The patient is a 37-year-old Caucasian male with history of viral myocarditis and dilated cardiomyopathy (diagnosed 10 years ago), who lost consciousness while preparing to participate in a triathlon the morning of September 20, 2015. The patient does triathlons on a regular basis. That morning he took three Advil Migraines for anti-inflammatory effects and drank an “electrolyte” sports drink. He became lightheaded and was observed by his girlfriend to drop to his knees, fall back, hit his head, and have seizure-like activity. Paramedics at the scene gave him a total of 7 shocks and a bolus of amiodarone before restoration of spontaneous circulation. The strips recorded were consistent with ventricular fibrillation (Figure 1). He regained consciousness at the scene and was brought to the emergency room, where blood work didn’t show any significant electrolyte abnormality and 12-lead ECG showed sinus rhythm with non-specific ST-T changes and corrected QT interval of 456 msec.
The patient’s left ventricular ejection fraction (LVEF) at echocardiography done around six months ago was 38%. He had one episode of pre-syncope in the remote past, and another episode while swimming around six months ago. He had urgent left heart catheterization that showed normal coronaries. Repeat 2D echo showed an LVEF of 30% with severe global hypokinesis. He underwent implantation of a single-chamber Evera MRI XT ICD with SureScan technology (Medtronic plc) on September 22, and was discharged the next day.
About the Technology
Medtronic received approval from the U.S. Food and Drug Administration (FDA) for the Evera MRI™ SureScan® ICD System on September 14, 2015. Until this date, patients with ICDs were contraindicated from receiving MRI scans due to potential interaction between MRI and device function, and possible subsequent risk to patients. Only a small number of tertiary care centers have been performing MRIs on patients with conventional ICDs, such as in situations where MRIs are vitally needed for diagnostic purposes or are lifesaving. However, this process has been labor-intensive and is usually not reimbursed by many insurers. Data have shown that 36% of patients with ICDs are likely to need an MRI within four years.1
The Evera MRI Clinical Trial was the first randomized study of the ICD system allowing for full-body 1.5 Tesla MRI scans.2 Results from the trial showed 100% freedom from MRI-related complications without any impact of MRI on the device’s sensing, detection, or therapy delivery. The FDA’s approval of this device launched a new era of diagnostic convenience, especially since MRI is considered the gold standard in soft tissue imaging and is used routinely for the diagnosis of certain conditions such as stroke, cancer, and muscle, bone, and joint pain.
We were very fortunate at Beebe Healthcare to be able to provide our young patient who survived sudden cardiac arrest with a MRI-compatible ICD within one week of FDA approval. He will rely on this device for the rest of his life to monitor his heart and deliver lifesaving energy if needed, without any limitation to full-body MRI. Many patients are receiving ICDs at a younger age and will likely require an MRI scan sometime during their lifetime. This advancement in ICD technology will allow patients receiving such devices to have a lifesaving MRI scan at any hospital in the near future, without any diagnostic or therapeutic limitations.
Disclosures: The author has no conflicts of interest to report regarding the content herein.
- Nazarian S, Reynolds M, Ryan M, et al. Estimating the Likelihood of MRI in Patients After ICD Implantation: A 10-Year Prediction Model. J Am Coll Cardiol. 2015;65(10_S). doi:10.1016/S0735-1097(15)61090-7.
- Gold MR, Torsten S, Schwitter J, et al. Full-Body MRI in Patients With an Implantable Cardioverter-Defibrillator: Primary Results of a Randomized Study. J Am Coll Cardiol. 2015;65(24):2581-2588. doi:10.1016/j.jacc.2015.04.047.