Effect of xamoterol (ICI 118587), a new beta1 adrenoceptor partial agonist, on resting haemodynamic variables and exercise tolerance in patients with left ventricular dysfunction.

Abstract

The effect of xamoterol, a beta1 adrenoceptor partial agonist, on resting haemodynamic measurements and exercise tolerance was studied in 10 patients with dyspnoea of effort. All patients had poor left ventricular function due to myocardial infarction with ejection fractions ranging from 15% to 35% (mean 28%). The cardiac index and stroke work index both rose significantly. The mean pulmonary artery pressure fell from 20(2) mm Hg to 16(2) mm Hg and pulmonary artery wedge pressure from 14(2) mm Hg to 10(2) mm Hg within the first four hours. Exercise tolerance, measured on the treadmill, increased significantly in seven patients but was unchanged in the three who had the lowest left ventricular ejection fractions. Exercise heart rate response was attenuated by the drug in all patients. It is concluded that xamoterol may be beneficial in patients with poor left ventricular function but can be harmful in extremely poor left ventricular function where high sympathetic drive may be important.

Xamoterol, a β1Adrenoceptor Partial Agonist: Pharmacology and Clinical Use

“…After xamoterol (200 mg) in patients with previous myocardial infarction and an ejection fraction of 15-35%, the cardiac index rose from 2.3 to 3.2 L/min/m2 (p < 0.001) with a decrease in pulmonary wedge pressure. Exercise tolerance rose in seven and was unchanged in the three patients with the lowest ejection fraction (58).…”

Therapeutic Progress—review Xxxiv: Congestive Cardiac Failure

“…On exercise the heart rate response is attenuated with no impairment in exercise haemodynamics due to a maintenance in the improved stroke volume seen at rest. There are few chronic studies to date but those available show favourable results with no evidence of tachyphylaxis and improvements in exercise capacity, haemodynamics and systolic and diastolic function (127)(128)(129)132). Theoretically, this stabilization of the heart's exposure to excessive sympathetic tone would be of long-term benefit particularly in preventing progressive deterioration in cardiac function.…”

Effects of xamoterol, a beta 1 adrenoceptor partial agonist, in patients with ischaemic dysfunction of the left ventricle.

“…All patients had previous episodes of heart failure with pulmonary congestion. The heart was enlarged (cardiothoracic ratio > 0-5) in 16 patients.…”