HF-CRT Echo Resynchronization Index Calculator
- HF-CRT Echo Resynchronization Index: Explanation and Clinical Context
The HF-CRT Echo Resynchronization Index is a composite echocardiographic measure designed to quantify the mechanical dyssynchrony and remodeling response in patients undergoing cardiac resynchronization therapy (CRT). It integrates key mechanical and electrical parameters that have been shown to predict CRT benefit, including septal-to-lateral delay, interventricular mechanical delay (IVMD), and QRS duration.
Definition and Calculation:
This index combines multiple dyssynchrony parameters into a unified numeric score. A higher value indicates greater electrical-mechanical discordance and a higher probability of left ventricular reverse remodeling after CRT. LV end-systolic volume (LVESV) reduction ≥15% from baseline at 6 months post-implantation is commonly used to define a “CRT Responder.”
Normal and Predictive Ranges:
Resynchronization Index >1.0 → strong predictor of favorable response
Resynchronization Index 0.7–1.0 → intermediate likelihood
Resynchronization Index <0.7 → low likelihood of response
Clinical Significance:
Patients with higher Resynchronization Index values exhibit greater mechanical coordination improvement and more pronounced LV reverse remodeling following CRT implantation. It may guide clinicians in pre-procedural selection and post-implantation optimization, especially in borderline candidates or those with non-LBBB morphology.
Clinical Interpretation Summary:
- Integrates QRS duration (electrical delay) and echocardiographic dyssynchrony (mechanical delay).
- Aids in identifying patients most likely to benefit from CRT.
- Useful for post-implant follow-up to evaluate mechanical remodeling progress.
Reference:
Yu CM, et al. Circulation. 2002;105:438–445.
Bax JJ, et al. J Am Coll Cardiol. 2005;46:1061–1071.
Chung ES, et al. N Engl J Med. 2008;358:222–234.
Gorcsan J, et al. J Am Coll Cardiol. 2009;53:1933–1943.
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