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Palpitations are the perception of cardiac activity by the patient. They may be described as a fluttering, racing, or skipping sensation. Sinus rhythm at a normal rate is not ordinarily perceived. Associated symptoms vary with etiology.
Etiology
Causes range from benign to life threatening. Some patients simply have heightened awareness of normal cardiac activity, particularly when exercise, febrile illness, or anxiety increases heart rate. However, in most cases, palpitations result from arrhythmia (see Arrhythmias and Conduction Disorders).
The most common arrhythmias are premature atrial contractions (PACs) or ventricular contractions (PVCs), which usually are harmless. Other arrhythmias include paroxysmal supraventricular tachycardia (PSVT), atrial fibrillation or flutter, and ventricular tachycardia. Some arrhythmias (eg, PACs, PVCs, PSVT) often occur spontaneously without serious disease, but others are often caused by an underlying cardiac disorder, such as myocardial ischemia, valvular heart disease, or conduction system disturbances. Disorders that increase myocardial contractility (eg, thyrotoxicosis, pheochromocytoma) may produce palpitations. Some drugs, including caffeine, alcohol, and sympathomimetics (eg, epinephrine , ephedrine , theophylline ), frequently produce palpitations. Anemia, hypoxia, and electrolyte abnormalities (eg, diuretic-induced hypokalemia) can trigger or exacerbate palpitations.
Evaluation
History:
PACs and PVCs are often described as occasional skipped beats; other symptoms are uncommon. Atrial fibrillation is identified as a sustained irregularity. Supraventricular or ventricular tachycardia is often perceived as a rapid, regular heartbeat with sudden onset and termination; previous similar episodes are common. Sometimes asking the patient to tap out the beat of palpitations is better than a verbal description.
The patient is asked about weakness, dyspnea, light-headedness, and syncope, which suggest coronary artery disease (CAD) or another serious underlying disorder. Chronic fatigue and weakness suggest anemia or heart failure. Palpitations in patients with CAD may be accompanied by ischemic chest pain due to decreased diastolic coronary flow during tachycardia or bradycardia.
The patient is asked about use of caffeine, alcohol, or other drugs (eg, cocaine, methamphetamine, other illegal stimulants, OTC diet aids, dietary supplements).
Physical examination:
Palpation of the arterial pulse and cardiac auscultation may reveal a rhythm disturbance, which, except for the unique irregular irregularity in some cases of rapid atrial fibrillation, is rarely diagnostic. Thyroid enlargement or tenderness with exophthalmos suggests thyrotoxicosis. Marked hypertension and regular tachycardia suggest pheochromocytoma.
Testing:
ECG is done; however, unless done during symptoms, it usually does not provide a diagnosis because most cardiac arrhythmias are intermittent. A patient in the emergency department may be placed on a cardiac monitor for 1 or 2 h. If no diagnosis is apparent, a 24-h Holter monitor or, if intermittent symptoms occur infrequently, an event recorder triggered by the patient is useful.
When a serious disorder is suspected, a pulse oximetry reading is taken. Serum electrolytes are measured in patients at risk of electrolyte abnormalities; a CBC is obtained when symptoms suggest anemia. Thyroid function tests are indicated when atrial fibrillation is newly diagnosed.
Treatment
For isolated PACs and PVCs, simple reassurance is usually sufficient. Identified rhythm disturbances and underlying disorders are treated. Precipitating drugs and substances are withdrawn or changed.
Last full review/revision November 2005
Content last modified November 2005
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