Transposition With Mustard Operation Patient With Risk of Sudden Death: Case submitted by Jim T. Vehmeijer, MD, Barbara J.M. Mulder, MD, PhD, Joris R. de Groot, MD, PhD

Case Synopsis

A 37-year-old man with transposition of the great arteries (TGA), ventricular septal defect (VSD), and pulmonary valve stenosis presented with a history of Mustard repair, surgical VSD closure, and pulmonary valvulotomy. Because of sick sinus syndrome and intermittent complete atrioventricular (AV) block he underwent permanent pacemaker implantation in 2006. Atrial and ventricular leads were routed via the systemic venous baffle to the left atrium and—subpulmonary—left ventricle, respectively. Fig. 11.1 displays an electrocardiogram showing left atrial and left ventricular pacing.

Over the years, his systemic right ventricle deteriorated (ejection fraction 20%), partly due to an inferior wall myocardial infarction with right ventricular (RV) involvement. This infarction was ascribed to embolization of a thrombus in the systemic right ventricle. In addition, moderate to severe tricuspid regurgitation was present, but surgical intervention was deemed to be too great of a risk. In 2009 he was diagnosed with atrial tachycardia, which converted to sinus rhythm with atrial antitachycardia pacing. Sotalol was started, but resulted in heart failure symptoms necessitating intravenous diuretic treatment, and was thus discontinued.

After a period of relative stability, he presented in 2014 with dyspnea, fever, and leukocytosis. The diagnosis was pneumonia, for which antibiotic therapy was started. During this period he also experienced syncope, which was attributed to a ventricular arrhythmia, particularly because of observed nonsustained ventricular tachycardia in the presence of poor systemic RV function. Therefore, an implantable cardioverter-defibrillator (ICD) implantation was considered. However, the addition of ICD leads through the systemic venous baffle was thought to be a risk for the development of baffle obstruction. After the signs of infection had dissipated, he underwent implantation of a subcutaneous implantable cardioverter-defibrillator (S-ICD), which was placed under the left serratus muscle ( Fig. 11.2 ). S-ICD sensing was accurate, during both normally conducted rhythm and during ventricular pacing, and there were no signs of pocket infection.

One week after discharge, the patient was readmitted with fever and chills. Again, there were no signs of S-ICD pocket infection. Transthoracic and transesophageal ultrasound revealed a long vegetation on one of the intracardiac pacemaker leads ( Fig. 11.3 ). After treatment for endocarditis was started with broad-spectrum antibiotics, blood cultures showed Propionibacterium acnes , and the antibiotic treatment was narrowed to penicillin, 2 million international units, 6 times daily, which was continued for 6 weeks. The anticipated high risk of intra- and periprocedural complications precluded lead extraction. As the PET-CT showed no signs of inflammation afterward, the patient was discharged in relatively good clinical condition. However, 1 week later he presented with chest pain, dyspnea, and general discomfort. Multiple pulmonary emboli were visible on CT scan, ascribed to a flare-up of the lead endocarditis. The patient's condition deteriorated due to a combination of endocarditis, pulmonary emboli, and therapy-resistant systemic RV failure. Eventually, the ICD was turned off, and together with the patient and his family, a choice was made to provide comfort care without further medical intervention. The patient passed away in his sleep.