Complete sustained reversal of cyclic ST-segment elevation (coronary cyclic flow variations) by low-dose intravenous nitroglycerin during acute coronary syndrome

BackgroundRecurrent ST-segment elevations in acute coronary syndromes have been attributed to coronary cyclic flow variations (CCFVs) possibly due to coronary vasospasm and unstable platelet aggregation in partially occluded arteries.MethodsWe describe the case of a patient with an acute myocardial infarction, recurrent ST-segment elevations and diffuse disease of the left anterior descending artery.ResultsThe post-angiography 12-lead continuous ECG monitoring revealed cyclic anterior ST-segment elevations that were completely abolished with continuous intravenous infusion of low-dose isosorbide-dinitrate.ConclusionThe complete and sustained response to low-dose nitrate suggests that vasoconstriction plays a crucial role to provoke CCFVs. This case underlines the importance of continuous 12-lead ECG monitoring with ST-segment trend analysis in the CCU.