Arrhythmias and Defibrillation
Causes and symptoms
Most arrhythmias have no known underlying cause. However some may be caused by conditions such as heart disease, thyroid conditions or high blood pressure. Arrhythmias can also be triggered by stress, smoking, consuming excess alcohol, caffeine and there a number of drugs, which have side effects that can induce arrhythmias.
The most common symptom of arrhythmias is palpitations where the heart suddenly beats very hard and can be accompanied by a feeling of apprehension, breathlessness, chest discomfort, or dizziness.
Persistent episodes of dizzy spells or blackouts may be an indicator of abnormally fast or slow heart rhythms, disorders of the heart muscle or valve function.