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

• Published in: Echocardiography (Mount Kisco, N.Y.) Vol. 31; no. 3; pp. 347 - 352
• Main Authors: Roshdy, Hisham S., Meshrif, Amir M., El-Dosouky, Ibtesam I.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.03.2014
• Subjects: Adult; Cardiac Output - physiology; Chi-Square Distribution; Cohort Studies; dobutamine stress echocardiography; Echocardiography - methods; Echocardiography, Stress - methods; Female; hemodynamic consequence of mitral stenosis; Hemodynamics - physiology; Humans; Male; Middle Aged; mitral stenosis; mitral valve resistance; Mitral Valve Stenosis - diagnostic imaging; Mitral Valve Stenosis - physiopathology; Prognosis; Prospective Studies; Rheumatic Heart Disease - diagnostic imaging; Rheumatic Heart Disease - physiopathology; ROC Curve; Severity of Illness Index; Statistics, Nonparametric; Young Adult; dobutamine stress echocardiography; mitral valve resistance; hemodynamic consequence of mitral stenosis; mitral stenosis
• ISSN: 0742-2822; 1540-8175
• DOI: 10.1111/echo.12363

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.