. The coronary arteries, may not receive enough blood to meet the demands of the heart.

30 Aortic Stenosis (cont.) Manifestation Murmur- rough systolic loudest in 2 nd RICS can be transmitted through shoulder, clavicle, neck vessels. Thrill may be present at suprasternal notch. fatigue dizziness with exertion shortness of breath irregular heartbeats or palpitations chest pain Therapeutic Management Beta blocker or Calcium Channel blocker- reduces cardiac hypertrophy. Post surgical anticogulation therapy thlibrary/cardiac/as.html Therapeutic management Repair options include the following: Balloon dilation - a cardiac catheterization When the tube is placed in the narrowed valve, the balloon is inflated to stretch the area open. Valvotomy - surgical release of adhesions that are preventing the valve leaflets from opening properly. Aortic valve replacement - the aortic valve is replaced with a new mechanism. Replacement valve mechanisms fall into two categories: tissue (biological) valves, which include animal valves, and mechanical valves, which can be metal, plastic, or another artificial mechanism. Aortic homograft - a section of aorta from a tissue donor with its valve intact is used to replace the aortic valve and a section of the ascending aorta. Pulmonary homograft (Ross procedure) - a section of the child's own pulmonary artery with the valve intact is used to replace the aortic valve and a section of the aorta. A section of pulmonary artery from a tissue donor with its valve intact is used to replace the transferred pulmonary artery.

31 Coarctation of the aorta Flow patterns are normal but are reduced below the coarctation. Blood pressure is increased in vessels leaving the aorta above the coarctation. The broken white arrow indicates diminished blood flow through the aorta.

32 Coarctation of the aorta (COA) Pathophysiology In coarctation of the aorta, the aorta is narrowed, at a point somewhere along its length. This restricts blood flow from the heart to the rest of the body. 30% of patients with coarctation also have a bicuspid aortic valve. Altered Hemodynamics In a critically ill newborn, the goals of management are to improve ventricular function and restore blood flow to the lower body. (PGE-1), is used to open the ductus arteriosus It is also often necessary to begin intravenous medications that improve the contraction of the heart. Babies will almost always need to be placed on a ventilator before surgery. In symptomatic newborns, surgical repair is usually done on an urgent basis following initial stabilization. Rarely, an infant will not improve with medical therapy and surgery must proceed before the infant has been stabilized.

33 COA cont Manifestations Murmur only occasionally present; soft or moderately loud systolic heard at apex & transmitted to L interscapular area. Hypertension in upper extremities Diminished pulses in the groin or the legs of an infant/ child. Left ventricle hypertrophy Therapeutic Management Cardiac catheter-based therapy. In selected cases, the area of narrowing may be dilated with a balloon. Occasionally placement of a meshcovered stent may be necessary in addition to the balloon dilation to keep the area open. The characteristics of the narrowing and the age of the child are considered in deciding if balloon dilation is an option for treatment. Therapeutic Management Surgical techniques to repair coarctation. The most common repair involves resection (removal) of the narrowed area with reanastamosis (reconnection) of the two ends to each other. Sometimes the resection (removal) must be extended towards the arch if there is a longer segment of narrowing. Less commonly, the narrowing may be opened with a patch or a portion of an artery may be used as a flap to expand the area (called a subclavian flap aortoplasty). Accessed through Left Thoracotomy. Child must be followed as recurrence of narrowing of the aorta at the area of the repair is possible, even years following treatment. The rate of restenosis is highest among newborns, occurring in almost 20 percent of patients.

34 Interrupted aortic arch 1 - interruption of aortic arch 2 - descending aorta connected to pulmonary artery by large patent ductus arteriosus 3 - ventricular septal defect Flow patterns are normal to the upper body. However, there is no flow of oxygenated blood to the lower body unless there exist, as in this drawing, shunts such as a ventricular septal defect that allows oxygenated blood into the pulmonary artery, and a patent ductus arteriosus that allows the partially oxygenated blood to travel from the pulmonary artery to the descending aorta (as indicated by the broken white arrow).

35 Interrupted aortic arch Pathophysiology- The aorta does not develop completely in the area of the arch. As a result, the aorta is divided into two parts that are not connected to each other. This prevents the flow of blood through the aorta. There are often other coexisting heart defects, such as a VSD. Altered Hemodynamics- Because blood flow through the aorta is blocked, the blood supply to the lower body is compromised. At birth, the open ductus arteriosus allows blood to flow from the right ventricle to the lower body.

36 Interrupted Aortic Arch Manifestations mottled or grey appearance to the lower body difference in systolic blood pressure between the right arm and the lower extremities difference in systolic blood pressure between the right arm and the lower extremities The 1st heart sound is normal. The 2 nd heart sound is usually single. Facial dysmorphism is frequently present because approximately 50% of patients with IAA have DiGeorge syndrome. Therapeutic Management Medical Management PGE Surgical Care Ross-Konno procedure Norwood-Rastelli procedure The arch interruption itself is usually treated with side-to-side anastomosis, rather than with conduit interposition. If the subaortic region is of good size, the ventricular septal defect is usually closed with a patch at the same occasion. Complications Persistent subaortic and aortic stenosis Residual ventricular septal defect Narrowing at the site of arch surgery

37 Disorders with Mixed Blood Flow

38 Transposition of the Great Arteries Transposition of the great arteries 1 - atrial septal defect or patent foramen ovale 2 - aorta connected to right ventricle 3 - patent ductus arteriosus 4 - pulmonary artery connected to left ventricle With the presence of an atrial septal defect, two parallel blood flows exist, with one recirculating oxygenated blood and one recirculating de-oxygenated blood. As shown in this diagram, mixing occurs via the atrial septal defect.

39 Pathophysiology In D-Transposition of the Great Vessels the aorta arises from the RV and the PA arises from the LV. In LTGA there is atrioventricular discordance as well as ventriculoarterial discordance. Systemic venous return enters the R atrium traverses a morphological mitral valve & LV which in turn gives rise to a Pulmonary Valve and Pulmonary Artery. Pulmonary venous return enters the LA, traverses a morphological tricuspid valve & RV which gives rise to a Aortic Valve & Aorta. DTGA & LTGA Altered Hemodynamics Desaturated venous blood is pumped back into systemic circulation and oxygen rich blood is pumped back to the PA. These Pts must have a communication between the systemic circulation & pulmonary circulation. Newborns with transposition survive only if they have one or more connections that let oxygen-rich blood reach the body. These connections may be in the form of a hole between the two ventricles, a patent foramen ovale or a patent ductus arteriosus. Most babies born with transposition are extremely blue soon after birth because their bodies are not receiving enough oxygenated blood.

40 Transposition of the great arteries Manifestation Severe cyanosis * rapid breathing labored breathing rapid heart rate cool, clammy skin *Cyanosis is noted in the first hours of life in about 50% of the infants with TGA, and within the first days of life in 90 % of them. The degree of cyanosis is related to the presence of other defects that allow blood to mix, including a patent ductus arteriosus which usually closes in the first few days after birth. Long term complications arrhythmias CHF/ Cardiomegaly leaky heart valves narrowing of one or both of the great arteries at the switch connection site(s) narrowing of the coronary arteries at their switch connection site Therapeutic management Balloon atrial septostomy may be performed to improve mixing of oxygen-rich (red) and oxygenpoor (blue) blood. Prostaglandin E1 Arterial Switch DTGA/ Double Switch in LTGA in first 1-2 weeks of life. High calorie MBM or formula Nasogastric feeding TX of arrhythmias TX of CHF

41 Partial anomalous pulmonary venous return 1 - location where right pulmonary veins normally enter left atrium 2 - right pulmonary veins entering right atrium Oxygenated blood flows from the right pulmonary veins into the right atrium instead of into the left atrium. PAPVR

42 Partial anomalous pulmonary venous return (PAPVR) Pathophysiology Exists when one or more of the pulmonary veins drain to the left atrium while the other vein is connected to the right atrium. The result is that some oxygen-rich blood is returned to the right atrium and mixes with venous blood, and is then returned to the lungs instead of flowing out of the heart to the body. The result of this anomaly is that the right side of the heart must work harder. PAPVD is often associated with an ASD or with more complex cardiac defects. Altered Hemodynamics The most important factor is the number of pulmonary veins that drain into the systemic circulation. The more veins that anomalously drain, the more blood returns to the right side of the heart. this defect becomes clinically significant when 50% or more of the pulmonary veins anomalously return.

43 Manifestation About 10% of patients with an atrial septal defect (ASD) also have PAPVC and may have symptoms of right-sided overload. Left parasternal lift reflects right ventricular dilation. Impulse in the second left intercostal space reflects pulmonary artery dilation. soft systolic ejection murmur is heard over the pulmonary area Dyspnea Palpitations / Cardiac arrhythmias Hemoptysis Chest pain /right-heart ischemia Recurrent bronchitis Peripheral edema can occur in adults with cardiac failure. PAPVR Therapeutic Management Medical therapy Not indicated for asymptomatic pts CHF can be treated with diuretics, cardiac glycosides, afterload reduction, and beta blockade. Surgical Therapy PAPVC to the superior vena cava (SVC), the repair techniques may include internal patch technique, with or without SVC enlargement, or the caval division technique with atriocaval anastomosis (Warden technique). Children with internal patch technique must be observed for obstruction of the SVC with SVC syndrome, sick sinus syndrome, obstruction of the pulmonary veins, and supraventricular tachyarrhythmias.

44 Total Anomalous Pulmonary Venous Return (TAPVR) Total anomalous pulmonary venous Return (showing pulmonary veins connected to the left innominate vein) 1 - superior vena cava 2 - atrial septal defect 3 - left innominate vein 4 - pulmonary veins Oxygenated blood returning from the lungs is routed back into the superior vena cava, rather than the left atrium. The presence of an atrial septal defect is necessary to allow partially oxygenated blood to reach the left side of the heart.

45 Total anomalous pulmonary venous Pathophysiology In TAPVR, the four pulmonary veins are connected somewhere besides the left atrium. There are several possible places where the pulmonary veins can connect. The most common connection is to a blood vessel that brings oxygenpoor (blue) blood back to the right atrium, usually the superior vena cava. In TAPVR, oxygen-rich (red) blood that should return to the left atrium, the left ventricle, the aorta, and then the body, instead mixes with the oxygen-poor (blue) blood flowing into the right side of the heart. Total anomalous pulmonary venous return makes up about 1 to 2 percent of all congenital heart defects and occurs equally in boys and in girls. return (TAPVR) Altered Hemodynamics This situation by itself will not support life, because there is no way for oxygen-rich (red) blood to be delivered to the body. Both congestive heart failure and pulmonary artery hypertension may develop. Signs of these may appear soon after birth and vary in severity. They include a lethargic appearance, pallor or cyanosis, poor feeding and weight loss. TAPVR is usually repaired

46 TAPVR (cont) Manifestations rapid breathing labored breathing rapid heart rate cool, clammy skin lethargy poor feeding Asplenic (frequently) This situation by itself will not support life, because there is no way for oxygen-rich (red) blood to be delivered to the body. Therapeutic Management Surgical repair The four pulmonary veins are reconnected to the left atrium, and any associated heart defects such as atrial septal defect, ventricular septal defect, patent foramen ovale, and/or patent ductus arteriosus are surgically closed.

47 Truncus Arteriosus One major artery or trunk arises from right and left ventricles.

48 Truncus Arteriosus Pathophysiology The aorta and pulmonary artery start as a single blood vessel, which eventually divides and becomes two separate arteries. Truncus arteriosus occurs when the single great vessel fails to separate completely, leaving a connection between the aorta and pulmonary artery. Usually accompanied with a VSD. Altered Hemodynamics Mixing of blood through the ventricular septal defect. This mixed blood then flows through the common truncal vessel. Some of it will flow through the branch that becomes the pulmonary artery and on to the lungs, and some of the mixed blood will go into the aortic branch and continue to the body. Altered Hemodynamics The pulmonary artery section of the common vessel gets more blood flow than the aorta does, because the resistance is lower in the lungs than the body and it is easier for blood to travel in that direction. If not repaired, the blood vessels in the lungs become damaged by the extra blood flow. As the pressure in the blood vessels in the lungs becomes higher, less blood goes to the lungs and more goes to the body. Cyanosis becomes worse as blood with lower amounts of oxygen travels to the body.

49 Truncus Arteriosus Manifestations Cyanosis Murmur from VSD fatigue sweating pale skin cool skin rapid breathing heavy breathing rapid heart rate congested breathing disinterest in feeding, or tiring while feeding poor weight gain Therapeutic Management Medical management Digoxin Diuretics ACE inhibitors Surgical Management- Surgery is usually performed after the infant is two weeks old, but before the blood vessels in the lungs are overwhelmed by extra blood flow and become diseased. The pulmonary arteries are detached from the common artery (truncus arteriosus) & connected to the RV using a homograft (a section of pulmonary artery with its valves intact from a tissue donor). Occasionally, a conduit (a small tube containing a valve) is used instead of a homograft (human tissue valve). The ventricular septal defect is closed with a patch.

50 Double Outlet Right Ventricle Double outlet right ventricle 1 - overriding aorta 2 - ventricular septal defect De-oxygenated blood enters the aorta from the right ventricle and is returned to the body.

51 DORV Pathophysiology Double outlet right ventricle (DORV) is a condition in which both the pulmonary artery and the aorta connect to the right ventricle. (several variations); DORV with subaortic ventricular septal defect: the VSD is located just below the aorta. DORV with subpulmonary VSD: the VSD occurs below the pulmonary artery. DORV with doubly committed VSD: the VSD occurs in two places, both below the aorta and the pulmonary artery. DORV with non-committed VSD: the VSD occurs in a position that is away from either of the great arteries. Altered Hemodynamics The two major symptoms are congestive heart failure and cyanosis. In some cases, cyanosis can become severe because of reduced pulmonary blood flow. Several associated cardiac anomalies; Pulmonary Stenosis % ASD % PDA- 16% AV Canal 8% Subaortic Stenosis 3-30% Coarctation, hypoplastic arch, IAA -2-45% Mitral Valve Anomalies 30%

52 Double outlet right ventricle (DORV) Manifestations Symptoms tend to occur early in life, often within days of birth. Fatigue Sweating Heart murmur Rapid breathing Congested breathing Shortness of breath Blue color of the skin, lips and nailbeds (cyanosis) Disinterest in feeding or tiring while feeding Poor weight gain Therapeutic Management Corrective repair- leads to biventricular repair; thus, the left ventricle is connected to the aorta, and the right ventricle is connected to the main pulmonary artery. Palliative repair Pulmonary banding BT Shunt / RV to PA conduit followed by Glenn and Fontan procedures. Kawashima procedure Damus-Kaye-Stansel repair

53 HLHS Hypoplastic left heart syndrome 1 - Patent Foramen Ovale / ASD 2 Coarctation of aorta 3 - Patent Ductus Arteriosus 4 Aortic Stenosis (Narrowed ascending aorta or aortic arch) 5 - Hypoplastic left ventricle 6 Aortic Valve atresia/ Mitral Valve atresia/stenosis

54 Pathophysiology (HLHS) refers to the grouping of congenital cardiac defects. The main characteristics are the marked hypoplasia (underdevelopment) or even absence of the left ventricle and severe hypoplasia of the aorta. Often a localized coarctation of the aorta is also present. The main pulmonary artery is enlarged, and gives rise to a large ductus arteriosus. This allows blood to flow from the right ventricle into the aorta and out to the body. Other characteristics of HLHS often include a combination of aortic and mitral stenosis or aortic and mitral atresia. The lack of a developed left ventricle, plus the aortic coarctation leads to reversed blood flow through the aorta. Partially oxygenated blood reaches the aorta after traveling through the patent foramen ovale, up the pulmonary trunk and through the patent ductus arteriosus. The major blood flow to the systemic circulation is through the PDA. HLHS Altered Hemodynamics The oxygenated blood is unable to flow from the Left atrium to the Left ventricle. So the blood is shunted to the Right side of the heart through a patent foramen ovale into the right atrium, where it is mixed with deoxygenated blood. Next the mixed oxygenated blood travels to the Right ventricle to the main pulmonary artery. (A portion of the blood goes out the branch pulmonary arteries to the lungs, coronary, and systemic circulation.

55 HLHS (Cont) Manifestations Infants usually present within the 1 st few day of life with: Tachypnea Early CHF (from increased pulmonary blood flow) Systemic hypoperfusion and shock (when the ductus arteriosus begins to close)* Grayish blue in color Dyspnea Hypotension Therapeutic Management Options: Supportive Care only Surgical staged repair Cardiac transplantation * Medical Management Emergency management addresses correction of the acid-base and electrolyte imbalance and reestablishment of the ductal patency with PGE. Surgical Management (2 choices) Cardiac transplant three-stage palliative repair.

56 Disorders with Decreased Pulmonary Blood Flow

57 Tetralogy of Fallot 1 - pulmonary stenosis (a form of right ventricular outflow tract obstruction) 2 - right ventricular hypertrophy 3 - overriding aorta 4 - ventricular septal defect the degree of pulmonary stenosis controls the flow patterns. The shaded blue arrows show blue blood mixing with red blood. The broken white arrows indicate diminished blood flow through the pulmonary artery. (TET or TOF)

58 Tet Position

59 TET Pathophysiology Most common cyanotic lesion in older infants and children Malalignment of the ventricular septum during fetal development result in four characteristics of the lesion: Ventricular Septal defect Pulmonary stenosis Overriding of the aorta (into the right ventricle instead of over the left ventricle Right ventricular hypertrophy Altered Hemodynamics Desaturated blood from the right ventricle shunts to the left into the aorta causing desaturated blood enter the systemic circulation Decreased pulmonary blood flow Severe pulmonary stenosis depends on PDA allowing blood to be oxygenated in the lungs

60 TET (cont.) Manifestation Cyanosis Squatting to get more air Tet spells - bluish skin during crying or feeding SOB Tire easily Difficult feeding and gaining weight Clubbing Boot-shaped heart of chest radiograph Therapeutic Management Monitor for worsening hypoxemia Prevent dehydration Hypercyanotic 100% oxygen, calm the infant or child, kneechest position Medical management Continuous PGE1 infusion to maintain PDA Surgical management Definitive repair cardiopulmonary bypass Usually done at 3-5 years

61 Tricuspid atresia (showing no opening between the right atrium and ventricle) 1 - atrial septal defect 2 - absent tricuspid valve 3 - ventricular septal defect Blood is shunted through an atrial septal defect to the left atrium and through the ventricular septal defect to the pulmonary artery. The shaded arrows indicate mixing of the blood. Tricuspid Atresia

62 Tricuspid Atresia Pathophysiology Tricuspid valve is missing, preventing blood from flowing from the right atrium into the right ventricle. Because the right ventricle has no blood to pump, it remains small and underdeveloped. Survival depends on the presence of two septal defects: an atrial septal defect (ASD) and a ventricular septal defect (VSD). The ASD allows the venous blood to flow from the right atrium into the left atrium. There, venous blood mixes with oxygen-rich blood from the lungs, flows to the left ventricle, into the aorta and out to the body. The rest of the mixture is pumped from the left ventricle through the VSD into the right ventricle, and on through the pulmonary artery back to the lungs. Altered Hemodynamics Desaturated blood enters the right atrium and shunted right to left through foramen ovale or ASD into left atrium and mixes with the saturated blood Some mixed saturated blood flows out of the aorta and some flows though VSD and into the right ventricle to the lungs If no VSD or has severe pulmonary stenosis, child relies of PDA for pulmonary blood flow. Sometimes the baby will also have other cardiac defects. These include transposition of the great arteries (to be discussed later), coarctation of the aorta or pulmonary atresia.

63 Tricuspid Atresia (cont.) Manifestation Cyanosis Only single first heart sound Murmur Clubbing SOB Difficult feeding and gaining weight Therapeutic management Monitor for worsening hypoxemia Prevent dehydration Hypercyanotic 100% oxygen Medical Management PGE1 to keep PDA open Cardiac Catheterization - Balloon atrial septostomy balloon inflated in the foramen ovale is pulled back to tear the septum. The majority of babies with tricuspid atresia are cyanotic at birth. These children will require surgery to place a tube (known in medical terms as a shunt), which will provide an increase in blood flow to the lungs. Other children have too much blood flowing to the lungs and need a procedure called pulmonary artery banding. In this procedure, a band is placed around the pulmonary artery to narrow it, and to reduce the blood flow and resultant high pressure in the lungs.

64 Pulmonary Atresia Pulmonary atresia 1 - atrial septal defect 2 - patent ductus arteriosus 3 - absent pulmonary valve 4 - hypoplastic right ventricle Abnormal blood flow (as indicated by the shaded blue arrow) is from the right atrium and right ventricle through an atrial septal defect to the left side of the heart. Blood can reach the pulmonary arteries only through a patent ductus arteriosus.

65 Pulmonary Atresia Pathophysiology No pulmonary valve exists. Blood is therefore unable to flow from the right ventricle into the pulmonary artery and onward to the lungs. As a further result, the right ventricle usually remains hypoplastic. In addition, the tricuspid valve or right atrioventricular valve is often poorly developed. Altered Hemodynamics The only means of getting blood flow to the lungs is through the ductus arteriosus, which connects the pulmonary artery and the aorta. The infant is usually cyanotic. Blood returning to the right atrium and right ventricle therefore needs to shunt across to the left side of the circulation, through either an ASD or a patent foramen ovale. A further problem arises when the ductus arteriosus closes, causing severe cyanosis.

66 Pulmonary Atresia Manifestation Cyanosis Rapid breathing Difficulty breathing Irritability Lethargy Pale, cool, or clammy skin Long term complications- Heart failure Clubbing Abnormal heart rhythms Recurrence of pulmonary artery narrowing Therapeutic management PGE1 to keep the ductus open. Cardiac catheterization - Depending on the child s anatomy and the size of the right ventricle, a balloon procedure may be used to open the pulmonary valve. The inflated balloon through the narrowed section of the pulmonary valve to stretch the area open. This procedure may require surgery in additional to assure adequate blood flow to the lungs. Types of surgical procedures that may be used include the RV to PA conduit or homograft, the Glenn procedure, and the Fontan procedure.

67 Acquired Heart Disease

68 Acquired Heart Disease Occurs after birth May be a complication of a congenital heart disease or a response to respiratory infection, sepsis, hypertension, or severe anemia Heart failure is a decrease in cardiac output necessary to meet the metabolic needs of the body

69 Congestive Heart Failure

70 Congestive Heart Failure (CHF) Pathophysiology Is a condition in which the heart cannot pump enough oxygenated blood to meet the needs of the body. The heart keeps pumping, but not as efficiently as a healthy heart. Heart failure often occurs in children with congenital (present at birth) heart defects. Altered Hemodynamics In children CHF is most often caused by: Volume overload Pressure overload - from and underlying defect. (e.g large shunts or palliated complex defects) Other causes: Congenital and acquired structural abnormalities Dysrhythmias Infections (endocarditis, myocarditis) Chronic Lung Disease Inborn metabolic disorders Anemia Hypertension Hemorrhage Tumors Drugs and Toxins

71 Manifestations Tachycardia Tachypnea Wheezing, cough, congestion Edema Neck Distention Decreased Urinary Output Enlarged liver Dyspnea Cyanosis Poor feeding from exhaustion and dyspnea. Failure to Thrive CHF (cont.) Therapeutic Management Medications that are commonly prescribed to treat heart failure in children include the following: digoxin - a medication that helps strengthen the heart muscle, enabling it to pump more efficiently. diuretics - helps the kidneys remove excess fluid from the body potassium-sparing diuretics - helps the body retain potassium, an important mineral that is often lost when taking diuretics. potassium supplements - replaces the potassium lost when taking diuretics. ACE (angiotensin-converting enzyme) inhibitors - dilates the blood vessels, making it easier for the heart to pump blood forward into the body. beta blockers - decrease the heart rate and blood pressure, and improve heart function by blocking the stress hormone adrenalin.

72 Pathophysiology Cardiomyopathy is any disease of the heart muscle in which the heart loses its ability to pump blood effectively. In some instances, heart rhythm is disturbed and leads to arrhythmias (irregular heartbeats). There may be multiple causes of cardiomyopathy, including viral infections. Sometimes, the exact cause of the muscle disease is never found. 3 types of cardiomyopathy affect both adults and children. Cardiomyopathy Dilated cardiomyopathy most common form of cardiomyopathy. The heart muscle is enlarged and stretched (dilated), causing the heart to become weak and pump inefficiently. Hypertrophic cardiomyopathy, the muscle mass of the left ventricle of the heart is larger than normal, or the wall between the two ventricles (septum) becomes enlarged. These abnormalities obstruct the blood flow from the left ventricle.often hereditary. Restrictive cardiomyopathy, the least common type of cardiomyopathy in the US, occurs when the heart muscle of the ventricles becomes excessively rigid, and the filling of the ventricles with blood between heart beats is impaired. This condition occurs rarely in children.

73 Cardiomyopathy Manifestations pale or ashen skin color cool, sweaty skin rapid heart rate rapid breathing rate shortness of breath fatigue irritability chest pain poor appetite slow growth Therapeutic Management Medical Treatment: decrease the workload of the heart decrease the oxygen requirements of the heart prevent blood clots from forming regulate irregular heartbeats Surgical treatment may include: removal of part of the enlarged muscle artificial pacemaker heart transplantation

74 Persistant Pulmonary Hypertension (PPHN) Pathophysiology Persistent pulmonary hypertension (PPHN) is also known as persistent fetal circulation. High blood pressure in the arteries that supply the lungs. Narrowing of the arteries creates resistance and increased work for the heart. Mean Pulmonary Artery Pressure of >20 mm Hg (15 Normal) Altered Hemodynamics When blood is shunted away from the baby's lungs, it is difficult for the lungs to do the work of exchanging oxygen and carbon dioxide. Even breathing air with 100 percent oxygen, babies with PPHN have low blood oxygen levels. This can be serious, as all of the body's organs are dependent on oxygen-rich blood being pumped to them and may become damaged from lack of oxygen.

75 PPHN Manifestations baby appears ill at delivery or in first hours after birth cyanosis rapid breathing rapid heart rate low blood oxygen levels while receiving 100 percent oxygen Therapeutic Management supplemental oxygen (giving 100 percent oxygen by a mask or plastic hood) Intubation & Ventilation inhalation of nitric oxide (to help dilate the blood vessels in the lungs) extracorporeal membrane oxygenation (ECMO) Treatment of PPHN is aimed at increasing the oxygen to the rest of the body systems. Longterm health problems may be related to damage from lowered oxygen in the body.

76 Rheumatic Fever

77 Rheumatic Fever Pathophysiology Rheumatic fever is a complicated, involved autoimmune disease that occurs as a delayed reaction to group A betahemolyticstreptococcus bacteria, such as strep throat and scarlet fever. It that affects the joints, skin, heart, blood vessels, and brain. The symptoms of rheumatic fever usually start about 1-5 weeks after child has been infected with streptococcus bacteria. Jones Criteria diagnostic tool Major criteria include: carditis (inflammation of the heart) polyarthritis (inflammation of more than one joint) chorea (unusual jerky movements, most often involving the face and hands) subcutaneous nodules (small, painless bumps under the skin, often over bony areas) rash (a red, macular irregular rash on the trunk) Minor criteria include: Fever arthralgia (pain in one or more joints) previous rheumatic carditis (inflammation of the heart) changes in the electrocardiogram (EKG) pattern prolonged P-R & QT intervals abnormal sedimentation rate or C- reactive protein

78 Rheumatic Fever Manifestations Fever Chorea Arthralgia Polyarthritis Erythema marginatum Subcutaneous nodules Elevated ESR, CRP Presence of Anti-streptococcal titer (ASO) Therapeutic Management Eradication of the streptococcal bacteria and treatment of other symptoms, such as joint inflammation, CHF, and chorea. Penecillin is the drug of choice. Once the diagnosis is firmly established, antiinflamatory agents, including aspirin, or corticosteroids in the presence of significant carditis, are administered to speed resolution of the inflammatory process. Children who have had rheumatic fever are susceptible to recurrent attacks, risk further cardiac valve damage, and require secondary prophylaxis to prevent recurrence. The child without cardiac complications should receive antibiotic prophylaxis for 5 years or through age 21 to 25 years. Those with rheumatic heart disease should continue prophylaxis for at least 10 years and at least until age 40 years.

79 Kawasaki Disease

80 Kawasaki Disease Pathophysiology- Kawasaki disease is the most common form of vasculitis that primarily affects children. It is not clear what causes Kawasaki disease. Scientists believe a virus may be responsible, but current research is still underway. Kawasaki disease does not appear to be contagious, nor does it appear to be hereditary. The vast majority of children who develop Kawasaki disease are under age 5. The average age child seen with the illness is 2 years old. It occurs in boys twice as often as in girls. Altered Hemodynamics The disease produces irritation and inflammation of many tissues of the body, including the hands, feet, whites of the eyes, mouth, lips, and throat. High fever and swelling of the lymph nodes in the neck also are characteristic of this illness. The inflammation is uncomfortable, but resolves with time. However, the main threat from Kawasaki disease comes from its effect on the heart and blood vessels. Heart-related complications can be temporary or may affect the child long-term. The heart, particularly the coronary arteries, is affected in as many as 15 percent to 25 percent of children with Kawasaki disease.

81 Kawasaki Disease Manifestations 3 phases The acute stage lasts approx. 10 to 14 days Fever lasting more than 5 days and is unresponsive to antibiotic treatment (101 F to 104 F), frequently rises and falls Bilateral, nonpurulent conjunctivitis Swelling of the hands and feet and erythema of the palms and soles Generalized erythamatous rash and enlarged cervical nodes Tachycardia and extreme irritability Subacute stage lasting 15 to 25 days Fever disappears, and most symptoms resolve Continued irritability Anorexia Desquamation of the fingers and toes Arthritis and arthralgia Cardiovascular manifestations (CHF, dysrhythmias, aneurysms) Convalescent stage begins on day 26 and lasts until all signs of illness have disappeared.