Quantitative Prediction of Right Ventricular Size and Function From the ECG

Figures

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  Figure 1. Study Inclusion flow diagram. Cardiac MRI and ECG inclusion diagram chart for UK Biobank (left) and Mount Sinai Hospital data sets (right). MRI indicates magnetic resonance imaging.

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  Figure 2. Classification of abnormal right ventricular ejection fraction and end‐diastolic volume. Receiver operating characteristic curves (blue) and precision recall curves (orange) to classify RV systolic dysfunction (A, left) and RV dilation (B, right) in UK Biobank data set (top), MSH data set (middle), and MSH prospective validation data set (bottom). Red dashed lines on receiver operating characteristic curves represent no model skill, and on precision recall curves represent baseline incidence of disease. AUROC indicates area under the receiver operating characteristic curve; AUPRC, area under the precision‐recall curve; MSH, Mount Sinai Hospital; and RV, right ventricular.

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  Figure 3. RVEF and RVEDV regression models, MSH data set. MSHoriginal regression model with ECG‐predicted vs cMRI‐expected scatter plots to predict numerical RVEF (A) and numerical RVEDV (C). Scatter plots plotted with line of perfect concordance (dashed black line) and Passing–Bablok regression best‐fit line (solid blue) with 95% CIs (dashed blue line). Difference plots analysis of RVEF (B) and RVEDV (D) with regression slope (red line) and 95% CIs of the errors (blue line) displayed. CCC indicates concordance correlation coefficient; EF ejection fraction; MAE, mean absolute error; MRI, magnetic resonance imaging; MSH, Mount Sinai Hospital; RV, right ventricle; and RVEDV, right ventricular end‐diastolic volume.

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  Figure 4. Saliency mapping. Saliency mapping ECG examples from the MSHoriginal test set. Leads are arranged from bottom to top: lead I, II, V1‐V6. Increasing shades of red indicate increasingly influential pixels in the model. A shows a true‐positive example of RV dysfunction. The P and QRS portions of V1, V5, and V6 are particularly influential. B shows a true‐negative example of RV dilation. QRS complex of lead I and P‐wave in V1 is particularly influential. MRI indicates magnetic resonance imaging; RVEF, right ventricular ejection fraction; and RVEDV, right ventricular end‐diastolic volume.

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  Figure 5. Unadjusted survival curves. Kaplan–Meier survival curves by presence of LVEF and RVEF dysfunction. Note that curves are truncated at 8 years due to low sample size after this time point. Risk table is displayed at bottom of figure. LVEF indicates left ventricular ejection fraction; and ECG‐RVEF, electrocardiogram‐predicted right ventricular ejection fraction.