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Acute hemodynamic effects of intravenous isradipine
1Cardiac Catheterization Laboratory, Dallas Veterans Administration Medical Center, Texas 75216.
Insights
This study evaluated the acute hemodynamic effects of isradipine, a new calcium antagonist, in men undergoing cardiac catheterization. Isradipine increased heart rate and cardiac index while decreasing vascular resistance.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Isradipine is a novel dihydropyridine calcium antagonist.
- Understanding the acute hemodynamic effects of new cardiovascular drugs is crucial for clinical application.
Purpose of the Study:
- To evaluate the acute hemodynamic effects of intravenous isradipine in men undergoing elective cardiac catheterization.
- To assess dose-dependent alterations in cardiac function and vascular resistance.
Main Methods:
- Sixteen men were administered low-dose (0.007 mg/kg) or high-dose (0.015 mg/kg) isradipine intravenously over 10 minutes.
- Hemodynamic parameters including heart rate, cardiac index, blood pressure, and vascular resistance were measured 10 minutes post-infusion.
Main Results:
- Both low and high doses of isradipine significantly increased heart rate, cardiac index, and coronary sinus blood flow.
- A significant decrease in mean aortic pressure, systemic, and coronary vascular resistance was observed with both doses.
- High-dose isradipine also increased stroke volume index and left ventricular stroke work index.
Conclusions:
- Isradipine exerts significant acute hemodynamic effects, including positive inotropic and vasodilatory actions.
- The drug demonstrates potential for managing cardiovascular conditions by improving cardiac output and reducing vascular resistance.
Abstract:
The acute hemodynamic effects of isradipine, a new dihydropyridine calcium antagonist, were evaluated in 16 men referred for elective cardiac catheterization. Low-dose (0.007 mg/kg, n = 8) and high-dose (0.015 mg/kg, n = 8) isradipine was administered intravenously over 10 minutes and the hemodynamic alterations assessed 10 minutes after completion of infusion. Low-dose isradipine caused increases in heart rate (68 +/- 9 to 79 +/- 12 beats/min, p less than 0.001) (mean +/- standard deviation), cardiac index (3.0 +/- 0.7 to 4.1 +/- 0.9 liter/min/m2, p less than 0.001) and coronary sinus blood flow (114 +/- 27 to 162 +/- 74 ml/min, p less than 0.01), and significant decreases in mean aortic pressure (104 +/- 17 to 92 +/- 10 mm Hg, p less than 0.01), systemic and coronary vascular resistance. High-dose isradipine caused similar effects: the heart rate increased (72 +/- 6 to 84 +/- 14 beats/min, p less than 0.005), as did the cardiac index (3.0 +/- 0.6 to 4.6 +/- 0.9 liter/min/m2, p less than 0.001) and coronary sinus blood flow (122 +/- 48 to 166 +/- 47 ml/min, p less than 0.025). In addition, there were increases in the stroke volume index (43 +/- 10 to 55 +/- 8 ml/m2, p less than 0.001) and left ventricular stroke work index (69 +/- 12 to 79 +/- 12 g-m/m2, p = 0.05) after the high-dose infusion. Vascular resistance declined significantly in the systemic, pulmonary and coronary beds.(ABSTRACT TRUNCATED AT 250 WORDS)