Utility of Ambulatory Non-Invasive Rhythm Monitoring in Pregnant Patients with Palpitations and Structurally Normal Hearts

Ambulatory Cardiac Monitoring (ACM) is often used to evaluate pregnant patients with palpitations without structural heart disease; however, the diagnostic yield is not well defined. This single-center retrospective cohort study included pregnant patients without structural heart disease evaluated in a tertiary care cardio-obstetrics clinic between June 2023 and June 2024. The primary outcome was the detection of a clinically significant arrhythmia. Secondary outcomes included symptom–rhythm correlation and adverse maternal cardiac, obstetric, and fetal outcomes. Out of 124 patients identified, 49 (40%) completed ACM. Two patients had symptomatic clinically significant arrhythmias detected on ACM, including non-sustained ventricular tachycardia that did not alter management (n = 1), and symptomatic supraventricular tachycardia (SVT) resulting in medical therapy (n = 1). Palpitations occurred during monitoring in 35 of the 49 remaining monitored patients; of those, symptoms correlated with non-significant arrhythmias (premature atrial and ventricular contractions) in 11 (31%). No adverse cardiac events occurred in the remaining patients. Obstetric and fetal outcomes did not differ between monitored and unmonitored patients. In this small single center study, ACM in pregnant patients without structural heart disease has a low diagnostic yield. These findings could be used in shared decision-making for pregnant patients being evaluated for palpitations.