No abstract

Clinical and experimental observations have suggested that newly developed collaterals usually remain even after successful revascularization. We present a patient in whom coronary collateral regression was angiographically demonstrated within about 1 month after percutaneous transluminal coronary angioplasty, which led to the development of acute myocardial infarction. This case suggests that there may be a possibility of unexplained clinically important anatomical or functional regression of collaterals after reperfusion.

No abstract

The occurrence of electrical alternans of the ST segment has been reported in patients with variant angina. The authors encountered a patient with typical electrical alternans of the ST segment in leads V4 through V6, which developed during percutaneous transluminal coronary angioplasty (PTCA) of the proximal left anterior descending artery. Hemodynamic pulsus alternans of the aortic pressure tracing was not observed during electrical alternans, and a Ca2+ blocker could not prevent this phenomenon during PTCA.

Direct visualization of the coronary arteries was performed by using a new ultrathin angioscopic catheter system in experimental animals and 4 patients with coronary artery disease during percutaneous transluminal coronary angioplasty (PTCA). In this catheter system, inspection of the coronary arteries was achieved during washout of blood by bolus infusion of 8-10 ml of saline into the coronary artery through the guide catheter. In the preliminary experience with this coronary angioscopic system, there were some limitations. In 2 patients, removal of coronary blood by manual injection of saline was not adequate, and diagnostic TV images could not be obtained. In 2 patients with tortuous coronary arteries, the catheter could not pass to the atheromatous plaques owing to lack of flexibility of the fiberoptic catheter. Furthermore, angina pectoris occurred in 2 patients during angioscopy, owing probably to interference with coronary blood flow by the guide catheter and/or fiberoptic catheter itself. For future clinical application of coronary angioscopy, further improvements in the instrument are necessary.