Hi every patient with chf does not need a pacemaker there are some indications for pacemaking in a patient iof congestive cardiac failure i am mentioning some of them, it depends on the stage of chf and how well it is controlled by medicines,Thirty to 50 percent of patients with advanced congestive heart failure have major intraventricular conduction defects, chf along with intraventricular conduction defect is a indication forpacemaking,especially complete left bundle branch block have been shown to be independent predictors of mortality. Delayed activation of the left ventricle as a result of left bundle branch block has been shown to produce significant dyssynchrony in left ventricular contraction and relaxation. The dyssynchrony can be minimized by biventricular pacing. so every patient with chf is not helped by pacemaker,your mother must not be having stage 4 chf and her interventricular conduction system would have been normal,so pacemaking is not required in her case