The effect of propafenone on premature ventricular contractions (PVC): an analysis based on heart rate dependency of PVCs

Elimination of Benign Ventricular Premature Beats or Ventricular Tachycardia with Catheter Ablation versus Two Different Optimal Antiarrhythmic Drug Treatment Regimens (Sotalol or Verapamil/Flecainide)

BACKGROUND

Symptomatic idiopathic ventricular arrhythmias (VA), including premature beats (VPB) and nonsustained ventricular tachycardia (VT) are commonly encountered arrhythmias. Although these VA are usually benign, their treatment can be a challenge to primary and secondary health care providers. Mainstay treatment is comprised of antiarrhythmic drugs (AAD) and, in case of drug intolerance or failure, patients are referred for catheter ablation to tertiary health care centers. These patients require extensive medical attention and drug regimens usually have disappointing results. A direct comparison between the efficacy of the most potent AAD and primary catheter ablation in these patients is lacking. The ECTOPIA trial will evaluate the efficacy of 2 pharmacological strategies and 1 interventional approach to: suppress the VA burden, improve the quality of life (QoL), and safety.

HYPOTHESIS

We hypothesize that flecainide/verapamil combination and catheter ablation are both superior to sotalol in suppressing VA in patients with symptomatic idiopathic VA.

STUDY DESIGN

The Elimination of Ventricular Premature Beats with Catheter Ablation versus Optimal Antiarrhythmic Drug Treatment (ECTOPIA) trial is a randomized, multicenter, prospective clinical trial to compare the efficacy of catheter ablation versus optimal AAD treatment with sotalol or flecainide/verapamil. One hundred eighty patients with frequent symptomatic VA in the absence of structural heart disease or underlying cardiac ischemia who are eligible for catheter ablation with an identifiable monomorphic VA origin with a burden ≥5% on 24-h ambulatory rhythm monitoring will be included. Patients will be randomized in a 1:1:1 fashion. The primary endpoint is defined as >80% reduction of the VA burden on 24-h ambulatory Holter monitoring. After reaching the primary endpoint, patients randomized to one of the 2 AAD arms will undergo a cross-over to the other AAD treatment arm to explore differences in drug efficacy and QoL in individual patients. Due to the use of different AAD (with and without β-blocking characteristics) we will be able to explore the influence of alterations in sympathetic tone on VA burden reduction in different subgroups. Finally, this study will assess the safety of treatment with 2 different AAD and ablation of VA.

Outflow tract premature ventricular depolarizations after atrial fibrillation ablation may reflect autonomic influences

PURPOSE

Autonomic modulation following catheter ablation of atrial fibrillation may promote the development of catecholamine-sensitive arrhythmias, such as outflow tract (OT) ventricular premature depolarizations (VPDs). The purpose of this study was to determine the incidence and prognostic significance of OT VPDs occurring in patients after atrial fibrillation (AF) ablation.

METHODS

We prospectively examined 53 consecutive patients undergoing wide-area circumferential antral pulmonary vein (PV) isolation; no patients had evidence of OT VPDs on 24 h of preprocedural telemetry monitoring. Cases (OT+) had postprocedure telemetry monitoring with >30 continuous beats or >3/min OT VPDs. Clinical follow-up included transtelephonic monitoring at 6 weeks, 6 months, and 1 year.

RESULTS

The incidence of OT VPDs in this population was 11% (6/53). There was no difference in AF recurrence at 1 year between those with or without OT VPDs (17 vs 28%, p = 0.6). There was a strong association with higher immediate postprocedure heart rate (HR) in OT+ compared to OT- patients (86 vs 76, p = 0.03); this difference persisted at 1 year (79 vs 60, p < 0.01). OT VPDs resolved in 5/6 of the OT+ patients over the 1-year follow-up. In a multivariable linear regression model, OT VPDs were associated with higher HR (odds ratio (OR) 1.14 [1.10-1.18], p < 0.001) despite adjustment for medication dose.

CONCLUSIONS

A minority of patients undergoing antral PV isolation develops OT VPDs associated with a sustained increase in mean heart rate; this effect may result from the modulation of adjacent autonomic ganglia.

Intermittent claudication caused by frequent premature ventricular complexes: resolution after radiofrequency ablation

A case of a 55-year-old woman with psoriasis and long-lasting history of typical intermittent claudication associated with frequent premature ventricular complexes is reported. Atherosclerotic and nonarterial pathologic conditions were taken into consideration and were excluded. Applying 6-minute walk test and resting and peak-exercise pulsed Doppler ultrasonography, it was possible to prove a decrease in perfusion during exercise-persistent ventricular bigeminy. Rapid improvement in symptoms was observed after a single dose of propafenone; however, it led to a worsening of psoriasis. The patient was referred for radiofrequency ablation. Radiofrequency ablation in the right ventricular outflow tract resulted in complete abolition of premature ventricular complexes and intermittent claudication. The patient remained free of claudication and symptoms related to arrhythmia with an ability to walk more than 5 km, without stopping. Relief of symptoms may be achieved by antiarrhythmic treatment; however, side effects of antiarrhythmic drugs or their ineffectiveness should encourage the use of radiofrequency ablation.

Prognostic significance of PVCs and resting heart rate

BACKGROUND

We sought to evaluate the prognostic significance of premature ventricular contractions (PVCs) on a routine electrocardiogram (ECG) and to evaluate the relationship between heart rate and PVCs.

METHODS

Computerized 12-lead ECGs of 45,402 veterans were analyzed. Vital status was available through the California Health Department Service.

RESULTS

There were 1731 patients with PVCs (3.8%). Compared to patients without PVCs, those with PVCs had significantly higher all-cause (39% vs 22%, P < 0.001) and cardiovascular mortality (20% vs 8%, P < 0.001). PVCs remain a significant predictor even after adjustment for age and other ECG abnormalities. The presence of multiple PVCs or complex morphologies did not add significant additional prognostic information. Those patients with PVCs had a significantly higher heart rate than those without PVCs (mean +/- SD: 78.6 +/- 15 vs 73.5 +/- 16 bpm, P < 0.001). When patients were divided into groups by heart rate (<60, 60-79, 80-99 and >100 bpm) and by the presence or absence of PVCs, mortality increased progressively with heart rate and doubled with the presence of PVCs. Using regression analysis, heart rate was demonstrated to be an independent and significant predictor of PVCs.

CONCLUSIONS

PVCs on a resting ECG are a significant and independent predictor of all-cause and cardiovascular mortality. Increased heart rate predicts mortality in patients with and without PVCs and the combination dramatically increases mortality. These findings together with the demonstrated independent association of heart rate with PVCs suggest that a hyperadrenergic state is present in patients with PVCs and that it likely contributes to their adverse prognosis.