Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
Patients with unrepaired atrial septal defects accumulate yearly risk of developing pulmonary arterial hypertension due to vascular remodeling in response to chronically increased pulmonary circulation. Electrocardiography, though readily available, has so far been of limited screening utility in this population. We hypothesize that vectorcardiographic parameters will aid in identifying increased ventricular afterload and thus provide an additional screening tool for pulmonary hypertension in this patient population.
Purpose
To establish whether vector electrocardiography can be used as a non-invasive screening tool for pulmonary hypertension screening in patients with atrial septal defects.
Methods
Retrospective chart review of patients with the diagnosis of secundum atrial septal defect who underwent cardiac catheterization at the University of Minnesota from January 2012 to September 2020. We excluded patients with other congenital heart diagnoses, insufficient hemodynamic data, or no sinus rhythm electrocardiogram. An electrocardiogram prior to or on the day of the intervention was assessed. Parameters analyzed include: Sokolow-Lion right ventricular hypertrophy criteria, PR duration, QRS duration, corrected QT intervals, QRS and Twave frontal plane axes, rSR’, rSR’ with the R’ of 5mm or more, as well as vectorcardiographic parameters (Kohr’s regression-related method) the QRS vector magnitude, T wave vector magnitude, and spatial QRS-T angle. These results were then used to compare those with and without pulmonary hypertension (diagnosed by mean pulmonary artery pressure of 25mmHg or more along with body surface area-indexed pulmonary vascular resistance of 3 Woods units/meter squared with normal left atrial/pulmonary vein wedge pressure). Mann-Whitney U-testing was used for non-parametric testing for significance within the dataset.
Results
Three hundred and five patients were identified with secundum atrial septal defects, but after exclusion, there were a total of 122 patients meeting criteria for assessment. Eight ASD patients had pulmonary hypertension (37% male, median age 7.5 years, interquartile range 0.4 to 23 years) while 114 patients did not (31% male, median age 5 years, interquartile range 3 to 13 years, p-value 0.68). Only the spatial QRS-T angle significantly differentiated pulmonary hypertension (median 104 degrees, interquartile range 55 to 137 degrees) from those ASD patients without pulmonary hypertension (median 37 degrees, interquartile range 21 to 63 degrees) with a p-value of 0.002. At a cut-off of 124 degrees, the positive and negative predictive values for identification of pulmonary hypertension was 36.4% and 96.4%, respectively, with an odds ratio of 13.4 (95% confidence interval of 2.9 to 63.7).
Conclusions
The spatial QRS-T angle may be a useful, non-invasive screening tool for pulmonary hypertension in patients with secundum atrial septal defects.
Predictors of pulmonary hypertension among children with atrial septal defects (ASD)
