Evaluation Of Cardiovascular Function In Patients With Chronic Renal Failure And Primary Hypertension By Wave Intensity Technique

Background and ObjectivesChronic renal failure (CRF) is a variety of primary or secondary progressive kidney disease caused by the development of kidney structure and function of irreversible damage in a clinical syndrome, harmful to human health. As one of the critical illness, it can affect many systems and organs of body. The most common cardiovascular complication can lead to higher mortality in patients with CRF.Over the past 20 years, the death caused by chronic renal failure in humans accounts for the fifth to the ninth, is a significant threat to human survival. Echcardiogaphy has the advantages in evaluating the structure and function of the cardiac and the ventricular wall motion abnormality, and Ultrasonography of two-dimensional and the color doppler imaging have the advantages in evaluating the vessel wall structure and the hemodynamic significance, therefore, they are widely applied in assessing cardiac complication in patients with CRF. There are some reports about CRF-related cardiac complication by traditional echocardiography methods, but these methods have some limitations. Cardiac complication can not be discoverd by these traditional echocardiography methods before appearing significant clinical manifestations and structure changes, so these methods is limited in clinical penetration. Primary hypertension (HTN) is a syndrome of high blood pressure as the main clinical manifestations with or without a variety of cardiovascular risk factor,,often referred to as hypertension. Hypertension is an important cause and risk factors to varied cardiovascular and cerebrovascular disease. It may affect many important organs, such as heart, brain and kidney, and ultimately lead to function failure of these organs. To date, it remains one of the main death causes in cardiovascular disease. Wave intensity(WI) technique can study the cardiovascular system hemodynamics and the relationship between the heart and blood vessels as a new ultrasonic image technique, and the new technology is characterized by detecting the arterial circulatory system at any point to assess the the overall function of the cardiovascular system. WI technique can discover cardiovascular complications before appearing significant structure changes,and it has the advantages in evaluating the cardiovascular function and structure, plaque, arterial elasticity and stiffness;and it is conveninent,noninvasive, and has no absolute contraindication,so it is widely used in clinincal practice.The purposes of this research project:First, to evaluate the changes in vessel elasticity with HTN patients and CRF patients using WI-related parameters; Second, to evaluate the changes in cardiac function with HTN patients and CRF patients using WI-related parameters; Third, to compare the relevant parameters with HTN patients and CRF patients; Fourth, to observe the relation of Serum levels of blood urea nitrogen and duration of CRF with vessel elasticity.Methods1. The objects were divided into three groups. CRF group:30 inpatients of our hospital during March to July in 2009, which satisfying Summary of the Forum meeting with chronic renal failure at the Huangshan Mountain in 1992,17 male and 13 female, mean age (46.7±15.4)years. Serum levels of blood urea nitrogen (Scr) 500-2000μmol/L, mean (1049.33±416.44)μmol/L. According to the classification of Scr,30 patients were graded as renal failure or above renal failure. Inclusion criteria were:no clinical evidence of present and/or previous cardiac disease, no atherosclerotic plaque.The history of CRF was 1-5 years, mean (3.0±0.1) years. HTN group:30 inpatients of our hospital satisfying the criteria of JNC7 during March 2009 to July in 2009,15 male and 15 female, mean age (46.5±10.6) years. Inclusion criteria were:no clinical evidence of present and/or previous cardiac disease, normal renal function, no atherosclerotic plaque.The history of HTN was at least one year, mean systolic blood pressure (170±10)mmHg, mean diastolic blood pressure (110±9)mmHg. Control group:35 healthy people,20 female and 15 male, mean age (44.2±10.2) years. All of them did not have abnormal findings by physical examination,ECG and echocardiography. Sex and age of the objects were matched between three groups.2.All of the studying objects in left-lateral position were connected with limb lead ECG Images were obtained by ALOKA ProSound a 10 system. At first, the left ventricular ejection fraction(LVEF) were obtained using Teichholz3.WI examinatin:①vascular sampling:objects were measured brachial artery blood pressure twice before the examination in calm, keeping the supine position and ECG connection status, biasing head contralateral, and took the site of 2.0cm under carotid artery sinus as the check site (to avoid the jugular vein),the patients with atherosclerotic plaque were excluded.②Start WI function:Regulation Beam Steer (B) keys within 0～20°, so that the carotid artery anterior and posterior wall shows clearly. Start the WI feature in the B/M mode. The two samples line of the B mode were placed at the junction of middle and outer membrane of anterior and posterior vascular wall, to ensure the two-dimensional sampling gate and the vessel wall perpendicular, M-mode Sweep Speed is set to 200mm/s, start WI blood flow display key, and WI blood sampling gate width is set to 4mm, and acoustic beam flow angle is set to≤60°.③capture images and data:Keeping objects and operators breath-hold at the same time, press Select key sampling, trace recorded graphics≥6, to freeze after confirming WI image to meet the requirements and store the first image. Measured blood pressure once again, using the average of three blood pressure,and pick five or more consecutive waveform to store for analysis. Testing parameters include:stiffness parameter (13), strain elastic modulus (Ep), one-pointpulse wave velocity (PWV13 and PWV-WI), instantaneous acceleration wave intensity(W1), transient deceleration wave intensity(W2), negative area(NA), interval between R wave of electrocardiogram and W1 (R-lst), interval between W1 and W2 (1st-2nd), arterial compliance(AC), argumentation index (AI), intima media thickness (IMT) and diameter(D). Statistical analysis was executed by SPSS10.0 software.Results1. The general information such as age, sex no statistically significance between three groups. Compare with the HTN group and the control group, Serum levels of blood urea nitrogen of the CRF group increased (P<0.05); compare with the control group, systolic and diastolic blood pressure of both the HTN group and the CRF group increased (P<0.05).2. Compared the conventional ultrasonic parameters, left ventricular ejection Fraction (EF) decreased gradually in the control group, HTN group and CRF group (P<0.05). And EF wasn't related to the W1 (P> 0.05).3. Compared parameters of WI technology,13, Ep, PWV13 and PWV-WI were higher in CRF patients and HTN patients comparing with the normal cases (P<0.05); the data of W1,W2, NA were higher in CRF patients comparing with both HTN and the normal cases (P<0.05); However, for either CRF or HTN patients the data of R-1st, 1st-2nd, AI, AC, IMT and D had no significant different from the indexs of normal control (P>0.05)4. Serum levels of blood urea nitrogen and duration were positively related to the W2,NA,β,Ep,PWVβ,PWV-WI by analysis correlation.Conclusions1.The left ventricular function in patients with CRF and HTN has been impaired. EF is useful indicators in assessing left ventricular systolic dysfunction with CRF and HTN patients. Further study on W1 in assessing left ventricular systolic dysfunction with CRF and HTN patients should be taken on.2. The arterial elasticity has been changed in CRF and HTN patients, performancing flexibility indicators were changed; cardiovascular complication can be discoverd by WI technique before appearing significant structure changes.3. The cardiovascular function has been damaged in patients with CRF and HTN, WI technology can be used as a new comprehensive method in evaluating cardiovascular function in patients with CRF and HTN.4. Serum levels of blood urea nitrogen and duration of CRF have consanguineous connection with vessel elasticity.