Donaldo Pereira Garcia

The "no-reflow" phenomenon in the coronary arteries

In the last twenty years, the treatment of coronary heart disease with cardiac catheterization has greatly advanced. This therapeutic approach has had unexpected side effects, however, for which solutions must be found, particularly in the are of interventional cardiology. The “noreflow” phenomenon, a side effect, is an uncommon and critical occurrence and, if not reversed, causes a high rate of morbidity and mortality. Its most intriguing clinical characteristic perhaps is its unpredictability. Kloner and co-workers 1 first described the “noreflow” phenomenon in 1974 in dogs with experimentally induced myocardial infarction. The coronary arteries of these dogs were occluded for 40 or 90 minutes, and after that, they were reperfused and studied by means of contrast medium injection. In the coronary arteries occluded for 40 minutes, there was uniform reperfusion of the ischemic myocardium; however, in those occluded for 90 minutes, there was no reperfusion after removal of the coronary occlusion. These investigators concluded that the absence of flow was an ischemic phenomenon, related to the duration of coronary occlusion, which resulted in muscle injury and death of myocardial cells 1 .

Sublingual isosorbide-5 mononitrate during coronary arteriography. Comparison with sublingual nitroglycerin

PURPOSE To evaluate the effect of sublingual isosorbide-5 mononitrate (ISMN) and nitroglycerin (NTG) on luminal diameter of epicardial coronary arteries, mean arterial pressure and deleterious effects. METHODS Fifty patients were submitted to cardiac catheterization and coronary arteriography, at baseline, and 5 min after sublingual administration of ISMN, group A (GA) or NTG, group B (GB). RESULTS Reference vessel diameter increased in both groups, without statistical significance. In GA and GB, a decrease (1.66 mmHg) and an increase (0.79 mmHg) in mean arterial pressure, respectively, were demonstrated (p = 0.123). There were no deleterious effects with the use of these drugs. CONCLUSION Sublingual ISMN is an alternative to administration of NTG during coronary arteriography, and represents a therapeutic alternative to ischemic heart disease treatment.