Coronary artery spasm is a known complication of coronary interventions, for which intracoronary nitroglycerin (ICN) is the treatment of choice. Some forms of intense spasm are resistant to ICN. Calcium channel antagonists are also known to be effective for coronary artery spasm, including nitroglycerin-resistant spasm. Here we describe a protocol for the clinical use of intracoronary diltiazem (ICD). By this protocol, ICD can be safely given without disturbing the clinical status of patients. ICD (2.5 mg) given slowly over 1 minute produced no vasodilitation of normal vessel segments but did produce significant dilatation of stenotic segments above and beyond the effects of nitrates. Mean minimum lumen diameter increased 18%, from 0.89 +/- 0.06 mm to 1.06 +/- 0.07 mm (mean +/- SEM, P < 0.001). ICD produced clinically insignificant changes in systolic blood pressure, diastolic blood pressure, heart rate, and PR, QRS, and QT intervals. This protocol has been employed to safely use ICD to relieve both nitroglycerin-resistant epicardial artery spasm and nitroglycerin-resistant distal microvascular spasm (the no-reflow phenomenon).
Directional coronary atherectomy (DCA) is an important advance in the mechanical revascularization of stenotic coronary arteries. The bulky nature of the DCA device has necessitated the use of guiding catheter designs that are more cumbersome to use than balloon angioplasty guiding catheters. Because engagement of coronary artery ostia with the currently available DCA guiding catheters is often difficult and because DCA guiding catheters significantly "relax" and reshape during the atherectomy procedure, angiography using these guiding catheters before and after atherectomy can be suboptimal. A new technique for angiography during atherectomy using long Judkin's diagnostic catheters inserted through the existing DCA guiding catheters is described. This technique can be used for optimal visualization of the coronary arteries with minimal use of contrast before and after sessions of atherectomy and also can be used to help engage the DCA guiding catheters. Some improvements in the design of guiding catheters for DCA are suggested.
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