Is an underlying cardiac condition causing your patient’s palpitations?

The diagnostic work-up

The most important goal of the evaluation of palpitations is to determine the presence, or risk, of structural heart or coronary artery disease (CAD) by means of the history, physical examination, and electrocardiography (EKG). Patients who have an increased risk of structural heart disease need further evaluation with echocardiography; those at increased risk of CAD should have stress testing.

Hemodynamically unstable patients need admission; patients who have a history of syncope with palpitations usually should be admitted for cardiac monitoring. Patients who have had a single episode of palpitations and have normal baseline results of laboratory testing and a normal EKG, and no risk factors for structural heart disease or known CAD, can usually be observed.^3,4,10 Patients with an abnormal baseline EKG, recurrent palpitations (especially tachyarrhythmia), or significant symptoms during palpitations (syncope, presyncope, dyspnea) need further evaluation with ambulatory monitoring^3,4,10 (Figure).

Take a thorough history; ask these questions

Have the patient describe the palpitations. The history should include the patient’s detailed characterization of the palpitations (sudden or gradual onset, rhythm, duration, frequency). Certain descriptions provide possible diagnostic clues:

• Palpitations lasting < 5 minutes are less likely to be of cardiac origin (likelihood ratio [LR] = 0.38; 95% CI, 0.2-0.6).⁴
• A patient who has a regular, rapid-pounding sensation in the neck has an increased probability of atrioventricular (AV) nodal reentrant tachycardia (AVNRT) (LR = 177; 95% CI, 25-1251); absence of this sensation decreases the likelihood of AVNRT (LR = 0.07; 95% CI, 0.03-0.2).⁴
• PACs and PVCs cause a sensation of a skipped heartbeat or a flipping sensation in the chest; they are not reported as a sustained rapid heartbeat.
• Patients with a supraventricular arrhythmia often report sudden onset and cessation of palpitations.
• Patients with palpitations since childhood are more likely to have supraventricular tachycardia (SVT).⁴

Elicit apparent precipitating and alleviating factors. The history should include notation of situations that appear to the patient to lead to palpitations (eg, context, positional variation). Palpitations that affect sleep (LR = 2.3; 95% CI, 1.3-3.9) and palpitations that occur at work (LR = 2.2; 95% CI, 1.3-5) increase the likelihood of a cardiac cause.⁴ Palpitations associated with sudden change in position, such as bending forward or squatting, are more likely due to AVNRT.¹¹

Patients with an abnormal baseline EKG, recurrent palpitations, or significant symptoms during palpitations need evaluation with ambulatory monitoring.

Ask about aggravating factors (eg, exercise) and relieving factors (eg, rest, performing a Valsalva maneuver). Patients with SVT are often able to have palpitations terminated with a Valsalva maneuver, such as carotid sinus massage. Palpitations and syncope during exertion can be associated with hypertrophic cardiomyopathy, congenital coronary anomalies, and ion channelopathies, and can cause sudden cardiac death in athletes (estimated incidence, 1-3/100,000 person–years¹²).

Endeavor to identify underlying cardiac disease. A comprehensive history should also evaluate for risk factors and symptoms (chest pain, dyspnea, diaphoresis, lightheadedness, syncope) of cardiac disease, such as CAD, valvular disease, cardiomyopathy, and congenital heart disease, which increase the likelihood that the presenting complaint is a cardiac arrhythmia (LR = 2; 95% CI, 1.3-3.1).⁴ A history of syncope in a patient with palpitations should prompt evaluation for structural heart disease, such as aortic stenosis or hypertrophic cardiomyopathy, in which outflow-tract obstruction impairs cardiac output and, subsequently, cerebral blood flow.

Obtain additional key information. Determine the following in taking the history:

• Is there a family history of inherited cardiac disorders or sudden cardiac death?
• What prescription and over-the-counter medications is the patient taking? How does the patient characterize his or her use/intake of recreational drugs, nicotine, caffeine, and alcohol?
• Does the patient have a history of panic disorder, which lessens concern about a cardiac cause (LR = 0.2; 95% CI, 0.07-1.01)?⁴ (Of note: A nonpsychiatric cause can coexist in such patients, and should be considered.)

Continue to: Physical examination clues, and the utility of vagal maneuvers