Related Experiment Videos
Systemic, left ventricular and coronary hemodynamic effects of intravenous diltiazem in coronary artery disease
Insights
Intravenous diltiazem effectively dilates coronary and systemic vessels in patients with effort angina. This medication improves myocardial oxygen supply and demand without increasing heart rate.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Effort angina is a condition characterized by chest pain due to myocardial ischemia.
- Understanding the hemodynamic effects of vasodilators is crucial for managing angina.
Purpose of the Study:
- To evaluate the systemic and coronary hemodynamic effects of intravenous diltiazem in patients with effort angina.
Main Methods:
- 14 patients with effort angina received intravenous diltiazem (250 mcg/kg bolus followed by 1.4 mcg/kg/min infusion).
- Systemic pressures, heart rate, left ventricular end-diastolic pressure, peak dP/dt, peripheral vascular resistance, stroke volume index, and coronary blood flow were measured.
Main Results:
- Diltiazem significantly decreased systolic, diastolic, and mean systemic pressures, and peripheral vascular resistance.
- Stroke volume index increased, while heart rate, left ventricular end-diastolic pressure, and peak dP/dt remained unchanged.
- Coronary resistance decreased, maintaining coronary blood flow and favorably altering myocardial oxygen supply and demand.
Conclusions:
- Intravenous diltiazem dilates coronary and systemic resistance vessels in patients with effort angina.
- The drug favorably alters myocardial oxygen supply and demand without increasing heart rate.
Abstract:
Systemic and coronary hemodynamic effects of intravenous diltiazem, administered as a bolus of 250 micrograms/kg followed by an infusion of 1.4 micrograms/kg/min, were examined in 14 patients with effort angina. There was no change in heart rate despite significant decreases in systolic, diastolic and mean systemic pressures (13%, 10% and 11%, respectively, all p less than 0.01). The blood pressure decrease was closely correlated with the initial blood pressure (r = 0.81, p less than 0.05). Neither left ventricular end-diastolic pressure nor peak dP/dt changed significantly, but peripheral vascular resistance decreased 16% (p less than 0.001) and stroke volume index increased 10% (p less than 0.05). The pressure-rate product decreased 15% (p less than 0.005), but coronary blood flow was maintained as coronary resistance decreased 14% (p less than 0.025). Diltiazem increased regional coronary flow in some patients. Thus, intravenous diltiazem dilates coronary and systemic resistance vessels, without an increase in heart rate, favorably altering indexes of myocardial oxygen supply and demand.