Akinesia becoming dyskinesia after exercise testing: Prevalence and relationship to clinical outcome

OBJECTIVES: The aim of this study was to determine the prevalence and prognostic implications of dyskinesia developing after exercise. BACKGROUND: The prevalence and prognostic implications of new-onset dyskinesia with exercise testing have not been previously described. METHODS: We considered 1,005 consecutive patients who underwent exercise echocardiography and had akinetic segments at rest. Patients were divided according to the presence or absence of exercise-induced dyskinesia. Baseline clinical and echocardiographic parameters were compared, and patients were followed up for a median of 2.7 years. RESULTS: One hundred four (10%) patients developed dyskinesia after exercise. Compared to patients with segments that remained akinetic, these patients were more likely to have electrocardiographic (ECG) evidence of prior myocardial infarction and, during exercise, had a less pronounced rise in systolic blood pressure and more often had ECG evidence of ischemia. Their resting left ventricular (LV) ejection fraction was worse and improved little after exercise. However, all-cause mortality and the incidence of major adverse cardiac events were similar in the two groups, even after correction for age, gender, and resting LV function (hazard ratio for major adverse cardiac events = 1.36, 95% confidence interval [CI] 0.82 to 2.26, p = 0.23; hazard ratio for total mortality = 1.20, 95% CI 0.75 to 1.94, p = 0.45). CONCLUSIONS: One in 10 patients with akinetic myocardium at rest will develop dyskinesia after exercise. This is associated with poorer LV function at rest and little improvement in systolic function after exercise. However, this response has no impact on prognosis.