Left atrial strain associated with interatrial block in patients with ST-segment elevation myocardial infarction.

Both interatrial block (IAB) and left atrium (LA) strain are associated with atrial arrhythmias in ST-segment elevation myocardial infarction (STEMI) patients, but the relationship between IAB and LA strain has not yet been reported. This study was to investigate the correlation between LA strain and IAB in STEMI patients. This is a single-center retrospective clinical observational study. The STEMI patients with primary percutaneous coronary intervention (pPCI) were enrolled, and all patients completed cardiac magnetic resonance (CMR). A standard 12-lead electrocardiogram (ECG) was recorded on the same day as CMR. IAB was measured by p duration on ECG at follow-up. 302 patients were enrolled, including 91 (30.1%) with IAB. The reservoir strain, conduit strain and booster strain were included in model 1, model 2 and model 3, respectively. In model 1, age (OR 1.025; 95%CI 1.003-1.047; p = 0.026), hypertension (OR 2.188; 95%CI 1.288-3.719; p = 0.004), and reservoir strain (OR 0.947; 95%CI 0.920-0.974; p < 0.001) were independent factors for IAB. In model 2, age (OR 1.031; 95%CI 1.009-1.053; p = 0.006), hypertension (OR 2.058; 95%CI 1.202-3.522; p = 0.008), RCA lesions (OR 1.797; 95%CI 1.036-3.113; p = 0.037), and conduit strain (OR 0.910; 95%CI 0.868-0.953; p < 0.001) were independent factors for IAB. In model 3, age (OR 1.022; 95%CI 1.001-1.045; p = 0.044), hypertension (OR 2.239; 95%CI 1.329-3.773; p = 0.002), and booster strain (OR 0.948; 95%CI 0.908-0.991; p = 0.019) were independent factors for IAB. With the lowest AIC and BIC values, model 2 was the best-fit model. LA strain associated with IAB in STEMI patients. The model including conduit strain was the best-fit one.