Demonstration of left ventricular dyssynchrony and resynchrony by ECG-gated SPECT with cardioGRAF in a patient with advanced heart failure and narrow QRS complex.

Accurate objective quantification of left ventricular (LV) dyssynchrony is a key to selecting candidates for cardiac resynchronization therapy (CRT), especially when screening among patients with a narrow QRS. CardioGRAF (cardio Gated single photon emission computed tomography Regional Assessment for left ventricular Function), a newly developed LV segmental time-volume analyzing program for myocardial perfusion single photon emission tomography, may be a promising tool. We describe the case of a 63-year-old male with non-ischemic cardiomyopathy with a QRS duration of 112 ms, in whom cardioGRAF successfully demonstrated baseline LV dyssynchrony and resynchronization achieved by CRT as evidenced by a significant decrease in dyssynchrony index (standard deviation of the duration from R to end-systole among 17 LV segments) x100/R-R interval).