Premature ventricular contractions
Premature ventricular contractions are early wide-complex beats from an ectopic ventricular focus, extremely common and usually benign in structurally normal hearts. A high burden can cause a reversible cardiomyopathy, and PVCs in the setting of structural heart disease carry prognostic weight, so evaluation targets burden and underlying disease; management ranges from reassurance and trigger reduction to a beta-blocker for symptoms and catheter ablation for high-burden disease.
- Topic reviewThe full article, organized the way the exam asks it.
- ABIM-format MCQsVignettes with an explanation for every wrong answer.
- Key factsThe numbers and thresholds worth memorizing, up front.
- AI tutorMedBrain answers the question you're stuck on.
What this article covers
- Overview
Definition: premature ventricular contractions (PVCs) are early depolarizations arising from an ectopic ventricular focus, appearing as a premature wide QRS not preceded by a related P wave, usually with a full compensatory pause.
- Epidemiology
Extremely common, present in most people on prolonged monitoring.
- Risk factors
Age and structural heart disease (prior infarction, cardiomyopathy).
- Pathophysiology
Ectopic ventricular focus: enhanced automaticity, triggered activity, or micro-reentry fires before the next sinus beat.
- Clinical features
Often asymptomatic. Palpitations, skipped beats, or a pounding post-PVC beat.
- Differential diagnosis
Premature atrial contractions with aberrancy: an early beat preceded by an abnormal P wave, distinguished by that preceding P wave and a QRS resembling the conducted beats (premature atrial contractions).
- Diagnosis
Establish with an ECG showing a premature wide QRS without a preceding related P wave and a compensatory pause: the diagnostic basis is a 12-lead ECG or rhythm strip demonstrating early wide…
- Management
First-line, reassure and correct reversible causes: for a structurally normal heart with a low burden, reduce caffeine, alcohol, and stimulants and replete potassium to above 4 mmol/L and magnesium to above 2 mg/dL.
- Complications
PVC-induced (reversible) cardiomyopathy with high burden.
- Prognosis
Benign in structurally normal hearts with a low burden.
- Prevention
Limit caffeine, alcohol, and stimulants. Maintain potassium above 4 mmol/L and magnesium above 2 mg/dL.
Read the whole article
Subscribing to Internal Medicine opens every article, the full question bank and MedBrain, on the web, iPhone and Android.
Related articles
- Ventricular tachycardia
Ventricular tachycardia is three or more consecutive ventricular beats at over 100 per minute, a wide-complex tachycardia that is life-threatening when sustained. Any regular wide-complex tachycardia is ventricular tachycardia until proven otherwise: unstable patients are cardioverted or defibrillated, and long-term risk is managed with an implantable defibrillator.
- Premature atrial contractions
Premature atrial contractions are early beats arising from an ectopic atrial focus, seen on ECG as a premature P wave of abnormal morphology followed by a usually narrow QRS. They are extremely common and usually benign, though a high burden is associated with incident atrial fibrillation and warrants risk-factor management.
- Dilated cardiomyopathy
Dilated cardiomyopathy is left ventricular (often biventricular) dilation with systolic dysfunction not explained by loading conditions or coronary disease, from genetic, viral, toxic, or peripartum causes, presenting as heart failure with reduced ejection fraction. Diagnosis is by echocardiography with a workup for reversible causes, and treatment is guideline-directed heart-failure therapy with device therapy for high-risk patients.