Comparison of isradipine with nitroprusside for control of blood pressure following myocardial revascularization: effects on hemodynamics, cardiac metabolism, and coronary blood flow.
The effects of isradipine (ISR) on cardiac performance, myocardial metabolism, and coronary blood flow were compared with those of sodium nitroprusside (SNP) when used to control blood pressure following myocardial revascularization. Twenty patients were randomized to receive either intravenous ISR or SNP if arterial blood pressure increased above 130 mm Hg systolic. Hemodynamic and metabolic parameters were studied using radial, pulmonary arterial, and coronary sinus catheters. Cardiac output and coronary blood flows were measured by thermodilution and blood was taken for calculation of myocardial oxygen consumption and lactate extraction. Electrocardiographic changes were recorded by Holter monitoring throughout the study. ISR and SNP both produced a satisfactory reduction in blood pressure accompanied by a decreased systemic vascular resistance (P less than 0.001). ISR infusion was associated with increases in cardiac output and stroke index (P less than 0.01), which were not apparent in the SNP group. Tachycardia occurred with SNP (P less than 0.01) but not with ISR therapy. Right and left ventricular stroke work indices and myocardial oxygen consumption were reduced with SNP. The ISR group showed unchanged myocardial oxygen consumption with increased right ventricular stroke work index. Coronary vascular resistance decreased (P less than 0.01) during ISR infusion but decreased only slightly in the SNP group. Great cardiac vein blood flow was significantly increased with ISR but not with SNP, resulting in a significant difference between the groups (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Underwood
S M
SM
London Chest Hospital, England.
Davies
S W
SW
Feneck
R O
RO
Lunnon
M W
MW
Walesby
R K
RK
D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D002302:Cardiac Output / Q000187:drug effects; D001026:Coronary Artery Bypass / Q000379:methods; D003326:Coronary Circulation / Q000187:drug effects*; D003331:Coronary Vessels; D005260:Female; D006321:Heart / Q000187:drug effects*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D017275:Isradipine; D007773:Lactates / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D009599:Nitroprusside / Q000008:administration & dosage / Q000627:therapeutic use*; D011651:Pulmonary Artery; D011669:Pulmonary Wedge Pressure / Q000187:drug effects; D011725:Pyridines / Q000008:administration & dosage / Q000627:therapeutic use*; D014655:Vascular Resistance / Q000187:drug effects
D000959:Antihypertensive Agents; D007773:Lactates; D011725:Pyridines; D009599:Nitroprusside; D017275:Isradipine