1. P wave and the development of atrial fibrillation
Katsuya Ishida, MD, Hideki Hayashi, MD, PhD, Akashi Miyamoto, MD, Yoshihisa Sugimoto, MD, PhD, Makoto Ito, MD, PhD, Yoshitaka Murakami, PhD, Minoru Horie, MD, PhD 
Heart Rhythm 
Volume 7, Issue 3, Pages (March 2010)
DOI: /j.hrthm
Copyright © 2010 Heart Rhythm Society Terms and Conditions

2. Figure 1
A: Twelve-lead ECG showing typical pattern of left atrial overload in lead V1. Red arrow indicates P-wave negative terminal portion in lead V1. Asterisks indicate P waves with identical morphology detected by template matching. B: Magnified ECG trace of lead V1. Blue arrow indicates P-wave onset. Green arrow indicates P-wave offset.
Heart Rhythm 2010 7, DOI: ( /j.hrthm )
Copyright © 2010 Heart Rhythm Society Terms and Conditions

3. Figure 2
Kaplan-Meier estimates of atrial fibrillation (AF)-free event rate in patients with left atrial overload (LAO) and control patients. The difference between the two groups was significant (P <.001 by log rank test).
Heart Rhythm 2010 7, DOI: ( /j.hrthm )
Copyright © 2010 Heart Rhythm Society Terms and Conditions

4. Figure 3
Kaplan-Meier estimates of atrial fibrillation (AF)-free event rate in patients with left atrial overload according to the area of P-wave initial portion in lead V1. The AF-free event rate in patients with area of P-wave initial portion ≥65 μV × ms was significantly lower than in those with area of P-wave initial portion <65 μV × ms (P = .02).
Heart Rhythm 2010 7, DOI: ( /j.hrthm )
Copyright © 2010 Heart Rhythm Society Terms and Conditions