Incidence and Fate of the Abnormal Septal Motion after Open Heart Surgeries

Abnormal septal motion (ASM), or septal bouncing, is a paradoxical bouncing motion of the interventricular septum. 1) During early diastolic period, interventricular septum initially directed towards and moves away from the left ventricle. ASM can be found frequently during echocardiographic examinations. If physician or echocardiographer found ASM during their studies, they should bear in mind the causative etiologies including constrictive pericarditis, pericardial tamponade, pulmonary hypertension, septal ischemia, left bundle branch block, congenital absence of pericardium and right ventricular pacing. Although they showed similar echocardiographic finding of ASM, their clinical presentations and managements were totally different. Some of them can be differentiate easily. However , some of them should be diagnosed to give appropriate and timely treatment. Of them, constrictive pericarditis is the most important etiology should be ruled out. In one study, sensitivity and specificity of ASM in the detection of constrictive pericardi-tis were 62% and 93%. 7) They also reported that the presence of vena caval plethora and pericardial adhesion were other echocar-diographic findings of constrictive pericarditis and ASM was the most consistent finding among examiners. ASM can be also seen in patients underwent pericardiotomy during open heart surgery. 8) In the previous study, they showed the incidence of ASM after open heart surgery retrospectively and they found valve surgery is more likely to cause ASM than coronary artery bypass surgery. In this study, the authors demonstrated the incidence of ASM with regular follow-ups, prospectively. There was no report about the chronological sequence of ASM in patients with open heart surgeries. The authors serially checked the incidence and fate of ASM in patients underwent open heart surgery. Interestingly, it appeared about 70% of patients immediately after the open heart surgery. The presence of ASM was associated with lower left ventricular ejection fraction and late mitral filling velocity. However, the authors showed ASM was not associated with myocardial ischemia and disappears with time (25% at 3-6 months and 15% after 1 year). The incidence of ASM in this study was much lower than that of previous report by Reyn-olds et al. 8) However, their result was a retrospective study and there was inhomogenous time-interval of the postoperative echocardiographic study. Because the authors showed the chronological sequence of ASM in patients underwent open heart surgery prospectively, the manuscript showed unique finding with exact incidence of ASM. There are several proposed mechanisms of ASM including the injury of interventricular septum during the …