Ventricular Premature Beats (Ventricular Extrasystoles)

Key Features

• Ventricular premature beats or PVCs are isolated beats typically originating from the outflow tract or His-Purkinje regions of ventricular tissue

• In most patients, the presence of PVCs is a benign finding; however, they may trigger ventricular tachycardia or ventricular fibrillation, especially in patients with underlying heart disease

Clinical Findings

• Patient may or may not sense the irregular beat

• Exercise generally abolishes premature beats in normal hearts, and the rhythm becomes regular

• Wide QRS complexes, differing in morphology from normal beats and usually not preceded by a P wave

• Fully compensatory pause (no change in PP interval) usually

• Bigeminy and trigeminy

  • Arrhythmias in which every second or third beat is premature

  • Confirm a reentry mechanism for the ectopic beat

Diagnosis

• Ambulatory ECG monitoring may reveal more frequent and complex ventricular premature beats than occur in a single routine ECG

• An echocardiogram should be performed when Holter monitoring has documented more than 10,000 PVCs per day

Treatment

• If no associated cardiac disease is present and if the ectopic beats are asymptomatic, no therapy is indicated

• Patients with mild symptoms or anxiety from palpitations can be reassured about the benign nature of this arrhythmia

• If ectopic beats are frequent, the following should be excluded:

  • Electrolyte abnormalities (especially hypokalemia or hyperkalemia and hypomagnesemia)

  • Hyperthyroidism

  • Occult heart disease

• Pharmacologic treatment is indicated only for patients who are symptomatic or in whom cardiomyopathy develops (thought to be due to high burden of PVCs [generally > 10% of daily heart beats])

• Beta-blockers or non-dihydropyridine calcium channel blockers are appropriate as first-line therapy

• Class I and III antiarrhythmic agents

  • May be effective in reducing ventricular premature beats

  • Poorly tolerated

  • Can be proarrhythmic in up to 5% of patients

• Catheter ablation is a well-established therapy for symptomatic individuals

  • Who do not respond to medication

  • Whose burden of ectopic beats has resulted in a cardiomyopathy