Assessment of Right Ventricular Function Using 2D Speckle Tracking Echocardiography in End Stage Renal Disease Patients on Regular Dialysis..

INTRODUCTION

Cardiovascular morbidity and mortality are higher in people with ESRD. The major cause of mortality in this group of people is cardiovascular disease. ¹

Previous studies revealed that in individuals with chronic renal failure, systolic RV function and diastolic function both decrease, which is linked to poor clinical results.²

A variety of techniques, including catheterization, MRI, and echocardiography, can be utilized to evaluate right ventricular function.

Numerous echocardiography parameters, like fractional    area   change   (FAC),  tricuspid     annular

systolic velocities, tricuspid annular plane systolic excursion (TAPSE), and myocardial performance

index (MPI), have been well established for evaluating right ventricle systolic and diastolic function.³

A study revealed that strain analysis of the RV and RA in two dimensions may be utilized to assess the right heart's physio-mechanics. Furthermore, it may offer characteristics that are not dependent on load status, which is very beneficial in individuals with right heart disease.⁴

This research aimed to assess right ventricular function in chronic hemodialysis patients using non-invasive techniques like traditional, tissue Doppler, and speckle tracking echocardiography.

PATIENTS AND METHODS

This research was performed at the Cardiology Department of Sayed Galal University Hospital as a single-center, cross-sectional, comparative study from September 2020 to March 2021.

A total of 61 individuals receiving hemodialysis on a regular basis were evaluated. Six patients were eliminated owing to valvular and ischemic heart disease, three patients were removed due to atrial fibrillation, and two patients have been ruled out owing to bad picture quality. The final study population included 50 patients (group I) who were matched by gender, age, and risk factors to ten patients (group II). The ethics council of Al-Azhar University's Faculty of Medicine approved the study after patients who participated in the research gave their informed consent.

The study included individuals over the age of 18 who had ESRD and were on continuous hemodialysis. Patients with one or more of the following conditions were barred from participating in the study: left ventricular systolic dysfunction [EF50%], coronary arteries, moderate to severe pericardial disease, congenital heart disease, significant valvular heart disease, non-sinus rhythm, prior renal transplantation, non-renal causes of pulmonary hypertension, suboptimal echocardiographic image, and patient refusal.

All patients underwent a complete physical examination, which included taking their age, gender, DM, HTN, and smoking, as well as a full clinical investigation, which included taking their pulse and measuring their blood pressure (systolic and diastolic) and cardiac auscultation and laboratory investigation: CBC, lipid profile, kidney function tests, and electrolytes.

Electrocardiography: Patients' heart rate and rhythm were assessed using a 12-lead surface ECG with a paper speed of 25 mm/s and an amplification of 10 mm/mv to rule out ischemic or other ECG changes.

Echocardiography: The images were all taken with the patients in the standard left lateral position with a stable ECG reading.

Conventional echocardiographic parameters:

Right atrial diameters:In the apical 4 chamber view, the right atrium's maximum long axis was measured parallel to the inter-atrial septum, and the minor axis was measured as the line connecting the midlevel of the right atrium free wall to the inter-atrial septum and running perpendicular to the long axis at the mid atrial level.⁵

Dimensions of the right ventricle: RV basal measurement (in the basal one-third), mid cavity (at the LV papillary muscles' level), and longitudinal dimensions on a 4-chamber right ventricle-focused image must be performed in people with right-sided cardiac illness. ⁶

FAC in the right ventricle is computed by dividing (end-diastolic area-end-systolic area) by 100 and expressed as a percentage. FAC is produced in the apical 4 chamber view by tracing the endocardium of the right ventricular in systole and diastole. ⁷

Pulmonary artery systolic pressure (PASP):The right ventricular systolic pressure (RVSP) was calculated from peak TR jet velocity utilizing the simplified Bernoulli equation and trying to combine such a result with a guesstimate of the RA pressure: RVSP = 4 (V) 2 + RA pressure, where V is the peak velocity (in m/sec) of the tricuspid valve regurgitant jet, and RA pressure is calculated using IVC diameter and respiratory variations. ⁸

TAPSE was calculated by passing an M-mode cursor through the tricuspid annulus and measuring the longitudinal motion of the annulus at maximum systole with a typical apical four-chamber window. ⁽⁸⁾

The left ventricular ejection fraction (LVEF) is determined utilizing the formula: (EDV-ESV)/EDV = EF. This was accomplished by amending Simpson's rule. ⁹

Tissue Doppler echocardiographic parameters:

The peak annular systolic velocity (S), early (E') and late (A') peak annular diastolic velocities, and systolic velocity period have been calculated using the ejection time (ET), isovolumetric relaxation time (IVRT, time between the end of ET and the starting of E"), and isovolumetric contraction time (IVCT, time between the end of A' and the starting of ET).

To get a global evaluation of the RV's systolic and diastolic functions, the TDI-derived MPI was computed by dividing the total of IVCT and IVRT by the ET. ¹⁰

Speckle tracking echocardiography:

RV global longitudinal strain:At end-systole, the RV free wall's endocardial boundary was manually traced and automatically modified to accommodate the whole myocardium. To guarantee appropriate tracking, the thickness of the myocardium was manually adjusted to the area of interest.¹¹

The strain rate and RV strain are important characteristics to consider when evaluating the RV's systolic function on a global and regional scale. The percentage of RV free wall shortening from base to apex during systole is defined as the longitudinal strain rate. ⁽¹²⁾

SPSS vs.25 was used for data administration and statistical analysis. Means and standard deviations have been utilized to sum up numerical data. Numbers and percentages have been utilized to summarize categorical data. To compare numerical variables between two groups, the Mann-Whitney U test has been utilized. To compare categorical variables, the Chi-square test has been utilized. Correlation analysis was conducted as needed using Pearson or Spearman correlation. The letter "r" denotes the correlation coefficient. This study's p values were all two-sided. If the P value is < 0.05, it is deemed significant.

RESULTS

Table 1: Patient's demographics. Regarding age and gender, both groups were similar.

Table 2: Both groups' risk factors and clinical characteristics: Both groups had comparable risk factors. Hemoglobin, urea and creatinin were measured for all patients. There were no statistically significant differences in blood pressure between the two groups at the time of presentation.

Table 3: Echocardiographic parameters (conventional and tissue Doppler): Regarding conventional echocardiographic measures, group I patients had larger right ventricular diameters (longitudinal, mid cavity, and basal) and areas (systolic and diastolic) and right atrial diameters (longitudinal and transverse).  When compared to group II patients, RV FAC and TAPSE were significantly lower in group I patients. In group I patients, the tricuspid valve's E wave velocity and the tricuspid E/A ratio were both substantially lower. In group I, the tricuspid valve's A wave velocity was substantially enhanced. The difference between the two groups in LV ejection percentage has not been statistically significant. Regarding Tissue Doppler echocardiographic parameters, The E^/ and S velocities of the tricuspid valve were substantially decreased in group I patients. In group I, the tricuspid valve A/ velocity was substantially higher. In comparison to group II, MPI was considerably greater in group I.

Table 4: Speckle tracking echocardiographic parameter of RVGLS.

Table 5: Correlation between RV global longitudinal strain and other parameters. RVGLS was significantly decreased in group I patients. It has been shown to be inversely linked to age, the diameters of the RV (longitudinal diameter, mid-cavity diameter), the RA transverse diameter, and the tricuspid E/A ratio. While it exhibited a significant positive connection with FAC and LV ejection fraction.