Determinants of Exercise-Induced Increase of Mitral Regurgitation in Patients with Acute Coronary Syndromes


Address for correspondence and reprint requests: Redi Pecini, M.D., Rigshospitalet, Department of Cardiology. 2142, Blegdamsvej 9, 2100 Copenhagen, Denmark. Fax: +45 3545 2513; E-mail:


Background: Mechanisms behind exercise-induced increase of mitral regurgitation (MR) in patients with chronic ischemic heart disease have been described earlier. We describe the determinants of exercise-induced changes in MR in patients with non-ST-elevation acute coronary syndrome (NSTACS). Methods: Forty-five consecutive patients (mean ± SD age 64 ± 10 years, 37 men) with NSTACS underwent exercise echocardiography on a supine bicycle the day before angiography. The exercise was started with a load of 10 W with increments of 10 W every minute until symptoms developed or a max load of 100 W. Effective regurgitation orifice (ERO) was measured at rest and at peak exercise. Results: Twelve patients had more than trace MR at rest with ERO 8 ± 5 (mean ± SD), range: 3–18 mm2. In these patients, ERO increased during exercise to 13 ± 6 (mean ± SD), range: 6–23 mm2 corresponding to an increase of 70% from rest (P = 0.001). Seven other patients developed new MR during exercise with ERO at peak exercise of 8 ± 4 mm2 (mean ± SD), range: 4–14 mm2. All these patients had significant increase in wall motion score index (WMSI) of 0.14 ± 0.18 (mean ± SD), P = 0.006, while in the 25 patients without MR at rest or during exercise, WMSI remained unchanged, −0.02 ± 0.08 (mean ± SD), P = 0.2. Conclusion: Exercise-induced increases of MR in patients with NSTACS are related to worsening of regional wall motions. (Echocardiography 2010;27:567-574)