Value of the Mitral Valve Resistance in Evaluation of Symptomatic Patients with Mild and Moderate Mitral Stenosis - A Dobutamine Stress Echocardiographic Study

Background Conventional stenosis indexes poorly reflect the major hemodynamic consequence of mitral stenosis (MS). Valve resistance (VR) is a physiologic expression of stenosis. Objectives This study aimed to demonstrate whether the mitral valve resistance (MVR) and its changes, relate to restricted exercise capacity in patients with mild and moderate mitral stenosis. Methods Twenty‐four patients with rheumatic mild‐to‐moderate MS underwent transthoracic echocardiographic study (resting and dobutamine stress echocardiography [DSE]), divided into two groups; group I: symptomatic (12 patients) and group II: asymptomatic (12 patients). Mitral valve area (MVA), mean transmitral diastolic pressure gradient (TMPG), cardiac output (CO), and MVR were measured in all patients at rest and at peak DSE. Changes (∆) in MVA, TMPG, CO, and MVR were calculated. Data underwent statistical analysis. Results From resting to peak dobutamine infusion, the MVR significantly decreased from 111.4 ± 28.2 to 83.6 ± 27.0 dynes sec/cm5 in group II (P