Life-Threatening Arrhythmias Flashcards

Ventricular fibrillation on an ECG is best described by which appearance?

Answer: Chaotic, irregular waveforms with no discernible QRS complexes

Ventricular fibrillation produces completely chaotic, irregular electrical activity with no organized QRS complexes — the ventricles quiver rather than contract effectively.

The immediate treatment for pulseless ventricular tachycardia is which intervention?

Answer: Unsynchronized defibrillation (cardioversion)

Pulseless VT is treated identically to VF with immediate unsynchronized defibrillation, as it represents a cardiac arrest requiring immediate restoration of organized rhythm.

Torsades de pointes is a form of polymorphic VT most closely associated with which ECG finding before its onset?

Answer: Prolonged QT interval

Torsades de pointes typically occurs in the setting of a prolonged QT interval, which indicates prolonged ventricular repolarization and increased risk of early afterdepolarizations.

Asystole on the cardiac monitor is confirmed by which finding?

Answer: Flat line in at least two leads with confirmed electrode placement

True asystole must be confirmed in at least two leads to rule out artifact or a disconnected electrode causing a false flat line — always check multiple leads before treating as asystole.

Pulseless electrical activity (PEA) is defined by which combination of findings?

Answer: Organized ECG rhythm with no detectable pulse

PEA is the presence of organized electrical activity on the ECG (excluding VT/VF) with no palpable pulse — the heart generates electrical signals but fails to produce effective mechanical contraction.

Sustained monomorphic ventricular tachycardia with a pulse is initially managed with which approach?

Answer: Synchronized cardioversion if unstable, or IV antiarrhythmics (amiodarone or procainamide) if stable

Stable monomorphic VT with a pulse may be treated pharmacologically (amiodarone, procainamide) while unstable VT (hypotension, altered consciousness, chest pain) requires immediate synchronized cardioversion.