Arrhythmia: Symptoms & Signs

Medically Reviewed on 9/10/2019

Arrhythmia is a medical term that describes an abnormal heartbeat. It does not necessarily mean that the heart rate is too slow or fast, and an arrhythmia can occur in the presence of a fast, normal, or slow hear rate. Many arrhythmias do not cause symptoms or signs, while others are associated with a reduction in cardiac output that leads to characteristic symptoms. Palpitations, fatigue, shortness of breath, and poor exercise tolerance are common symptoms as well as lightheadedness, dizziness, fainting, or chest pain. Arrhythmias can arise from problems at any location in the heart, including the atria (upper chambers) or ventricles (lower chambers). With certain arrhythmias, blood clots can form in the heart (thrombi) that may break off and travel to other parts of the body (emboli), leading to complications. Some arrhythmias, like ventricular fibrillation, are life-threatening unless treated immediately.

Causes of arrhythmias

Arrhythmias arise because of damage to or an abnormality in the electrical system that conducts impulses through the heart muscle, signaling it to beat. Many different events can cause damage to the heart's electrical system. These include coronary artery disease, damage to heart muscle such as injury from a heart attack, electrolyte imbalances in the blood (such as sodium or potassium), or even heart surgery. Some arrhythmias arise due to defects in the heart's electrical system that are present at birth. Some examples of arrhythmias include atrial fibrillation, atrial flutter, ventricular fibrillation, paroxysmal supraventricular tachycardia, long QT syndrome, and ventricular tachycardia. Not all of the symptoms listed are present with every arrhythmia, and the specific symptoms depend upon the precise type of arrhythmia that is present.

Other arrhythmia symptoms and signs


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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.