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Impact of Changes in Myocardial Velocity Assessed by Tissue Doppler Imaging during Exercise on Dynamic Mitral Regurgitation in Patients with Nonischemic Cardiomyopathy
Author(s) -
Kang SooJin,
Lim HongSeok,
Hwang Jungwon,
Choi JungHyun,
Seo KyoungWoo,
Choi ByungJoo,
Choi SoYeon,
Hwang GyoSeung,
Yoon MyeongHo,
Shin JoonHan,
Tahk SeungJea
Publication year - 2008
Publication title -
echocardiography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 62
eISSN - 1540-8175
pISSN - 0742-2822
DOI - 10.1111/j.1540-8175.2007.00621.x
Subject(s) - cardiology , medicine , supine position , doppler imaging , mitral regurgitation , cardiomyopathy , dilated cardiomyopathy , heart failure , nuclear medicine , blood pressure , diastole
Background: We evaluated the myocardial contractile reserve related to exercise‐induced changes in functional mitral regurgitation (MR) by tissue Doppler imaging (TDI). Methods: Supine bicycle exercise was performed in 35 patients with nonischemic cardiomyopathy (age 51 ± 12 years; EF < 40%) and resting, and peak exercise 2D echocardiographic parameters, and TDI data were obtained. V avg was defined as the average of peak systolic velocities of six basal LV segments by TDI. Myocardial contractile reserve, which was calculated by [peak exercise V avg – baseline V avg ], was represented as ΔV avg . Dyssynchrony index was derived from the standard deviation of the time to the peak systolic velocity of 12 LV segments. Results: During exercise (9.7 ± 2.4 minutes), the mean V avg increased from 4.0 ± 0.8 cm/s to 5.5 ± 1.0 cm/s. The effective regurgitant orifice area (ERO) and the ratio of MR jet area to the left atrial area (JLA%) were 1.9 ± 2.9 mm 2 and 12 ± 12%, respectively. During exercise, ERO and JLA% significantly increased to 6.2 ± 6.4 mm 2 and 21 ± 13% (P < 0.05), respectively, with individually variable changes. Tenting area was found to be an independent factor that showed a relationship with the baseline severity of MR (r = 0.561, P < 0.001). Dyssynchrony index and ΔV avg were found to correlate with both maximal MR severity at peak exercise and changes in MR during exercise. By multivariate analysis, ΔV avg was found to be an independent determinant of exercise‐induced changes in ERO (ΔERO; r =−0.707, P< 0.001) and changes in JLA% (ΔJLA%; r =−0.663, P< 0.001). Conclusion: In patients with nonischemic cardiomyopathy, impaired contractile reserve assessed by TDI velocity data may be an independent determinant affecting exercise‐induced changes in dynamic MR.