Heart Failure: Signs and symptoms, pathophysiology, how does it present in children?

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1 Gilbert Lam Reviewed and Edited by Brenda Law, MD, Pediatrics Resident Heart Failure: Signs and symptms, pathphysilgy, hw des it present in children? General Presentatin Backgrund Heart Failure (HF) is the clinical cnditin in which the heart fails t meet the metablic and circulatry demands f the bdy. It presents as the final cmmn pathway f a cmbinatin f structural, functinal and bilgic mechanisms. Pulmnary and/r systemic cngestin may develp as a cnsequence f heart failure, resulting in Cngestive Heart Failure (CHF) Althugh the incidence f Heart Failure in children is difficult t estimate, its imprtance lies in its many causes and etilgical factrs. Presentatin Fundamentally, differences exist depending n whether r nt HF presents in patients with a structurally nrmal heart, r patients with cngenital heart disease. Virtually all patients wh develp HF frm cngenital heart lesins d s by 6 mnths f age. Patients wh acquire HF frm acquired cnditins may d s at any age. Infants with heart failure ften presents with nn-specific signs, including irritability, diaphresis with feeds, failure t thrive. Older Children with HF may present with mre classic features such as fatigue, exercise intlerance, breathlessness, and/r evidence f pulmnary cngestin. Pathphysilgy CHF ccurs due t the heart s inability t keep up with hemdynamic needs, and can result frm wrsening systlic and/r diastlic dysfunctin. In systlic dysfunctin, the strke vlume decreases, thereby reducing cardiac utput. Subsequently, the heart respnds with 3 cmpensatry mechanisms: a) increasing left ventricular vlume r elasticity, b) increasing cntractile state by activatin f circulating catechlamines, r c) increasing filling r prelad. Each cmpensatry mechanism is limited, s in an untreated patient, the heart fails, leading t HF. On the ther hand, in diastlic dysfunctin, strke vlume is decreased frm decreased ventricular filling. T cmpensate, left ventricular end-diastlic pressure is increased. Diastlic dysfunctin may be caused by cnditins such as hypertensin (causing ventricular hypertrphy). Particularly in children, ne f many cngenital abnrmalities may lead t dysfunctin f the heart, causing increased cmpensatry mechanisms and ths

2 HF. The mechanism fr heart failure include vlume verlading (frm right t left sided shunting, fr example), valvular incmpetence, increased afterlad (such as valvular stensis r carctatin), and thers. Questins t Ask Infants: (asking the parents) Hw are they feeding? Des the baby tire ut, r have t rest in the middle f feeding? Des the baby change clur during feeds? Is the baby grwing? Any episdes f blueness arund the lips r face? Children D yu feel shrt f breath when exercising? Can yu keep up with ther children? Can yu run r play as much as befre? D yu feel shrt f breath when lying dwn? D yur hands and/r feet feel cnstantly cld? D yu ften feel sweaty? T parents: Have yu nticed a change in their activity level? Are they keeping up with ther kids? Any episdes f blueness? Nticed any facial puffiness? (facial edema) D they seem tired? Differential Diagnsis The etilgy f HF varies depending n whether r nt the cngenital abnrmalities exist. Tables 1 and 2 list cmmn causes f HF in patients with a structurally nrmal heart, and with cngenital heart disease, respectively. Table 1: Cmmn causes f heart failure in the structurally nrmal heart Prenatal Nenates and infants Childhd Anemia Anemia Acquired valve disrders Arrhythmia Arrhythmia Anemia Arterivenus fistula Arterivenus fistula Arrhythmia Cardimypathy Dilated cardimypathy Dilated cardimypathy Twin-twin transfusin Endcrinpathies Hypertensin Hypglycemia Renal failure

3 Hypthyridism Restrictive cardimypathy Hypxic ischemic injury Hypertensin Infectin/sepsis Kawasaki syndrme Table 2: Cmmn causes f heart failure in patients with cngenital heart disease. Prenatal Nenates and Infants Children Atriventricular valve regurgitatin Mitral stensis with intact atrial septum Systemic utflw bstructin Artic valve stensis Carctatin f the arta Subartic stensis Systemic inflw bstructin Pulmnary venus stensis Systemic ventricular vlume verlad Artic r mitral regurgitatin Atrial/Ventricular septal defect Mitral stensis Patent ductus arterisus Artic regurgitatin Mitral regurgitatin Mitral stensis Pulmnary vein stensis Physical Examinatin: a cmplete general physical exam with vitals

4 Vital signs: Tachycardia (>160 beats per minute in the nenate; >120 beats per minute in the lder infant) Tachypnea (>60 breaths per minute in the nenate; >40 breaths per minute in the lder infant) Bld pressure. D 4 limb bld pressures if artic carctatin is suspected. Oxygen saturatin is present in cyantic cngenital heart diseases. Grwth parameters, especially weight pr weight gain is a key indicatin f prly cmpensated heart failure. General appearance: Perspiratin, Dysmrphic features (ften assciated with syndrmes), cyansis, increased wrk f breathing Cardivascular Exam: Pulses feel fr brachial, femral, and pedal pulses. Pulses may be bunding r weak, depending n the underlying cause and the significance f the heart failure. There may als be a delay between the brachial and femral pulses, in the case f carctatin Capillary refill time JVP Useful in children lder than 5-6 years ld, althugh it may be difficult t btain. In infants and yunger children, right sided cngestin tend t present as hepatmegaly and facial edema. Precrdial exam: Palpate fr thrills and right and left sided heaves Listen fr S1, S2. Abnrmal S1 S2 may be a clue t valvular disease. A lud P2 is in strng indicatin f pulmnary verlad. Listen fr gallp rhythms (S3, S4) and murmurs Infants with cardimypathy ften present with a quiet precrdium Respiratry Exam: Signs f increased wrk f breathing, including tachypnea, indrawing, tracheal tugging. Auscultatin, listening fr signs f pulmnary edema

5 Labratry Investigatins: Chest X-ray: very cmmnly demnstrates cardimegaly. The shape f the cardiac silhuette may gives clues t certain structural heart diseases, and als t right versus left sided heart invlvement. Pulmnary markings are ften increased, shwing pulmnary cngestin. Hwever, right sided heart failure may result in decreased pulmnary perfusin. Electrcardigram: usually abnrmal, and althugh nt useful in assessing HF, may give diagnstic hints fr the underlying disrder thrugh demnstrating ventricular enlargement, artrial enlargement, ST changes assciated with mycarditis / pericarditis, and arrhythmias. Urine test: In chrnic heart failure, prteinuria and high specific gravity f urine are cmmn. Bld test: An increase in bld urea nitrgen and creatinine levels may be present, as renal functin decreased due t decreased perfusin. CBC, differential may give clues t anemia and infectin causing r cmplicating HF. Brain natriuretic peptide (BNP) may be used in sme cases t track heart failure. Echcardigram: Invaluable in ruling ut structural heart disease and evaluating cardiac functin, including atrial and ventricular size, systlic and diastlic functin, valve anatmy and functin, and the presence and hemdynamic signficance f intra-cardiac shunts. Endmycardial bipsy: fr evaluatin f mycarditis Thyrid, Renal and Hepatic functin tests References Hay, W. Levin, M. Deterding, R., and Sndheimer, J. Current Diagnstic and Treatment Pediatrics (19e) McPhee, S.J., and Hammer G.D. Pathphysilgy f Disease, An Intrductin t Clinical Medicine (6e) Keane, J. F., Lck, G. E., and Fyler, D. C. Nadas Pediatric Cardilgy (2e)