Rapid assessment of left ventricular systolic function in a pacemaker clinic using a hand-carried ultrasound device
Pacemaker recipients with left ventricular (LV) dysfunction are potential candidates for upgrades to implantable defibrillators or cardiac resynchronization devices. This study sought to determine if a hand-carried ultrasound (HCU) device could be used for rapid, inexpensive identification of LV dysfunction in a busy pacemaker clinic. Eighty patients undergoing routine pacemaker check were enrolled. Patients underwent HCU imaging in the sitting position during device interrogation, by an internist who had 20 h of didactic training and 20 practice examinations. LV dysfunction was defined as ejection fraction (EF) <40%. Patients also underwent echocardiography limited to EF assessment by a sonographer using a full-feature platform. The mean age was 75 ± 13 years; 49% were female. Coronary artery disease was present in 29%; 82% were NYHA class I or II. At the time of HCU imaging, 48% of patients were receiving RV pacing. HCU images were interpretable in 91% (73/80) and required 3.7 ± 0.9 min to complete. Based on the full-feature echo, LV dysfunction prevalence was 17/80 (21%); 25% of these patients were NYHA class I. The sensitivity of the HCU exam was 75%, specificity was 91%, negative predictive value was 93%, positive predictive value was 71%, and accuracy was 88%. HCU screening in a pacemaker clinic by a non-cardiologist can rapidly and accurately identify pacemaker recipients with at least moderate LV dysfunction who might be candidates for device upgrades. Ventricular dyssynchrony associated with RV pacing does not limit HCU identification of LV dysfunction.