Outflow-tract ventricular tachycardia: Can 12 lead ECG during sinus rhythm identify underlying cardiac sarcoidosis?

Debabrata Bera; Daljeet Saggu; Sachin Yalagudri; Jugal Kishor Kadel; Rakesh Sarkar; Soumen Devidutta; Johann Christopher; Behzad Pavri; Calambur Narasimhan

doi:10.1016/j.ipej.2020.02.003

Outflow-tract ventricular tachycardia: Can 12 lead ECG during sinus rhythm identify underlying cardiac sarcoidosis?

Indian Pacing Electrophysiol J. 2020 May-Jun;20(3):83-90. doi: 10.1016/j.ipej.2020.02.003. Epub 2020 Feb 29.

Authors

Debabrata Bera¹, Daljeet Saggu¹, Sachin Yalagudri¹, Jugal Kishor Kadel², Rakesh Sarkar³, Soumen Devidutta³, Johann Christopher⁴, Behzad Pavri⁵, Calambur Narasimhan⁶

Affiliations

¹ Dept of Electrophysiology, Care Hospitals, Hyderabad, India.
² Dept of Rheumatology, Care Hospitals, Hyderabad, India.
³ Care Hospitals, Hyderabad, India.
⁴ Dept of Cardiac Imaging, Care Hospitals, Hyderabad, India.
⁵ Thomas Jefferson University Hospital, Philadelphia, USA.
⁶ Dept of Electrophysiology, Care Hospitals, Hyderabad, India. Electronic address: calambur1@gmail.com.

Abstract

Background: Patients with outflow tract ventricular tachycardia (OTVT) with normal echocardiogram are labeled as idiopathic VT (IVT). However, a subset of these patients is subsequently diagnosed with underlying cardiac sarcoidosis (CS).

Objective: Whether electrocardiogram (ECG) abnormalities in sinus rhythm (SR) can differentiate underlying CS from IVT.

Methods: We retrospectively analyzed the SR-ECGs of 42 patients with OTVT/premature ventricular complexes (PVC) and normal echocardiography. All underwent advanced imaging with cardiac magnetic resonance (CMR)/¹⁸FDG PET-CT for screening of CS. Twenty-two patients had significant abnormalities in cardiac imaging and subsequently had biopsy-proven CS (Cases). Twenty patients had normal imaging and were categorized as IVT (Controls). SR-ECGs of all patients were analyzed by 2 independent, blinded observers.

Results: Baseline characteristics were comparable. Among the ECG features analyzed - fascicular (FB) or bundle branch block (BBB) was seen in 9/22 Cases vs. 1/20 controls (p = 0.01). Among patients without FB or BBB, fragmented QRS (fQRS) was present in 9/13 cases but in none of the controls (p < 0.001). Low voltage QRS was more often seen among cases as compared to controls (10/22 vs. 3/20 p = 0.03). A stepwise algorithm based on these 3 sets of ECG findings helped to diagnose CS among patients presenting with OTVT/PVC with sensitivity of 91%, specificity of 75%, a PPV of 80%, and a NPV of 88%.

Conclusions: In patients presenting with OTVT/PVC: FB/BBB, fQRS, and low QRS voltage on the baseline ECG were more often observed among patients with underlying CS as compared to true IVT. These findings may help to distinguish underlying CS among Cases presenting with OTVT/PVC.

Keywords: 12 lead ECG; Cardiac sarcoidosis; Fascicular and bundle branch block; Outflow tract ventricular tachycardia; QRS voltage.