|Number 15-01: Early Recognition of Hypertrophic Cardiomyopathy Phenotype by CMR.|
Number 15-01: Early Recognition of Hypertrophic Cardiomyopathy Phenotype by CMR.
Case from: Arun Dahiya1,2, Mark Hansen3, Bruno Jesuthasan1,Prasad Challa1
2Royal Brisbane and Women’s Hospital, Queensland Australia
3Qscan Radiology, Queensland, Australia
Clinical history: A 16-year-old boy was found to have an abnormal ECG (Figure 1) during his appendectomy surgery. His background was remarkable for a small muscular VSD, which had undergone spontaneous closure on an echocardiogram performed two years prior. His father had a history of hypertrophic obstructive cardiomyopathy resulting in severe LV systolic dysfunction and requiring heart transplantation. The patient’s echocardiogram and electrocardiograms (Figure 2) performed 2 years ago were not diagnostic of hypertrophic cardiomyopathy. However on this occasion his abnormal ECG led to an Echo followed by CMR. Echo showed mild prominence of the septum and raised the possibility of HCM. Therefore CMR was performed for further delineation.
Figure 1. ECG was borderline for LVH by voltage criteria and showed deep t inversion the infero-lateral leads
Figure 2. ECG 2 years ago.
CMR Findings: CMR showed asymmetrical hypertrophy of the basal infero-septum (1.6cm, LV mass 60g/m2) with deep intramuscular crypts predominantly involving the infero-septum, inferior wall and anterior wall (Movies 1-4). Overall LV systolic function was normal. Papillary muscles were normal in thickness with normal attachments. There was no LVOT obstruction and there was no obvious VSD seen on this study.
Movie 1 - Two chamber SSFP. Movie 2 - Three chamber SSFP.
Movies demonstrate asymmetrical hypertrophy of the basal infero-septum with deep intramuscular crypts predominantly involving the infero-septum, inferior wall and anterior wall. Normal aspect of papillary muscles. Movie 2 further demonstrates absence of LVOT obstruction.
Movie 3 - Four chamber SSFP. Movie 4 - Short-axis SSFP.
Movies demonstrate normal LV systolic function. No obvious VSD seen on these images.
Four chamber perfusion revealed no obvious communication between the left and right (Movie 5). Furthermore flow quantification through pulmonary artery and aorta were not suggestive of significant intra-cardiac shunting (Figure 3).
Movie 5. Four chamber perfusion demonstrating no obvious communication between the left and right ventricle.
Figure 3. Phase contrast flow quantification.
Post-gadolinium delayed enhancement imaging revealed focal area fibrosis in the thickened septum (Figure 4 and 5).
Figure 4. 2D inversion recovery (LGE) in short-axis view demonstrating focal pattern of delayed enhancement in the infero-septal region
Figure 5. 2D inversion recovery (LGE) in four chamber view demonstrating a focal pattern of delayed enhancement in the septal region.
Conclusion: These findings were consistent with early phenotypic manifestation of HCM in a patient with a family history of HCM. Therefore CMR provided incremental information, which was crucial towards ongoing care of this patient. Subsequent to this study patient was diagnosed with HCM and his family was referred for genetic testing. Results of genetic testing are pending. Patient is not considered for ICD at this stage, as he didn’t have other high-risk features for sudden cardiac death but will be under ongoing surveillance. He was previously involved in active sports therefore it was recommended for him to follow recreational (Noncompetitive) sports activities and exercise guidelines as per the latest AHA/ACCF document.
COTW handling editor: Pranav Bhagirath
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