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Background: Determination of pulmonary vascular resistance (PVR) in patients with suspected or known pulmonary hypertension (PH) requires right heart catheterization. Our purpose was to use Doppler echocardiography to estimate PVR in patients with PH. Methods: Patient population consisted of 52 patients (53 ± 12 years; 35 females) who underwent Doppler echocardiography and right heart catheterization within 24 hours of each other. The ratio of peak tricuspid regurgitation velocity (TRV) and right ventricular outflow time-velocity integral (VTIRVOT) was measured via transthoracic echocardiography and correlated to invasively determined PVR. A linear regression equation was generated to determine PVR by echocardiography based upon the TRV/VTIRVOT ratio. PVR by echocardiography was compared to invasive PVR using Bland-Altman analysis. Results: Significant correlation was demonstrated between TRV/VTIRVOT and PVR by catheterization (r = 0.73; P < 0.001). However, Bland-Altman analysis showed that agreement between PVR determined by echocardiography and invasive PVR was poor (bias = 0; standard deviation = 4.3 Wood units). In a subset of patients with invasive PVR < 8 Wood units (26 patients), correlation between TRV/VTIRVOT and invasive PVR was strong (r = 0.94; P < 0.001). In these patients, agreement between PVR by echocardiography and invasive PVR was satisfactory (bias = 0; standard deviation = 0.5 Wood units). There was no correlation between TRV/VTIRVOT and invasive PVR in patients with PVR > 8 Wood units (n = 26; r = 0.17). Conclusion: While TRV/VTIRVOT correlates significantly with PVR, using it to estimate PVR in a PH patient population cannot be recommended. [ABSTRACT FROM AUTHOR]

Aims: Several echocardiographic methods have been proposed to assist in patient selection for cardiac resynchronization therapy (CRT). The prevailing hypothesis is that echocardiography may be superior to the electrocardiogram to qualify abnormalities in regional mechanical activation, because QRS widening is only a surrogate for ventricular dyssynchrony. Methods and Results: This review will focus on tissue Doppler (TD) and strain imaging, including their advantages and disadvantages for patient selection for CRT. Colour-coded TD remains to be one of the most promising means to quantify dyssynchrony. Tissue Doppler velocity data have a more favourable signal-to-noise ratio compared with TD strain or strain rate imaging. However, velocity data are affected by Doppler angle of incidence and passive or tethering motion. A newer promising method is speckle-tracking echocardiography to calculate strain. An opposing wall delay in peak TD velocity > or =65 ms has been associated with clinical and ventricular response to CRT. The initial experience with speckle tracking used the short-axis view to calculate radial strain. An anterior-septal to posterior wall peak strain delay > or =130 ms has been associated with an ejection fraction response to CRT. Conclusion: Although no ideal echo-Doppler method has yet been discovered to select patients for CRT, technical refinements and advances in understanding of pathophysiology continue to favourably impact on potential clinical applications. [ABSTRACT FROM AUTHOR]

Aims Several echocardiographic methods have been proposed to assist in patient selection for cardiac resynchronization therapy (CRT). The prevailing hypothesis is that echocardiography may be superior to the electrocardiogram to qualify abnormalities in regional mechanical activation, because QRS widening is only a surrogate for ventricular dyssynchrony. Methods and results This review will focus on tissue Doppler (TD) and strain imaging, including their advantages and disadvantages for patient selection for CRT. Colour-coded TD remains to be one of the most promising means to quantify dyssynchrony. Tissue Doppler velocity data have a more favourable signal-to-noise ratio compared with TD strain or strain rate imaging. However, velocity data are affected by Doppler angle of incidence and passive or tethering motion. A newer promising method is speckle-tracking echocardiography to calculate strain. An opposing wall delay in peak TD velocity ≥65 ms has been associated with clinical and ventricular response to CRT. The initial experience with speckle tracking used the short-axis view to calculate radial strain. An anterior-septal to posterior wall peak strain delay ≥130 ms has been associated with an ejection fraction response to CRT. Conclusion Although no ideal echo-Doppler method has yet been discovered to select patients for CRT, technical refinements and advances in understanding of pathophysiology continue to favourably impact on potential clinical applications. [ABSTRACT FROM PUBLISHER]