From the Guidelines

Less than 1% of ectopic beats (premature ventricular contractions or PVCs) are clinically significant.

Clinically significant PVCs are those that are associated with underlying cardiac disease, increased risk of adverse cardiovascular outcomes, or symptoms.
The presence of multifocal PVCs, frequent PVCs (>2000 per 24 hours), or nonsustained ventricular tachycardia (NSVT) is generally considered a risk factor for adverse cardiovascular outcomes 1.

The detection of PVCs, particularly if multifocal and frequent, should prompt evaluation to ensure that there are no underlying conditions that warrant further treatment to reduce risk 1.
A 12-lead ECG, exercise stress test, and echocardiogram are recommended as the initial evaluation for patients with PVCs 1.
Catheter ablation may be considered for patients with frequent symptomatic PVCs or NSVT, especially if associated with left ventricular dysfunction 1.

Studies have shown that PVCs are common and increase in frequency with age, but most are benign 1.
However, frequent PVCs (>2000 per 24 hours) are associated with an increased risk of underlying cardiac disease, estimated at 30% in this subgroup 1.
PVC-induced cardiomyopathy is a reversible cause of left ventricular dysfunction that can be effectively treated with catheter ablation 1.

From the Research

PVCs are early depolarizations of the myocardium originating in the ventricle, with an estimated prevalence of 40% to 75% in the general population on 24- to 48-hour Holter monitoring 2.
They are relatively common, occurring in 3%-20% of the general population 3.

Traditionally, PVCs have been thought to be relatively benign in the absence of structural heart disease, but they represent an increased risk of sudden death in structural heart disease, especially in ischemic heart disease 2.
The frequency and complexity of PVCs are associated with mortality, and implantable cardioverter defibrillator therapy is indicated in patients with nonsustained ventricular tachycardia (NSVT) due to prior myocardial infarction, left ventricular ejection fraction less than or equal to 40%, and inducible ventricular fibrillation or sustained ventricular tachycardia at electrophysiological study 2.
A high premature atrial contraction (PAC) count is independently associated with increased mortality, higher rate of atrial fibrillation, stroke, and heart failure adverse events in patients with frequent PVCs 4.
The presence of NSVT is independently associated with increased arrhythmic adverse events, but not with overall mortality, atrial fibrillation, stroke, or heart failure events 4.

Extended ambulatory electrocardiogram (AECG) monitoring can better identify clinically significant ectopy, with median time to detecting an individual's maximum PVC burden being 6 days (interquartile range: 2-11 days) 5.
While most patients with PVC burdens ≥20% were detected with 24 hours of monitoring, extended monitoring nearly doubled the identification of those reaching the 10% threshold 5.
PVC burden varies widely from day-to-day, and individual ranges of daily PVC burden crossed thresholds of 10%, 15%, and 20% of total heartbeats in 26.7%, 16.8%, and 6.9% of patients, respectively 5.

Frequent PVCs can lead to cardiomyopathy, and the SR beat preceding the PVC demonstrates significant mechanical abnormalities, suggesting perturbations in cellular physiological processes such as excitation-contraction coupling may underlie the generation of frequent PVCs 6.
PVCs did not provide significant incremental prognostic information beyond readily available clinical variables in congestive heart failure, and NSVT should not guide therapeutic interventions 2.