Acute cardiac arrest in a patient with oculodentodigital dysplasia (QF_TH_071)

A 17-year-old female with history of syndactyly reported feeling unwell during basketball practice and experienced cardiac arrest. CPR was started and an AED was placed. She was in ventricular fibrillation, received 7 defibrillations, and was transported to her local medical center. There she received antiarrhythmics, inotropes and 5 more cardioversion attempts before she was converted to sinus rhythm. She had significantly elevated BNP (1264 pg/mL, normal 0-100) and troponin (17,428 ng/L, normal ≤ 27). An echocardiogram revealed severe biventricular dysfunction.

In her work-up for sudden cardiac death, a CT was obtained and revealed normal coronary anatomy. By history, she had a normal echocardiogram, ECG, and Holter monitor a year prior after being seen by a cardiologist for bradycardia. Her family history was significant for oculodentodigital dysplasia (ODDD) in multiple family members, an uncle with sudden cardiac death at an early age, and a 1^st cousin who require an ICD.

Diagnostic Techniques and Their Most Important Findings:

To investigate for myocarditis and myopathies, cardiac MRI was obtained a week after hospitalization. Cine GRE imaging revealed moderately depressed left ventricular systolic function (LVEF 43%) with mild hypokinesis of the lateral and apical walls. There was low normal right ventricular systolic function (RVEF 47%). Rest perfusion imaging revealed no perfusion defect. On late gadolinium imaging there was apical thinning with near transmural hyperenhancement. < ![if !supportAnnotations] >[YC1]< ![endif] > Prior to discharge, genetic testing showed a mutation in the GJA1 gene, consistent with oculodentodigital dysplasia. The patient was discharged home without significant neurologic deficits.
 

Learning Points from this Case:

ODDD is a rare syndrome caused by mutations in the GJA1 gene. Phenotypic expression is characterized by a variable phenotype including dysmorphic facial features, ocular and dental anomalies, syndactyly and neurologic changes.  GJA1 encodes gap junction protein connexin-43 which has an essential role in action potential propagation within the heart. Cardiac findings have included patients with arrythmias, dilated cardiomyopathy, and sudden cardiac death.
This is the first report of cardiac MRI findings in ODDD. In this patient with aborted sudden cardiac death, late gadolinium enhancement and T1 mapping demonstrated near transmural fibrosis circumferentially from the mid left ventricle to the apex. The identification of ODDD patients at risk for sudden cardiac death is challenging, as demonstrated in this case with a reassuring echo, ECG, and Holter a year prior to presentation. The identification of ODDD patients with myocardial fibrosis may allow clinicians to risk stratify these patients appropriately and assist in assessing the need for ICD in this population.  Cardiac MRI should be considered as a screening tool for sudden cardiac death risk in ODDD patients.