Paget’s disease of bone characteristically causes a large head size. Cardiovascular lesions include large arteriovenous (AV) fistulas that may cause congestive heart failure. Calcification of the aortic valve may cause a loud murmur produced by aortic sclerosis without stenosis. Calcification of the electrical conduction system may result in a slow heart rate (bradycardia), and occasionally complete heart block that may require an electronic pacemaker.