Significant improvement of quality of life following atrioventricular synchronous pacing in patients with hypertrophic obstructive cardiomyopathy - Data from 1 year of follow-up

Aims Atrioventricular synchronous pacing exerts beneficial effects, includi ng reduction of left ventricular outflow tract gradients, in patients with hypertrophic obstructive cardiomyopathy. The Pacing in Cardiomyopathy study was initiated to explore the effects of pacing in a double-blind randomize d crossover fashion. The aims were to ascertain the beneficial effects of p acing in a controlled study and to rule out a placebo effect by pacing. Thi s paper deals with the outcome of pacing on quality of life during 1 year o f follow-up. Methods Quality of life was evaluated with the Karolinska questionnaire, va lidated for patients paced for bradyarrhythmias and ischaemic heart disease . Drug-refractory patients with hypertrophic obstructive cardiomyopathy wer e recruited for the study and after a temporary pacing procedure implanted with permanent pacemakers. Patients were randomized to two study arms defin ing the sequence of pacemaker programming. In one arm the pacemaker was ina ctive, in the other active. After 3 months the pacemaker was reprogrammed t o the alternate mode and a further 3 months followed. After this period sub sequent pacemaker programming corresponded to the mode preferred by the pat ient. A last assessment was made 1 year after baseline examinations. Results Eighty patients completed the first crossover period and 75 complet ed the full 1 year of follow-up. Active pacing induced significant quality of life improvements, in the order of 9-44%, regardless of programming sequ ence. Discontinuation of pacing after a first active period resulted in the return of symptoms. Fourteen patients requested early reprogramming after having been programmed to inactive pacing after a first period of active pa cing. Seventy-six patients preferred active pacing after the crossover peri od. A further 6 months of pacing induced progressive improvement in symptom s already favourably influenced. Conclusion Atrioventricular synchronous pacing has a profound beneficial ef fect on most domains of quality of life in patients with hypertrophic obstr uctive cardiomyopathy refractory to drug treatment.