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[Effects of diltiazem on rest and stress hemodynamics in coronary disease]
Insights
Calcium channel blocker Diltiazem (D) did not negatively impact heart function in patients with coronary heart disease. Diltiazem reduced blood pressure and heart rate, likely decreasing myocardial oxygen consumption during stress.
Area of Science:
- Cardiology
- Pharmacology
- Physiology
Context:
- Assessing the acute hemodynamic effects of calcium antagonists is crucial for managing coronary heart disease (CHD).
- Diltiazem is a commonly used calcium antagonist with known cardiovascular effects.
- Understanding its impact during cardiac catheterization provides insights into its therapeutic potential.
Purpose:
- To evaluate the acute hemodynamic effects of intravenous Diltiazem (0.3 mg/kg) in patients with coronary heart disease undergoing diagnostic cardiac catheterization.
- To assess changes in ventricular performance, arterial pressure, and heart rate at rest and during ergometric stress before and after Diltiazem administration.
Summary:
- Intravenous Diltiazem (0.3 mg/kg) administration resulted in a transient increase in left ventricular filling pressure, followed by significant decreases in systolic and mean arterial pressure.
- Heart rate did not exhibit reflex increase and was significantly lower 15 minutes post-infusion. Stroke volume index showed a modest increase.
- During ergometric stress, Diltiazem reduced left ventricular filling pressure and blunted the heart rate response, suggesting no significant negative inotropic effect and a probable decrease in myocardial oxygen consumption.
Impact:
- Diltiazem, at the specified dose, appears safe for acute hemodynamic management in CHD patients undergoing stress testing.
- The findings suggest Diltiazem may reduce myocardial oxygen demand by lowering systolic pressure and heart rate during exertion.
- This study provides evidence supporting the use of Diltiazem in patients with CHD, highlighting its favorable hemodynamic profile under stress.
Abstract:
The acute hemodynamic effects of the Ca-antagonist Diltiazem were measured in the course of diagnostic cardiac catheter examinations in 10 patients with coronary heart disease. After initial step-wise ergometric stress, Diltiazem (D) was applied intravenously for 5 min at a dose of 0.3 mg/kg. The effects on right and left ventricular performance as well as on arterial pressure and heart rate were registered 1, 3, 5, 10 and 15 min after termination of the infusion. Then, a second period of ergometric exertion under identical stress conditions was performed. The results under resting conditions show that D effects a significant increase in left ventricular filling pressure (p greater than 0.005), which, however, only lasts a few minutes. After D, the systolic and mean arterial pressure decreases significantly (p greater than 0.001); there is no reflex-induced increase in the heart rate, which on the contrary is significantly lower (p greater than 0.005) 15 min after termination of the infusion than the initial value. The stroke volume index increases from 40 to maximally 48 ml/m2 after D. Comparison of the hemodynamic parameters under ergometric stress before and 20 min after D shows that, on termination of stress, the filling pressure of the left ventricle is reduced. This behavior can largely be attributed to the reduction of the systolic pressure after D (maximal value before D 181, after D 167 mm Hg). Also, the stress-induced increase in the heart rate takes a flatter course after D than before it. The results obtained thus provide evidence that, at a dosage of 0.3 mg/kg, D has no significant negative inotropic effect and probably leads to a decrease of the myocardial oxygen consumption reducing the systolic pressure and, to a lesser degree, heart rate.