Impact of the cone operation on left ventricular size, function, and dyssynchrony in Ebstein anomaly: a cardiovascular magnetic resonance study

Rebecca S Beroukhim,Brandon K Fornwalt,Andrew J Powell,Abba Mejia-Spiegeler,David M Harrild,Sitaram Emani,Linyuan Jing,Jonathan Rhodes

doi:10.1186/s12968-018-0452-0

Abstract

BackgroundIn addition to tricuspid regurgitation (TR) and right ventricular (RV) enlargement, patients with Ebstein anomaly are at risk for left ventricular (LV) dysfunction and dyssynchrony. We studied the impact of the cone tricuspid valve reconstruction operation on LV size, function, and dyssynchrony.MethodsAll Ebstein anomaly patients who had both pre- and postoperative cardiovascular magnetic resonance (CMR) studies were retrospectively identified. From cine images, RV and LV volumes and ejection fractions (EF) were calculated, and LV circumferential and longitudinal strain were measured by feature tracking. To quantify LV dyssynchrony, temporal offsets (TOs) were computed among segmental circumferential strain versus time curves using cross-correlation analysis and patient-specific reference curves. An LV dyssynchrony index was calculated as the standard deviation of the TOs.ResultsTwenty patients (65% female) were included with a median age at cone operation of 16 years, and a median time between pre- and postoperative CMR of 2.8 years. Postoperatively, there was a decline in the TR fraction (56 ± 19% vs. 5 ± 4%, p < 0.001), RV end-diastolic volume (EDV) (242 ± 110 ml/m2 vs. 137 ± 82 ml/m2, p < 0.001), and RV stroke volume (SV) (101 ± 35 vs. 51 ± 7 ml/m2, p < 0.001). RV EF was unchanged. Conversely, there was an increase in both LV EDV (68 ± 13 vs. 85 ± 13 ml/m2, p < 0.001) and LV stroke volume (37 ± 8 vs. 48 ± 6 ml/m2, p < 0.001). There was no change in LV EF, or global circumferential and longitudinal strain but basal septal circumferential strain improved (16 ± 7% vs. 22 ± 5%, p = 0.04). LV contraction become more synchronous (dyssynchrony index: 32 ± 17 vs. 21 ± 9 msec, p = 0.02), and the extent correlated with the reduction in RV EDV and TR.ConclusionsIn patients with the Ebstein anomaly, the cone operation led to reduced TR and RV stroke volume, increased LV stroke volume, improved LV basal septal strain, and improved LV synchrony. Our data demonstrates that the detrimental effect of the RV on LV function can be mitigated by the cone operation.

Highlights

In addition to tricuspid regurgitation (TR) and right ventricular (RV) enlargement, patients with Ebstein anomaly are at risk for left ventricular (LV) dysfunction and dyssynchrony
Studies on the short- and medium-term outcomes of the cone operation have reported a dramatic reduction in TR and RV end-diastolic volume (EDV) [2, 5, 6]; the impact on LV mechanics and synchrony have not been fully described
The timing of surgery was determined by the primary cardiologist and surgeon, and was largely based on symptoms, and degree of TR and RV dilation

Summary

Introduction

In addition to tricuspid regurgitation (TR) and right ventricular (RV) enlargement, patients with Ebstein anomaly are at risk for left ventricular (LV) dysfunction and dyssynchrony. We studied the impact of the cone tricuspid valve reconstruction operation on LV size, function, and dyssynchrony. Ebstein anomaly of the tricuspid valve is characterized by a failure of delamination of the septal and posterior leaflets, redundancy and fenestrations of the anterior leaflet, and dilatation of the annulus. This combination of factors often leads to progressive tricuspid regurgitation (TR), and right ventricular (RV) enlargement and dysfunction. We chose cardiovascular magnetic resonance (CMR) as our principle assessment tool because of its superior ability to visualize all LV segments pre- and postoperatively

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Results

Conclusion