During which phase of the cardiac cycle do the coronary arteries receive blood flow?

Get ready for the Paramedic Readiness Exam 5. Study with multiple-choice questions, detailed explanations, and effective strategies. Enhance your exam preparedness today!

Multiple Choice

During which phase of the cardiac cycle do the coronary arteries receive blood flow?

The main moment for coronary blood flow is when the heart is relaxed—diastole. As the heart relaxes, the aortic valve is closing and aortic pressure drives blood into the coronary openings at the base of the aorta. The myocardium isn’t squeezing the vessels, so the coronary arteries can fill and nourish the heart muscle. In contrast, during systole the contracting myocardium raises intramyocardial pressure, compressing the coronary vessels (especially in the subendocardium) and limiting blood flow. While some flow can occur in the right coronary artery during systole, the bulk of coronary perfusion happens in diastole due to reduced compression and ongoing aortic-to-coronary pressure gradient.

The main moment for coronary blood flow is when the heart is relaxed—diastole. As the heart relaxes, the aortic valve is closing and aortic pressure drives blood into the coronary openings at the base of the aorta. The myocardium isn’t squeezing the vessels, so the coronary arteries can fill and nourish the heart muscle.

In contrast, during systole the contracting myocardium raises intramyocardial pressure, compressing the coronary vessels (especially in the subendocardium) and limiting blood flow. While some flow can occur in the right coronary artery during systole, the bulk of coronary perfusion happens in diastole due to reduced compression and ongoing aortic-to-coronary pressure gradient.

More practice questions