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

Background: Some previous studies performed with radionuclide ventriculography and thallium scintigraphy reported that patients with idiopathic mitral valve prolapse (MVP) had some degree of left ventricular (LV) systolic dysfunction and that this dysfunction was more commonly found in symptomatic patients.
Hypothesis: The aim of the present prospective study was to investigate LV systolic function and its relationship with symptoms in patients with MVP with dobutamine stress test without associated certain mitral regurgitation and coronary artery disease.
Methods: Thirty-three patients with echocardiographically diagnosed idiopathic MVP were enrolled into the study and were divided into two groups as symptomatic (MVP-s) and asymptomatic (MVP-a). Patients underwent dobutamine stress echocardiography (DSE) to determine wall motion abnormalities and ejection fraction (EF) changes during rest state and increased heart rates. Results were compared with the DSE findings of 25 healthy individuals.
Results: Symptomatic patients (MVP-s) had lower EFs during the pretest period 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 patients in the MVP-s group at submaximal heart rates. For EF values calculated 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 between 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 patients had nearly normal LV function, a subgroup of symptomatic patients showed diminished LV function and wall motion abnormalities.