Dual chamber pacing for patients with hypertrophic obstructive cardiomyopathy: A clinical perspective in 2000

In some patients with hypertrophic cardiomyopathy, the dynamic left ventric ular outflow tract obstructive gradient results in exercise-limiting sympto ms of dyspnea, angina, and syncope, Dual chamber pacing has been proposed a s a widely available alternative treatment for a subset of patients with sy mptomatic hypertrophic obstructive cardiomyopathy, Initial studies showed a reduction in gradient and an improvement in symptoms in almost 90% of pati ents with severe symptoms. We report the Mayo Clinic experience with dual c hamber pacing in 38 patients with hypertrophic obstructive cardiomyopathy w ho had permanent pacemakers implanted for limiting symptoms intractable to medical therapy. After a mean +/- SD follow-up of 24+/-14 months, subjectiv e improvement was reported in 47% of patients. However, there was no statis tical difference between the maximal oxygen consumption at last follow-up a nd AAI pacing (atrial sensing and atrial pacing) (18.6+/-1.1 mL.kg(-1).min( -1)) (ie, when the pacemaker was implanted but not pacing continuously). Th is article discusses the clinical perspective on the utility of dual chambe r pacing for patients with hypertrophic obstructive cardiomyopathy.