Ventricular Premature Beats (Ventricular Extrasystoles)

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

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

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

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