Effect of intravenous prenalterol on haemodynamics and myocardial lactate extraction in patients with left ventricular failure.

To assess the immediate haemodynamic and myocardial metabolic effects of the beta 1-agonist prenalterol, we studied by cardiac catheterisation the response to 50 and 100 micrograms/kg given intravenously in 16 patients with congestive heart failure secondary to coronary artery disease or non-ischaemic cardiomyopathy. At peak effect, cardiac index increased from 2.6 +/- 0.5 to 3.2 +/- 0.8 1/min/m2 (mean +/- SD) p less than 0.001); peak rate of left ventricular pressure development rose from 963 +/- 242 to 1355 +/- 411 mm Hg per second (p less than 0.001); left ventricular end-diastolic pressure fell from 27 +/- 6 to 13 +/- 7 mm Hg (p less than 0.001); coronary sinus blood flow increased from 120 +/- 39 to 147 +/- 55 ml/min (p less than 0.01); myocardial oxygen consumption was augmented from 12.9 +/- 3.9 to 15.7 +/- 5.8 ml/min (p less than 0.001); and heart rate increased slightly (76 +/- 12 to 86 +/- 14 beats per minute, p less than 0.05). No significant changes occurred in left ventricular systolic pressure, stroke volume index, myocardial lactate extraction rate, myocardial arteriovenous oxygen difference and no patient developed angina, ECG-changes or ventricular arrhythmias. Infusion of prenalterol effectively improved the haemodynamic function and cardiac metabolism in congestive cardiomyopathy.