Abstract 2485: Magnetocardiography (MCG) Can Predict Clinical Response to Cardiac Resynchronization Therapy (CRT)
Background: Cardiac resynchronization therapy (CRT) has recently emerged as an effective treatment for patients with severe systolic heart failure, but it is not effective in some cases partly because of electrical dyssynchrony. Echocardiography (predominantly tissue Doppler imaging technique) is a good method for assessing mechanical dyssynchrony but electrocardiography is not enough for assessing electrical dyssynchrony. We hypothesized that magnetocardiography (MCG) with high spatial and temporal resolution is useful for evaluating electrical dyssynchrony and. predicts clinical response to CRT.
Methods: We analyzed 64-channel MCGs (MC-6400, Hitachi) in 14 patients with advanced LV dysfunction (LVEF <35%, 28+/−9%) and venricular conduction disturbance (ECG QRS width >120ms, CLBBB in 11, intraventricular conduction disturbance; IVCD in 3) and divided into 2 Groups (Group-A: Single directional vector in QRS current, Group-B: Multidirectional vector in QRS current) using 2-dimentional current mapping. We examined the difference between the Groups about background, cardiac function, NYHA, and response 6 months after CRT. CRT responder was defined as NYHA improvement and 10% decline of LVDd or 10% improvement of LV Ejection Fraction.
Results: We found 6 responders in 7 patient devided into Group-A and 6 non-responders in 7 patients devided into Group-B. There were no significant differences between Group-A and Group-B about background, cardiac function, BNP, and NYHA class (LVDd 67+/−12 vs70+/−11mm, LVEF 29+/−11 vs 28+/−7%, NYHA class 2.7+/−0.5 vs 3.1+/−0.7)
Conclusion: MCG can reveal electrical dyssynchrony and predict clinical response to CRT.