Symptom-Triggered 6-Lead ECG Monitoring Significantly Increases Arrhythmia Detection Beyond Traditional Ambulatory Monitoring.

BACKGROUND: Patients with palpitations and dizziness are typically monitored using ambulatory electrocardiographic (ECG) monitoring including Holter monitors and extended continuous ECG monitors. The KardiaMobile 6L (KM6L), a portable medical-grade ECG recorder, enables patients to initiate 6-lead ECG recordings during symptoms when needed. OBJECTIVES: This study aimed to assess the comparative effectiveness in detecting clinically significant arrhythmias between ambulatory ECG monitoring modalities and 30-day use of KM6L. METHODS: Patients with palpitations or other arrhythmic symptoms who were referred to for standard ambulatory monitoring (either 24- or 48-hour Holter or ambulatory ECG patch) were asked to perform 1-minute, 6-lead ECG recordings with the KM6L device during symptomatic episodes over a 30-day period. Clinically significant arrhythmias were defined as atrial fibrillation/flutter, second/third-degree atrioventricular block, wide complex tachycardia, supraventricular tachycardia >100 bpm, pauses >3 seconds, or sinus tachycardia >130 bpm. Detection rates between KM6L and standard monitoring were compared using McNemar test. RESULTS: We enrolled 350 (40%, n = 140 with 24/48-hour Holter) patients who recorded 6,251 KM6L recordings (median 15 per patient). Significant arrhythmias were detected in 66 patients (18.9%) using either ambulatory ECG monitoring or KM6L. Ambulatory ECG monitoring modalities identified arrhythmias in 27 patients (7.7%), whereas KM6L detected arrhythmias in 52 patients (14.9%) (P < 0.001). Importantly, 39 arrhythmia episodes (11.1%) were detected exclusively by KM6L (P = 0.0008), most commonly atrial fibrillation (n = 23). CONCLUSIONS: These findings demonstrate that patient-initiated, symptom-triggered ECG monitoring substantially enhances arrhythmia detection compared with traditional short-duration monitoring.