Background:

Different electrocardiographic abnormalities have been associated with left ventricular systolic dysfunction (LVSD), although the association with standard electrocardiographic frontal plane ST-segment depression (STD) has not been established.

Objective:

The aim of this study was to evaluate whether lead I STD (STD-I) allows predicting the presence of LVSD.

Methods:

Patients with risk factors or stable chronic heart disease, and baseline electrocardiogram (ECG) and echocardiogram that provided evaluation of left ventricular ejection fraction (LVEF), left ventricular wall motility, and dichotomous evaluation of left ventricular hypertrophy (LVH), were prospectively included in the study. ST-segment morphology in leads I and V6 was evaluated, defining horizontal (≥1mm at 80 ms from the J point) or downsloping STD as abnormal STD-I and STD-6.

Results:

A total of 691 patients; with mean age of 69.8 ± 12 years and 61.6% men, were prospectively analyzed. STD-I and STD-6 were identified in 250 (36.2%) and 199 (28.8%) cases, respectively. Presence of STD-I and STD-6 was associated with a significantly lower LVEF compared with the absence of this finding: 44.8 ± 13.9% vs. 55.6 ± 8.9% (p <0.0001) and 45.8 ± 14.1% vs. 54.1±10.4% (p <0.0001), respectively. Both were associated with the presence of LVSD, defined as LVEF <50%, although STD-I showed better diagnostic performance than STD-6 [area under the ROC curve 0.72 (95% CI 0.69-0.76) vs. 0.64 (95% CI 0.61-0.68), p = 0.0001].

Conclusions:

This study showed that STD-I predicts the presence of LVSD better than STD-6. The potential relevance of these findings should be placed in the current context of the emerging use of wearable devices that analyze electrocardiographic information through a single lead.