Long term impact of cardiac contractility modulation on QRS duration
Susanne Röger1, Julia Michels1, Felix Heggemann1
1Medical Faculty Mannheim of the University of Heidelberg, 1st Department of Medicine, Mannheim, Germany; DZHK (German Centre for Cardiovascular Research) partner site Mannheim, Germany.
Background And Purpose:
Cardiac contractility modulation (CCM) is an implantable device treatment for heart failure with reduced ejection fraction. CCM therapy improves patient functional status but its effect on intra-ventricular conduction remains unknown.
Methods:
70 patients treated with CCM between 12/2002 and 5/2013 had 12-vector-ECG recordings made at baseline and final follow-up visits. QRS complex duration was measured at each time point.
Results:
Mean follow-up was 2.8 years. Mean QRS duration was unchanged from baseline (112.0 ms) to last follow up (112.9 ms, p=n.s.). These results are strikingly different from comparative published data of several studies with heart failure patients without CCM, consistently indicating an increase in QRS duration (6.0-23.4 ms) over a similar time period.
Conclusions:
CCM prevents chronic ventricular depolarization delay that occurs in heart failure and that is associated with poorer outcomes. This supports the safety of long-term CCM therapy and suggests a possible long-term benefit in maintaining QRS duration.
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