Twelve-lead ambulatory ECG recording using a seven-electrode recorder: An alternative method for electrophysiological evaluation.

INTRODUCTION

Conventional three-lead ambulatory electrocardiogram recording (3L-AECG) is used for the quantitative diagnosis of arrhythmias. However, the lack of crucial information, such as QRS morphology and orientation, renders the 3L-AECG incomplete for planning electrophysiological interventions. The 12-lead AECG (12L-AECG) merges the temporal resolution 3L-AECG with the spatial resolution of the standard electrocardiogram (S-ECG). Although it provides more detail, it is not widely used. This study aimed to verify whether the seven-electrode 12L-AECG and S-ECG have similar waveforms.

METHODS

A questionnaire consisting of 240 side-by-side comparisons (12 leads from 20 patients) was created. These consisted of a QRS registered using the 12L-AECG and a QRS from the same patient, registered using the S-ECG. The questionnaire was submitted to cardiologists trained in electrophysiology. For each comparison, the evaluator assigned "similar" or "different" depending on their own judgment.

RESULTS

Five cardiologists completed the questionnaire, resulting in 1200 answers. The AECG-12 was similar to the ECG in 84.50 % of the instances (95 % confidence interval [CI] 83.20-86.50). The interobserver agreement was moderate (0.542, p < 0.001). The similarity between specific leads ranged up to 98 % (95 % CI 92.96-99.76). No significant differences were found among patients (p = 0.407).

CONCLUSION

The seven-electrode 12L-AECG and S-ECG produced comparable waveforms. This similarity supports the use of 12L-AECG for accurate arrhythmia tracking and assists in planning electrophysiological procedures.