Unexpected Cause for Chest Pain

Abstract

A 71-year-old man was admitted to our hospital with new onset of typical symptoms of angina on exertion corresponding to a Canadian Cardiovascular Society functional class III. The patient had undergone mitral valve replacement with a mechanical bileaflet valve (ATS medical prosthesis, ATS Medical Inc., Minneapolis, Minn.) in December 1997 and transvenous pacemaker implantation for intermittent high-degree atrioventricular node block (Biotronik Philos II DR, ventricular demand inhibited pacemaker mode VVIR0, Biotronik SE & Co. KG, Berlin, Germany) in 2006. Medical history revealed chronic kidney disease and diabetes mellitus. He had chronic atrial fibrillation and was taking oral anticoagulants. The ECG showed discrete ST depression in leads I, II, III, and aVF (Figure 1). Cardiac troponin T on admission was slightly elevated (0.046 ng/mL; reference value at our institution is <0.0014 ng/mL), and his creatine kinase-MB was negative. Anterior-posterior and lateral chest x-ray showed a fracture of the sixth sternal wire with the lateral view showing a protrusion of the cerclage loop into the anterior mediastinum (Figure 2). Transthoracic echocardiography revealed moderately …