Electrical surrogate for detection of severe left ventricular systolic dysfunction

Background: Early diagnosis and therapy improves outcomes in heart failure with severely reduced left ventricular ejection fraction (LVEF ≤35%), but some patients may remain undiagnosed. We hypothesized that a combination of electrocardiogram (ECG) markers may identify individuals with severely reduced LVEF. Methods: From a community-based study in the Northwest US (the Oregon Sudden Unexpected Death Study), we evaluated the prevalence of conventional ECG markers by LVEF. We then evaluated the association of nine additional ECG markers and LVEF. We validated the correlation of these ECG markers and LVEF in a separate, large health system in Los Angeles, California. Results: In the discovery population (n = 1,047), patients with LVEF ≤35% were twice as likely as those with LVEF >35% to have ≥1 conventional ECG abnormality. In the subset without conventional ECG abnormalities, ≥4 abnormal ECG markers from the expanded panel were found in 12% vs. 1% of patients with LVEF ≤35% and >35%, respectively. In the validation population (n = 9,742), 44% with LVEF ≤35% and 17% with LVEF >35% had ≥1 conventional ECG abnormality. In patients without conventional ECG abnormalities (n = 7,601), 40% with LVEF ≤35% and 5% with LVEF >35% had ≥4 abnormal ECG markers from the expanded panel. Each additional abnormal ECG marker from the expanded panel (range 0 to ≥4) more than doubled the odds of LVEF ≤35%. Conclusions: An expanded panel of easily obtained ECG markers correlated strongly with severely reduced LVEF in two separate populations. This electrical surrogate score could facilitate diagnosis of severely reduced LVEF, and warrants prospective evaluation.