Position-wise comparison of handheld 6-lead ECG versus the standard 12-lead ECG in patients with arrhythmia: comparative study

As 12‑lead electrocardiographs (ECGs) require a clinical infrastructure that limits timely access, portable 6‑lead devices may extend diagnostics to community and remote settings. We evaluated the signal equivalence of a handheld 6‑lead ECG (HATIV^® P30) versus the standard 12‑lead in an arrhythmia cohort, considering posture and synchrony.

In this prospective single-center study, simultaneous 10-s 12-lead ECGs and time-aligned 10-s segments from 30-s 6-lead recordings were obtained from arrhythmia patients in both supine and sitting positions. A blinded electrophysiologist performed rhythm classification and ECG measurements. Diagnostic accuracy and numerical agreement of key parameters (PR interval, QRS duration, QT/QTc intervals, and amplitudes) were evaluated.

A total of 229 paired recordings were analyzed after excluding 6 pairs. The overall diagnostic accuracy of the 6‑lead versus 12‑lead was 99.1% in the supine position (n = 113) and 99.1% in the sitting position (n = 116); one atrial flutter was misclassified as atrial fibrillation in each position. Bland–Altman analyses showed small mean differences (12‑lead minus 6‑lead): PR + 12.1/ + 7.4 ms (supine/sitting), QRS − 6.4/ − 6.0 ms, QT − 10.3/ − 5.3 ms, QTc − 11.5/ − 6.4 ms; heart‑rate difference ≈0.03 bpm. The absolute differences were < 20 ms in approximately ~ 70% for PR and ~ 55–62% for QT/QTc. In an exploratory asynchronous pairing (supine 12‑lead vs sitting 6‑lead; n = 103), accuracy decreased to 97.1% and parameter differences widened, consistent with postural/temporal effects.

In patients with arrhythmia, the handheld 6‑lead showed near‑perfect rhythm agreement and small numerical differences versus the 12‑lead under synchronized acquisition in both positions. Asynchronous or posture-mismatched comparisons reduce the agreement, and acquisition conditions should be considered. The 6‑lead may be a practical alternative when the 12‑lead is unavailable in patients with arrhythmia.