What's going on with the rhythm?
The cells of the sinus node are gradually replaced by connective tissue, which is why impulses are produced less frequently or are carried out with a delay. The heart can make long pauses, especially at night, and under load it does not give the necessary increase in rhythm - this is called chronotropic insufficiency. Some patients alternate between periods of deceleration and attacks of atrial fibrillation: this option is called tachycardia-bradycardia syndrome. It is important to distinguish the disease from the norm: in trained people and during sleep, a rare pulse is physiological and does not cause complaints.
- Persistent sinus bradycardia
- Pauses and stops of the sinus node
- Sinoatrial blockade
- Chronotropic insufficiency during exercise
- Tachycardia-bradycardia syndrome
- Rare pulse in athletes is a normal variant
Causes and risk factors
The main reason is age-related sclerotic changes in the conduction system, so the disease is more common in the elderly. Contributions include coronary heart disease, previous heart attack, inflammatory and hereditary myocardial lesions. A separate and important group of causes is reversible: slowing of the rhythm due to medications, electrolyte imbalances and hypothyroidism. This form goes away after the cause is eliminated, and a pacemaker is not needed, so the doctor always first looks for removable factors.
- Age-related fibrosis of the conduction system
- Coronary heart disease, previous heart attack
- Myocarditis, cardiomyopathies
- Beta blockers, some antiarrhythmic drugs
- Hypothyroidism
- Elevated blood potassium levels
- Conditions after heart surgery
Symptoms
The complaints are explained by insufficient blood supply to the brain and muscles. A person gets tired quickly, has difficulty climbing stairs, notices darkening of the eyes when standing up, dizziness and decreased memory. The most alarming sign is fainting without warning; it can cause injuries. Some patients do not associate weakness with the heart for a long time and explain it by age or blood pressure, so if you experience unexplained fatigue after 60 years, it is worth counting your pulse.
- Weakness and fatigue
- Dizziness, darkening of the eyes
- Fainting and presyncope
- Shortness of breath with normal exertion
- Feeling of heart sinking, interruptions
- Decreased memory and concentration
Diagnostics
A regular ECG does not always detect a violation, because pauses occur sporadically. Therefore, the basis of diagnosis is daily or multi-day ECG monitoring, during which the patient keeps a diary of complaints - the coincidence of the symptom and the rhythm change is important. Additionally, the structure of the heart is assessed by echocardiography, the reaction of the rhythm to stress, and avoidable causes are excluded. If fainting is rare, your doctor may recommend long-term recording of the rhythm.
- ECG at rest
- 24-hour Holter ECG monitoring
- Symptom diary during monitoring
- Echocardiography to assess the structure of the heart
- Exercise test
- Thyroid hormones, blood potassium
- Review of medications taken
Treatment
If a removable cause is found, they start with it: cancel or replace drugs that slow down the rhythm, correct hypothyroidism and potassium levels. There are no medications that reliably and safely speed up your own rhythm in the long term. For persistent symptoms, fainting and significant pauses, the method of choice is the implantation of a permanent pacemaker - a small device under the skin that protects the heart when its own impulse does not come. When combined with attacks of atrial fibrillation, treatment is selected comprehensively, including the issue of prevention of thrombosis.
- Cancellation or replacement of rhythm-lowering drugs according to the doctor’s decision
- Treatment of hypothyroidism and correction of electrolytes
- Pacemaker implantation for symptoms and pauses
- Selection of therapy for tachycardia-bradycardia syndrome
- Assessing the risk of thromboembolism in atrial fibrillation
- Regular monitoring by a cardiologist and checking the stimulator
- Refusal to self-administer medications for blood pressure and pulse
