Echocardiography for cardiac resynchronization therapy: recommendations for performance and reporting: a report from the American Society of Echocardiography Dyssynchrony Writing Group endorsed by the Heart Rhythm Society.
Gorcsan J 3rd, Abraham T, Agler DA et al.
Comments:
This consensus report evaluates the contemporary applications of echocardiography for CRT including relative strengths and technical limitations of several techniques and proposes guidelines regarding current and possible future clinical applications. A simplified post-CRT screening for atrioventricular optimization using Doppler mitral inflow velocities is also proposed.
Reference: JASE 2008;21:191-213.
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Optimal use of echocardiography in cardiac resynchronisation therapy.
Bleeker GB, Yu CM, Nihoyannopoulos P et al.
Comments:
As in reference 2, this paper reviews the current evidence regarding the use of echocardiography in CRT. It gives however a more European focused point of view.
Reference: Heart 2007;93:1339-50.
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Mechanism of improvement in mitral regurgitation after cardiac resynchronization therapy.
Ypenburg C, Lancellotti P, Tops LF et al.
Comments:
The authors studied radial strain assessed by speckle tracking in 68 CRT patients at baseline and followed the patients for 6 months. The site of latest activation in early responders was mostly inferior of posterior (adjacent to the posterior papillary muscle), whereas the lateral wall was the latest activated segment in late responders. These results suggest that dyssynchrony involving the posterior papillary muscle may lead to an immediate reduction in MR, whereas LV dyssynchrony in the lateral wall results in late reponse to CRT.
Reference: EHJ 2008;29:757-65.
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Gradaus R, Stuckenborg V, Löher A et al. Diastolic filling pattern and left ventricular diameter predict response and prognosis after cardiac resynchronization therapy.
Comments:
This study evaluated 122 consecutive heart failure patients with an indication for CRT and presence of LV dyssynchrony assessed by echocardiography including Tissue Doppler imaging. The authors looked for clinical and echocardiographic predictors of reponse. Overall nearly 30% of patients had no benefit from CRT. On multivariate analyses, patients with and increased LV end systolic diameter and concomitant diastolic dysfunction (restrictive filling pattern) had a significantly worse outcome.
Reference: Heart 2007, Nov 5 (Epub ahead of print).
Becker M, Hoffman R, Schmitz F et al.
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Relation of optimal lead positioning as defined by three-dimensional echocardiography to long-term benefit of cardiac resynchronization.
Comments:
In this study 58 congestive heart failure patients were studied with 3D echocardiography at baseline and 12 months after CRT implantation. Using volume/time curves the segments with the latest minimum of systolic volume were determined preoperatively and during follow-up. Correspondence of the segment with the latest preoperative LV contraction with the segment with the greatest effect based on CRT resulted in a significantly greater benefit of ejection fraction and peak oxygen consumption and a greater improvement in LV remodelling.
Reference: Am J C 2007;100:1671-6.
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