Constrictive Pericarditis Diagnosed by Cardiac Magnetic Resonance Imaging in a Pacemaker Patient
A 71-year-old male was referred for evaluation of 6 months of progressively worsening dyspnea on exertion and peripheral edema, mainly of the legs. During the symptomatic period, he had undergone 3 thoracentesis procedures, each draining more than 1500 mL of transudative fluid. His functional impairment was so severe that he contemplated suicide. His cardiac history was significant for syncope attributable to sinus node dysfunction 19 years earlier, requiring implantation of an atrioventricular pacing system. Because of atrial lead fracture, a second atrial lead had been placed 1 month before the onset of the dyspnea and leg edema. Physical examination revealed diminished breath sounds over both lung fields and moderate (2+) edema of both lower extremities to the level of the knee.
The 12-lead ECG demonstrated normal sinus rhythm at 79 bpm with low-voltage and diffuse ST and T-wave abnormalities (Figure 1). A chest x-ray revealed a dual-chamber permanent cardiac pacemaker, 2 retained leads, and bilateral pleural effusions (Figure 2). Transthoracic and transesophageal echocardiography and invasive cardiac catheterization failed to establish the cause of the patient’s symptoms or define a treatment plan. Multislice computed tomography revealed a thickened pericardium (Figure 3). To establish a definitive diagnosis, a pacemaker cardiac magnetic resonance imaging (MRI) study was performed according to published protocol.1
The MRI showed normal left and right ventricular systolic function, with marked pericardial thickening and adherence of the pericardium to the myocardium over the right and left ventricular apices and along the left lateral wall of the left ventricle (Figure 4). Adherence was confirmed by myocardial tagging (Figure 5). Phase–velocity mapping of the mitral inflow tract was consistent with impaired diastolic filling of the left ventricle (Figure 6). Additionally, an MRI signal-void artifact was noted in the area of the right atrial appendage extending superiorly in the pericardial space along the right lateral wall of the aorta (Figure 7). This finding suggests perforation of the lead into the pericardial space, but because of the magnitude of the lead artifact, lead tip position could not be absolutely located. The patient tolerated the cardiac MRI procedure without clinical sequelae. Pulse-generator function remained unaffected.
Constrictive pericarditis was confirmed at surgery, and a pericardiectomy was performed. Because of the extensive fibrosis around the myocardium, pacemaker lead perforation could not be visually identified. Normal pacemaker function was confirmed in the hospital before surgery. After surgery, the patient had complete resolution of his symptoms and returned to full functional status.
Cardiac MRI has been shown to be useful in the diagnosis of constrictive pericarditis.2,3 Because MRI has been thought to be an absolute contraindication for patients with pacemakers, it usually is not considered as a useful test in this patient population. However, recent studies have suggested that MRI in pacemaker patients may represent only a relative contraindication if previously established protocols are followed.1,4 Patients with retained postsurgical pacing wires have also safely undergone MRI.5 The unique anatomic orientation, soft-tissue characterization, and spatial resolution of MRI make it ideal for evaluation of pericardial disease. In this particular case, an accurate diagnosis was not made by other modalities, necessitating consideration of a cardiac MRI study. Although caution is appropriate, wider use of MRI for pacemaker patients may be justified and necessary to provide optimal patient care.
Dr Martin has received honoraria from GE Medical Systems and the Guidant Corporation. Dr Mikolich has received honoraria from GE Medical Systems.
The online-only Data Supplement, consisting of Movies I through III, is available with this article at http://circ.ahajournals.org/cgi/content/full/115/7/e191 /DC1.