Palpitations are a common complaint, experienced by up to 16% of outpatients. The wide differential diagnosis includes structural cardiac disease or comorbid medical conditions (atrial fibrillation or flutter, atrioventricular node reentry, tachycardia or atrioventricular reentry tachycardia, atrial tachycardia, ventricular tachycardia, premature ventricular contractions or premature atrial contractions, or multifocal atrial tachycardia), sinus tachycardia (caused by hyperthyroidism, anxiety or panic disorder, fever, hypovolemia, stimulants and alcohol, medications, blood loss, pheochromocytoma, hypoglycemia), and normal sinus rhythm (with a heightened cardiac perception for an unclear reason).
Certain historical features in a patient with palpitations make a significant arrhythmia more or less likely. The previous diagnosis of a panic disorder (LR 0.26) and duration less than 5 minutes (LR 0.38) make a significant arrhythmia less likely (but cannot be used alone to rule this out) (D).
A known history of cardiac disease (LR 2.03; 95% CI: 1.33 to 3.11), palpitations affected by sleeping (LR 2.29; 95% CI: 1.33 to 3.94) or while at work (LR 2.17; 95% CI: 1.19 to 3.96) slightly increase the likelihood of a cardiac arrhythmia. More reliably, the presence of a regular rapid-pounding sensation in the neck increases the likelihood of atrioventricular node reentry tachycardia (LR 177; 95% CI: 25 to 1251) (A). Equally helpful is the absence of pounding in the neck makes an arrhythmia much less likely (LR 0.07; 95% CI: 0.03 to 0.19)
A thorough history and physical examination, along with analysis of the ECG, are the cornerstone to assessing a patient with palpitations. Asking the patient to “tap out” the sensation is especially helpful when the symptoms have resolved, and may give the physician insight as to its rate and regularity; in addition, what may be described as palpitations may actually be a “skipped beat” when tapped out, making a solitary PAC or PVC with a pause more likely.
Although important to assess, the yield of a 12-lead ECG even during symptoms is low, ranging from 3 to 26% for any arrhythmia and 2% for significant arrhythmias. If a patient has risk factors for cardiac disease or has high-risk historical features, further workup with an echocardiogram to assess cardiac structure or correlation of symptoms with cardiac monitoring is needed. Lack of high-risk features does not make this patient low-risk for an arrhythmia (B). Unfortunately, there is no perfect test: even a 24-hour Holter monitor has a 34% yield for any arrhythmia and between 3 to 24% yield for a significant arrhythmia (similar to ECG, just with more opportunity to catch it).
If symptoms occur daily, 24-hour Holter monitoring is indicated. For symptoms that occur less frequently, an intermittent event recorder such as a loop monitor may be more helpful. For patients with low suspicion for arrhythmia who will not undergo further immediate testing, close follow up is essential.
Thavendiranathan P, Bagai A, Khoo C, Dorian P, Choudhry NK. Does This Patient With Palpitations Have a Cardiac Arrhythmia? JAMA. 2009;302(19):2135-2143