Unique ECG Finding in a Patient With an Axial Blood Flow Pump
After implanting a permanent Jarvik 2000 Heart (Jarvik Heart, Inc) in a patient with end-stage heart failure (Figure 1), we simultaneously recorded ECG and Doppler flow velocity in the vascular graft that connects the blood pump and descending aorta. With the pump temporarily switched off, the graft blood flow reversed, passing from the descending aorta through the device to the left ventricle. The peak systolic flow velocity in the graft decreased from 120 to 15 cm/s, and diastolic regurgitant flow developed at 30 cm/s. These changes in graft flow velocity completely reversed within 6 cardiac cycles after the pump had been switched on again (Figure 2). With the pump operational, artifacts were present on ECG throughout the cardiac cycle (Figure 3A). When the pump was switched off, a reverberating wave was present only from the end of the T wave to the onset of QRS complex (Figure 3B).
We attribute the reverberating wave during regurgitant graft flow to electrical current generated by reversed spinning of the impeller within its electromagnet housing. This unique ECG provides an opportunity to substantiate or rule out the possibility of thrombotic binding of the impeller in the event of device malfunction.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to the Circulation Editorial Office, St Luke’s Episcopal Hospital/Texas Heart Institute, 6720 Bertner Ave, MC1-267, Houston, TX 77030.