ARRHYTHMIAS RECOGNITION AND TREATMENT IN GENERAL PRACTICE Koh Kok Wei MBBS MRCP Cardiology Fellow Electrophysiology and Cardiac Pacing Unit
Outline Cardiovascular Updates for Doctors & Allied Healthcare Normal heart rhythm Incidental findings Irregular heart beat Slow heart beat Fast heart beat
Aim at the end of lecture (~ 20mins) To distinguish normal vs abnormal ECGs Normal ECG Abnormal ECG
Normal ECG 60-100 BPM Normal axis Normal P waves PR 120-200ms QRS 80-120ms Normal T waves
Normal ECG Positive Negative Transition from negative to positive Quick screen on axis
Normal ECG Positive Negative Biphasic Quick screen on P wave
Common presenting symptoms Palpitation Missed beat or extra beat Giddiness Syncope Dyspnea Chest discomfort Seizure
Scenario 35 year-old gentleman, had cough and runny nose. Also noted pricking chest pain
Incidental findings Sinus arrhythmia P-P interval gradually lengthens and shortens in a cyclical fashion Normal sinus P waves with a constant morphology Constant P-R interval
Incidental findings Sinus bradycardia 300 6 big boxes = 50 bpm Can be asymptomatic, commonly in athletes Patient may be on beta-blockers, calcium channel blockers
Incidental findings Right bundle branch block Can be asymptomatic, 0.8% in healthy population Maybe associated with HPT, ASD, IHD
Incidental findings First degree AV Block Enhanced vagal tone (for example in athletes) Drugs: beta blocker, CCB
Irregular heart beat Premature Atrial Contraction Early abnormal P-wave Next normal P- wave comes later Premature atrial beat Exact cause of PAC is unclear May be asymptomatic or felt missed beat Maybe associated with alcohol, caffeine, salbutamol etc
Irregular heart beat Premature Ventricular Contraction Early broad complex Next normal P- wave on time May be asymptomatic or felt missed beat, discomfort Benign causes: idiopathic, alcohol, caffeine, salbutamol, hyperthyroidism
Worrying if A lot of PVCs Multifocal PVCs Associated with chest pain, syncope, dyspnea Family history of sudden cardiac death Causes: IHD, myocarditis, cardiomyopathy, inherited arrhythmia syndromes
Further investigations in GP setting CXR
Further investigations in GP setting 24-Holter Monitoring
Irregular heart beat Atrial fibrillation Irregular RR interval No obvious P waves
Atrial fibrillation Assess thromboembolic stroke risk
Atrial fibrillation Assess thromboembolic stroke risk
Atrial fibrillation Options of OAC: Dabigatran (Pradaxa) Apixaban (Eliquis) Rivaroxaban (Xarelto) If CHADS2 is 1, may want to calculate detail CHA2DS2VASc score
Atrial fibrillation Rate control Aim resting HR <100 bpm Drugs commonly used Beta blockers (BB) ND-CCB (diltiazem, verapamil) Digoxin Combination of BB + digoxin Amiodarone
Atrial fibrillation How to calculate rate? By manual palpation of the pulse By ECG 1 big box = 0.2s 5 big boxes = 1.0s 30 big boxes = 6.0s Calculate total QRS within 30 big boxes 8 QRS in 6 seconds (x 10) 80 QRS in 60 seconds 80 beats per minute!
Slow heart beat Do you know that a Galapagos tortoise s heart beats about 6-20 bpm?
Slow heart beat Sinus Node Dysfunction Sinus bradycardia Exercise stress test may unmasked chronotropic incompetence May need permanent pacemaker
Slow heart beat Sinus Node Dysfunction Sinus arrest Need permanent pacemaker
Slow heart beat Sinus Node Dysfunction Sinoatrial block May be symptomatic or asymptomatic Exercise stress test may unmasked chronotropic incompetence
Slow heart beat AV block Second degree Type 1 (Wenckebach) Normal in athletes, on drugs: BB, CCB Reassurance
Slow heart beat AV block Complete AV Block Usually very symptomatic Permanent pacemaker required Unless in asymptomatic congenital CHB with no structural heart disease
Slow heart beat AV block Second degree Type 2 May be symptomatic or asymptomatic Important to recognize Precursor to disaster Need permanent pacemaker
Slow heart beat Atrial fibrillation Slow ventricular response Stop BB, digoxin, CCB May need permanent pacemaker
Fast heart beat
Fast heart beat Narrow complex tachycardia Sinus tachycardia Fever, pain, anxiety, emotional stress
Fast heart beat What can you do in GP setting? Reassurance, treat underlying cause Pulse rate diary Fever, pain, anxiety, emotional stress
Fast heart beat Narrow complex tachycardia Atrial tachycardia
Fast heart beat Narrow complex tachycardia Atrial tachycardia
Fast heart beat Narrow complex tachycardia SVTs: AVNRT, AVRT Acute Management carotid sinus massage, exposure of the face to ice water, Valsalva maneuver, coughing IV adenosine, verapamil, amiodarone Long term Management Beta-blocker CCB EP Study and RF Ablation
Fast heart beat Narrow complex tachycardia Atrial flutter 4:1 AV conduction ~ 75bpm 2:1 AV conduction ~ 150bpm
Fast heart beat Narrow complex tachycardia Atrial flutter post adenosine 4:1 AV conduction ~ 75bpm Acute Management Usually well tolerated if rate controlled IV amiodarone may revert to SR BB, CCB for rate control DC Cardioversion Long term Management RF Ablation superior than medical therapy Consider OAC if CHADS > 1 in persistent/paroxysmal atrial flutter
Fast heart beat Narrow complex tachycardia Atrial fibrillation
Fast heart beat Broad complex tachycardia Ventricular tachycardia until proven otherwise Basic life support, ACLS DC cardioversion! Call ambulance Two large bore IV branula
Fast heart beat Sometimes, palpitation or tachycardia terminates before ECG is done What to look for?
Fast heart beat Delta waves WPW syndrome
Fast heart beat Cardiomyopathic changes HCM, DCM
Fast heart beat Brugada syndrome
Fast heart beat QTc 654ms 600ms 840ms Long QT acquired, inherited
Fast heart beat Long QT precursor to Torsade de Pointes