PO-700-06 ROLE OF SINUS RHYTHM QRS AMPLITUDE, FRACTIONATION AND DURATION TO IDENTIFY CLINICAL RESPONSE TO MEDICAL TREATMENT IN PATIENTS WITH CARDIAC SARCOIDOSIS AND FDG-PET UPTAKE

Abstract

Myocardial fibrosis and inflammation in patients with cardiac sarcoidosis (CS) may lead to sinus rhythm abnormalities such as, low QRS amplitude (QRSa), QRS fractionation (QRSf) and longer QRS duration (QRSd). To determine if reduction of myocardial inflammation associated with medical treatment may improve and/or reverse these 12-lead ECG parameters. 23 consecutive patients (pts) with CS referred for VT ablation between 2009 and 2018 with18-fluorodeoxyglucose (FDG) uptake in a positron emission tomographic (PET1) scan at baseline were studied. All pts received high-dose prednisone 40 mg for 4 to 8 weeks followed by a taper and maintenance therapy with methotrexate ± low-dose prednisone, (≤20 mg/day), until clinically stable and resolution of inflammation on PET2 performed up to 2 years after initial. In addition to immunosuppression, pts with reduced LV ejection fraction (13/23pts) received guideline directed pharmacological therapy for heart failure. Based on the PET2 results, pts were divided into PET positive uptake [PET +, (n=12)] and PET negative uptake [PET -, (n=11)]. 12-lead ECGs of pts with native conduction from baseline (ECG1) and at up to 2-years after initial ECG (ECG2) were analyzed for QRSd, ≥2QRSf contiguous leads and QRSa. Baseline findings in patients who had PET2 (+) vs PET2 (-) were similar: sex (men 83% vs 100%), age (55±8.3 vs 55±8 years), average FDG uptake SUV maximum (5.8±2.7 vs 6.9±3.9) and average number of AADs tried before VT ablation (1.6 vs 1.5); all p value >0.05. Baseline 12-lead ECG1 showed similar QRSd, ≥2QRSf contiguous leads and QRSa for PET2 (+) vs PET2 (-). At follow-up ECG2, 7/11 patients (63.3%) PET2 (-) vs 1/12 patients (8.3%) still PET2 (+) showed ECG improvement p=0.009. Figure 1. ECG changes included QRSa increase in Lead 1 ≥.2 mV (>2 SEM) - [PET2 (+) 1 pt vs PET2 (-) 4 pts], QRSd decrease by ≥18 ms (>2 SEM) - [PET2 (+) 0 pts vs PET2 (-) 1 pt] and/or loss of QRS fractionation [PET2 (+) 0 pts vs PET2 (-) 3 pts]. In patients with cardiac sarcoidosis and VT, 12-lead ECG QRS demonstrating reversal of fractionation, increase in QRS amplitude and/or decrease in QRS duration, can help identify a positive response to medical treatment as indexed by negative FDG-PET at follow-up.