'The imitation game': a heart failure case report with a great diagnostic twist.

Background: Arrhythmogenic ventricular cardiomyopathy (AVC) is a hereditary cardiomyopathy that has been associated with mutations in genes encoding for components of the cardiac desmosome including desmoglein-2 (DSG-2). Case summary: A 49-year-old male presented with decompensated heart failure and ventricular arrythmias. A cardiac magnetic resonance scan demonstrated a dilated left ventricle (LV) with severely impaired systolic function and extensive subepicardial late gadolinium enhancement in the lateral wall. An 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scan identified myocardial uptake consistent with inflammation. Following treatment with steroids for presumed cardiac sarcoidosis, a repeat FDG-PET confirmed resolution of inflammation. A dilated cardiomyopathy/AVC gene panel, however, subsequently identified a pathogenic variant in the DSG-2 gene. Discussion: We describe the case of a patient presenting with clinical and imaging features suggestive for cardiac sarcoidosis, however genetic testing established a diagnosis of DSG-2 associated AVC. DSG-2 mutations in AVC are associated with frequent LV involvement and heart failure. Active inflammation has been observed in other cardiomyopathies, specifically in desmoplakin cardiomyopathy which has a similar clinical course to DSG-2. To our knowledge, this is the first case of DSG-2 cardiomyopathy presenting in this manner. We encourage clinicians to have a high index of suspicion of inflammatory cardiomyopathies as a differential to myocarditis and cardiac sarcoidosis, when patients present with evidence of decompensated heart failure, arrhythmias, and active myocardial inflammation.

The central role of CT coronary angiography in postcardiac arrest care in the young adult.

A 32-year-old man with no medical history went into ventricular fibrillation while running at the gym. He was transferred to our tertiary centre post successful resuscitation where admission electrocardiography and echocardiography were unremarkable. The initial cause of cardiac arrest was suspected arrhythmogenic and he was admitted for further investigations including exercise testing, ajmaline challenge, CT coronary angiography (CTCA) and cardiovascular MRI, with the likely outcome of cardioverter-defibrillator implantation. CTCA, however, revealed significant stenosis in the proximal left anterior descending artery as the likely cause for his arrest. Invasive coronary angiography confirmed this and facilitated successful stent implantation, avoiding the need for implantable cardioverter-defibrillator implantation. This case highlights the importance of CTCA, a non-invasive and readily-available test in the investigation of young patients postcardiac arrest, who require active exclusion of coronary artery disease and anomalous coronary anatomy, though they represent a low-risk population group.

A rare case of primary cardiac lymphoma.

A 71-year-old man presented with shortness of breath and tachycardia along with systemic symptoms of weight loss and lethargy. A pulmonary embolus was the initial suspected diagnosis but through extensive investigations a rarer cause of his symptoms was identified. This case demonstrates the importance of cardiac imaging in the assessment and non-invasive tissue characterisation of a suspected cardiac tumour; in our case, this was subsequently confirmed by careful histological/immunocytochemical evaluation of the pericardial effusion as a primary cardiac B-cell non-Hodgkin's lymphoma, thus enabling appropriate management leading to an excellent clinical outcome.

Pseudomembranous collagenous colitis: an unusual cause of chronic diarrhoea.

An 81-year-old woman presented with a history of severe chronic diarrhoea resulting in an admission with syncope and electrolyte abnormalities. Imaging studies of the bowel were normal. However, biopsies taken during colonoscopy enabled a diagnosis to be made and effective treatment to be initiated. This case report details the presentation, diagnosis and management of a rare injury pattern affecting the bowel: pseudomembranous collagenous colitis.