Deactivation vs. asynchronous pacing - prospective evaluation of a protocol for rhythm management in patients with magnetic resonance conditional pacemakers undergoing adenosine stress cardiovascular magnetic resonance imaging

Abstract

Background: Cardiovascular Magnetic Resonance (CMR) imaging with adenosine stress is an important diagnostic tool in patients with known or suspected coronary artery disease (CAD). However, the method is not yet established for CAD patients with pacemakers (PM) in clinical practice. A possible reason is that no recommendations exist for PM setting (paused pacing or asynchronous mode) during adenosine stress. We elaborated a protocol for rhythm management in clinical routine for PM patients that considers heart rate changes under adenosine using a test infusion of adenosine in selected patients. Methods: 47 consecutive patients (mean age 72.3 ± 10,0 years) with MR conditional PM and known or suspected CAD who underwent CMR in clinical routine were studied in this prospective observational study. PM indications were sinus node dysfunction (SND, n = 19; 40,4%), atrioventricular (AV) block (n = 26; 55.3%) and bradyarrhythmia in permanent atrial fibrillation (AF, n = 2; 4.3%). In patients with SND, normal AV-conduction and resting HR >45 bpm at the time of CMR and in AF the PM was deactivated for the scan. In intermittent AV-block a test infusion of adenosine was given prior to the scan. All patients with permanent higher degree sinuatrial or AV-block or deterioration of AV-conduction in the adenosine test were paced asynchronously during CMR, in patients with preserved AV-conduction under adenosine the pacemaker was deactivated. CMR protocol included cine imaging, adenosine stress perfusion and late gadolinium enhancement. Results: The adenosine test was able to differentiate between mandatory PM stimulation during CMR and safe deactivation of the device. In patients with permanent sinuatrial or AV-block (n = 11; 23.4%) or deterioration of AV conduction in the adenosine test (n = 5, 10.6%) asynchronous pacing above resting heart rate did not interfere with intrinsic rhythm, no competitive stimulation was seen during the scan. 10 of 15 (66,7%) patients with intermittent AV-block showed preserved AV-conduction under adenosine. As in SND and AF deactivation of the PM showed to be safe during CMR, no bradycardia was observed.

Occupational Exposure to Electromagnetic Fields and Health Surveillance according to the European Directive 2013/35/EU

“…In cases of the appearance of interference, usually only older devices—e.g., in the case of pacemakers those with unipolar configurations, and only in case of quite relevant exposure levels, e.g., determined by close proximity with a welding cable or with an electronic article surveillance gate—can be affected [ 28 ]. Nevertheless, in cases of quite high EMF exposure levels, as e.g., in the case of operators working close to a MRI scanner, newer devices can also have interference problems, and this is the reason why even patients with an MRI-conditional AIMD need an appropriate setting for their devices when undergoing a procedure [ 29 , 30 ].…”

Feasibility of adenosine stress cardiovascular magnetic resonance perfusion imaging in patients with MR-conditional transvenous permanent pacemakers and defibrillators

“…However, data on the safety of stress CMR in these patients is scarce, particularly for patients paced during the vasodilator stress test. Klein-Wiele et al did not report relevant safety issues in a small cohort of 16 patients who were paced during adenosine infusion [ 13 ]. Our data on 66 patients, including 30 with implanted ICDs, are confirm this observation, as no pacing-related side effects occurred, i.e.…”

“…no pacing interference with the intrinsic rhythm, no competitive stimulation, no bradycardia and asystole. In line with the results reported in a testing protocol to identify patients at risk of adenosine-induced deterioration of AV-blocks [ 11 – 13 ], we decided to systematically pace all patients with > 1% of pacing as documented on the pre-CMR device interrogation. With this easily applicable approach, no adverse arrhythmic events occurred during the adenosine stress perfusion CMR examinations.…”

“…However, the application of adenosine stress-CMR in patients implanted with MR-conditional devices has only been investigated in a limited number of studies [ 11 , 12 ]. Pezel et al showed that patients with PPMs without inducible ischemia or late gadolinium enhancement (LGE) had a very low cumulative rate (0.9%) of major adverse cardiovascular events (MACE) over a 7-year follow-up [ 13 ] demonstrating the good prognostic value of stress perfusion CMR. Despite these results, the use of stress perfusion CMR in this population remains limited, mainly due to the possible occurrence of artefacts related to the metallic components of the devices and to the risk of adenosine interaction with cardiac pacing.…”

“…Despite these results, the use of stress perfusion CMR in this population remains limited, mainly due to the possible occurrence of artefacts related to the metallic components of the devices and to the risk of adenosine interaction with cardiac pacing. It is worth mentioning that asynchronous pacing above resting heart rate (HR) during adenosine stress CMR as suggested by Klein-Wiele et al was not found to interfere with the intrinsic cardiac rhythm [ 12 , 13 ]. Although patients with cardiac conduction disorders may frequently suffer from underlying or concomitant coronary artery disease (CAD) [ 14 ], only a limited number of patients with atrioventricular (AV)-block requiring continuous pacing during adenosine stress-CMR have been reported (< 8 patients) [ 11 – 13 ].…”