Fluctuations in premature ventricular contraction burden can affect medical assessment and management

Frequent premature ventricular contractions (PVCs) can cause disabling symptoms and decrease left ventricular ejection fraction. PVC burden, typically quantified by a 24-hour monitor, is one of the factors that determines the clinical management of PVCs.

The purpose of this study was to evaluate the extent of variability in 24-hour PVC burden during 14-day ambulatory cardiac monitoring in patients with significant PVC burden.

All patients referred for PVC evaluation received a 14-day ambulatory cardiac monitor. Parameters of interest included mean 14-day PVC burden, minimum and maximum 24-hour PVC burden, and absolute change in 24-hour PVC burden (maximum minus minimum). We included only patients with a mean 14-day PVC burden of more than 5%.

Fifty-nine patients were included in the study. The median of mean 14-day PVC burden, maximum 24-hour PVC burden, and minimum 24-hour PVC burden were 9.0% (IQR 6.4%-17.9%), 16.2% (IQR 11.7%-26.2%), and 4.5% (IQR 2.6%-11.2%) respectively (P < .001). The median of the absolute 24-hour PVC burden change was 9.9% (IQR 5.4%-14.5%). There was a 2.45-fold (IQR 1.68- to 5.55-fold) median difference between maximum 24-hour PVC burden and minimum 24-hour burden in the same patient. When categorized by low (<10%), intermediate (10%-20%), and high (>20%) 24-hour PVC burden, 72.9% patients fell into at least 2 categories depending on the 24-hour period considered.

There is a significant variation in 24-hour PVC burden when measured over a 14-day period in patients with of PVC burden of more than 5%. This variation might impact critical clinical decisions in a significant proportion of such patients.