Emergent use of an MRI-conditional external pacemaker in a patient with sinus arrest facilitating diagnosis of a temporal lobe neoplasm

Cardiac Magnetic Resonance Imaging-Based Screening for Cardiac Sarcoidosis in Patients With Atrioventricular Block Requiring Temporary Pacing

Background Some myocardial diseases, such as cardiac sarcoidosis, predispose to complete atrioventricular block. The European Society of Cardiology Guidelines on cardiac pacing in 2021 recommend myocardial disease screening in patients with conduction disorder requiring pacemaker with multimodality imaging, including cardiac magnetic resonance (CMR) imaging. The ability of CMR imaging to detect myocardial disease in patients with a temporary pacing wire is not well documented. Methods and Results Our myocardial disease screening protocol is based on using an active fixation pacing lead connected to a reusable extracorporeal pacing generator (temporary permanent pacemaker) as a bridge to a permanent pacemaker. From 2011 to 2019, we identified 17 patients from our CMR database who underwent CMR imaging with a temporary permanent pacemaker for atrioventricular block. We analyzed their clinical presentations, CMR data, and pacemaker therapy. All CMRs were performed without adverse events. Pacing leads induced minor artifacts to the septal myocardial segments. The extent of late gadolinium enhancement in CMR imaging was used to screen patients for the presence of myocardial disease. Patients with evidence of late gadolinium enhancement underwent endomyocardial biopsy. If considered clinically indicated, also 18-F-fluorodeoxyglucose positron emission tomography and extracardiac tissue biopsy were performed if sarcoidosis was suspected. Eventually, 8 of 17 patients (47.1%) were diagnosed with histologically confirmed granulomatous inflammatory cardiac disease. Importantly, only 1 had a previously diagnosed extracardiac sarcoidosis at the time of presentation with high-degree atrioventricular block. Conclusions CMR imaging with temporary permanent pacemaker protocol is an effective and safe early screening tool for myocardial disease in patients presenting with atrioventricular block requiring immediate, continuous pacing for bradycardia.

Cardiac magnetic resonance imaging in a patient with temporary external pacemaker: a case report

Background 

Magnetic resonance imaging (MRI) is increasingly becoming the imaging modality of choice for many clinical disorders due to superior image quality and absence of radiation. However, access to MRI remains limited for most patients with cardiac implantable electronic devices due to potential safety concerns. In line with guidelines, there is no absolute contraindication to perform MRI, but warrants careful risk-benefit assessment.

Case summary 

A 59-year-old man was admitted with a 5-day history of central chest pain and few week’s history of general malaise, dry cough, and breathlessness. Electrocardiogram confirmed complete atrioventricular block (CAVB). A slight increase in cardiac enzyme was noted. Coronary angiogram revealed atheromatous changes, but no obstructive coronary lesion. A temporary transvenous pacemaker was inserted. Transthoracic echocardiogram confirmed a dilated left ventricle with severely reduced left ventricular function. To facilitate diagnosis (hence prognosis), management and mobilization, investigation with cardiovascular magnetic resonance (CMR) was warranted but contraindicated by the temporary transvenous pacemaker. An active fixation pacemaker lead was therefore placed in the right ventricle via percutaneous puncture of the right subclavian vein and connected to a pulse generator, both secured to the skin with sutures and adhesive medical dressing. Appropriate device programming and close patient monitoring ensured that CMR could be performed without any adverse effects. A diagnosis of acute myocarditis was confirmed. Regular device interrogation during an extended 3-week period with temporary pacing ruled out any device failure. As there was no resolution of CAVB, the patient received a dual-chamber pacemaker.

Discussion 

Cardiovascular magnetic resonance was feasible and safely performed on a patient with a temporary permanent external pacemaker system using a standard screw-in pacing lead and a regular pulse generator fixed to the skin. Although more studies are needed for generalizability, CMR may be used in highly selected patients with a temporary pacemaker.

Clinical experience of magnetic resonance imaging in patients with cardiac pacing devices: unrestricted patient population

Background

Magnetic resonance imaging (MRI) in patients with cardiac pacing devices has become available despite previously being considered absolutely contraindicated. However, most institutional safety protocols have included several limitations on patient selection, leaving MRI unavailable for many patients.

Purpose

To evaluate the first 1000 MRI examinations conducted on patients with cardiac pacing devices at Helsinki University Hospital for any potential safety hazards and also to evaluate the long-term functionality of the safety protocol in “real-life” clinical practice.

Material and Methods

A total of 1000 clinically indicated MRI scans were performed with a 1.5-T MRI scanner according to the safety protocol. The following information was collected from the electronic medical record (EMR): patients’ date of birth; sex; pacing device generator model; date of MRI scan; date of the latest pacing device generator implantation; and the body region scanned. The EMR of these patients was checked and especially searched for any pacing device related safety hazards or adverse outcomes during or after the MRI scan.

Results

Only one potentially dangerous adverse event was noted in our study group. In addition, patients with abandoned leads, temporary pacing devices, and newly implanted pacing device generators were scanned successfully and safely.

Conclusion

MRI scans can be performed safely in patients with cardiac pacing devices if the dedicated safety protocol is followed.