Comments

As shown in these examples, the proximal coronary arteries can often be visualized on TEE. The left main coronary artery arises from the left coronary sinus of Valsalva, is easily visualized in over 85% of patients and has a normal diameter of 4.2 ± 0.7 mm, with a slightly smaller average diameter in women (3.5 mm) compared with men (4.3 mm). The left main coronary artery bifurcates into the left anterior descending coronary, with a normal proximal diameter of 3.5 ± 1.0 mm, which supplies the anterior wall and anterior septum, and the circumflex coronary artery, with a normal diameter of 3.0 ± 0.6 mm, which supplies the lateral left ventricular wall. The right coronary artery arises from the right coronary sinus, with an average diameter of 3.6 ± 0.8 mm. The right coronary artery gives rise to the posterior descending coronary artery, supplying the inferior and posterior walls, in about 80% of patients (e.g., a right-dominant coronary circulation). The right coronary artery is not always visualized on TEE, being seen in about 50% of cases in one series.

The apical segments of the ventricle are often supplied by the left anterior descending artery, although the posterior descending coronary artery may extend to the inferior apex in some cases. The posterior (or inferior–lateral) left ventricular wall is variably supplied by either the circumflex or the posterior descending coronary artery. Coronary blood flow can be recorded using pulsed Doppler in many patients, with the typical pattern showing prominent diastolic flow, with a velocity about 0.6 cm/s, with little flow in systole. Although an increased velocity (>1 m/s) suggests stenosis and Doppler evaluation of coronary flow reserve is possible, these data are rarely used clinically.

TEE evaluation of the coronary arteries is most useful for detection of coronary artery aneurysms, coronary fistula, and anomalous origins from a different sinus of Valsalva or from the pulmonary artery. Although some studies have shown that TEE evaluation is sensitive and specific for detection of significant left main or proximal coronary stenosis, TEE has not gained clinical acceptance as an approach to evaluation of atherosclerotic coronary disease. In addition to variable image quality, the inability to visualize distal vessel anatomy is a major limitation. Echocardiographic evaluation of coronary disease currently relies on evaluation of regional myocardial function at rest and with stress.

Suggested reading

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  Lenter C, editor: Geigy Scientific Tables, Vol. 5: Heart and Circulation, Basel, Switzerland, 1990, CIBA-GEIGY Limited, pp 173–181.

  
  
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  Oxorn D, Edelist G, Smith MS: An introduction to transoesophageal echocardiography: II Clinical applications, Can J Anaesth 43:278–294, 1996.

  
  
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  Lang R, Badano L, Victor Mor-Avi V, et al: Recommendations for cardiac chamber quantification by echocardiography in adults: An update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging, J Am Soc Echocardiogr 28:1–39, 2015.

Comments

Coronary artery dissection can occur spontaneously or as a complication of cardiac catheterization. Coronary dissection is a rare cause of acute myocardial infarction in younger patients. Although there are no specific clinical predictors of spontaneous coronary dissection, it is more common in women than in men and the risk is increased during pregnancy.

Coronary dissection owing to diagnostic cardiac catheterization is rare but can result in acute severe myocardial ischemia, as in this case. The overall incidence of myocardial infarction with diagnostic coronary angiography is 0.06%, with infarction more often due to vessel thrombosis or embolization rather than to coronary dissection. When coronary dissection complicates a diagnostic or therapeutic percutaneous coronary procedure, the dissection flap may propagate retrograde into the aorta, as in this case.

Suggested reading

• 1.
  

  Saw J: Spontaneous coronary artery dissection, Can J Cardiol 29(9):1027–1033, 2013.

  
  
• 2.
  

  Crea F, Battipaglia I, Andreotti F: Sex differences in mechanisms, presentation and management of ischaemic heart disease, Atherosclerosis 241(1):157–168, 2015.

  
  
• 3.
  

  Alfonso F, Bastante T, Cuesta J, et al: Spontaneous coronary artery dissection: Novel insights on diagnosis and management, Cardiovasc Diagn Ther 5(2):133–140, 2015.

  
  
• 4.
  

  Lou X, Mitter SS, Blair JE, et al: Intraoperative coronary artery dissection in fibromuscular dysplasia, Ann Thorac Surg 99(4): 1442–1444, 2015.

Comments

On echocardiography, air in the cardiac chambers appears as mobile echodensities, e.g., echo contrast. The echocardiographer may be asked to evaluate residual air as the patient is weaned from cardiopulmonary bypass. Air detected by TEE is associated with transient ST-segment elevation on the electrocardiogram (ECG) and wall motion abnormalities on two-dimensional (2D) imaging. The association between intracardiac air and neurologic events after cardiac surgery is less clear, with some studies suggesting that left-sided microbubbles are not predictive of neurologic recovery, but other studies showing better postoperative cognitive function in patients with fewer microbubbles after surgery.

Suggested reading

• 1.
  

  Jha AK, Malik V, Hote M: Minimally invasive cardiac surgery and transesophageal echocardiography, Ann Card Anaesth 17(2):125–132, 2014.

  
  
• 2.
  

  Akiyama K, Arisawa S, Ide M, et al: Intraoperative cardiac assessment with transesophageal echocardiography for decision-making in cardiac anesthesia, Gen Thorac Cardiovasc Surg 61(6):320–329, 2013.