Which factors increase the risk of premature ventricular contractions (PVCs)?

Updated: Jan 13, 2017
  • Author: James E Keany, MD, FACEP; Chief Editor: Erik D Schraga, MD  more...
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Answer

Ventricular ectopy associated with a structurally normal heart most commonly occurs from the right ventricular outflow tract beneath the pulmonic valve. The mechanism is thought to be enhanced automaticity versus triggered activity. These arrhythmias are often induced by exercise, isoproterenol (in the electrophysiology laboratory), the recovery phase of exercise, or hormonal changes in female patients (pregnancy, menses, menopause).

The characteristic ECG pattern for these arrhythmias is a large, tall R wave in the inferior leads with a left bundle-branch block pattern in V1 . If the source is the left ventricular outflow tract, there is a right bundle-branch block pattern in V1 . Beta-blocker therapy is first-line treatment for symptomatic patients.

Factors that increase the risk of PVCs include male sex, advanced age, African American race, hypertension and underlying ischemic heart disease, a bundle-branch block on 12-lead ECG, hypomagnesemia, [1] and hypokalemia.


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