One of the two upper chambers of the heart. The right atrium pumps blood into the right ventricle, and the left atrium pumps blood into the left ventricle. A heart rhythm disorder in which the heart beats at less than 60 beats per minute. This heart rate may be too slow or irregular to meet the body's demands. This is different than a physically fit person who may have a heart rate below 60.
Symptomatic bradycardia is the most common medical condition requiring a pacemaker.
Symptoms of bradycardia may include dizziness, extreme fatigue, shortness of breath, or fainting spells. Bradycardia is most commonly caused by sick sinus syndrome or heart block. Bradycardia may also result after an ICD delivers a defibrillation shock. If this occurs, a Medtronic ICD can deliver bradycardia pacing therapy until the heart begins to beat normally on its own again. A medical situation characterized by the stopping of normal heart function.