Bradycardia is a type of arrhythmia characterized by reduced heart rate, which is less than 60 beats per minute (bpm). It can be considered as a variation of the norm in well-trained athletes, but most often it accompanies various cardiovascular pathologies. Slow heart rate is manifested by fatigue, semi-conscious state or transient loss of consciousness, cold sweats, darkening in the eyes, chest pain, dizziness, unstable levels of blood pressure; although, it can be asymptomatic as well.
If a person experiences any of the above symptoms, he or she should seek medical advice as soon as possible, since bradycardia can cause the following complications:
• Stokes-Adams attacks – periodic loss of consciousness. Such faints are followed by general muscle spasms, the pulse becomes too slow or undetectable, skin cover becomes very pale and breathing – deep;
• Sudden cardiac arrest;
• Arterial hypertension or unstable blood pressure;
• Coronary heart disease, effort or rest (unstable) angina pectoris;
• Development of chronic circulatory failure.
Pathological bradycardia can be the symptom of the following:
• Hypothyroidism – reduced production of thyroid hormones;
• Cardiovascular disorders like myocardial infarction, endocarditis or myocarditis;
• Acute intoxication (lead, pesticides, nicotine, narcotic substances);
• Traumatic brain injury, increased intracranial pressure;
• Infections such as typhoid, viral hepatitis, sepsis;
• Side effect of certain medications, for example, beta-blockers, cardiac glycosides, etc.
However, regardless of the cause of bradycardia, disturbed function of the sinus node (it means it cannot synthesize electrical impulses with the rate over 60 bpm) or inadequate spread of the impulses through the conduction pathways lie at the heart of this condition.
Preventive measures of bradycardia may include control and management of blood pressure and heart rate, healthy diet (reduced fat and salt consumption), smoking cessation and adequate alcohol consumption, maintenance of the work-rest regimen, fresh air, and regular physical activity. Annual medical check-ups will help to detect and cure any type of bradycardia.
Here are the basic principles of bradycardia treatment:
• If the heart rate is less than 60 bpm but no diseases of the cardiovascular system or other body organs are found, it's enough to apply preventive measures;
• The treatment of an underlying disease that provokes bradycardia;
• Change in the medications that can cause bradycardia;
• Severe bradycardia (heart rate less than 40 beats per minute) that leads to the development of heart failure can require a surgery to implant a pacemaker.
Dangerous forms of bradycardia require emergency treatment and hospitalization of the patient. Self-treatment is not an option.