Prognostic significance of postinfarction arrhythmias and biventricular dysfunction under stress

The prognostic relevance on mortality of right ventricular dysfunction in comparison with left ventricular function during stress, complex arrhythmias detected by Holter monitoring, and variables of exercise performance, was evaluated via a retrospective follow-up of more than four years for cardiac mortality of all patients in the chronic stage after myocardial infarction who were referred serially during a one-year period to stress radionuclide-ventriculography and 24-h Holter monitoring. A sample of 47% (213) of all patients admitted after myocardial infarction to the rehabilitation center during 1983 was investigated by scintigraphic stress testing and Holter monitoring and were followed up. Subsequent medication and invasive therapeutic interventions were documented. The mortality during a mean follow-up period of 3.9 years in 213 patients (mean age, 56 years) was 14.6%. Significantly decreased values of left and right ventricular ejection fractions during stress scintigraphy (38 +/- 14 versus 50 +/- 15%, p = 0.000 and 45 +/- 13 versus 54 +/- 11%, p = 0.001, respectively) were revealed in the cardiac deceased patient cohort compared with the remainder. Complex arrhythmias during Holter monitoring occurred twice as often (62 vs. 34%, p = 0.0059) in later deceased patients. Lifetable analysis demonstrated that patients with biventricular stress dysfunction had a significantly worse survival prognosis than those with monoventricular dysfunction. Multivariate nonlinear Cox survival analysis revealed that left and right ventricular ejection fraction during stress and arrhythmias were of independent prognostic significance compared with multiple clinical variables including those of exercise performance. Thus, apart from left ventricular dysfunction and arrhythmias, scintigraphically assessed right ventricular stress dysfunction is a further marker of poor prognosis after myocardial infarction. This reflects the previously neglected pathophysiologic significance of right ventricular performance in patients after myocardial infarction.