RESUMO
STUDY OBJECTIVE: We compare the quality of ECG recordings obtained with conventional and prewired electrodes in an emergency setting. METHODS: This was a prospective, randomized, open comparison study in an emergency medical services setting. Participants were patients undergoing ECG between April and May 2007 (n=105). Two 12-lead ECG recordings were made in random order with conventional and prewired electrodes. Artifacts, ie, signal noise (>0.4 seconds of recording affected) and baseline instability (>1-mV variation), were analyzed and scored by 3 blinded reviewers. Results were expressed as number of affected leads, score/lead (0 to 3 scale for signal noise; 0 to 4 scale for baseline instability), and number of leads that were totally artifact free. Time to make recordings was measured. RESULTS: Recordings were nearly as easy and took 20% less time with prewired than with conventional electrodes (118 [interquartile ratio (IQR) 90 to 150] versus 144 [IQR 120 to 182]). With prewired electrodes, fewer leads were affected by noise (1 [IQR 0 to 3] versus 3 [IQR 0 to 6]) and baseline instability (0 [IQR 0 to 2] versus 2 [IQR 0 to 4]). The mean score/lead was lower for both noise (1 [IQR 0 to 3] versus 3 [IQR 0 to 8]) and instability (0 [IQR 0 to 2] versus 2 [IQR 0 to 5]); the number of artifact-free leads was greater (38 [36%] versus 19 [18%]). There was no significant difference between electrode types in the prevalence of P-wave and QRS complex abnormalities. CONCLUSION: Recordings with prewired electrodes took significantly less time. Signal noise and baseline instability were significantly reduced. The time saved was not at the expense of the quality of the recording.