Arrhythmias & Conduction Disorders
Recognize common and lethal rhythms, decide whether the patient is stable, and select cardioversion, pacing, medication or anticoagulation when appropriate.
Module format: each study session covers what to learn, how the presentation appears clinically, investigation/management priorities, safety issues and common MCCQE traps.
Module 4 — Topic map
- Atrial fibrillation and atrial flutter: rate/rhythm strategies and thromboembolic risk
- Anticoagulation decision-making in atrial fibrillation, including bleeding-risk considerations
- Regular narrow-complex tachycardia / SVT and vagal/adenosine principles
- Wide-complex tachycardia, monomorphic/polymorphic VT and ventricular fibrillation
- Premature atrial/ventricular beats and clinically significant palpitations
- Sinus bradycardia, sinus-node dysfunction and symptomatic bradyarrhythmia
- First-degree, Mobitz I, Mobitz II and complete AV block
- Bundle branch blocks and conduction clues relevant to acute disease
- Pre-excitation / WPW and dangerous combinations with atrial fibrillation
- Long-QT syndrome, torsades de pointes and medication/electrolyte triggers
- Synchronized cardioversion versus defibrillation; temporary/permanent pacing principles
Acute + Chronic CareECG recognitionManagementAnticoagulation safety
Study Session 4.1 — Atrial Fibrillation / Flutter & Anticoagulation
Focused MCCQE cardiovascular study session
Core topics & learning goals
- Recognize AF and flutter on ECG and assess hemodynamic stability.
- Identify reversible precipitants such as infection, thyroid disease, alcohol, ischemia and electrolyte disturbance.
- Use stroke-risk assessment and bleeding-risk review to guide anticoagulation.
- Understand rate-control versus rhythm-control strategies and cardioversion timing principles.
Clinical recognition & investigation
- Assess duration of AF, symptoms, structural disease and thromboembolic risk.
- Know when valvular disease/mechanical valves alter anticoagulant choice.
Management & patient-safety priorities
- Perform synchronized cardioversion for unstable tachyarrhythmia.
- Use appropriate rate/rhythm and anticoagulation strategy for stable patients.
MCCQE exam traps
- Do not withhold indicated anticoagulation solely because a bleeding-risk score is elevated; correct modifiable risks.
- Irregular wide-complex tachycardia with pre-excitation is dangerous.
Study Session 4.2 — SVT, Pre-Excitation & Regular Tachycardia
Focused MCCQE cardiovascular study session
Core topics & learning goals
- Differentiate sinus tachycardia from re-entrant SVT.
- Use vagal maneuvers and adenosine appropriately for regular narrow-complex SVT.
- Recognize WPW/pre-excitation and atrial fibrillation with an accessory pathway.
- Identify situations where AV-nodal blocking drugs can be dangerous.
Clinical recognition & investigation
- Treat the underlying cause of sinus tachycardia rather than simply suppressing rate.
- Assess stability before rhythm-specific maneuvers.
Management & patient-safety priorities
- Synchronized cardioversion for unstable tachycardia.
- Refer recurrent symptomatic SVT for electrophysiology/ablation consideration.
MCCQE exam traps
- Adenosine is not the treatment for an irregular wide-complex tachycardia.
- Do not mistake sinus tachycardia from sepsis/bleeding for primary SVT.
Study Session 4.3 — Ventricular Arrhythmias, Long QT & Sudden Death
Focused MCCQE cardiovascular study session
Core topics & learning goals
- Recognize monomorphic VT, polymorphic VT/torsades and VF.
- Know shockable versus non-shockable arrest rhythms.
- Identify ischemia, cardiomyopathy, electrolyte and drug triggers.
- Recognize prolonged QT and inherited/channelopathy clues.
Clinical recognition & investigation
- Assume wide-complex tachycardia is VT when uncertain in a high-risk clinical context.
- Assess post-arrest cause and secondary-prevention needs.
Management & patient-safety priorities
- Defibrillate pulseless VT/VF; synchronize cardioversion for unstable tachycardia with a pulse.
- Correct potassium/magnesium and stop QT-prolonging causes when relevant.
MCCQE exam traps
- Do not synchronize defibrillation for VF/pulseless VT.
- Torsades management requires addressing QT/electrolytes, not simply AV-nodal blockade.
Study Session 4.4 — Bradycardia, AV Block & Pacing
Focused MCCQE cardiovascular study session
Core topics & learning goals
- Recognize sinus bradycardia, sinus-node dysfunction and AV blocks.
- Differentiate Mobitz I from Mobitz II and complete heart block.
- Identify ischemic, medication, metabolic and degenerative causes.
- Know features suggesting urgent pacing or permanent pacemaker assessment.
Clinical recognition & investigation
- Relate symptoms—syncope, hypotension, ischemia, HF—to rhythm severity.
- Review beta blockers, non-DHP calcium-channel blockers, digoxin and other contributors.
Management & patient-safety priorities
- Treat symptomatic unstable bradycardia promptly and escalate to pacing when required.
- Correct reversible causes.
MCCQE exam traps
- Mobitz II and complete block are higher risk even if transiently well tolerated.
- Do not dismiss syncope with bifascicular/conduction disease without appropriate evaluation.