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The effect of nitroglycerin cardioplegia on myocardial cooling in patients undergoing myocardial revascularization
Insights
Intracoronary nitroglycerin did not improve cardioplegia distribution or myocardial cooling in patients with coronary artery disease. However, it significantly reduced cardioplegia delivery time, decreasing total ischemia time during myocardial revascularization.
Area of Science:
- Cardiology
- Cardiac Surgery
- Pharmacology
Background:
- Myocardial revascularization requires effective cardioplegia for myocardial protection.
- Ensuring uniform cardioplegia distribution is crucial, especially in patients with coronary artery disease.
- Nitroglycerin is sometimes used to improve coronary blood flow.
Purpose of the Study:
- To evaluate the impact of intracoronary nitroglycerin on cardioplegia distribution and myocardial cooling.
- To assess the effect of nitroglycerin on cardioplegia delivery time and total ischemia duration.
Main Methods:
- A study involving 45 patients undergoing elective myocardial revascularization.
- Patients were divided into three groups receiving potassium blood cardioplegic solution with varying doses of nitroglycerin.
- Myocardial temperature was measured in different coronary artery distributions.
Main Results:
- Nitroglycerin did not significantly alter myocardial cooling or reduce temperature gradients in patients with occlusive coronary artery disease.
- Cardioplegia delivery rate increased by 134% with nitroglycerin at similar infusion pressures.
- Regional disparities in cardioplegia distribution were not improved by nitroglycerin.
Conclusions:
- Intracoronary nitroglycerin does not improve cardioplegia distribution or cooling in severe coronary artery disease.
- Nitroglycerin administration accelerates cardioplegia delivery, leading to a reduction in total ischemia time.
Abstract:
The effect of intracoronary administration of nitroglycerin on the distribution of cardioplegia and myocardial cooling was assessed in 45 patients undergoing elective myocardial revascularization. The patients were divided into three groups. Myocardial temperature was measured over the right and left coronary artery distributions in Group 1 after the infusion of 1 liter of potassium blood cardioplegic solution (20 mEq of potassium per liter). Similar temperature measurements were made in Group 2 after the addition of 300 micrograms of nitroglycerin to the cardioplegic solution and in Group 3 after the addition of 1,000 micrograms of nitroglycerin. Nitroglycerin did not affect myocardial cooling, and large temperature gradients persisted after delivery of cardioplegia in patients with occlusive coronary artery disease. Unexpectedly, however, the rate of cardioplegia delivery increased by 134%, within the same range of infusion pressures, in patients receiving nitroglycerin. Although nitroglycerin cardioplegia does not affect the regional disparity in the distribution of cardioplegia in patients with severe coronary artery disease, intracoronary administration of nitroglycerin reduces the time required for administration of cardioplegia and thereby decreases the total ischemia time.