[Variations between 2 ECG as predictors of atrial fibrillation: Cohort study]

Objetive: To evaluate the association between delta variations in the parameters of 2 sinusal ECG with atrial fibrillation (AF) onset.

Method: Retrospective cohort of 9,975 adult patients and members of the prepaid system at Hospital Italiano de Buenos Aires from Argentina, who had at least 2 sinusal ECG between 2006 and 2011. Population was followed up for detection of AF. All measurements and electrocardiographic deltas (differences between the 2 ECG) were standardized. Hazard ratio (HR) was estimated for the development of AF for each delta of the different ECG parameters using a Cox regression model.

Results: During a median follow up of 3.5 years, 189 patients (1.89%) developed AF. Heart rate delta, ST interval delta and P wave amplitude were predictors of AF. Hazard ratio Adjusted for clinical characteristics and ECGbasal values was 0,86 (CI95%: 0.75-0.98, p=0.024) for heart rate delta, 1.12 (CI95%: 0.98-1.27, p=0.082) for ST interval delta and 1.21 (CI95%: 1.05-1.38, p=0.006) for P wave amplitude delta.

Conclusion: Differences of heart rate and P wave amplitude between ECG's measurements may predict AF, independently of clinical features and ECGbasal values.