Determinants of electrocardiographic abnormalities in patients with pectus excavatum.

BACKGROUND Electrocardiographic abnormalities such as cardiac axis deviation, conduction abnormalities and ST-segment, and T &P wave abnormalities have been reported in patients with pectus excavatum. The precise determinants of these electrocardiographic abnormalities have however not been systematically evaluated. We therefore carried out this exploratory study to assess the electrocardiographic abnormalities and their determinants in children and young adults with pectus excavatum. METHODS Patients aged between 6 and 22 years with unrepaired pectus excavatum were eligible for enrollment in this preliminary hypothesis generating study, if they were seen at University of Chicago Medical Center between Jan 1, 2017 to Nov 30, 2020, and underwent an electrocardiogram during comprehensive evaluation for pectus excavatum. Pertinent data was collected from the medical charts. Unadjusted and adjusted logistic regression models were used to determine the effect of variables including age, BMI, inspiratory Haller's index, gender, right ventricular geometric distortion and FEV1/FVC (% predicted) on odds of electrocardiographic abnormalities (primary outcome variable). P-values of <0.05 were considered significant. RESULTS The study group (16.6 ± 2.9 years, 80% symptomatic) consisted of 28 patients [Caucasian, male (n = 24, 86% each)]. A high proportion (86%) of these patients had geometric distortion of the right ventricle on noninvasive imaging and these patients had a higher Haller's index (4.4 ± 0.95 vs 3.3 ± 0.2, p = 0.03). Approximately 60% of the patients had an abnormal electrocardiogram. Unadjusted and adjusted logistic regression models were utilized to study the determinants of these electrocardiographic abnormalities. Haller's index, BMI, age, gender, geometric distortion of the right ventricle and lung function parameters [FEV1/FEV (% predicted)] were not associated with increased odds of electrocardiographic abnormalities. CONCLUSIONS Electrocardiographic abnormalities, particularly deviation of cardiac axis, are common in patients with pectus excavatum. In this exploratory hypothesis generating study, Haller's index and geometric distortion of the right ventricle were not associated with these abnormalities. However, systematic multicentric efforts are needed to better define electrocardiographic abnormalities in patients with pectus excavatum and elucidate their precise determinants.