Which vessels supply blood to the myocardium

Due to the high pressures generated in the ventricular myocardium during systole, most myocardial tissue perfusion occurs during diastole. Additionally, catecholamines such as norephinephrine, which normally cause vasoconstriction will instead cause vasodilation within the coronary arteries. This mechanism is due to beta-adrenergic receptors in the coronary arteries and helps enable the increased cardiac output associated with fight-or-flight responses.

A myocardial infarction heart attack may be caused by prolonged ischemia oxygen deprivation in the heart, which occurs due to blockage of any of the coronary arteries.

Since there is very little unnecessary blood supply to the myocardium, blockage of these vessels can cause serious damage. When these vessels become blocked, the myocardium becomes oxygen-deprived, a condition called ischemia. Brief periods of ischemia in the heart are associated with intense chest pain called angina, which may either be transient if the clot breaks up on its own or stable if it does not. As the time period of ischemia increases, the hypoxic conditions cause muscle tissue to die, causing a myocardial infarction heart attack.

Myocardial infarction is one of the most common causes of death worldwide. The clots that cause the infarction are usually the result of ruptured atherosclerotic plaques that break off and occlude the coronary arteries, but arterial thrombosis from injury or pooled blood may also cause a heart attack. The tissues of the heart do not regenerate, so those that survive a myocardial infarction will generally have scar tissue in their myocardium and may be more susceptible to other heart problems in the future.

Coronary Artery Structure The coronary arteries originate from the left side of the heart descending from the aorta. Systole and Diastole In systole, the ventricular myocardium contracts, generating high intraventricular pressure and compressing the subendocardial coronary vessels while allowing the epicardial coronary vessels to remain fully open.

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Read our strategy. See the latest vacancies. Search vacancies near you. Get in touch with any enquiries. Contact us. Coronary arteries supply blood to your heart. See a picture of the heart and coronary arteries. Close to the heart, the two main coronary arteries branch off of your aorta. The coronary arteries also include the collateral coronary arteries, small blood vessels that connect the normal coronary arteries with one another. When the heart is healthy, these vessels play only a minor role.

When a coronary artery becomes obstructed, though, collateral coronary arteries help increase the flow of blood to the area of the heart that is being deprived of blood flow. These vessels, although small, may actually succeed in providing sufficient blood to help prevent major damage to the heart muscle during a heart attack.

When the heart doesn't get enough oxygen-rich blood through the coronary arteries, the affected heart muscle can weaken or die. This is what happens during a heart attack. The damaged heart muscle cannot pump effectively, leading to heart failure. Author: Healthwise Staff. Medical Review: Rakesh K. This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information.

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