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

Feasibility of cardiac magnetic resonance imaging in temporary permanent pacemaker implants in pediatric myocarditis and complete atrioventricular block

Background

Diagnosing myocarditis in children presenting with complete AV block (CAVB) is challenging. Temporary permanent pacing support using standard transvenous active fixation lead can be inserted percutaneously until recovery. However, access to cardiac magnetic resonance (CMR) imaging may be limited due to safety concerns.

Cases

We report three cases where CMR was performed using temporary permanent pacemaker in situ. We evaluated the effect of device artefacts on image quality and examined any instances of device malfunction.

Conclusion

In children with CAVB and myocarditis, a temporary permanent pacemaker can provide reliable pacing until recovery, and CMR can be safely performed with the implanted pacemaker without compromising image quality.

Magnetic resonance imaging in patients with temporary external pacemakers

AIMS

To describe safety and feasibility of magnetic resonance imaging (MRI) in patients with transvenous temporary external pacemakers and whether artefacts affect the diagnostic image quality during cardiac MRI.

METHODS AND RESULTS

We reviewed records of all patients treated with temporary external pacing between 2016 and 2020 at a tertiary centre. Temporary pacing was established using a transvenous standard active fixation pacing lead inserted percutaneously and connected to a MRI-conditional pacemaker taped to the skin. All patients undergoing cardiac or non-cardiac MRI during temporary transvenous pacing were identified. Before MRI, devices were programmed according to guidelines for permanent pacemakers, and patients were monitored with continuous electrocardiogram during MRI. Of 827 consecutive patients receiving a temporary external pacemaker, a total of 44 (5%) patients underwent MRI (mean age 71 years, 13 [30%] females). Cardiac MRI was performed in 22 (50%) patients, while MRI of cerebrum, spine, and other regions was performed in the remaining patients. Median time from implantation of the temporary device to MRI was 6 (3-11) days. During MRI, we observed no device-related malfunction or arrhythmia. Nor did we detect any change in lead sensing, impedance, or pacing threshold. We observed no artefacts from the lead or pacemaker compromising the diagnostic image quality of cardiac MRI. MRI provided information to guide the clinical management in all cases.

CONCLUSION

MRI is feasible and safe in patients with temporary external pacing established with a regular MRI-conditional pacemaker and a standard active fixation lead. No artefacts compromised the diagnostic image quality.

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.

2020 MR Safety for Cardiac Devices: An Update for Radiologists

Magnetic resonance imaging (MRI) is a unique and powerful diagnostic tool that provides images without ionizing radiation and, at times, can be the only modality to properly assess and diagnose some pathologies. Although many patients will need an MRI in their lifetime, many of them are still being unjustly denied access to it due to what were once considered absolute contraindications, including MR nonconditional pacemakers and implantable cardioverter-defibrillators. However, there are a number of large studies that have recently demonstrated that MRI can safely be performed in these patients under certain conditions. In addition, there are an increasing number of novel cardiac devices implanted in patients who may require an MRI. Radiologists need to familiarize themselves with these devices, identify which patients with these devices can safely undergo MRI, and under which conditions. In this article, we will review the current literature on MR safety and cardiac devices, elaborate on how to safely image patients with cardiac devices, and share the expertise of our tertiary cardiac institute.