Apulsed-wave Doppler spectral profile can be used as a modality to objectively assess flows in the descending thoracic aorta.1 The normal profile reveals systolic antegrade flow; however, a small amount of retrograde diastolic flow is physiologic and increases with age and decreasing aortic compliance. The image on the left reveals holodiastolic flow reversal and increased end-diastolic velocity, as seen with the yellow arrow and asterisk, revealing continuous retrograde flow in the descending thoracic aorta. Both increased velocities and holodiastolic reversal correlate with increasing severity of aortic insufficiency, large arteriovenous fistula, patent ductus arteriosus, and systemic to pulmonary artery communications such as Blalock–Taussig shunt.1 A computed tomographic angiography scan, right image, reveals a markedly dilated right coronary artery (RCA) extending in a serpiginous fashion laterally and along the undersurface of the heart. In this plane, the right coronary artery is cut along its short axis revealing a severely dilated coronary sinus (CS) communicating with the right coronary artery via fistula, marked by the red arrow. The continuous pressure gradient from the arterial (high pressure) to venous (low pressure) system explains the flow reversal pattern in the descending aorta while hemodynamically responsible for the decreased diastolic forward flow and left-to-right shunting. The consequences of a significantly increased shunt-flow include volume overload, pulmonary hypertension, and heart failure.2 The fistulous communication with the venous system is responsible for diverting oxygenated blood, leading to myocardial ischemia. Anesthetic management includes avoiding hemodynamic fluctuations as anesthesia-induced hypotension decreases coronary perfusion and potentiates myocardial ischemia while hypertension increases the risk of rupturing a dilated coronary artery.3
The authors declare no competing interests.