Hemodynamic effects of prolonged enoximone infusion (7 days) in patients with severe chronic heart failure

Summary

This study investigated the hemodynamic effects and tolerance of infusion of 10 µg/kg/min enoximone over 7 days in 12 patients (mean age 64.3 years) with severe chronic heart failure (10 NYHA Class III and 2 Class IV) with idiopathic dilated cardiomyopathy. Hemodynamic parameters were measured 10 minutes, 3 hours, 6 hours, 18 hours, 24 hours, and 7 days after the start of infusion. Catecholamines were assayed before the start of the infusion and on day 7. The heart rate increased on an average from 90.8±13.7 before infusion to 108.5±8.2 beats/min (p<0.05) on day 7 (+20%). The mean arterial pressure decreased by approximately 10% (p<0.05) between the start and end of the infusion. The pulmonary artery diastolic pressure dropped by a maximum of 30% at the 24th hour (23.1±5.1 to 16±5.4 mm Hg; p<0.01). This decrease remained significant on day 7; the index cardiac was increased a maximum of 40% between the 18th and the 24th hour; p<0.01). This increase was still significant on day 7 (2.35±0.44; p<0.05; +22%). Finally, the decrease in systemic arterial resistance, which reached a maximum of 30% of the 24th hour, persisted on day 7 (−22%); 2076±451 to 1612±283 dynes/sec/cm⁵; p<0.05). The norepinephrine level did not change significantly (4.5±1.2 nmol/l before infusion vs. 4.2±1.1 nmol/l on day 7). Infusion had to be stopped in one patient after 30 minutes because of prolonged severe hypotension. Frequent supraventricular extrasystoles were observed in another patient during the entire period of infusion. In conclusion, a beneficial hemodynamic effect persisted on day 7 of enoximone infusion in patients with chronic heart failure, and clinical and biologic tolerance were good despite moderate tachycardia.