Right Ventricular Functions in Hemodialysis Patients: Tissue Doppler Study

Background: Cardiovascular disease is the leading cause of mortality in patients undergoing dialysis, accounting for 50% of deaths. In particular, heart failure is the most common finding in these patients and is associated with poor prognosis. Hemodialysis (HD) which is usually carried out via a surgically created native Arteriovenous Fistula (AVF) has been associated with an increased risk of pulmonary hypertension, a condition reported as a predictor of mortality in these patients. Aim of the Work: The aim of this study is to assess right ventricular function in patients with end stage renal disease on hemodialysis using tissue Doppler imaging of the right ventricle. Subjects and Methods: The study population consisted of 40 patients with end-stage renal disease on a regular dialysis program and 20 normal subjects as a control group (mean age 54.9±12.7 years, male/female: 33/27. The study group comprises 40 HD patients with brachial AVF. Patients were receiving HD sessions 3 times per week. Each session lasted for 4 hours and used bicarbonate-buffered dialysate. Standard Kt/V (K=in vitro clearance of dialystae, t=time of dialysis and V=volume distribution of blood urea nitrogen) was calculated. The study was done in the period between January 2013 and July 2014 in Urology and Nephrology Center and Mansoura Specialized Hospital in Mansoura, Egypt. All subjects underwent clinical evaluation with special concentration upon cardiovascular system, laboratory evaluation, ECG and tissue Doppler examination. Results: HD patients were older than control subjects; however the difference was not statistically significant. Heart rates were significantly higher in dialysis patients as compared to controls. There was significant deterioration of systolic and diastolic function of the RV in the dialysis group either using conventional echocardiography or tissue Doppler imaging. Patients on HD presented higher right ventricular diameters and volumes than control group. Right ventricular ejection fraction was significantly reduced in HD patients as compared to control group. TDI indices of diastolic and systolic function were significantly lower in patients undergoing HD. Ea velocity, measured at both lateral and septal tricuspid annulus was significantly and progressively reduced in controls and HD patients. Compared to control group, HD patients showed a prolonged isovolumic relaxation time. TDI indices of systolic function showed that lateral and septal Sa velocities were progressively reduced among HD patients as compared to control group. Conclusion: Hemodialysis is associated with right ventricular dysfunction with significantly lower RV ejection fraction by using conventional Doppler echocardiography and significantly higher TDIMPI at both lateral and septal tricuspid annulus which is independent to high systolic pulmonary artery pressure. So, we recommend the use of TDI evaluation of right ventricular function for early detection of preclinical dysfunction in hemodialysis patients.