EFFECTS OF THE ALDOSTERONE ANTAGONIST SPIRONOLACTONE ON VENTRICULAR ARRHYTHMIAS AND SERUM ELECTROLYTE LEVELS IN CONGESTIVE-HEART-FAILURE

The effects of spironolactone 75 mg/day on heart failure and arrhythmi a were evaluated in patients with chronic heart failure who had been m aintained on a loop diuretic (furosemide) for 4 weeks or more. The eff ects on heart failure, indicated by improvement in subjective symptoms and clinical signs, were observed. While the frequencies of premature ventricular contraction measured by the two Holter monitorings at the pretreatment period did not differ significantly from each other, eac h of two Holter monitorings performed after treatment was initiated sh owed a tendency rewards lower frequency compared with the two pretreat ment measurements. Serum potassium levels were increased after treatme nt, but remained within the normal range throughout the treatment peri od. In the present study, we found that the aldosterone antagonist spi ronolactone improved the condition of patients with chronic heart fail ure [ie. subjective symptoms and clinical signs improved, cardiothorac ic ratio and echocardiographic parameters (left ventricular end-diasto lic and -systolic dimensions and percentage of fractional shortening) significantly improved (p < 0.05), and New York Heart Association clas s also improved] treated with a loop diuretic, without inducing an imb alance in serum electrolyte levels. Furthermore, changes after spirono lactone treatment in plasma renin activity, plasma aldosterone, plasma angiotensin II and human atrial natriuretic peptide were compared bet ween the total evaluable patients and evaluable subpatients for occurr ence of premature ventricular contractions. In the total evaluable pat ients, levels of the above first three parameters were increased, whil e human atrial natriuretic peptide decreased significantly. Similar re sults were obtained in those evaluable for occurrence of premature ven tricular contractions. It was concluded that the abovementioned action of spironolactone possibly influenced ventricular arrhythmia associat ed with heart failure, contributing to an ameliorating tendency in arr hythmia.