It is known as extreme bradycardia when the heart beats 30 times or less in one minute. The heart rate considered normal is between 60-100 beats per minute.
Multiple causes have been described including myocardial infarction, severe infection, shock, complication of cardiac surgery, blood electrolyte imbalance, congenital heart disorder, drugs and sleep apnoea.
Symptoms are due to the heart's insufficient blood pumping: dizziness, weakness, tiredness, chest pain, shortness of breath, mental confusion and loss of consciousness (syncope). In severe cases it can lead to cardiorespiratory arrest.
The suspected diagnosis is made by taking a medical history, and confirmed by taking vital signs and performing an electrocardiogram. The cause will be studied with complementary tests such as blood tests, cardiac ultrasound, or cardiac catheterisation.
Pharmacological treatment aims to increase the heart rate and improve blood pressure. If necessary, a pacemaker will be placed to ensure the electrical stimulation that will mark the heart beats per minute. If you suffer a cardiorespiratory arrest, it is essential to initiate cardiopulmonary resuscitation (CPR) measures as soon as possible, performing cardiac compressions until you recover or a specialised health team arrives.
If you have any of these symptoms and notice that your pulse is very low, call your local emergency medical system or go to the A&E immediately.
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- UpToDate [Internet]. Waltham. 2017. Syncope in adults: Epidemiology, pathogenesis, and etiologies; [citado el 25 de julio de 2017]. Disponible en: http://www.uptodate.com/contents/syncope-in-adults-epidemiology-pathogenesis-and-etiologies?source=search_result&search=bradicardia+extrema&selectedTitle=26~150
