Minimisation of medical terminology in secondary care correspondence in patients with chronic health conditions: impact on understanding and patient reported outcomes

Abstract

Background: Electrocardiogram (ECG)-based detection of left ventricular systolic dysfunction (LVSD) has poor specificity and positive predictive value, even when including major ECG abnormalities such as left bundle branch block (LBBB) within the criteria for diagnosis. Advanced ECG (A-ECG), using multiparameter scores, has superior diagnostic utility to strictly conventional ECG for identifying various cardiac pathologies, including LVSD. Methods:We evaluated the diagnostic utility of A-ECG in a case-control study of 40 patients with LVSD (LV ejection fraction (LVEF) <50% by echocardiography) due to nonischaemic cardiomyopathy (NICM) and 39 other patients without LVSD. Diagnostic sensitivity and specificity for LVSDwere determined after applying a previously validated probabilistic A-ECG score for LVSD to standard (10-sec) 12L ECGs. In 25 of the NICM patients who had serial ECGs, changes in the A-ECG score versus in echocardiographic LVEF were compared. Results: Blinded analyses by A-ECG had a sensitivity of 95% for LVSD (93% if excluding N=11 patients with LBBB) and specificity of 95%. In the 29 NICMpatients without LBBB who had serial ECGs, sensitivity improved to 97% when all ECGs were considered. By comparison, the best human reader had a sensitivity of 90% and specificity of 63%. AECG score trajectories demonstrated improvement, deterioration or no change in LVSD, which agreed with echocardiography, in 76% of cases (n=25). Conclusion: A-ECG scoring can detect LVSD, due to NICM, with high sensitivity and specificity. Serial A-ECG score trajectories also represent an accurate method for inexpensively estimating changes in LVSD.