Single ventricle with persistent truncus arteriosus as two rare entities in an adult patient: a case report

As a child, the patient had normal growth and mental development, but marked cyanosis, weakness, clubbing, and intolerance of moderate physical activity. The patient was referred to a medical institute in Moscow at age 18, after several episodes of syncope. A diagnosis of severe pulmonary stenosis with ventricular septal defect was considered at that time. A right Blalock-Taussig shunt was performed. The postoperative diagnosis was single ventricle type BIII with severe pulmonary artery stenosis and hypoplasia. After surgery, the patient was treated with digoxin, pentoxifylline, and spironolactone. The patient's condition improved significantly and he was able to walk several blocks without significant dyspnea.

The patient's condition remained stable for the next five years. He had shortness of breath with moderate exertion, but he was asymptomatic at rest. At 27 years of age, the patient reported an increase in dyspnea with minimal exertion. He was diagnosed with thrombosis of the Blalock-Taussig anastomosis and was treated with heparin for 4 weeks. He never returned to his improved, postoperative condition. He complained of palpitations, dull chest pain at rest, episodes of shortness of breath at rest, and abdominal pain. The patient had several documented episodes of ventricular tachycardia at age 35 years and was successfully treated with propafenone.

At 39 years of age, the patient presented to our hospital in Belarus. At the time of presentation, he complained of severe cyanosis, shortness of breath with minimal exertion, and chest pain. An electrocardiogram indicated sinus tachycardia of 120 beats per minute. The QRS axis was to the right (mean axis +130°). High QRS voltage suggestive of ventricular hypertrophy was noted. There were also ventricular extrasystoles in a trigeminal pattern and horizontal ST-segment depression in the inferior leads. A 24-hour cardiac monitor showed multiple episodes of non-sustained ventricular tachycardia with subjective feelings of palpitation and lightheadedness. The patient was switched empirically from propafenone to mexiletine with better control of his ventricular tachycardia. His hematocrit was 58% to 64%. Transcutaneous oxygen saturation was 75% to 85% on room air. The patient could tolerate well most of his daily activities such as walking for two blocks, grocery shopping, and performing minor work at home. Over the next 6 years he had repeated hospitalizations for dyspnea, chest pain, and near syncope. He was treated with phlebotomies, saline and/or dextran infusions to improve viscosity, and medications including spironolactone, pentoxifylline, and aspirin.

At the time of the terminal hospitalization, physical examination was remarkable for a 3/6 systolic murmur heard at the upper left sternal border, edema of the right ankle and foot, and tachycardia of 140 beats per minute. The patient was noted to experience severe shortness of breath with even minimal exertion and was deeply cyanotic. The electrocardiogram is shown in Figure 1 and demonstrated sinus rhythm with a mild tachycardia at a rate of 110 beats per minute, right axis deviation, and a non-specific intraventricular conduction delay with diffuse ST-T changes. Chest radiograph indicated a small pleural effusion on the right and increased pulmonary vascularity. The heart was moderately enlarged with prominence of the aorta. An echocardiogram was performed (Figure 2). A single ventricle with unremarkable atrioventricular valves was seen. The end diastolic diameter of the ventricle was measured as 69 mm, the posterior wall thickness was 17 to 19 mm, and the left atrium measured 29 mm. The estimated ejection fraction was 45% to 50%. A vessel with a semilunar valve (the truncal valve) arising from the ventricle was seen. The cusps of the valve were hyperechogenic. Moderate regurgitation was noted. No pulmonary artery was seen. Doppler study of the lower extremities showed thrombosis in the veins of the right calf. Heparin therapy and intravenous fluids were initiated. The patient's condition deteriorated rapidly and several hours later he became comatose and died.