Cardiac sarcoidosis mimicking arrhythmogenic right ventricular dysplasia in a patient presenting with monomorphic ventricular tachycardia

A case of cardiac sarcoidosis with successful heart transplantation after COVID-19 infection

Arrhythmogenic right ventricular cardiomyopathy and cardiac sarcoidosis can both present with ventricular tachycardia. We report a case of a patient whose histological diagnosis was not only confirmed by the transplanted heart but who also underwent successful transplantation after overcoming COVID-19.

Arrhythmia in Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is a complex disease that can manifest as a diverse array of arrhythmias. CS patients may be at higher risk for sudden cardiac death (SCD), and, in some cases, SCD may be the first presenting symptom of the underlying disease. As such, identification, risk stratification, and management of CS-related arrhythmia are crucial in the care of these patients. Left untreated, CS carries significant arrhythmogenic morbidity and mortality. Cardiac manifestations of CS are a consequence of an inflammatory process resulting in the myocardial deposition of noncaseating granulomas. Endomyocardial biopsy remains the gold standard for diagnosis; however, biopsy yield is limited by the patchy distribution of the granulomas. As such, recent guidelines have improved clinical diagnostic pathways relying on advanced cardiac imaging to help in the diagnosis of CS. To date, corticosteroids are the best studied agent to treat CS but are associated with significant risks and limited benefits. Implantable cardioverter-defibrillators have an important role in SCD risk reduction. Catheter ablation in conjunction with antiarrhythmics seems to reduce ventricular arrhythmia burden. However, the appropriate selection of these patients is crucial as ablation is likely more helpful in the setting of a myocardial scar substrate versus arrhythmia driven by active inflammation. Further studies investigating CS pathophysiology, the pathway to diagnosis, arrhythmogenic manifestations, and SCD risk stratification will be crucial to reduce the high morbidity and mortality of this disease.

Epidemiological Impact of Myocarditis

Myocarditis is an inflammatory disease of the heart muscle with a wide range of potential etiological factors and consequently varying clinical patterns across the world. In this review, we address the epidemiology of myocarditis. Myocarditis was considered a rare disease until intensified research efforts in recent decades revealed its true epidemiological importance. While it remains a challenge to determine the true prevalence of myocarditis, studies are underway to obtain better approximations of the proportions of this disease. Nowadays, the prevalence of myocarditis has been reported from 10.2 to 105.6 per 100,000 worldwide, and its annual occurrence is estimated at about 1.8 million cases. This wide range of reported cases reflects the uncertainty surrounding the true prevalence and a potential underdiagnosis of this disease. Since myocarditis continues to be a significant public health issue, particularly in young adults in whom myocarditis is among the most common causes of sudden cardiac death, improved diagnostic and therapeutic procedures are necessary. This manuscript aims to summarize the current knowledge on the epidemiology of myocarditis, new diagnostic approaches and the current epidemiological impact of the COVID-19 pandemic.

A case report of isolated right ventricular lymphocytic myocarditis

Background

Lymphocytic myocarditis is an uncommon condition with a variety of clinical presentations. Isolated involvement of the right ventricle (RV) is very rare. We present a case of a young woman who developed right ventricular dysfunction and arrhythmias as a consequence of this condition, which appeared to be chronic at diagnosis.

Case summary

A 26-year-old lady was admitted to hospital following routine echocardiography, requested for screening of pulmonary hypertension in the context of known hypersensitivity pneumonitis. This echocardiogram demonstrated severe right ventricular dilatation and impairment. She was also experiencing atrial fibrillation and non-sustained, symptomatic episodes of ventricular tachycardia. Endomyocardial biopsy revealed lymphocytic myocarditis. She was managed with azathioprine and prednisone, as well as sotalol and apixaban for her atrial fibrillation, and has had no complications in the 12 months since discharge.

Discussion

Lymphocytic myocarditis isolated to the RV has only been reported in two previous cases, both of which were acute, dramatic presentations. This is the first report of a chronic example of this disease process. Due to her intercurrent immunosuppression, this patient may have been pre-disposed to the condition either by re-activation of a latent viral infection or partial treatment of a true autoimmune lymphocytic myocarditis.