Electrocardiographic Findings in Pectus Excavatum

Pectus excavatum is one of the thoracic deformities characterized by the depression of xiphisternal area and subsequent compression and displacement of adjacent cardiopulmonary system. Although electrocardiographic (ECG) findings of pectus excavatum have been so far reported sporadically, these are not fully understood. Therefore, we analyzed ECG of six university male students with pectus excavatum recorded by annual health check-up program. Most frequently recognized finding was the completely negative P wave polarity in V_1 lead. So-called early repolarization (normal variant ST elevation) and juvenile T wave pattern (broad range T wave inversion in right precordial leads) were also found in 4 of 6 subjects. Small q wave formation in V_1 lead and clock-wise rotation were recognized in half of these students. Completely negative P wave and q wave in V_1 lead were considered to be ascribed to the left-sided cardiac dislocation and malapposition of the V_1 electrode, which faced right-sided thorax due to xiphisternal depression. In conclusion, ECG in pectus excavatum is influenced greatly by the interaction of cardiac displacement and precordial electrodes malapposition