HOLTER ST MONITORING EARLY AFTER ACUTE MYOCARDIAL-INFARCTION - MECHANISMS OF ISCHEMIA IN PATIENTS TREATED BY THROMBOLYSIS

Objective-To investigate the mechanisms of Holter ST shift in patients with acute myocardial infarction treated by thrombolysis. Design-Pros pective observational study. Setting-A London district general hospita l. Subjects-The study group consisted of 94 patients with acute myocar dial infarction treated by thrombolysis. Interventions-All underwent e arly 48 hour Holter ST monitoring and elective coronary arteriography. Main outcome measures-Relation of Holter ST shift to multivessel coro nary disease, coronary patency, collateralisation, and morphology of t he infarct related lesion. Results-There was a trend towards an increa sed prevalence of Holter ST shift in patients with patency of the infa rct related artery and those with multivessel disease. This was only s ignificant in patients with three vessel disease, a significantly high er proportion of whom had >3 episodes of ST shift (41% v 14%; p = 0.02 ) or a total duration of ST shift >1 hour (35% v 13%; p = 0.04) than t hose with less extensive coronary disease. Holter ST shift occurred in a significantly higher proportion of patients with complex lesion mor phology (Ambrose type 2 or 3) compared with those with lesions of Ambr ose morphology type 1 or 2 (60% v 33%; p = 0.05). Conclusion-Holter ST shift detected early after thrombolysis is an ischaemic phenomenon wi th a complex pathophysiology. It reflects both remote ischaemia in pat ients with multivessel disease, and dynamic ischaemic processes relate d to complex lesion morphology in those with a patent infarct related artery.