PVCs

Premature ventricular contractions (PVCs) are extra heartbeats that originate in the ventricles rather than the atria. On electrocardiography they appear as wide, abnormal QRS complexes that occur earlier than the next expected beat, typically without a preceding P wave, and are usually followed by a brief compensatory pause. PVCs can occur in healthy individuals and in people with heart disease.

PVCs are common and may be solitary or occur in patterns. They can be isolated, occur in pairs (couplets), triplets, or in repeating patterns such as bigeminy (every other beat) or trigeminy (every third beat). A run of three or more consecutive PVCs is considered non-sustained ventricular tachycardia. The clinical impact ranges from incidental findings with no symptoms to palpitations, lightheadedness, chest discomfort, or fatigue.

Causes and triggers include structural heart disease (ischemia, cardiomyopathy, heart failure), electrolyte disturbances (low potassium or magnesium), hypoxia, stimulants (caffeine, alcohol, nicotine), thyroid disorders, certain medications, and acute illness. In many people with no heart disease, PVCs occur sporadically and are considered benign.

Diagnosis typically involves an electrocardiogram to document the PVC morphology and rhythm, with longer-term monitoring (Holter or event recorder) if symptoms are infrequent. Echocardiography is used to assess heart structure and function, while labs evaluate electrolytes and thyroid status.

Management depends on symptoms and underlying heart disease. Asymptomatic individuals with a normal heart often require no treatment beyond reassurance and lifestyle modification to avoid triggers. Symptomatic PVCs or those associated with cardiomyopathy may be treated with beta-blockers or other antiarrhythmic agents, and catheter ablation is an option for frequent or bothersome PVCs, particularly when they impair function or contractile performance. Prognosis is generally favorable in healthy individuals but high PVC burden can occasionally be linked to cardiomyopathy.