Abstract 16785: Reliable Estimation of Left Ventricular Ejection Fraction Using High Resolution Surface Electrocardiography
Background: Estimation of left ventricular (LV) systolic function is central to the prescription of medical and device therapy. Yet, significant variability in LV ejection fraction (EF) values exist among the methods used. Of these, radionuclide angiography (MUGA) is considered to reliably estimate LVEF. The purpose of this study was to develop and validate a simple, inexpensive method of estimating LV systolic function.
Methods: A method of estimating LVEF from high-resolution orthogonal (X,Y,Z) ECG data was developed (ECG-EF). It utilizes advanced mathematical techniques to estimate LVEF from alterations in LV conduction and repolarization. Separate test and validation sets of post-myocardial infarction (MI) patients with paired high-resolution ECG and MUGA data were used. Test data (n = 91) were used to optimize the algorithms. A separate group (n = 233; validation) was used to assess the comparability of ECG-EF vs. MUGA-EF in terms of LVEF and prognosis. Bland Altman, receiver operating characteristic (ROC), and Cox methods were used.
Results: Test and validation groups were similar in terms of mean age (61 vs. 62 years), female gender (11% vs. 16%), mean MUGA-EF (45±11% vs. 47±12%), anterior MI location (70% vs. 60%) and mean follow up (45±18 vs. 42±12 months), respectively. Estimated ECG-EF was similar to MUGA-EF in the validation group, with a mean difference of -2.5% (95% confidence interval -4.3 to -0.7%; Figure). Among the validation group the ROC areas were similar for the two EF methods (p = 0.90). The prognostic utility of the EF methods was also similar. Each 10% increase in MUGA-EF was associated with a 40% reduction in the risk of death (21% to 60%; p = 0.01), while each 10% increase in ECG-EF was associated with a 54% reduction (19% to 74%; p = 0.007).
Figure. Bland Altman plot of ECG-EF vs. MUGA-EF (n = 233).
Conclusions: We describe a novel ECG-based method for estimating LV systolic function that corresponds well with MUGA-EF in terms of estimated LVEF and prognosis.
- © 2013 by American Heart Association, Inc.