Image of the month. Non-invasive coronary angiography in a patient with chronic type-a aortic dissection.

Abstract

Herz 29 · 2004 · Nr. 5 © Urban & Vogel A 69-year-old male patient with chronic dissection of ascending aorta (Stanford type-A aortic dissection) was referred for elective preoperative evaluation including coronary angiography. Transesophageal echocardiography demonstrated a dissecting membrane beginning just above the aortic valve and significant compression of the true lumen (TL) by the large false lumen (FL). The aortic valve was competent without major regurgitation. Subsequently, the patient underwent coronary angiography. However, selective intubation of the coronary arteries was not possible, even using a variety of different catheter sizes and shapes. Therefore, non-invasive coronary angiography using contrast-enhanced electron beam computed tomography (EBCT) was performed (Figure 1, right panel, axial source plane). The left main stem as well as the left anterior descending (LAD) coronary artery could be clearly visualized, arising from the highly compressed TL, without evidence of significant coronary stenoses (Figure 1, left upper panel, maximal intensity projection [MIP]). The right coronary artery showed evidence of ostial obstruction by the dissection membrane, but there was no hint of obstructive atherosclerotic coronary artery disease (Figure 1, left lower panel, MIP). Besides concomitant obstructive coronary artery disease, compression of coronary arteries by the dissection membrane is an important cause of impaired myocardial perfusion in patients with type-A aortic dissection. Invasive coronary angiography may be particularly difficult in these patients and furthermore bears the risk of injuring the dissection membrane. In this regard, noninvasive coronary angiography using ultrafast CT-techniques may be a safe and effective alternative to visualize the coronary anatomy in patients prior to elective surgical repair. In patients with acute type-A dissection, however, emergency surgical repair immediately after establishing the diagnosis is pivotal. In these patients, coronary angiography only delays the vital operation.