Israel Medical Association Journal

Background: The decision to perform primary percutaneous coronary intervention in unconscious patients resuscitated after out-of-hospital cardiac arrest is challenging because of uncertainty regarding the prognosis of recovery of anoxic brain damage and difficulties in interpretation of ST segment deviations. In ST elevation myocardial infarction patients after OHCA[1], primary PCI[2] is generally considered the only option for reperfusion. There are few published studies and no randomized trial has yet been performed in this specific group of patients.

Objectives: To define the demographic, clinical and angiographic characteristics, and the prognosis of STEMI[3] patients undergoing primary PCI after out-of-hospital cardiac arrest.

Methods: We performed a retrospective analysis of medical records and used the prospectively acquired information from the Rambam Primary Angioplasty Registry (PARR) and the Rambam Intensive Cardiac Care (RICCa) databases.

Results: During the period March1998 to June 2006, 25 STEMI patients (21 men and 4 women, mean age 56 ± 11years) after out-of-hospital cardiac arrest were treated with primary PCI. The location of myocardial infarction was anterior in 13 patients (52%) and non-anterior in 12 (48%). Cardiac arrest was witnessed in 23 patients (92%), but bystander resuscitation was performed in only 2 patients (8%). Eighteen patients (72%) were unconscious on admission, and Glasgow Coma Scale > 5 was noted in 2 patients (8%). Cardiogenic shock on admission was diagnosed in 4 patients (16%). PCI procedure was successful in 22 patients (88%). In-hospital, 30 day, 6 month and 1 year survival was 76%, 76%, 76% and 72%, respectively. In-hospital, 30 day, 6 month and 1 year survival without severe neurological disability was 68%, 68%, 68% and 64%, respectively.

Conclusions: In a selected group of STEMI patients after out-of-hospital cardiac arrest, primary PCI can be performed with a high success rate and provides reasonably good results in terms of short and longer term survival.

Background: Magnetic resonance imaging is a diagnostic tool of growing importance. Since its introduction, certain medical implants, e.g., pacemakers, were considered an absolute contraindication, mainly due to the presence of ferromagnetic components and the potential for electromagnetic interference. Patients with such implants were therefore prevented from entering MRI systems and not studied by this modality. These devices are now smaller and have improved electromechanical interference protection. Recently in vitro and in vivo data showed that these devices may be scanned safely in the MRI.

Objectives: To report our initial experience with three patients with pacemakers who underwent cerebral MRI studies.

Methods: The study included patients with clear clinical indications for MRI examination and who had implanted devices shown to be safe by in vitro and in vivo animal testing. In each patient the pacemaker was programmed to pacing-off. During the scan, continuous electrocardiographic telemetry, breathing rate, pulse oximetry and symptoms were monitored. Specific absorption rate was limited to 4.0 W/kg for all sequences. Device parameters were assessed before, immediately after MRI, and 1 week later.

Results: None of the patients was pacemaker dependent. During the MRI study, no device movement was felt by the patients and no episodes of inappropriate inhibition or rapid activation of pacing were observed during the scan. At device interrogation here were no significant differences in device parameters pre-, post-, and 1 week after MRI. Image quality was unremarkable in all imaging sequences used and was not influenced by the presence of the pacemaker.

Conclusion: Given appropriate precautions, MRI can be safely performed in patients with a selected permanent pacemaker. This may have significant implications for current MRI contraindications.