A 25-year-old man with a history of panic disorder complains of an intermittent rapid heartbeat accompanied by chest pain, a sense of impending doom, and dizziness. He has had these symptoms for 6 months, but they have become more frequent over the past 2 weeks. He "may have blacked out for a few seconds" during an episode a few days ago. He is worried about a possible fatal arrhythmia.
- Which aspect of the history is most concerning?
- Using the history, how does one determine the etiology of palpitations?
- Does a history of panic disorder exclude a serious underlying etiology?
Palpitations are defined as the awareness of one's own heartbeats. Palpitations are a frequent reason for visits to both primary care and cardiology practices, reported in up to 16% of medical outpatients.1 Although many patients with palpitations have a psychiatric disorder or other benign condition, potentially morbid or mortal arrhythmias must also be considered. Investigation may include expensive and sometimes invasive diagnostic testing, underscoring the importance of a thoughtful clinical evaluation. Because many patients have intermittent symptoms that do not occur during the clinician's examination, the history plays a key role.
|Palpitations||An awareness of one's own heartbeats.|
|Arrhythmia||A heart rhythm that results from abnormal or disorganized cardiac conduction.|
|Supraventricular tachycardia (SVT)||An arrhythmia originating in the atria or the atrioventricular node.|
|Ventricular tachycardia (VT)||An arrhythmia originating from the ventricles, usually denoting serious cardiac pathology.|
|Syncope||Transient loss of consciousness with spontaneous recovery (see Chapter 29).|
|Presyncope||Sensation that one may lose consciousness.|
|Panic disorder||A psychiatric disorder characterized by episodic panic attacks about which there may be persistent concern or anxiety.|
|Somatization||A dysfunctional psychological process characterized by the generation of physical symptoms as a result of psychological distress.|
Palpitations may result from an abnormal cardiac rhythm, sinus tachycardia associated with a medical condition or psychiatric disorder, or heightened awareness of normal sinus rhythm (Table 28–1). The literature on palpitations generally distinguishes between any cardiac rhythm disturbance such as sinus tachycardia or ectopy (ie, premature atrial or ventricular contractions) and a serious rhythm disturbance such as supraventricular tachycardia (SVT) or ventricular tachycardia (VT). In a widely cited study, Weber and Kapoor2 followed 190 patients with palpitations presenting to the emergency department (ED), to a clinic, or for hospital admission. They found a cardiac etiology in 43.2% (68% were serious arrhythmias and 25% were premature atrial or ventricular beats), whereas psychiatric causes constituted 30.5%. In outpatient subjects (28% of the sample), the etiology of palpitations was psychiatric in 45% of patients and cardiac in only 21%. This finding suggests that ED patients have a higher pretest probability of cardiac etiology, although presentation to the ED was not an independent predictor of cardiac etiology.2 A more recent study of 127 outpatients with palpitations reported an arrhythmia prevalence of 65%, but ...