Influence of Nuss surgical operation for pectus excavatum on electrocardiogram abnormality considering anatomical severity as indicated by Haller index acquired by computed tomography and age

Abstract Background Pectus excavatum (PEX) is a depression of the sternum relative to costal cartilages and sometimes depress heart anatomically which cause abnormal ECG change. Nuss operation is minimal invasive technique for PEX repair. Purpose We speculated this Nuss operation would improve these ECG abnormalities. We also considered the Haller index (HI) and age to these influences. HI is an anatomical severity indicator of PEX calculated from CT. Methods A total of 17 patients (14 male, 12±6 years), who underwent Nuss operation for PEX, underwent unenhanced CT and ECG before and after the Nuss operation. Results All Nuss operation was successfully performed. On CT, HI was significantly improved from 5.62±2.29 to 3.29±0.65 (P=0.0002). A P wave with a negative portion >1 mm deep and >40 ms duration in V1 lead, incomplete right bundle branch block (RBBB), sinus arrhythmia, and right-axis deviation of a QRS wave were diagnosed in 15, 6, 12, and 5 patients, respectively. Comparing before with after Nuss operation, there were no significant differences of the degree of electrical axis of QRS waves, the degree of electrical axis of P waves, or the PQ interval, respectively (All P=NS). Absolute values of voltage of a negative portion of the P wave in V1 lead was significantly improved after the operation (1.55±1.25 vs 0.76±0.91mm, P<0.001). Among 12 patients with sinus arrhythmia, only one patient improved to that without. Among 6 patients with incomplete RBBB, only one patient improved to that without. The correlation coefficient (CC) between “values of the improvement of negative portion of the P wave in V1 lead after the operation” and “HI before operation” was 0.305 (P<0.05). The CC between “absolute values of the improvement of negative portion of the P wave in V1 lead after the operation” and “age at the operation” was −0.216 (P<0.05). Conclusion In patients with PEX, successful Nuss operation could achieve improvement of negative portion of the P wave in V1 lead positively correlated with “HI before operation” and negatively correlated with “age”. Nuss procedure would be more effective to abnormal ECG change, when anatomical severity is severer or age is younger. Improvement of negative P wave Funding Acknowledgement Type of funding source: None