Assessment of left ventricular systolic function in patients with idiopathic mitral valve prolapse using dobutamine stress echocardiography

Background: Some previous studies performed with radionuclide ventriculogra phy and thallium scintigraphy reported that patients with idiopathic mitral valve prolapse (MVP) had some degree of left ventricular (LV) systolic dys function and that this dysfunction was more commonly found in symptomatic p atients. Hypothesis: The aim of the present prospective study was to investigate LV systolic function and its relationship with symptoms in patients with MVP w ith dobutamine stress test without associated certain mitral regurgitation and coronary artery disease. Methods: Thirty-three patients with echocardiographically diagnosed idiopat hic MVP were enrolled into the study and were divided into two groups as sy mptomatic (MVP-s) and asymptomatic (MVP-a). Patients underwent dobutamine s tress echocardiography (DSE) to determine wall motion abnormalities and eje ction fraction (EF) changes during rest state and increased heart rates. Re sults were compared with the DSE findings of 25 healthy individuals. Results: Symptomatic patients (MVP-s) had lower EFs during the pretest peri od than the control group (59.0 +/- 4.8% and 68.3 +/- 5.7%. respectively, p < 0.05). Basal wall motion abnormalities were found in one patient in the MVP-a group (6%) and in two patients in the MVP-s group (12%). During DSE, new wall motion abnormalities (inferoapical dyskinesia) occurred in two pat ients in the MVP-s group at submaximal heart rates. For EF values calculate d when patients reached submaximal heart rate, the MVP-s group showed only a 2.7 +/- 3.1% increase from baseline values. This increase was 5.1 +/- 3.8 % in the MVP-a group and 9.3 +/- 4.3% in the control group (p < 0.05 betwee n MVP-s and control groups). Conclusion: There is a close relationship between symptoms and ventricular function in patients with idiopathic MVP, and although many asymptomatic pa tients had nearly normal LV function, a subgroup of symptomatic patients sh owed diminished LV function and wall motion abnormalities.