Where do we go from here? Beyond the MagnaSafe trial: A focus beyond a 'safety-first' notion. An MRI study in 500 consecutive patients.

BACKGROUND: In patients with conventional pacemakers or ICD's, MRI is infrequently performed due to safety concerns. Recent reports have allayed many of these concerns. However, the additive clinical value of scanning patients with cardiac implants has not been established. OBJECTIVE: Assessing the additive value of thoracic and non-thoracic MRI in patients with implantable cardiac devices. METHODS AND RESULTS: Prospective data were analyzed in 500 patients with implanted cardiac devices that underwent MRI over a 12 year period at a single institution (Allegheny General Hospital, Pittsburgh, PA). A set of three questions were answered following scan interpretation by both the MRI technologist and interpreting MRI physician(s): 1) Did the primary diagnosis change? 2) Did MRI provide additional information to the existing diagnosis? 3) Did patient management change? If 'Yes' was answered to any of the above questions, it was considered that the MRI scan was of value to patient diagnosis and/or guiding therapy. Scans encountered were neurological/neurosurgical 354 (70.8%), cardiac 98 (19.6%) and orthopedic 48 (9.6%) in nature. In 431 (86%) MRI added additional information to the primary diagnosis and in 277 (55.4%) MRI changed the primary diagnosis. In 304 (60.8%) cases management changed, 265 (53%) due to a change in diagnosis and in 39 (7.8%) due to providing additional information. No safety issues were encountered and no adverse effects of MRI scan were noted. CONCLUSIONS: MRI in patients with implanted cardiac devices was of additive value to diagnosis and management thereby informing risk-benefit considerations. CONDENSED ABSTRACT: 500 patients with implanted cardiac devices who underwent a MRI examination over a 12 year period were followed prospectively. Imaging primarily focus on three anatomical regions (neurological/neurosurgical, cardiac and orthopedic) providing added information to the primary diagnosis in 431 (86%) cases and changing the primary diagnosis in 277 (55.4%) cases. In 304 (60.8%) cases management changed with 265 (53%) being due to a change of diagnosis and in 39 (7.8%) due to providing additional information. No safety issues were encountered using a defined protocol. CONCLUSIONS: MR imaging retains its diagnostic yield in patients with implanted devices.

Diagnostic Value of MRI in Patients With Implanted Pacemakers and Implantable Cardioverter-Defibrillators Across a Cross Population: Does the Benefit Justify the Risk? A Proof of Concept Study.

OBJECTIVES: The objective of this study was to assess the diagnostic usefulness of thoracic and nonthoracic magnetic resonance imaging (MRI) imaging in patients with implantable cardiac devices (permanent pacemaker or implantable cardioverter-defibrillators [ICDs]) to determine if there was a substantial benefit to patients with regard to diagnosis and/or management. BACKGROUND: MRI is infrequently performed on patients with conventional pacemakers or ICDs. Multiple studies have documented the safety of MRI scans in patients with implanted devices, yet the diagnostic value of this approach has not been established. METHODS: Evaluation data were acquired in 136 patients with implanted cardiac devices who underwent MRIs during a 10-year period at a single institution. Specific criteria were followed for all patients to objectively define if the diagnosis by MRI enhanced patient care; 4 questions were answered after scan interpretation by both MRI technologists and MRI physicians who performed the scan. 1) Did the primary diagnosis change? 2) Did the MRI provide additional information to the existing diagnosis? 3) Was the pre-MRI (tentative) diagnosis confirmed? 4) Did patient management change? If "Yes" was answered to any of the preceding questions, the MRI scan was considered to be of value to patient diagnosis and/or therapy. RESULTS: In 97% (n = 132) of patients, MR added value to patient diagnosis and management. In 49% (n = 67) of patients, MRI added additional valuable information to the primary diagnosis, and in 30% (n = 41) of patients, MRI changed the principle diagnosis and subsequent management of the patient. No safety issues were encountered, and no adverse effects of undergoing the MRI scan were noted in any patient. CONCLUSIONS: MRI in patients with implanted pacemakers and defibrillators added value to patient diagnosis and management, which justified the risk of the procedure.

Iatrogenic Transient Complete Heart Block in a Preexisting LBBB.

Catheter induced cardiac arrhythmia is a well-known complication encountered during pulmonary artery or cardiac catheterization. Injury to the cardiac conducting system often involves the right bundle branch which in a patient with preexisting left bundle branch block can lead to fatal arrhythmia including asystole. Such a complication during central venous cannulation is rare as it usually does not enter the heart. The guide wire or the cannula itself can cause such an injury during central venous cannulation. The length of the guide wire, its rigidity, and lack of set guidelines for its insertion make it theoretically more prone to cause such an injury. We report a case of LBBB that went into transient complete heart block following guide wire insertion during a central venous cannulation procedure.