Figure legends
Figure 1. Study flowchart.
Among 258 patients with newly implanted CIEDs, 101 patients without a previous diagnosis of AF and with preceding sinus rhythm ECGs were selected. In all patients, the appearance of new-onset AHRE was evaluated in the initial one year after CIED implantation. The 101 patients were then divided into two groups in accordance with the presence or absence of AHREs.
Figure 2. Definition.
P-wave analysis including PWD was evaluated just prior to CIED implantation. AHRE was defined as any episodes of sustained atrial tachyarrhythmia of more than 170 bpm and longer than five minutes, with at least one detected episode occurring during the initial one year after CIED implantation.
Figure 3.
Analysis of P-wave.
P-wave duration was measured from the beginning of the P-wave deflection from the isoelectric line to the end of the deflection returning to the isoelectric line in all simultaneous 12 leads of ECG. When a P-wave exhibited a biphasic form, the latter negative phase was also included for the measurement of P-wave duration. The P-wave amplitude was measured as the height of the peak of positive deflection or the depth of the bottom of negative deflection from the isoelectric line of the onset point. In the case of a biphasic P-wave, the P-wave amplitude was measured as the difference between the positive peak and the negative bottom of the recording.
B) Representative examples of the analysis of PWD.
PWD was defined as the difference between the maximum and the minimum P-wave durations as detected in the body-surface 12-lead ECG. The maximum and minimum P-wave durations were calculated from the standard ECG during sinus rhythm. PWD was derived by subtracting the minimum P-wave duration from the maximum duration in any of the 12 ECG leads.
Figure 4. ROC analysis for determining the cutoff value of PWD.
The best cutoff value of PWD in CIED patients with AHREs was determined to be 48 ms, achieving a sensitivity of 73.8% and specificity of 77.9% (area under the curve: 0.90; p < 0.0001). The arrows indicate the most powerful cutoff points for the appearance of new-onset AHRE.