Magnitude of myocardial dysfunction is greater in painful than in painless myocardial ischemia: An exercise echocardiographic study

Objectives. This study sought to assess the presence and extent of inducible myocardial dysfunction during painful and painless (silent) myocardial ischemi in homogeneous patient cohort with coronary artery disease and no previous myocardial infarction. Background. The functional significance of painless versus painful demand-driven ischemi remains controversial, with conflicting results in published reports regarding the amount of myocardium in jeopardy. Methods. Exercise echocardiography was performed in 89 patients (mean [±SD] age 59.3 ± 8.2 years) with significant coronary artery disease and positive exercise stress test results. Patients were taking no antianginal medications and were classified into painless and painful cohorts after the outcome of symptom-limited treadmill exercise test. No patients had previous coronary artery bypass surgery. Images were acquired in digital format before and immediately after treadmill exercise testing. Results. Fifty-eight patients had painful and 31 painless myocardial ischemia. Clinical and demographic characteristics as well as coronary artery anatomy were similar in both groups. Patients with painless ischemi achieved better exercise performance with greater exercise duration (p < 0.001) and higher maximal rate-blood pressure product (p < 0.001) than those with painful ischemia. New wall motion abnormalities were seen in 54 patients (93%) with painful versus 17 (55%) with painless ischemi (p < 0.001). Total ischemic score was greater in patients with painful than in those with painless ischemi (15.9 ± 3.7 vs. 12 ± 1.4, p < 0.001, respectively), with greater number of ischemic myocardial segments in painful than in painless ischemi (101 [16%] vs. 21 [6%], p < 0.001, respectively). Conclusions. Patients with painless ischemi frequently have regional myocardial dysfunction on exertion detected by echocardiography, but painful episodes are accompanied by greater magnitude of myocardial dysfunction.