Echocardiologist in Chikkajala, Bangalore • Bradycardia Occasionally patients may be aware of a slow pulse rate. These are usually people who regularly count their pulse for sporting or introspective reasons. A regular resting bradycardia may be a normal variant, a sign of physical training (due to increased vagal tone), caused by beta-blockers or some calcium channel antagonists, or due to hypothyroidism. In such cases the rhythm is sinus bradycardia. Patients with more severe bradycardia due to heart block are more likely to present with dizziness or syncope than palpitations, but Möbitz type I or even type II heart block is an occasional incidental finding in athletes or people on beta-blockers. However, it is more often a sign of significant conduction system disease. It can be a complication of myocardial infarction