Effects of Spironolactone and Metoprolol on QT Dispersion in Heart Failere

Abstract

SUMMARYThe effects of spironolactone or metoprolol added to a conventional treatment protocol on QT dispersion, which is accepted as a sudden cardiac death predictor, were evaluated in heart failure patients.?A total of 105 New York Heart Association class III patients were included in this study. The conventional treatment protocol was standardized by giving ramipril, furosemide, and digoxin to all patients for 3 weeks at the same doses. At the end of this period, the patients were divided into three groups. Conventional treatment was continued in group 1, 25 mg spironolactone was added in group 2, and 12.5 mg metoprolol was added in group 3. Patients were followed for 12 weeks and clinical and laboratory tests were conducted at 3 week intervals.No significant change in corrected QT dispersion was observed in group1 at the end of 12 weeks (corrected QT dispersion: 80 ± 2 msc to 79 ± 2 msc, P: 0.22). However, corrected QT dispersion in group 2 was reduced by 32.5% (83 ± 2 msc to 56 ± 1 msc; P: 0.01). A 32.9% reduction in corrected QT dispersion (79 ± 2 msc to 53 ± 2 msc; P: 0.01) was observed in group 3.In conclusion, the addition of spironolactone or metoprolol to a conventional treatment in heart failure patients resulted in improved clinical conditions and the significant decrease in sudden death predictors corrected QT dispersion. The effects of spironolactone and metoprolol on corrected QT dispersion were similar. (Jpn Heart J 2003; 44: 681-692)

Effects of Mineralocorticoid Receptor Antagonists on the Risk of Sudden Cardiac Death in Patients With Left Ventricular Systolic Dysfunction

“…Six trials enrolling 11654 patients reported data on SCD and CV mortality, 11, 12,25–27 and 7 trials enrolling 11826 patients reported data on total mortality. 11,12,24–26,28,29 TWO trials met criteria for poor methodological quality, 27,28 and the other 6 trials met criteria for good quality (Table I in the online-only Data Supplement for quality assessment data for the trials). The Eplerenone Postacute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS) trial accounted for more than half of the patients for this meta-analysis.…”

Conditional Mineralocorticoid Receptor Expression in the Heart Leads to Life-Threatening Arrhythmias

“…The synthetic mineralocorticoid fludrocortisone exacerbates 37 while spironolactone improves 38,39 electrophysiological parameters such as QT interval dispersion. Spironolactone increases heart rate variability 38,40 and decreases PVBs and nonsustained VT episode occurrence 41,42 in patients with heart failure at rest and during exercise 42 ; consistent with these observations, cardiac hMR overexpression, as reported here, reduced HRV and increased PVB and nonsustained VT episodes.…”

Autonomic Effects of Spironolactone and MR Blockers in Heart Failure

“…Spironolactone reduces QT parameters in patients with heart failure [17,49], and interestingly has maximum effect on these parameters in the morning when both aldosterone and sympathetic activity are rising. Unfortunately it is difficult to discern how much of the benefit of spironolactone is due to the alterations in electrolytes that it produces [43].…”