Ventricular Tachycardia as a Presentation of Isolated Cardiac Sarcoidosis: How to Manage It When We Do Not See Granulomas

Abstract

A 47-year-old male was referred for rapid palpitations and an electrocardiogram compatible with sustained monomorphic ventricular tachycardia (VT) that required synchronized electrical cardioversion due to hemodynamic instability. After the initial clinical certainty, an etiological search is carried out. The transthoracic echocardiogram (TTE) revealed moderate dilatation and left ventricular systolic dysfunction due to global hypokinesia. Coronary angiography did not show significant coronary stenosis. Cardiac magnetic resonance (CMR) guarantees a nonischemic dilated cardiomyopathy with moderate systolic dysfunction and a pattern of subepicardial and intramyocardial late gadolinium enhancement (LGE) in medial-lateral and median inferolateral segments. Lastly, a positron emission tomography-computed tomography (PET-CT) scan showed diffuse fixation of the radiotracer in the left ventricular (LV) walls, with greater uptake on the lateral and inferolateral surfaces of inflammatory origin. After ruling out other alternative pathologies and according to current diagnostic criteria, the clinical judgment of probable isolated cardiac sarcoidosis (ICS) is established. An implantable cardioverter-defibrillator was implanted as secondary prevention of the acute arrhythmic event. Specific treatment for systolic dysfunction was prescribed, as well as immunosuppressive therapy with corticosteroids and methotrexate, after which the patient remained in clinical remission, with disappearance of active inflammation on cardiac imaging tests and progressive ventricular systolic function. The initial diagnosis of isolated cardiac sarcoidosis can be complex and challenging, especially in those patients in whom the diagnosis of extracardiac sarcoidosis has not been previously established. The limitations of endomyocardial biopsy in this entity make it necessary to have a high index of clinical suspicion with the early use of new cardiac imaging techniques and to include this picture in the differential diagnosis of patients with sustained ventricular arrhythmias or left ventricular systolic dysfunction of nonspecific etiology clarified. Early initiation of aggressive immunosuppressive therapy has been shown to prevent disease progression and limit its potential cardiac complications.

Keywords: cardiac sarcoidosis; heart failure with reduced ejection fraction; magnetic resonance imaging; positron emission tomography-computed tomography; ventricular tachycardia.