Bradycardia is a reduction in the heart rate to 60 or less beats per minute in an adult (up to 100 beats per minute in newborns, up to 80 - 70 beats per minute in children from 1 to 6 years of age).
Patients with mild symptoms may complain of a feeling of fatigue, irritability, emotional lability and forgetfulness. With the progress of the disease and further circulatory disturbances, cerebral symptoms become more pronounced (the appearance or intensification of dizziness, instantaneous memory dips, paresis, "swallowing" of words, insomnia, memory loss). When the disease progresses, symptoms, associated with bradycardia, are noted. The most frequent complaints include a feeling of dizziness, severe weakness, even to syncope (Morgagni-Adams-Stokes syndrome). Fainting of cardiac nature is characterized by a lack of aura, seizures.
- sclerotic changes in the myocardium affecting the sinus node;
- exposure to cold;
- an increase in the tone of the parasympathetic nervous system;
- increased intracranial pressure (with edema of the brain, tumors, meningitis, hemorrhages in the brain);
- influence of medicinal preparations (digitalis, quinidine);
- lead poisoning, nicotine poisoning;
- hypothyroidism (decreased thyroid function);
- starvation, typhoid fever, jaundice, etc.
Identifying of this type of arrhythmia is not only possible by the clinical picture, but also by the electrocardiogram.
- decrease in heart rate to 59-40 beats per minute;
- maintaining the right sinus rhythm;
- positive P wave in the leads I, II, aVF, V4-V6