Ultrasound and Alternative EchoTechniques


Please note: You’ve reached this site because you’ve been made aware your patient has been implanted with a medical device known as the WiSE Cardiovascular Resynchronization Therapy (CRT) System. The WiSE CRT System consists of (i) an ultrasound transmitter implanted in the lower left area of the chest between the ribs; (ii) a separate battery module under the left armpit area; and (iii) a small ultrasound-sensitive Electrode implanted inside the left ventricle of the patient’s heart.


  • Be cautious in exposing this patient to sources of Ultrasound. There is a slight potential that the Electrode implanted in the left ventricle of their heart could receive ultrasound pulses and convert them to untimed stimulation pulses. Hence, imaging devices used in echocardiography for transthoracic imaging, for vascular imaging, intracardiac imaging, doppler echocardiography, and transesophageal echocardiography should be used with caution on this patient. Focusing ultrasound energy directly on the electrode during imaging or using high intensities of ultrasound throughout the body increases the potential for this extra stimulation for this patient. In the event of extra stimulation during a transthoracic echocardiography procedure immediately remove the imaging probe from the patient and discontinue imaging. To continue with imaging, consideration must be given to reducing the power output, selecting a different imaging mode, or using a different imaging position to avoid focusing on the electrode.
  • Reference the “Alternate Echocardiography Guidelines with Reduced Power Settings” document PRIOR to performing an echocardiography.
  • Whenever therapeutic or diagnostic ultrasound is used for patients implanted with the WiSE CRT system, a defibrillator should be available in case of tachyarrhythmia (abnormally fast heart rates) occurring. In the event of an external or internal defibrillation shock, the performance of the implanted device will need to be checked by the implanting physician (see the patient wallet card for contact information).
  • Avoid exposure to High Intensity Ultrasound Sources. (e.g. Lithotripsy therapy or therapeutic ultrasound) High intensity ultrasound may cause inappropriate cardiac stimulation or damage to the Pulse Generator.

Other Medical Interactions Requiring Caution Or To Be Avoided

  • Be cautious after the patient has received an external or internal defibrillation shock. Always check for correct device performance after the patient has received a defibrillation shock as the device may have reset its operation.
  • Be cautious in changing the programming of the patient’s co-implanted pacemaker, ICD, or CRT system. The WiSE-CRT system relies on detection of a specific pulse width used for right ventricle pacing in order to synchronize pacing of the left ventricle. Programming changes may inhibit pacing from the WiSE-CRT system.
  • Avoid exposure to Magnetic Resonance Imaging (MRI). The implanted system may be permanently and unpredictably damaged by strong magnetic fields associated with MRI and may cause harm to the patient.
  • Avoid exposure to Radiofrequency-based devices. Do not expose the WiSE-CRT system to RF devices used for tissue ablation and/or cauterization in close proximity to the implanted devices as this may damage the device.
  • Avoid exposure to Diathermy. Do not expose the WiSE-CRT system to diathermy which heats tissue by delivery of high frequency electromagnetic radiation, electric current or ultrasonic waves as this may damage the device.
  • Avoid exposure to Radiation. Do not expose the WiSE-CRT system to Radiation therapy, particularly focused radiation in close proximity to the implanted devices as this may damage the device.
  • Avoid exposure to Transcutaneous Electrical Nerve Stimulation (TENS) or other Neurological Stimulation devices. Use of these devices in patients with a WiSE-CRT System may cause inappropriate sensing leading to inappropriate cardiac stimulation at the Electrode.


The WiSE-CRT pacing mode may be programmed Off using a specific programmer instrument. Contact the patient’s physician (see the patient’s wallet card) or contact the manufacturer to program the device.