Atrio-ventricular block requiring pacemaker in patients with late onset Pompe disease.

Enzyme replacement therapy consistently improves cardiac function in infantile and juvenile onset patients with Pompe disease and cardiomyopathy, but is apparently not effective in preventing rhythm disorders, an emerging cardiac phenotype in long term survivors. In patients with late onset Pompe disease cardiomyopathy is an exceptional finding while heart rhythm disorders seem to be more frequent. We retrospectively identified, among a cohort of 131 French late onset Pompe disease patients, four patients with severe atrio-ventricular blocks requiring pacemaker implantation. These patients had no other risk factors for cardiovascular diseases or cardiomyopathy. In one patient the atrioventricular block was discovered while still asymptomatic. Cardiac conduction defects are relatively rare in late onset Pompe disease and may occur even in absence of cardiac symptoms or EKG abnormalities. However because of the possible life-threatening complications associated with these conduction defects, cardiac follow-up in patients with late onset Pompe disease should include periodical Holter-EKG monitoring.