Cardiac Sarcoidosis: diverse arrhythmological presentations pointing to the right diagnosis in a patient with  former unknown cardiomyopathy

Veronica Buia (Fürth)1, D. Stangl (Fürth)1, J. Walaschek (Fürth)1, D. Bastian (Fürth)1, H. Rittger (Fürth)1, L. Vitali-Serdoz (Fürth)1

1Klinikum Fürth Med. Klinik I - Kardiologie Fürth, Deutschland

 

Patient Presentation:

 

A 56-year-old male experienced sudden fatigue and measured his heart rate 170/min. Upon the ambulance's arrival an ECG showed a monomorphic ventricular tachycardia with an inferior axis, negative in leads DI and avL (missing precordial leads). The patient was hemodynamically stable. 300 mg of Amiodarone were administered , and the patient was subsequently transported to our emergency department. During transport, the rhythm converted to sinus rhythm with ventricular pacing. His medical history included the implantation of a pacemaker approximately 12 years prior due to third-degree atrioventricular block and an upgrade to a CRT-D device in 2023 for secondary prophylaxis after sustained ventricular tachycardias.

 

Initial Workup:

 

Laboratory tests indicated signs of heart failure (pro BNP 6900 pg/ml) and minimally elevated troponin markers, with normal electrolyte levels. The ECG showed sinus rhythm with a heart rate of 66/min and biventricular pacing with occasional ventricular extrasystoles. The echocardiogram revealed a non-dilated, non-hypertrophic left ventricle with an ejection fraction of 47% and no significant valvular pathology. Speckle tracking showed GLS -18% (normal lower limit -17.2%) with reduced segmental strain and time-to-peak strain, raising suspicion of hypokinetic non-dilated cardiomyopathy (HNDC) with basal interventricular septal thinning. The device interrogation detected 15 sustained ventricular tachycardias below the minimum therapeutic threshold (185/min). The monitoring zone and VT1 zone were expanded. An antiarrhythmic therapy with sotalol was initiated.

 

Diagnosis and Management:

 

A PET-CT scan was performed by suspicion of cardiac sarcoidosis. The exam showed increased FDG uptake in the antero-basal septum and in the right ventricle, consistent with this diagnosis. There was also FDG-positive lymphadenopathy in the bilateral hilar and mediastinal regions, along with isolated FDG-positive granulomatous changes in the lungs. Prednisolone therapy at 60 mg/day was initiated on top of heart failure management. A myocardial biopsy was suggested, but the patient refused.

 

Follow Up:

One month after discharge, the patient remained asymptomatic and tolerated sotalol therapy. During the follow-up, there were no sustained or non-sustained ventricular tachycardias, but the biventricular stimulation remained suboptimal (<80%) due to frequent ventricular extrasystoles. Prednisolone dosage was reduced to 30 mg/day until the next two-month follow-up. Following the prednisolone therapy, a reassessment of biventricular stimulation and arrhythmic burden will determine the appropriateness of ventricular extrasystole ablation to ensure biventricular stimulation above 90%.

 

Conclusions:

 

Cardiac sarcoidosis remains a challenging diagnosis due to the lack of defined diagnostic criteria. Despite its rarity, young patients with a history of conduction system dysfunction or signs of heart failure should be evaluated for this disease which can manifest as non-dilated or hypokinetic cardiomyopathy, with typical echocardiographic signs including basal septal thinning and abnormal speckle tracking. Arrhythmologically, sarcoidosis may present with both life-threatening bradycardias and tachycardias, as in this case. The Japanese circulation society has the newest guidelines which encompass major and minor criteria to establish this often missed diagnosis. 

Diese Seite teilen