Patients with Isolated Focal Right Ventricular Dyskinetic Segments: Toward a Better Understanding of This Cohort

Abstract

BACKGROUND The 2010 revised Task Force criteria for the diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) provided guidance for the classification of patients as definitive, borderline or possible ARVC. However, many patients with clinical suspicion for ARVC have isolated RV dyskinetic segments only and partly meet cardiac magnetic resonance (CMR) imaging criteria. This subgroup of patients and the implication of this imaging finding remain not well defined. METHODS There were 65 consecutive patients with clinical suspicion for ARVC who were referred for CMR between 2015 and 2017. The presence of fatty infiltration and fibrosis were assessed using T2 imaging and myocardial delayed enhancement sequences, respectively. RV wall motions, volumes and ejection fraction (EF) of all patients were re-analysed and quantified. Available data on family history, Holter findings, and electrocardiograms were also reviewed. RESULTS There were 5 patients (7.7%) that fulfilled major CMR criteria for ARVC: 4 were classified as having definitive ARVC; and 1/5 as borderline. There were 33 patients with no RV dyskinetic segments: none were classified as having definitive or borderline ARVC; 4/33 were classified as possible ARVC, leaving 29/33 as normal or no ARVC. Finally, there were 27 remaining patients (41.5%) with isolated RV dyskinetic segments: 1/27 was classified as definitive ARVC; 4/27 as borderline; 8/27 as possible; leaving 15/27 as indeterminate. Compared to control, those with isolated RV dyskinesia (including the subgroup labelled as indeterminate 15/27) had more abnormal RVEF, larger RV end-diastolic volume index (82 ± 12 mL/m 2 vs. 72 ± 12 mL/m 2 , p-value 0.0127), and a trend for higher odds of dilated RV (odds ratio 3.0 [0.81–11], p-value 0.09). CONCLUSIONS Among patients with a clinical suspicion for ARVC, almost 40% had isolated focal RV dyskinetic segments with the majority remaining unclassified. This cohort had more RV dilation and abnormal EF compared to control.

Comparison of CMR Findings according to the Presence or Absence of Isolated Focal Right Ventricular Dyskinetic Segments in Patients with Clinical Suspicion of ARVC

“…In addition, it remains difficult to differentiate normal variations in RV wall motion near the moderator band insertion and pathological RV wall motion abnormalities by CMR 7). In this issue of the Journal of Cardiovascular Imaging , Mansour MJ et al10) assessed the CMR findings of 65 patients with clinically suspected ARVC (definite or borderline ARVC in 5 [7.7%] patients, isolated focal dyskinetic RV segments in 27 [41.5%] patients, and no RV dyskinetic segments in 33 [50.8%] patients). They found that 27 patients with isolated RV dyskinetic segments had slightly lower RVEF (55 ± 7% vs. 57 ± 5%), larger RV end-diastolic volume indices (82 ± 12 ml/m 2 vs. 72 ± 12 ml/m 2 , p = 0.0127), and a trend for higher odds of dilated right ventricle (odds ratio 3.0 [0.81-11], p = 0.09) compared to 33 patients with no ARVC.…”