Figure 4.
The relationships between ECG parameters as a continuous variable and the risk of progression to AF episode ≥24 h. The figure shows the risk of AF progression to the first episode ≥24 h as a function of PR interval (A), P-wave duration (B), P-wave voltage in Lead I (C), P-wave terminal force in Lead V1 (D), QTc interval estimated using the Framingham formula (E), and QRS duration (F) among 418 patients debuted with shorter AF duration, superimposed on a histogram of the distribution of each of the ECG parameters. Hazard ratios were estimated by using the respective medians as the references in multivariate Cox models with death as a competing risk. The dashed lines represent 95% confidence intervals. Abbreviations: AF, atrial fibrillation; ECG, electrocardiogram; QTc, heart rate-corrected QT interval.