Ventricular ectopy is a modifiable risk factor for congestive heart failure

iStock_000024649569XSmallHigher frequency of extra heartbeats is a predictor factor of left ventricular ejection fraction (LVEF) decrease and congestive heart failure (CHF)


Premature ventricular contractions (PVCs) are premature ectopic beats that occur in the ventricles. They cause myocardium dyssynchrony. PVCs are the most common arrhythmia, however most people remain asymptomatic. It is estimated that the incidence of PVCs in the general population is around 1% – 4%, while in those over 75 yo it is about 69%. It is widely considered that PVCs without organic heart disease is mild arrhythmia and it is associated with good prognosis (1). However, studies show that PVCs in patients with existing left ventricular (LV) dysfunction are the cause of deterioration of LV function. In these patients ablating result in normal LV function restore and prevention of heart failure (2). The prognostic significance of PVCs frequency in asymptomatic patients with normal LV function has not yet been ultimately explained (3).

A study published in the Journal of the American College of Cardiology in July 14 shows that PVCs may be a modifiable risk factor for congestive heart failure. Research has been carried out by Jonathan Dukes et al. (4) and the aim of this study was to determine the relationship between the frequency of the PVC and the risk of congestive heart failure. The study enrolled 1139 participants from the national Cardiovascular Health Study (prospective cohort study, conducted in 5887 healthy people aged over 65 yo, the participants were subjected to systematic research, they maintained constant contact with them for 10 years). The study over the PVCs enrolled people with normal left ventricular ejection fraction with registration of 24-hour Holter ECG performed during follow-up. This method has allowed an accurate assessment of PVCs frequency which may be varying during a day and it was possible to specify the severity of arrhythmias in individuals. In the next five years Holter monitoring was repeated. Studies have shown that doubling the percentage of PVCs (relative to the total number of heartbeats) was associated with a statistically significant decrease in LVEF. Congestive heart failure has developed in 308 participants (27%) after an observation period (median 13.7 years). There were 729 deaths reported (64%) after observation period (median of 15.2 years). It has been observed that higher percentage of PVCs is associated with increased mortality. The increase in mortality seems to be partly justified by an increase in incidence of congestive heart failure. In summary, population-based cohort study which involved more than 1,100 participants aged over 65 years demonstrated relationship between the percentage of PVCs and LVEF decline, increase in incidence of congestive heart failure and increase in mortality in those patients. This is the first research in the world which proves that the risk of left ventricular systolic dysfunction in the general population is associated with the percentage of PVCs. This is important, especially given that almost 50% of congestive heart failure cases are not associated with any known risk factors (such as obesity, hypertension, diabetes, coronary artery disease) (4).

Previous studies suggested a relationship between PVCs and LVEF decline. These analyzes had significant limitations (were conducted in small groups, concerned only those with already developed heart failure (2), 24-hour ECG the analysis was not carried out (5)), therefore it did not prove the risk of left ventricular dysfunction in the general population. Researches conducted by Jonathan Dukes et al. (4) are unequivocal proof of the relationship between the percentage of PVCs and the likelihood of congestive heart failure. Further researches are needed to define the benefits of the implementation of ablation in asymptomatic patients with PVCs.

Written by: Monika Klimek, Marta Misztal, Paulina Rudzka

Source:
1.Cha, Y. M., Lee, G. K., Klarich, K. W. & Grogan, M., Premature Ventricular Contraction-Induced Cardiomyopathy: A Treatable Condition. Circulation: Arrhythmia and Electrophysiology 5 (1), 229-236 (2012).
2.Baman, T. S. et al., Relationship between burden of premature ventricular complexes and left ventricular function. Heart Rhythm 7 (7), 865-869 (2010).
3.Niwano, S. et al., Prognostic significance of frequent premature ventricular contractions originating from the ventricular outflow tract in patients with normal left ventricular function. Heart 95 (15), 1230-1237 (2009).
4.Dukes, J. W. et al., Ventricular Ectopy as a Predictor of Heart Failure and Death. Journal of the American College of Cardiology 66 (2), 101-109 (2015).
5.Agarwal, S. K. et al., Relationship of Ventricular Premature Complexes to Heart Failure (From the Atherosclerosis Risk in Communities [ARIC] Study). The American Journal of Cardiology 109 (1), 105-109 (2012).

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