Myocardial perfusion scintigraphy before and after cardioversion for atrial fibrillation: Recovery of quantitative parameters

Case presentation. A 54-year-old woman with a history of paroxysmal atrial fibrillation (AF) was referred to our department for myocardial perfusion scintigraphy (MPS) due to suspicion of coronary artery disease. The history revealed several cardioversions and two ablation-procedures for the treatment of AF. Adenosine stress test was used because the b-blockade medication was not stopped before of the exercise test. Prior to the adenosine-stress MPS, the electrocardiogram showed AF with a ventricular rate of 120 beats/minute (bpm) (Figure 1). 712 MBq Tc-tetrofosmin was administrated at the third minute during adenosine infusion (140 lg/kg body weight/minute for 6 min with simultaneous handgrip exercise). During adenosine infusion the patient complained of palpitations; however, no hemodynamic changes and no progression of the initial significant ST-T segment changes were observed. Immediately after acquisition of the images the patient underwent electric cardioversion and was discharged from the hospital the same day with sinus rhythm. Three days later the patient underwent rest MPS during sinus rhythm (60 bpm) (Figure 2). 768 MBq Tc-tetrofosmin was injected and 45 min later rest-images were acquired. Gated myocardial perfusion stressand rest-images were acquired using a three-headed Gamma Camera (GCA-9300, Toshiba, Japan) and analyzed using the 4DM-software (Corridor 4DM, INVIA, Ann Arbor, University of Michigan Medical Center). Perfusion images (both stress and rest) showed slightly decreased tracer uptake anteroseptal due to breast attenuation, but no other abnormalities were observed. The left ventricular ejection fraction (LVEF) was 56% during adenosine-stress and 58% at rest. The left ventricular volumes during adenosine-stress were 86 ml (left ventricular end-diastolic, LVED) and 38 ml (left ventricular end-systolic, LVES), but significantly increased at rest to 137 and 58 ml, respectively (Figure 3). Nine months later, a second MPS at rest was performed during sinus rhythm (55 bpm) to evaluate the functional parameters and volumes. In the time between the two rest MPS studies, the patient did not have any cardioversion or other cardiac intervention. The second MPS study at rest (sinus rhythm) showed a LVEF of 67% with LVED volume of 133 ml and LVES volume of 44 ml. The perfusion images did not show any significant changes. The changes in left ventricular volumes between the 3 MPS acquisitions are displayed in Figure 4. Discussion. AF is the most common arrhythmia and occurs in 0.4% of the general population. Furthermore, the incidence and prevalence increase with the age. Cardioversion of AF is generally performed in an effort to improve cardiac function, to relieve symptoms and to decrease the incidence of thrombus formation. Although left ventricular dysfunction has been shown to improve after cardioversion, it can persist for a few weeks. In this case, we present the effect of cardioversion on left ventricular volumes and ejection fraction shown by MPS. The early and late effects of cardioversion on left ventricle volumes and function has been reported before, using cinematographic breath-hold magnetic resonance imaging and echocardiography. This report showed the shortand long-term effects of cardioversion on left ventricular function by MPS. In this case, myocardial dysfunction is probably due to tachycardia with a ventricular rate of 120 bpm at From the Departments of Nuclear Medicine, and Cardiology Leiden University Medical Center, Leiden, The Netherlands; and Department of Nuclear Medicine, Antoni van Leeuwenhoekhospital, Amsterdam, The Netherlands. Reprint requests: Imad Al Younis, MD, Department of Nuclear Medicine, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands; [email protected]. J Nucl Cardiol 2011;18:192–5. 1071-3581/$34.00 Copyright 2010 The Author(s). This article is published with open access at Springerlink.com doi:10.1007/s12350-010-9299-y