What are the symptoms of bradycardia (abnormally slow heart rate)?

From the Guidelines

Bradycardia symptoms should be treated with permanent cardiac pacing if they are symptomatic and attributable to an intrinsic pathology of the sinus node, as this is the only effective treatment for symptomatic bradycardia. Bradycardia symptoms occur when the heart rate falls below 60 beats per minute and can range from mild to severe depending on how slow the heart rate is and the underlying cause. Common symptoms include fatigue, weakness, dizziness, lightheadedness, confusion, shortness of breath, chest pain or discomfort, and fainting (syncope) 1. Some people may experience heart palpitations or the feeling that their heart is skipping beats. In severe cases, bradycardia can lead to decreased exercise tolerance, reduced ability to concentrate, and even cardiac arrest if left untreated. Not everyone with bradycardia experiences symptoms, particularly those with mild bradycardia or physically fit individuals who naturally have lower heart rates. Symptoms typically develop when the slow heart rate prevents adequate blood flow to the body's organs and tissues. The brain is particularly sensitive to reduced blood flow, which explains symptoms like dizziness and confusion.

Key Considerations

• Identifying temporal correlation between symptoms and bradycardia is important when deciding on the necessity of therapy 1.
• Healthy young individuals, particularly athletes, have sinus bradycardia that is not associated with symptoms 1.
• In some patients presenting with symptomatic bradycardia, a reversible extrinsic cause may be identifiable such as metabolic abnormality, endocrine dysfunction, infection, or over-medication 1.
• Complications associated with PPM implantation range from 3% to 7% and there are significant long-term implications for pacing systems that use transvenous leads 1.

Treatment Approach

• The goal of anti-bradycardia therapy in SND is to increase the heart rate so that cardiac output is normalized, and the perfusion of brain and other end organs is maintained to meet physiologic demand 1.
• Permanent pacing may be necessary for patients with symptomatic sinus bradycardia attributable to an intrinsic pathology of sinus node 1.
• Consider expert consultation and transvenous pacing for patients with severe bradycardia symptoms 1.

From the Research

Bradycardia Symptoms

• Bradycardia is a heart rate lower than 60 beats/min, which can be due to sinus, atrial, or junctional bradycardia or to a problem with the conduction system 2
• Symptoms of bradycardia can include:
  • Syncope
  • Dizziness
  • Chest pain
  • Dyspnea
  • Fatigue 2, 3
• Asymptomatic bradycardia is common, especially among trained athletes or during sleep 2, 3
• In patients with confirmed or suspected bradycardia, a thorough history and physical examination should include possible causes of sinoatrial node dysfunction or AV block 4

Management of Bradycardia

• Management of bradycardia is based on the severity of symptoms, the underlying causes, presence of potentially reversible causes, presence of adverse signs, and risk of progression to asystole 4
• Treatment should rarely be prescribed solely on the basis of a heart rate lower than an arbitrary cutoff or a pause above certain duration 5
• Pharmacologic therapy and/or pacing are used to manage unstable or symptomatic bradyarrhythmias 4
• The only therapy for persistent bradycardia is placement of a permanent pacemaker 2
• Symptomatic patients with sick sinus syndrome and high second- or third-degree atrioventricular blocks require placement of permanent pacemakers 2