The electrocardiogram and the secundum atrial septal defect: a reexamination in the era of echocardiography.

BACKGROUND

Ostium secundum atrial septal defects (ASDs) often present subtly and may be a diagnostic challenge to the community physician. Characteristic abnormalities of the electrocardiogram (ECG) have been described in adults.

OBJECTIVE

To determine whether ECG abnormalities are consistently present in children with a hemodynamically significant ASD, and their potential for differentiating this group from patients with innocent murmurs.

DESIGN

Retrospective evaluation of clinical characteristics, echocardiographic data, and ECGs was undertaken in 67 consecutive children with an ASD (mean age 2.9 +/- 2.8 years, 63% female) and 77 patients with innocent murmur (mean age 3.2 +/- 2.6 years, 61% male). Predetermined ECG criteria were derived from adult studies (rsR'-V1 with evidence of right ventricular hypertrophy, isolated rsR'-V1, and unequivocal right ventricular hypertrophy without rsR'-V1). ECGs were interpreted blindly by two observers.

RESULTS

In the ASD group 58 (87%) patients had an ECG that met predetermined criteria compared with three (3.9%) controls (P < 0.001). Completely normal ECGs were found in only four (6.0%) ASD patients compared with 66 (86%) controls (P < 0.001). The ECG criteria had a sensitivity of 86% (95% CI 0.784 to 0.947) and a specificity of 96% (95% CI 0.918 to 1.000). When any ECG abnormality was considered the sensitivity increased to 94% (95% CI 0.884 to 0.997) with a decline in specificity to 86% (95% CI 0.779 to 0.935).

CONCLUSIONS

The ECG is potentially a valuable adjunct to the physical examination in differentiating children with an ASD from those with an innocent murmur in the primary care setting.