By using an orderly approach the physician is able to correlate bedside observations and laboratory findings with pathophysiology and the basic elements of cardiac pathology, as shown in the following specimen.
Normal coronary artery cross section
This is a cross section of a normal coronary artery showing the normal intima, media and adventitia. Note the lumen is widely patent.
Cross section with angina pectoris
This is a cross section of a coronary artery from a patient who had angina pectoris. An atheromatous plaque has caused marked narrowing of the vessel lumen. Atherosclerosis begins in the intima with endothelial injury or dysfunction. This results in the uptake of lipids, a proliferation of smooth muscle in the media and often in fibrosis and calcification of the media.
Intravascular ultrasound (IVUS)
Intracoronary imaging techniques have advanced the understanding of the pathogenesis of coronary artery disease. Intravascular ultrasound is an example. It visualizes the arterial lumen and its layers by providing high resolution cross sectional images. Information about vessel morphology and plaque composition, that was previously available only by histologic study, is obtained by images of the full 360° circumference of the vessel wall. An example of this procedure follows. It demonstrates direct, real-time video images that can be correlated with basic pathophysiology.
WNL proximal left coronary IVUS
This is a still-frame image of an intravascular ultrasound study of the proximal left main coronary artery in a patient with angina pectoris. The vessel shown here is normal in appearance. There is an echo-dense intima, a translucent media and an echo-dense adventitia. The dark circular structure in the center of the image represents the ultrasound catheter, and the white density adjacent to the catheter represents the artifact created by the guide wire. Note especially the size of the normal vessel lumen.
Plaque in distal left coronary IVUS
This is a still-frame of the distal portion of the left main coronary artery from the same patient. Note the echo-dense mass in the lower left quadrant adjacent to the intimal layer. It was not present in the proximal vessel, and represents fibrocalcific atherosclerotic plaque. It has clearly narrowed the vessel lumen. The real-time study that follows will begin in the normal proximal vessel, as shown on the previous still-frame. As the catheter is advanced, note that the artery will taper, and the echo-dense mass shown here will appear in the distal vessel.