Synergistic effect of captopril and dobutamine on left ventricular pressure-volume and pressure-shortening relations in severe cardiac failure.
The acute effects of captopril and dobutamine, alone and in combination, on left ventricular contractility were assessed from left ventricular end-systolic pressure-volume and pressure-shortening relations in 6 patients with severe end-stage cardiac failure. Dobutamine was given by constant intravenous infusion on two occasions 48 hours apart, on one of these occasions the patient also received oral captopril in a dose of 37 +/- 12 mg 6-hourly. Pressures and cardiac index were measured, and left ventricular volumes and ejection fraction computed from simultaneously recorded radionuclide ventriculography. Dobutamine alone did not cause a statistically significant increase in stroke index, stroke work index, cardiac index and ejection fraction, although pulmonary capillary wedge pressure and right atrial pressure fell (P less than 0.05). There was no change in systemic or pulmonary vascular resistance nor in arterial blood pressure. Following administration of captopril, diastolic arterial pressure decreased (P less than 0.05), and the dobutamine challenge produced a greater and significant rise in stroke and stroke work index (P less than 0.05) and cardiac index (P less than 0.01). The left ventricular contractile state was unaltered by captopril but appeared to increase with dobutamine and more so during combined therapy with captopril and dobutamine, indicating a synergistic effect of the two drugs when given in combination.
Lewis
B S
BS
Department of Cardiology, Lady Davis Carmel Hospital, Haifa, Israel.
Halon
D A
DA
Rodeanu
M E
ME
Merdler
A
A
Saggie
Y
Y
Hardoff
R
R
D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002216:Captopril / Q000627:therapeutic use*; D002302:Cardiac Output / Q000187:drug effects; D002306:Cardiac Volume / Q000187:drug effects; D004280:Dobutamine / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects*; D013318:Stroke Volume / Q000187:drug effects
D004280:Dobutamine; D002216:Captopril