Treatment of acute right coronary artery occlusion during anesthesia

Abstract

Purpose: Perioperative coronary artery occlusion is a potentially dangerous complication causing myocardial infarction and circulatory collapse. We report a case showing severe ST segment depression in leads II and V5 during anesthesia. Diltiazem and nifedipine, but not nitroglycerine, partially improved the ST changes which were normalized by a percutaneous cardiopulmonary system (PCPS).Clinical Features: A 71-yr-old man with cerebrovascular disease was scheduled for coronary artery bypass grafting (CABG). Past medical history included myocardial infarction due to right coronary artery (RCA) occlusion. Both the femoral artery and vein were cannulated percutaneously before operation and the PCPS was prepared as a back-up system. Depression of the ST segments in leads V5 and II was observed following heparinization. Although hemodynamic stability was maintained with continuous infusion of catecholamines, the ST changes were not improved by intravenous nitroglycerine. Intravenous diltiazem followed by nasal nifedipine partially improved the ST changes. The changes were normalized after induction of PCPS. No neurological complications were observed. The postoperative coronary angiography confirmed the total occlusion of RCA.Conclusion: Calcium channel blockers were more effective than nitroglycerine in treating perioperative ST depression. However, none of them produced complete reversal of the ischemic changes which were normalized with PCPS.Objectif : L'occlusion périopératoire de l'artère coronaire est une complication potentiellement dangereuse et peut causer un infarctus du myocarde et un collapsus circulatoire. Nous signalons un cas qui montre un sousdécalage sévère en D II et V5 pendant l'anesthésie. Le diltiazem et la nifédipine, mais non la nitroglycérine, ont partiellement amélioré les changements du segment ST qui ont été normalisés par un système cardiopulmonaire percutané (SCPP).Éléments cliniques : Un homme de 71 ans, victime d'accidents vasculaires cérébraux, devait subir un pontage aortocoronarien. Ses antécédents comprenaient un infarctus du myocarde provoqué par une occlusion de l'artère coronaire droite (ACD). On a inséré des canules percutanées dans l'artère et la veine fémorales avant l'opération et le SCPP a été préparé en qualité de système de réserve. L'abaissement des segments ST en V5 et II a été observé à la suite de l'héparinisation. Même si la stabilité hémodynamique a été maintenue avec une perfusion continue de catécholamines, les changements ST n'ont pas été améliorés par la nitroglycérine intraveineuse. Le diltiazem intraveineux, suivi de nifédipine nasale, a partiellement amélioré les changements ST. Les modifications ont été normalisées après l'entrée en fonction du SCPP. Aucune complication neurologique n'a été observée. L'angiographie coronaire postopératoire a confirmé l'occlusion totale de l'ACD. Conclusion :Les inhibiteurs calciques ont été plus efficaces que la nitroglycérine pour traiter la dépression péri-opératoire du segment ST. Cependant, aucun d'eux n'a produit de renv...

Progressive epicardial coronary blood flow reduction fails to produce ST-segment depression at normal heart rates

“…UA/NSTEMI patients commonly present with normal or even slow heart rates due to beta-blocker administration (2,13,29,38). Furthermore, a significant proportion of these patients (23-42%) demonstrate Ͻ70% coronary diameter stenosis in the culprit vessel (50).…”

“…In stable angina patients and in classic animal models, moderately severe coronary lesions produce ST-segment depression only in the presence of tachycardia, which shortens the diastolic filling time and reduces perfusion more severely in the subendocardium than in the subepicardium (22,35,36). On the contrary, in UA/NSTEMI patients, plaque rupture and activation of the coagulation and inflammatory cascades commonly generate ST-segment depression at normal heart rate in the presence of coronary stenoses of severity comparable to that of stable angina patients (2,13,29,38). Finally, a smooth spectrum of ST-segment behavior typical of a single mechanism operating along a spectrum of values cannot be found when the evolution of ST-segment changes during ACS is carefully examined.…”