The heart
Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella in Essentials of Human Physiology and Pathophysiology for Pharmacy and Allied Health, 2019
The area of the heart affected by a myocardial infarction will be determined by which coronary blood vessel is occluded. The two main coronary arteries supplying the myocardium are the left coronary artery (which subdivides into the left anterior descending and circumflex branches) and the right coronary artery. The left anterior descending artery supplies blood to the bulk of the anterior left ventricular wall, while the left circumflex artery provides blood to the left atrium and the posterior and lateral walls of the left ventricle. The right coronary artery mainly provides blood to the right atria and right ventricles. Nearly 50% of all myocardial infarctions involve the left anterior descending artery that supplies blood to the main pumping mass of the left ventricle. The next most common site for myocardial infarction is the right coronary artery, followed by the left circumflex. A myocardial infarction may be transmural, meaning it involves the full thickness of the ventricular wall or subendocardial, in which the inner one-third to one-half of the ventricular wall is involved. Transmural infarcts tend to have a greater effect on cardiac function and pumping ability because a greater mass of ventricular muscle is involved.
Functions of the Cardiovascular System
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal in Principles of Physiology for the Anaesthetist, 2020
The left and right coronary arteries, which are end arteries, arise from the aortic root behind the cusps of the aortic valve. The aortic root has three dilatations (aortic sinuses) just above the aortic valve. The right coronary artery arises from the anterior aortic sinus and supplies blood to the right ventricle, the right atrium, the SA node in 60% of people and the AV node in 85% of people. It passes between the right atrium and pulmonary trunk and descends along the atrioventricular groove to the inferior border of the heart. The right coronary artery divides into smaller branches, including the right posterior descending (posterior interventricular) artery and the acute marginal artery. Together with the left anterior descending artery, the right coronary artery helps supply blood to the septum of the heart (Figure 23.4).
Acute coronary syndrome: Acute ST-segment elevation myocardial infarction
Ever D. Grech in Practical Interventional Cardiology, 2017
Ischaemic and reperfusion ventricular tachy- and brady-arrhythmias are common which may cause severe haemodynamic disturbance and can be promptly treated by intravenous drugs or electrical cardioversion. Reperfusion idioventricular arrhythmias are, however, often transient and managed conservatively. Right coronary artery procedures are often associated with sinus arrest, atrioventricular block, idioventricular rhythm and severe hypotension. The interventionalist must be ready to recognise and promptly correct these sudden aberrations, whilst simultaneously carrying out the procedure. Although surgical backup may be available, emergency bypass is now a rare event as even the most serious complications can be more rapidly addressed within the cath lab itself. Rare surgical indications include coronary anatomy unsuitable for PCI, post-infarction ventricular septal defect, acute papillary muscle rupture or ventricular free wall rupture causing haemopericardium and tamponade (Figure 20.6). The rapid availability of portable echocardiography in the cath lab has made this a valuable diagnostic tool in managing such problems.
Anabolic androgenic steroid–induced acute myocardial infarction with multiorgan failure
Published in Baylor University Medical Center Proceedings, 2018
Frederick J. Flo, Obiajulu Kanu, Mohamed Teleb, Yuefeng Chen, Tariq Siddiqui
A 41-year-old male fitness trainer presented with sudden-onset chest pain at rest 3 hours prior to presentation. He had no significant past medical, surgical, or family history. He abused AAS for >20 years in significant amounts. At presentation, the electrocardiograph was consistent with inferior ST segment myocardial infarction with a heart rate of 54 beats/min. His troponin level initially was 0.100 ng/mL and quickly rose to 95.200 ng/mL. Consequently, an angiogram showed a totally occluded right coronary artery. Thrombectomy and percutaneous coronary intervention with insertion of a drug-eluting stent were performed. His high-density lipoprotein was 30 mg/dL. Liver enzymes were initially mildly elevated (aspartate transaminase, 74 IU/L; alkaline phosphatase, 117 IU/L; alanine transaminase, 83 IU/L). His total bilirubin was 1.8 mg/dL with an international normalized ratio of 1.7; brain natriuretic peptide was 1626 pg/mL; blood urea nitrogen was elevated at 41 mg/dL; and creatinine was 3.14 mg/dL with an estimated glomerular filtration rate of 22 mL/min/1.73 m2. Urinalysis showed mild proteinuria and a moderate amount of blood. The remaining workup was negative.
Diagnostic efficacy of fractional flow reserve with coronary angiography in dual-source computed tomography scanner
Published in Acta Cardiologica, 2018
Guozhi Xia, Di Fan, Xiaowei Yao, Gongchang Guan, Junkui Wang
Selective ICA was performed by standard protocol, via either the femoral or the radial approach, with a minimum of two projections obtained per vessel distribution and with the projection angles optimised based on the cardiac position [11]. Intracoronary nitroglycerine (200 μg) was administered to minimise vasospasm prior to the angiographic acquisitions. The ICA images were transferred to an angiographic core laboratory for blinded analysis of all assigned vessels. ICA was evaluated for maximum patients- and vessels-based diameter stenosis by luminal estimation. Per-patient and per-vessel lesions were the maximum stenosis identified in all segments or in all segments within a vessel distribution, respectively. Vessel distributions were categorised as the left anterior descending artery, the left circumflex artery and the right coronary artery.
Coronary anomaly: when you think you've seen it all
Published in Acta Cardiologica, 2019
W. Holvoet, C. Mihl, A. W. Ruiters, B. L. J. H. Kietselaer, S. C. A. M. Bekkers
A 71-year old man known with hypertension presented with progressive dyspnoea on exertion. Because of global and mild left ventricular (LV) systolic dysfunction on echocardiography, invasive coronary angiography (ICA) was performed. Although obstructive coronary artery disease was ruled out, an unusual coronary artery anomaly (CAA) was revealed. The right coronary artery (RCA) originated from the left sinus of Valsalva giving off a left anterior descending (LAD) and circumflex artery (Cx) (Figure 1, panel A–B). A second LAD giving off a diagonal (D) and septal (S) branch originated from a separate ostium also in the left sinus of Valsalva (panel C). Computed tomographic coronary angiography (CTCA) showed a subpulmonic course (between aorta and right ventricular outflow tract) of the RCA, a retro-aortic course of its Cx and pre-pulmonic course of its LAD (panel D–F). Besides an acute angle take-off, no other malignant features of the aberrant RCA were present. Because additional dobutamine-stress echocardiography was normal, he was managed conservatively with antihypertensive medication only. LV systolic function normalised after seven months.
Related Knowledge Centers
- Aortic Sinus
- Aortic Valve
- Coronary Circulation
- Artery
- Heart
- Coronary Sulcus
- Crux Cordis
- Sinoatrial Nodal Artery
- Right Marginal Branch of Right Coronary Artery
- Posterior Descending Artery