Left axis deviation in children without previously known heart disease

BACKGROUND: Left axis deviation (LAD) discovered in children via electrocardiogram (ECG) is uncommon but can be associated with heart disease (HD). The optimal diagnostic approach in a seemingly healthy child with LAD is unclear. We sought to better stratify which patients with LAD but without previously known HD may warrant additional workup. METHODS: A retrospective chart review was performed to identify patients ≥1 to <18 years of age with LAD (QRS frontal plane axis 0 to -90) on an ECG between January 2002 and December 2014. Patients with known HD before their initial ECG were excluded. RESULTS: Overall, 296 patients were identified (n = 181 [61%] male; mean age: 10.8 ?} 4.6 years; mean QRS axis: -24 ?} 22°). An echocardiogram was performed in 158 (53%) patients, with 24 (15%) having HD. Compared with those with an echocardiogram but without HD (n = 134), patients with HD had a more negative mean QRS axis (-42 vs -27°; P = .002) and were more likely to have a QRS axis ≤-42° (58% vs 26%; P = .003), ECG chamber enlargement or hypertrophy (38% vs 5%; P < .0001), and abnormal cardiac physical examination findings (75% vs 8%; P < .0001). CONCLUSIONS: LAD discovered in isolation in the asymptomatic pediatric patient may not necessitate further cardiovascular investigation. Clinicians should consider obtaining an echocardiogram in patients with LAD and ECG cardiac chamber enlargement or hypertrophy, a QRS axis ≤-42°, and/or the presence of abnormal cardiac physical examination findings.