If the heart beats slower than normal, we speak of bradycardia. Under normal conditions, the heart rhythm begins when an electrical impulse is generated, which is then sent by the sinus node – also called the “sinoatrial” – located in the right atrium.
This node is in charge of establishing the heart rate and rhythm. Therefore, it is considered a kind of “pacemaker.” Sometimes if the conduction pathways are damaged, or if there is an additional pathway, the heart changes rhythm; therefore, it may beat too fast (tachycardia), too slow (bradycardia), or irregularly.
These abnormal beats are known as “arrhythmias” and can occur in both the upper chambers (atria) and the lower chambers of the heart (ventricles). In this case, we focus on the definition of bradycardia and the available treatments for it.
What is bradycardia?
The term bradycardia refers to a number of conditions in which the heart beats slower than usual. In particular, there are less than 60 beats or beats per minute.
According to an article in Trends in Cardiovascular Medicine, it is a normal phenomenon in young athletes or as part of the aging process or disease. In turn, it can be classified according to the level of alternation within the hierarchy of the cardiac conduction system.
Causes of bradycardia
Bradycardia can occur in athletes or in people who enter a state of deep relaxation. It is also common in patients with heart disease or who are under certain drug treatments. Its possible causes, according to the Mayo Clinic, include the following:
- Damage to heart tissue due to aging.
- Alterations in heart tissue due to heart disease.
- Congenital heart defects.
- Infections in the heart tissue.
- Complication of heart surgery.
- Lack of control of potassium or calcium levels in the blood.
- Obstructive sleep apnea.
- Inflammatory diseases, such as lupus.
- Medicines for heart rhythm disorders.
Main symptoms
The clinical presentation of arrhythmias ranges from asymptomatic electrocardiographic signs to a wide variety of symptoms. In the case of bradycardia, the most common are the following:
- Dizziness or lightheadedness
- Fainting
- Fatigue
- Chest pain
- Difficulty breathing
- Confusion
It is important to note that if the symptoms are severe, pharmacological management and the placement of an emergency pacemaker should be indicated.
Complications of the disease
Without prompt treatment, bradycardia can lead to health complications. Next, we detail the most relevant ones:
- Inability of the heart to pump enough blood (heart failure).
- Sudden cardiac arrest or sudden death.
- Repeated fainting.
- Changes in blood pressure (hypotension and hypertension).
Diagnosis
To establish the diagnosis of bradycardia, it is crucial to find a causal relationship between the symptoms and the various abnormalities that may show up on the electrocardiogram (ECG). Given the intermittent and unpredictable nature of this condition, the process can be difficult.
It is important to take into account the medical history, and to perform a 12-lead surface ECG. An electrocardiogram Holter recording (long-duration Holter ECG) and a stress test can also be performed;
Bradycardia treatment
Treatment of bradycardia should be limited to patients in whom a clear correlation between symptoms and rhythm has been documented. Patients who are asymptomatic do not require specific treatment.
In general, the first measure for the treatment of symptomatic people is the discontinuation of any medication that slows the heart rate. In addition, any related underlying condition is intervened.
Ultimately, when other treatments don’t work, the doctor suggests implantation of a permanent pacemaker. If so, the professional will inform all the necessary details, such as risks, benefits and preparation for the placement of the same.
Progression and Prognosis
The progression and prognosis of bradycardia will depend on several factors, including the following:
- Age
- Smoking
- Alcohol consumption
- The use of recreational drugs
- Coexisting cardiovascular diseases
- Thromboembolic complications
The natural history of this alteration is highly diverse and often unpredictable. Patients with a history of fainting due to bradycardia may continue to have it recurrently.
The incidence of sudden death is low, and pacemaker treatment does not appear to improve overall survival. However, it does reduce morbidity.
In any case, it is advisable to maintain regular medical control, since appropriate interventions avoid complications. The family doctor or professional in cardiology will require tests and treatments whenever the alteration requires it.
