Number 10-21: Role of CMR in the diagnosis of ARVC
Case from: Andreas Schuster, Amedeo Chiribiri, Eike Nagel Institution: King's College London BHF Centre of Excellence, Division of Imaging Sciences, NIHR Biomedical Research Centre at Guy's and St. Thomas' NHS Trust Foundation, Wellcome Trust EPSRC Medical Engineering Centre; The Rayne Institute, St. Thomas' Hospital, London, United Kingdom.
Clinical history: A 78 year old patient was admitted to the Accident and Emergency department with a syncope. The ECG on admission showed a broad complex tachycardia (left bundle-branch morphology with superior axis) with a rate of 230 bpm, necessitating DC cardioversion under sedation. The patient reported a 3 week history of dizziness and palpitations. Further investigation by cardiac MRI was requested.
Movie 1 Movie 2
Movie 3 Movie 4
CMR: There is reduced image quality due to multiple ventricular extra systoles. Movies 1-4 show standard projections for the assessment of ARVC: Cine SSFP 4-Chamber View (Movie 1), RVOT View (Movie 2), SA-View (Movie 3), and straight transverse view (Movie 4). There is reduced ejection fraction of the dilated right ventricle (RV-EF: 32%, RV-EDV 135 ml/m2). There is regional akinesia/dyskinesia seen in the RV free wall and the RVOT. There is normal left ventricular systolic function of the normal sized left ventricle.
The tricuspid and pulmonary valves are competent and there is no evidence of a left to right shunt on the velocity encoded images: Qp/Qs 1.1. Similarly, there is no evidence of pulmonary hypertension, underlying lung disease or cor pulmonale.
In the LGE images, there is no late myocardial enhancement (Figure 1) which allows to reasonably exclude the presence of coronary artery disease with RV infarct as an alternative diagnosis for the RV dysfunction and regional wall motion abnormalities observed.
Diagnosis: The CMR images fulfill one major criterion of ARVC: "Regional RV akinesia or dyskinesia or dyssynchronous RV contraction and 1 of the following: Ratio of RV end-diastolic volume to BSA ≥ 110 mL/m2 (male) or ≥ 100 mL/m2 (female) or RV ejection fraction ≤ 40%." The ECG at admission fulfilled a second major criterion: "Nonsustained or sustained ventricular tachycardia of left bundle-branch morphology with superior axis (negative or indeterminate QRS in leads II, III, and aVF and positive in lead aVL)."1
Based on this evidence, the diagnosis of ARVC was made in this case. The patient underwent subsequent ICD implantation.
Perspective: The original 1994 International Task Force criteria for the clinical diagnosis of ARVC were based on structural, histological, ECG, arrhythmic, and familial features of the disease2. Abnormalities were subdivided into major and minor categories according to the specificity of their association with ARVC. These task force criteria have been recently revised1. According to the revised criteria a definite diagnosis can be made in presence of 2 major or 1 major and 2 minor criteria or 4 minor from different categories. Borderline are cases in presence of 1 major and 1 minor or 3 minor criteria from different categories; Possible are cases in presence of 1 major or 2 minor criteria from different categories.
ICD therapy is increasingly used for secondary and also primary prevention of sudden death in patients with ARVC. However, prospective evidence based on randomized trials is lacking. Patients with ARVC have a high recurrence of VT suggesting that ICD therapy improves long-term prognosis and survival. However, prophylactic ICD may not be indicated in asymptomatic patients because of their low arrhythmic risk regardless of familial sudden death.3
1. Marcus FI, McKenna WJ, Sherrill D, Basso C, Bauce B, Bluemke DA, Calkins H, Corrado D, Cox MGPJ, Daubert JP, Fontaine G, Gear K, Hauer R, Nava A, Picard MH, Protonotarios N, Saffitz JE, Sanborn DMY, Steinberg JS, Tandri H, Thiene G, Towbin JA, Tsatsopoulou A, Wichter T, Zareba W. Diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia: proposed modification of the task force criteria. Circulation. 2010;121(13):1533-1541.
2. McKenna WJ, Thiene G, Nava A, Fontaliran F, Blomstrom-Lundqvist C, Fontaine G, Camerini F. Diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy. Task Force of the Working Group Myocardial and Pericardial Disease of the European Society of Cardiology and of the Scientific Council on Cardiomyopathies of the International Society and Federation of Cardiology. Br Heart J. 1994;71(3):215-218.
3. Corrado D, Calkins H, Link MS, Leoni L, Favale S, Bevilacqua M, Basso C, Ward D, Boriani G, Ricci R, Piccini JP, Dalal D, Santini M, Buja G, Iliceto S, Estes NA 3rd, Wichter T, McKenna WJ, Thiene G, Marcus FI. Prophylactic implantable defibrillator in patients with arrhthmogenic right ventricular cardiomyopathy/dysplasia and no prior ventricular fibrillation or sustained ventricular tachycardia. Circulation 2010. In press.
4. Riley MP, Zado E, Bala R, Callans DJ, Cooper J, Dixit S, Garcia F, Gerstenfeld EP, Hutchinson MD, Lin D, Patel V, Verdino R, Marchlinski FE. Lack of uniform progression of endocardial scar in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy and ventricular tachycardia. Circ Arrhythm Electrophysiol. 2010;3(4):332-8.