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

Roshdy, Hisham S.; Meshrif, Amir M.; El‐Dosouky, Ibtesam I.

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 < 0.001). The increase in MVR in group I (13.8 ± 10.3 dynes sec/cm5) compared with its reduction (−27.8 ± 15.6 dynes sec/cm5) in group II were highly significant different (P < 0.001). A reduction in MVR by less than 21.5 dynes sec/cm5 at peak dobutamine infusion reflect a cutoff value considered to detect the hemodynamic significance of mild-to-moderate MS with a sensitivity of 92% and a specificity of 73%. Conclusion The changes in the MVR can be used as a DSE parameter for expression of stenosis severity and to describe discrepancy in symptom status in patients with mild-to-moderate mitral stenosis.

CHI-squared test; DOBUTAMINE; ECHOCARDIOGRAPHY; HEART function tests; MITRAL stenosis; STATISTICS; T-test (Statistics); U-statistics; DATA analysis; RECEIVER operating characteristic curves; DATA analysis software; DESCRIPTIVE statistics

Echocardiography, 2014, Vol 31, Issue 3, p347

0742-2822

Academic Journal

10.1111/echo.12363