Welcome to Touch Briefings

David J Nicholson, Edward L Passen and Samuel Wann
American Heart Hospital Journal Volume 8 No.1

A 53-year-old with a history of surgically corrected tetralogy of Fallot (TOF) presented with dyspnea, fatigue, and increased abdominal girth. The patient was cyanotic as an infant and underwent a palliative left Blalock-Taussig (BT) shunt. At eight years of age he underwent corrective surgery with patch repair of a ventricular septal defect and resection of the infundibular region of the right ventricular (RV) outflow tract. The BT shunt was ligated at that time. The patient did well until 2007, when he developed atrial dysrhythmias that were recalcitrant to medical therapy. Ultimately, the patient underwent atrioventricular nodal ablation and bi-ventricular pacemaker placement.

Examination revealed a cachectic-appearing male who was mildly dyspneic at rest. Jugular venous distension was prominent. The lungs were clear to auscultation. Cardiac examination revealed diminished S1 with S3 present. A blowing 2/6 holosystolic murmur and a rumbling 2/4 diastolic murmur were heard at the left lower sternal border. There was a 2/6 holosystolic murmur at the apex. The abdomen was distended with prominent ascites. No peripheral edema was present.

An electrocardiogram (ECG) revealed atrial fibrillation with intrinsic atrioventricular conduction and intermittent ventricular paced complexes. An echocardiogram was performed and demonstrated a dilated and hypokinetic right ventricle by M-mode and 2D assessment. No residual RV outflow tract gradient was identified. There was moderate to severe pulmonic valve insufficiency with an estimated pulmonary artery diastolic pressure of 31mmHg. There was also severe tricuspid valve insufficiency with a peak regurgitant velocity of 5.7m/sec, consistent with pulmonary artery hypertension. There was mild aortic and mitral valve insufficiency with mildly depressed left ventricular (LV) systolic function.

Further imaging of RV size and function was requested for potential surgical replacement of the pulmonic valve. Cardiac magnetic resonance (CMR) imaging is considered the gold standard for evaluation of RV chamber size and function in congenital heart disease.¹ Unfortunately, the patient had a bi-ventricular pacemaker, which is a relative contraindication to CMR. The patient was referred for cardiac multidetector computed tomography (MDCT) since recent studies have demonstrated agreement and correlation between cardiac MDCT and CMR in assessing RV size and ejection fraction.^2,3 MDCT provided additional information regarding coronary anatomy and post-TOF repair cardiac anatomy, which is essential for surgical planning. The MDCT protocol for this case was complex due to congenital heart disease with multiple prior cardiac surgeries and atrial fibrillation with irregular R-R intervals with intermittent ventricular pacing. Metoprolol, 100mg by mouth, was given two hours before the scan. Diltiazem, 20mg intravenously (IV), was administered prior to the scan.

View Article here