Quick Fire Cases
Bijia Shi, MBChB, PhD
Advanced Cardiac Imaging Fellow
University of British Columbia, Canada
Bijia Shi, MBChB, PhD
Advanced Cardiac Imaging Fellow
University of British Columbia, Canada
John K. Khoo, MD
Advanced Cardiac Imaging Fellow
University of British Columbia, Canada
Fionn Coughlan, MD
Advanced Cardiac Imaging Fellow
University of British Columbia, Canada
Aisha Ferkh, MD, PhD
Advanced Cardiac Imaging Fellow
University of British Columbia, Canada
Bijia Shi, MD, PhD
Advanced Cardiac Imaging Fellow
University of British Columbia, Canada
Philipp Blanke, MD
Associate Professor
University of British Columbia, Canada
Jonathon Leipsic, MD
Head Department of Radiology
University of British Columbia, Canada
A 72-year-old female presented to the adult congenital heart clinic with chief complaint of shortness of breath on exertion. The patient reported having been diagnosed with an unspecified congenital heart disease during her childhood in Hong Kong. At that time, she was told that surgical repair was unnecessary. She has always had difficulty walking up hills or stairs and becomes short of breath on exertion. As a teenager, she had a cardiac catheterization and was again advised against surgery.
The patient is unable to climb hills or stairs. She experiences shortness of breath when attempting to run. She has no recollection of having experienced blue spells. She denies the presence of angina, orthopnea, paroxysmal nocturnal dyspnea, edema, palpitations, or syncope.
Diagnostic Techniques and Their Most Important Findings:
Cardiac MRI was performed at our institution on a 1.5 T scanner (GE HealthCare, Chicago, USA) using a standard adult congenital heart protocol. MRI demonstrated a membranous VSD, overriding aorta, severe right ventricular hypertrophy with preserved RVEF (68%), and combined severe RVOT obstruction and pulmonic stenosis consistent with unrepaired tetralogy of Fallot (TOF) (Figure 1-3). Right heart catheterization revealed a peak RVOT pressure gradient of more than 100 mmHg. Phase contrast imaging showed no significant left-to-right shunting across the VSD (Qp:Qs 1.09).
The main pulmonary artery was dilated to a maximum diameter of 36 mm. No extracardiac shunts were found. After multidisciplinary discussion, RVOT patch repair and bioprosthetic pulmonary valve replacement were recommended to prevent right ventricular failure. The patient declined surgery.
Learning Points from this Case:
TOF is the most common cyanotic congenital heart defect. Individuals with unrepaired TOF rarely reach adulthood, with a survival rate for untreated patients over the age of 40 estimated to be less than 3%. To date, there have been fewer than ten case reports published in the literature of patients with unrepaired TOF who are older than 70 years of age. The reason for the prolonged preservation of cardiac function in this case remains unclear. However, it may be attributed to a gradual development of right ventricular outflow tract (RVOT) stenosis and a relatively small ventricular septal defect (VSD) size. Cardiovascular magnetic resonance has established its role as the reference standard imaging modality to assess anatomy and cardiac function in patients with repaired TOF. Although MRI cases of unrepaired TOF in adults remain the exception, it is important to be familiar with their typical imaging findings, as shown in this case, to help guide clinical management and decision making.
