Palpitation: evaluation, reassurance and warning features
THE CONTEXT
Palpitation is usually benign, but associated symptoms and underlying heart disease determine the need for investigation and treatment.
Prognosis and management
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The outlook is good even when palpitation is caused by an arrhythmia, provided there is no underlying structural heart disease.
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Most cases reflect awareness of the normal heartbeat, sinus tachycardia or benign extrasystoles; explanation and reassurance may be sufficient.
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Palpitation associated with pre-syncope or syncope may indicate serious structural or electrical disease and requires investigation without delay.
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Other arrhythmias may require drugs or ablation.
Clinical evaluation
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Establish whether symptoms are continuous or intermittent, whether the heartbeat is regular, and the approximate heart rate.
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Ask whether symptoms occur in discrete attacks, whether onset is abrupt, and how attacks terminate.
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Assess associated symptoms, including chest pain, lightheadedness and polyuria; polyuria is a feature of supraventricular tachycardia.
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Identify precipitating factors such as exercise or alcohol excess, and ask about structural heart disease, including coronary artery disease and valvular disease.
Ventricular fibrillation and sudden arrhythmic death
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Ventricular fibrillation is described as a bizarre, chaotic rhythm; the illustrated episode was initiated by two ventricular ectopic beats in rapid succession.
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Coronary artery disease accounts for 85% of sudden arrhythmic deaths. Listed settings include myocardial ischaemia, acute myocardial infarction and prior infarction with myocardial scarring.
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Structural heart disease accounts for 10%. Listed causes include aortic stenosis, hypertrophic cardiomyopathy, dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and congenital heart disease.
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The remaining 5% occur without structural heart disease. Listed causes include long QT syndrome, Brugada syndrome, Wolff–Parkinson–White syndrome, adverse drug reactions causing torsades de pointes, and severe electrolyte abnormalities.