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[Complex ventricular arrhythmias and carvedilol: efficacy in hemodialyzed uremic patients]
G Cice1, E Tagliamonte, L Ferrara
1Cattedra di Cardiologia, Istituto Medico-Chirurgico di Cardiologia, Seconda Università degli Studi, Napoli.
Insights
Carvedilol effectively reduces ventricular arrhythmias in patients with end-stage renal disease on hemodialysis. This beta-blocker improves underlying cardiac conditions like hypertension and coronary artery disease, proving safe and beneficial.
Area of Science:
- Nephrology
- Cardiology
- Pharmacology
Background:
- Ventricular arrhythmias are common in end-stage renal disease (ESRD) patients undergoing hemodialysis.
- These arrhythmias are often linked to underlying cardiac conditions such as systemic hypertension and coronary artery disease.
- Uremic patients exhibit increased adrenergic tone, correlating with premature ventricular contractions.
Purpose of the Study:
- To assess the efficacy and safety of carvedilol in treating ventricular arrhythmias in ESRD patients on hemodialysis.
- To evaluate carvedilol's impact on complex ventricular arrhythmias (Lown's class III-V) in hypertensive and ischemic patients.
- To compare carvedilol's antiarrhythmic effects against a placebo over a 6-week period.
Main Methods:
- A randomized, double-blind, placebo-controlled study involving 98 uremic patients on maintenance hemodialysis.
- Patients had complex ventricular arrhythmias and were divided into mild-to-moderate hypertension or coronary artery disease groups.
- Carvedilol (50 mg/day) was administered and compared to placebo for 6 weeks.
Main Results:
- Carvedilol significantly reduced total ventricular premature contractions, repetitive ventricular premature contractions, and ventricular tachycardia episodes in both hypertensive and ischemic groups (p < 0.001).
- Placebo treatment did not yield significant changes in these arrhythmia parameters.
- Carvedilol demonstrated a significant positive effect on myocardial ischemia and systemic hypertension without significant side effects.
Conclusions:
- Carvedilol is effective in reducing ventricular arrhythmias in ESRD patients on hemodialysis.
- The antiarrhythmic effect of carvedilol is partly attributed to its improvement of underlying cardiac conditions.
- Carvedilol's modulation of the adrenergic system and potential impact on hemodialysis-induced hypokalemia contribute to its therapeutic benefits.
Abstract:
Carvedilol has been shown to be effective in systemic hypertension and coronary artery disease in patients with end-stage renal disease, on maintenance hemodialysis. The aim of our study was to assess the effects of carvedilol on ventricular arrhythmias in these patients. Ninety-eight uremic patients maintained on hemodialysis, with complex ventricular arrhythmias (class III, IV and V of Lown's classification), not only during dialysis, were included in the study. They were divided into two groups, with mild-to-moderate hypertension or coronary artery disease. The efficacy and safety of carvedilol (50 mg/day) was compared to placebo in a 6-week randomized, double-blind study. Carvedilol significantly reduced, in both hypertensive and ischemic patients, total ventricular premature contractions (82.7 +/- 11.3 vs 358.1 +/- 73.9, p < 0.001; 88.3 +/- 24.4 vs 369.9 +/- 77.8, p < 0.001), repetitive ventricular premature contractions (1.3 +/- 1.3 vs 6.3 +/- 3.5, p < 0.001; 1.2 +/- 0.7 vs 6.9 +/- 2.6, p < 0.001) and episodes of ventricular tachycardia (1.1 +/- 1.2 vs 11.8 +/- 7.5, p < 0.001; 1.4 +/- 1.2 vs 14.0 +/- 8.3, p < 0.001). In placebo-treated patients, instead, these parameters were not significantly changed (329.1 +/- 76.5 vs 361.7 +/- 71.7, NS, and 324.6 +/- 79.7 vs 359.3 +/- 58.1, NS; 6.2 +/- 3.7 vs 7.3 +/- 3.7, NS, and 4.9 +/- 2.2 vs 6.1 +/- 3.2, NS; 9.8 +/- 6.3 vs 13.3 +/- 8.0, NS, and 9.0 +/- 6.2 vs 12.4 +/- 7.8, NS). Carvedilol confirmed a significant effect on myocardial ischemia and systemic hypertension. No significant side effects were reported. Ventricular arrhythmias are frequent in patients with end-stage renal disease maintained on hemodialysis. They are often due to an underlying cardiac disease, namely systemic hypertension with left ventricular hypertrophy and coronary artery disease. The results of our study show that the antiarrhythmic effect of carvedilol is linked, at least partly, to an improvement of the underlying cardiac disease. Uremic patients have a chronic increase in adrenergic tone, with a direct correlation between norepinephrine plasmatic concentration and frequence of premature ventricular contractions. Beta-blockers are very important in these patients because of their modulation on the adrenergic system. They also reduce potassium flow, from extracellular to intracellular fluid. Therefore carvedilol can affect the sudden hypokalemia occurring in the first phase of hemodialysis treatment, that may be an important cause of intradialytic arrhythmias.