Occlusion of the right coronary artery is most likely to produce ischemia in which of the following portions of the heart?
Explanation
Correct Answer:
SA node
Take-Home Message:
The artery to the SA node (arrow 1, below) is a branch of the right coronary artery.
Explanation of Correct Answer:
The two coronary arteries, right and left, usually supply defined territories of the heart. The right coronary generally has a smaller area of supply than the left although there is some variation in this. The right coronary arises from the right sinus of Valsalva, just superior to the right cusp of the aortic valve and travels around the right side of the heart in the atrio-ventricular groove. As it passes by the right atrium, it gives a small branch that penetrates to supply the SA node. Another branch supplies the AV node. The artery then usually continues around to the inferior surface of the heart to supply the posterior portion of the interventricular septum.
Explanation of Incorrect Answers:
In over 70% of patients, the cardiac apex is supplied by the left anterior descending coronary artery, a branch of the left coronary artery.
The circumflex coronary artery, a branch of the left coronary artery, generally gives branches that supply the left cardiac border (left marginal arteries).
The anterior interventricular septum is virtually always supplied by the left anterior descending coronary artery, which is a branch of the left coronary artery
Clinical Pearls:
Since the right coronary artery supplies both the sinoatrial (SA) and atrioventricular (AV) nodes, myocardial infarction due to right coronary artery occlusion can be associated with dangerous cardiac arrhythmias.
For more information on this topic, please click on the following link(s):
(While these web sources have been vetted by our content experts, please use them with caution --- the peer-reviewed literature should be the ultimate source of medical information.)
http://www.texasheartinstitute.org/HIC/Anatomy/conduct.cfm
http://www.texasheartinstitute.org/HIC/Anatomy/coroanat.cfm
http://www.med.yale.edu/intmed/cardio/imaging/anatomy/coronary_territories/index.html
SA node
Take-Home Message:
The artery to the SA node (arrow 1, below) is a branch of the right coronary artery.
Explanation of Correct Answer:
The two coronary arteries, right and left, usually supply defined territories of the heart. The right coronary generally has a smaller area of supply than the left although there is some variation in this. The right coronary arises from the right sinus of Valsalva, just superior to the right cusp of the aortic valve and travels around the right side of the heart in the atrio-ventricular groove. As it passes by the right atrium, it gives a small branch that penetrates to supply the SA node. Another branch supplies the AV node. The artery then usually continues around to the inferior surface of the heart to supply the posterior portion of the interventricular septum.
Explanation of Incorrect Answers:
In over 70% of patients, the cardiac apex is supplied by the left anterior descending coronary artery, a branch of the left coronary artery.
The circumflex coronary artery, a branch of the left coronary artery, generally gives branches that supply the left cardiac border (left marginal arteries).
The anterior interventricular septum is virtually always supplied by the left anterior descending coronary artery, which is a branch of the left coronary artery
Clinical Pearls:
Since the right coronary artery supplies both the sinoatrial (SA) and atrioventricular (AV) nodes, myocardial infarction due to right coronary artery occlusion can be associated with dangerous cardiac arrhythmias.
For more information on this topic, please click on the following link(s):
(While these web sources have been vetted by our content experts, please use them with caution --- the peer-reviewed literature should be the ultimate source of medical information.)
http://www.texasheartinstitute.org/HIC/Anatomy/conduct.cfm
http://www.texasheartinstitute.org/HIC/Anatomy/coroanat.cfm
http://www.med.yale.edu/intmed/cardio/imaging/anatomy/coronary_territories/index.html
The goal is to reduce the risk of blood clots that can form when patients have an irregular heartbeat and make their way to other parts of the body. These clots can potentially lodge in small blood vessels within the brain, lungs and other structures. Narrowing of Heart Arteries
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