Tricuspid annular abnormalities in isolated left ventricular noncompaction – a three-dimensional speckle-tracking echocardiographic study
Authors: Nemes A , Racz G , Kormanyos A 
Published: October 2021

Abstract

Introduction
Left ventricular (LV) noncompaction (LVNC) is a rare cardiomyopathy due to arrest of the normal maturation process of the myocardium. It is characterized by prominent LV trabecularization with deep intratrabecular recesses. In most of cases LVNC is isolated, but biventricular forms are also known. The tricuspid valve is a complex anatomical structure which incorporates the three-dimensional (3D) saddle-shaped fibrosus annulus (TA). 3D speckle-tracking echocardiography (STE) is a novel non-invasive imaging method with capability of not only measuring volumetric, strain and rotational parameters of heart chambers, but with finding optimal valvular planes in the 3D space evaluation of TA dimensions respecting cardiac cycle is allowed. The present study was designed to assess TA morphological and functional abnormalities by 3DSTE in LVNC patients without right ventricular (RV) involvement.

Methods
The present study consisted of 15 patients with LVNC (mean age: 52.1±11.4 years, 9 males). LVNC was defined according to the Jenni's criteria. Their results were compared to 21 age- and gender-matched healthy controls (mean age: 52.4±3.9 years, 14 males). Complete routine 2-dimensional Doppler echocardiographic examination with 3DSTE was performed in all LVNC patients and healthy controls.

Results
Enlarged left atrial and LV dimensions with reduced LV ejection fraction could be seen in LVNC patients. The mean number of noncompacted segments proved to be 6.9±2.0. Grade 1 and 2 mitral regurgitation (MR) could be demonstratred in 5 and 5 LVNC patients, respectively. Higher grade of MR could not be found. Grade 1 and 2 tricuspid regurgitation (TR) could be demonstrated in 4 and 1 LVNC patients, respectively. Only one LVNC patient has grade 4 TR. Tricuspid annular plane systolic excursion (TAPSE) and RV fractional area change (RV-FAC) proved to be 13.9±3.9 mm and 34.1±2.7%, respectively. LVNC patients showed significantly dilated end-diastolic and end-systolic TA diameter (2.6±0.3 cm vs. 2.2±0.3 cm, p&lt;0.05 and 2.2±0.2 cm vs. 1.8±0.3 cm, p&lt;0.05, respectively), area (8.4±1.7 cm2 vs. 7.0±1.5 cm2, p&lt;0.05 and 6.5±1.7 cm2 vs. 5.3±1.4 cm2, p&lt;0.05, respectively) and tendentiously larger perimeter (11.2±1.4 cm vs. 10.5±1.2 cm, p=ns and 9.8±1.5 cm vs. 8.9±1.0 cm, p=ns, respectively), which was accompanied with tendentiously lower TA functional properties represented by TA fractional area change (TAFAC, 22.2±12.3% vs. 23.7±11.7%, p=ns) and TA fractional shortening (TAFS, 15.9±5.6% vs. 18.8±8.0%, p=ns). TAPSE and RV-FAC showed mild correlations with TAFAC (r=0.39, p=0.05; r=0.36, p=0.05, respectively) and TAFS (r=0.37, p=0.05; r=0.38, p=0.05). Extent of LV noncompaction did not correlate with any echocardiographic parameters.

Conclusions
TA is dilated in LVNC patients without obvious RV involvement. Longitudinal (TAPSE) and sphincter-like (TAFAC, TAFS) TA motions correlate with each other.

Funding Acknowledgement
Type of funding sources: None.