Lets talk first about pacing in patients with hypertrophic cardiomyopathy.
Subsequently, randomized double-blinded trials did not shown a significant benefit of pacing in hypertrophic obstructive cardiomyopathy. The quality of life is improved, but it is impossible to demonstrate any improvement in exercise capacity before and after pacing or with sham pacing. So at the present time, pacing should not be recommended as primary therapy for hypertrophic obstructive cardiomyopathy. The sequence of ventricular contraction is altered and hopefully that will decrease outflow tract gradient. Unfortunately, at the present time, it is impossible to exactly describe this patient and to find out who would benefit beforehand.