Abstract 13068: Epsilon and Inverted T Waves in Right Side Precordial Leads in Pulmonary Hypertensive Patients With or Without Right Ventricular Hypertrophy or Fibrosis on Cardiac Computed Tomography

Abstract

Introduction: Epsilon and inverted T waves on V1-3 leads are known as specific ECG findings in patients with arrhythmogenic right ventricular (RV) cardiomyopathy (ARVC), which suggests the presence of RV conduction delay. Right bundle branch block (RBBB) is often observed in ARVC. In patients with pulmonary hypertension (PH) due to RV pressure load, the occurrence of RV hypertrophy and fibrosis are frequently observed, which may also lead to the occurrence of RV conduction delay and epsilon waves. Hypothesis: We hypothesized that there were epsilon and inverted T waves in right side precordial leads on ECG in PH patients with RV hypertrophy and/or RV fibrosis, both confirmed on cardiac CT. Methods: We retrospectively analyzed 43 patients (33 females, 55 ± 15 years, 31 chronic thromboembolic PH, 7 idiopathic pulmonary arterial hypertension) with proven PH by right heart catheterization. On CT, RV fibrosis was defined as a contrast defect in the early phase and a conversely abnormal enhancement in the late phase. Results: 32 and 9 patients had RV hypertrophy and RV fibrosis, respectively; of these, 4 had both. Of 32 PH patients with RV hypertrophy, 2 had complete RBBB and 8 had incomplete RBBB. Of 22 PH patients with RV hypertrophy but without any RBBB, only one (5%) had typical epsilon waves and 2 (9%) had waves with abnormal small upward spikes after the QRS wave that were more marked in II and aVF leads than V1 and 2 leads; these were not typical epsilon waves. 14 had a negative T wave in V1-3 leads (5 had only a V1 lead, one had only V1 and 2 leads, 4 had only V1-3 leads, and 4 had V1-4 leads, respectively). Of 9 PH patients with RV hypertrophy, one had complete RBBB and one had incomplete RBBB. Of 7 PH patients with RV fibrosis but without any RBBB, none (0%) had epsilon waves in V1-3 leads. All 7 had a negative T wave in V1-3 leads (3 had only a V1 lead, one had only V1 and 2 leads, 2 had only V1-3 leads, and one had V1-4 leads). Conclusions: In a total of 37 PH participants with an organized RV myocardial change, such as RV hypertrophy and fibrosis confirmed on cardiac CT, only one (3%) had typical epsilon waves that are frequently found in patients with ARVC. The mechanism of epsilon waves occurring predominantly in V1-3 leads seems not only to be caused by an organised RV myocardium, but also by other factors.