Investigation of palpitations.

The uncomfortable awareness of a beating heart--palpitations--is a common complaint that can occur under normal or abnormal circumstances. For example, normal palpitations occur with exercise, emotions, and stress, or after taking substances that increase adrenergic tone or diminish vagal activity (coffee, nicotine, and adrenergic or anticholinergic drugs). Normal palpitations are recognised as such because individuals who experience them realise or are told that something happened to accelerate the normal rhythm of the heart. However, some people find sinus tachycardia troublesome enough to seek medical attention. In other situations palpitations are clearly abnormal. The heart beat which is felt for no apparent reason, may be fast, or strong and slow, or feel like a missed or extra beat. Although these abnormal palpitations usually point to a cardiac arrhythmia, this is not always the case. Moreover, many patients with arrhythmias do not have palpitations but manifestations such as syncope, shock, and chest pain (sudden death is also possible). We will discuss the approach to the patient who seeks medical attention because of a history of palpitations, with special emphasis on the history, physical examination, and 12-lead electrocardiogram (ECG) because they are simple and inexpensive diagnostic tools that are available to most physicians.