Echo Dyssynchrony Index (Ts-SD 12 LV) Calculator

Echo Dyssynchrony Index (Ts-SD 12 LV): Explanation and Clinical Context The Echo Dyssynchrony Index, calculated as the standard deviation of time to peak systolic velocity (Ts) across 12 left ventricular segments using tissue Doppler imaging, is a validated measure to quantify mechanical dyssynchrony in patients with heart failure. It was originally described by Yu et al. (2004) and has been used to predict response to cardiac resynchronization therapy (CRT). A higher Ts-SD indicates greater intraventricular dyssynchrony, while values below 33 ms are considered indicative of mechanical synchrony.

This tool helps clinicians identify heart failure patients likely to benefit from CRT and optimize device programming.