On the mechanism of augmentation of electrocardiogram QRS complexes in patients with congestive heart failure responding to diuresis

Patients with congestive heart failure (CHF) responding to diuresis reveal marked augmentation of the QRS complexes (AUG-QRS) in their electrocardiograms (ECGs). Recently, such change in the ECG has been observed in patients with anasarca (AN) of varying etiology commensurate with partial alleviation of the volume overload; similar ECG change has been noted in patients with end-stage renal failure after hemodialysis. The mechanism for the AUG-QRS in patients with CHF has been debated, and many have ascribed this ECG change to the “Brody effect,” linking the AUG-QRS to reduction of intracardiac blood volumes resulting from diuresis. However, the Brody effect (a theoretical formulation not fully validated by experimentation and associated with controversy in its clinical implementation) has not provided a satisfactory explanation for the AUG-QRS in patients with CHF. In contrast, the described association between amelioration of AN in a diverse patient population and AUG-QRS suggests that this ECG change in patients with CHF is due to an increased electrical resistance of the passive body volume conductor, resulting from water loss effected by diuresis. This thesis is supported by theoretical work, animal experimentation, and clinical evidence.