ABSTRACT
Cardiac resynchronization therapy [CRT] has been introduced as a promising therapeutic choice in heart failure [HF] patients with ventricular dyssynchrony, shown with a wide QRS. In previous study, we showed a positive effect of CRT on ejection fraction. This study aimed to evaluate the effect of CRT on the severity of mitral regurgitation [MR] quantitatively using the volumetric Doppler method in HF patients. In this prospective before-after survey, 22 HF patients with wide QRS [>/=120 ms] and NYHA class III who were included. All patients were evaluated initially for QRS width, NYHA class, MR volume, MR fraction and mitral valve area [MV area]. Biventricular pacing was done through cardiac-resynchronization device along with three pacing leads and same evaluations were done after CRT. The mean [SD] QRS width and NYHA class were significantly decreased after CRT in HF patients [p<0.001]. Also MR volume [46.9 +/- 30.2 mL vs. 27.0 +/- 26.4 mL, p<0.001] and fraction [40.1 +/- 25.5% vs. 26.8 +/- 22.7%, p=0.002] were improved following CRT. The decrease of MV area after CRT was also significant [10.6 +/- 3.0 cm[2] vs. 8.6 +/- 2.6 cm[2], p<0.001]. As MR is associated with morbidity and mortality in HF patients and the standard surgical therapy may not be practical for a majority of them, this novel treatment may improve their disease condition significantly
ABSTRACT
Left ventricular twist/torsion is believed to be a sensitive indicator of systolic and diastolic performance. To obtain circumferential rotation using tissue Doppler imaging, we need to estimate the time-varying radius of the left ventricle throughout the cardiac cycle to convert the tangential velocity into angular velocity. The aim of this study was to investigate accuracy of measured LV radius using tissue Doppler imaging throughout the cardiac cycle compared to two-dimensional [2D] imaging. A total of 35 subjects [47 +/- 12 years old] underwent transthoracic echocardiographic standard examinations. Left ventricular radius during complete cardiac cycle measured using tissue Doppler and 2D-imaging at basal and apical short axis / levels. For this reason, the 2D-images and velocity-time data derived and transferred to a personal computer for off-line analysis. 2D image frames analyzed via a program written in the MATLAB software. Velocity-time data from anteroseptal at basal level [or anterior wall at apical level] and posterior walls transferred to a spreadsheet Excel program for the radius calculations. Linear correlation and Bland-Altman analysis were calculated to assess the relationships and agreements between the tissue Doppler and 2D-measured radii throughout the cardiac cycle. There was significant correlation between tissue Doppler and 2D-measured radii and the Pearson correlation coefficients were 0.84 to 0.97 [P<0.05]. Bland-Altman analysis by constructing the 95% limits of agreement showed that the good agreements existed between the two methods. It can be concluded from our experience that the tissue Doppler imaging can reasonably estimate radius of the left ventricle throughout the cardiac cycle