Optimal use of a novel miniaturized electrocardiographic (ECG) recorder in patients with atrial fibrillation

Abstract

Background: Electrocardiogram (ECG) has been used to help screen patients for the presence of left ventricular systolic dysfunction (LVSD). For example, QRS duration of more than 120 milliseconds is a widely used ECG criterion for selecting patients for cardiac resynchronization therapy. However, ECG abnormalities are not always associated with hemodynamic impairment. Therefore, acoustic cardiography (Inovise Medical, Inc, Portland, OR, USA), a technique that acquires and algorithmically analyzes simultaneous digital ECG and heart sound data, has been developed. In this study, we compared the abilities of acoustic cardiography vs the standard ECG to detect LVSD. Methods: We studied a convenience sample of 278 dyspneic patients (182 males; mean age, 60 ± 14 years) from whom contemporaneous acoustic cardiographic, standard 12-lead ECG, and echocardiographic data had been obtained. Of these, 122 (44%) had LVSD defined as echocardiographic left ventricular ejection fraction less than 50%. We compared the diagnostic performances for detecting LVSD of QRS duration more than 120 milliseconds vs the acoustic cardiographic parameter percentage of electromechanical activation time (%EMAT).%EMAT is the interval in from QRS onset to the first heart sound divided by the RR interval. %EMAT reflects the time required by the left ventricle to generate sufficient force to close the mitral valve. Results: The following table shows the results: