Blood Pressure Variability and Atrial Fibrillation in Patients with Acute ST Segment Elevation Myocardial Infarction: The Relation with Left Atrial Electromechanical Delay – A 1-Year Follow-Up Study

Abstract

To investigate the association between 24-h blood pressure variability (BPV) and atrial electromechanical delay (EMD) in patients with ST segment elevation myocardial infarction (STEMI) who developed new-onset atrial fibrillation (NOAF). Materials and Methods: A total of 175 STEMI patients (age 56.6 ± 10.5 years) who underwent primary percutaneous coronary intervention were subjected to in-hospital 24-h ambulatory BP monitoring, comprehensive echocardiography, and assessment of atrial EMD. The parameters of BPV analyzed were: (a) 24-h standard deviation (SD), (b) the coefficient of variation, and (c) the average of the daytime and nighttime SDs weighted for the duration of the daytime and nighttime interval (SD dn). Results: Based on the median of BPV index (SD dn) = 9.5 mm Hg of all participants, patients were stratified into low and high variability groups (SD dn : 7.1 ± 1.5 vs.13.5 ± 2.9; p < 0.001). Of the 175 patients with STEMI, 29 (16.7%) patients developed NOAF; 26 (28.9%) were in the high variability group and 3.5% were in the low variability group (p < 0.001). Echocardiographic data showed that the left atrial volume index (p < 0.01) and E/e′ ratio (p < 0.001) were significantly higher in patients with high BPV. Inter and intra-atrial EMD were significantly increased in the high variability group compared to the low variability group (p < 0.001). With multiple linear analysis, there was significant correlation between SD dn and intra-left