Three different septal circumferential strain patterns in patients with LBBB. AVO marks the opening of aortic valve and AVC marks the closure of aortic valve. A. Type Ia. Dyskinesis of the anteroseptum. Inferoseptum εcc shortening is reduced. B. Corresponding ECG, QRS = 154 ms. C. Type Ib. Dyskinesis of the entire septum. D. Corresponding ECG, QRS = 150 ms. E. Type II. No dyskinesis but reduced septal εcc. F. Corresponding ECG, QRS = 156 ms. Arrows point to presystolic contraction. AS = anteroseptum, IS = inferoseptum, and IL = inferolateral wall. AVO = aortic valve opening. AVC = aortic valve closure.