The arrhythmic burden in patients with sarcoidosis. Is it a real concern?

Abstract

BackgroundSarcoidosis is a multisystem disease characterized histologically by the formation of granulomas in many tissues. In many cases, cardiac involvement may be clinically silent but in others it may be the only clinical feature. Sudden death has been reported in 12–65% of cardiac sarcoidosis cases, and is usually attributed to malignant ventricular arrhythmias. We assessed the prevalence of cardiac arrhythmias in patients with sarcoidosis not complaining from cardiac symptoms aiming for early detection of cardiac involvement. MethodsFifteen patients with sarcoidosis (either thoracic or extrathoracic) were enrolled in the current study. Clinical diagnosis was based on tissue biopsy. All patients were symptoms free as regards their cardiac condition. Standard ECG was done for detection of bundle branch block (BBB), or atrioventricular block. 24h ambulatory ECG (holter) was done to detect significant premature beats (>10/h), runs of supraventricular or ventricular tachycardia (>3 beats), or ventricular fibrillation. Echocardiographic examination was done for assessment of left and right ventricle systolic and diastolic function and significant segmental wall motion abnormalities (SWMA) (>2 segments). All patients were under steroid therapy. Patients with a history of Ischemic heart disease, previous myocardial infarction (MI), congestive heart failure, electrolyte abnormalities, and patients with previously implanted permanent pacemakers or cardiac defibrillators were excluded from the study. ResultsMean age of the study group was 49.6±10.4 including 9 females and 6 male patients. Resting ECG was abnormal in 3 (20%) cases. Six patients (40%) had diastolic dysfunction however LV and RV systolic function and resting SWM were normal. No significant bradyarrhythmias were observed during holter monitoring however significant tachyarrhythmias including frequent premature atrial and ventricular beats, runs of non-sustained SVT and VT were observed in 5 patients. Life-threatening sustained VT was observed in a single patient that required Radiofrequency (RF) ablation followed by ICD implantation. ConclusionsHolter monitoring provides a useful, convenient and inexpensive mean of non-invasive screening for cardiac involvement in sarcoidosis especially in patients without cardiac symptoms. Extended holter should be a part of the routine work-up of any patient with sarcoidosis. The exact effect of steroid therapy on the arrhythmia burden remains a matter of debate. Cardiac MRI should be done to all patients with sarcoidosis having either abnormal symptoms or abnormal basic screening tools especially abnormal holter.