Exaggerated Liver Injury Induced by Renal Ischemia Reperfusion in Diabetes: Effect of Exenatide

Background/Aim:

This study was designed to investigate the possible effect of exenatide (Glucagon like Peptide-1 receptor agonist) on liver injury (distant organ) induced by renal ischemia reperfusion (IR) in diabetic rats.

Materials and Methods:

In vivo renal IR was performed in both type 2 diabetic and normal rats. Each protocol comprised ischemia for 30 minutes followed by reperfusion for 24 hours and a treatment period of 14 days before induction of ischemia.

Results:

Lipid peroxidation, xanthine oxidase activity, myeloperoxidase activity and nitric oxide level in liver tissue were significantly increased (P < 0.01, P < 0.001, P < 0.001, P < 0.05, respectively), after IR in diabetic rats compared to normal rats. Antioxidant enzymes like glutathione, superoxide dismutase, catalase and glutathione peroxidase were significantly reduced (P < 0.05, P < 0.05, P < 0.01, P < 0.05, respectively), after IR in diabetic rats compared to normal rats. Exenatide treatment significantly normalized (P < 0.01), these biochemical parameters in treated rats compared to diabetic IR rats. Serum creatinine phosphokinase activity and liver function enzymes were also significantly normalized (P < 0.001, P < 0.001, respectively), after administration of exenatide.

Conclusion:

Exenatide exerted protective effect on exaggerated remote organ (liver) injury induced by renal IR in diabetes.     

Utility of right ventricular tissue Doppler imaging: correlation with right heart catheterization

Objectives: The objective of this study was to correlate tissue Doppler imaging of the right ventricle (RV) with pulmonary hemodynamics in patients referred for right heart catheterization. Methods: Seventy subjects (mean age 54 ± 13; 35 males) prospectively underwent tissue Doppler imaging of the RV and right heart catheterization within 1 day of each other. Peak systolic velocity and strain were measured at the RV free wall and correlated with pulmonary hemodynamics. Results: RV myocardial velocity demonstrated no correlation with any hemodynamic variable. While RV strain demonstrated significant correlation with cardiac index (r =−0.61; P < 0.001), correlations with transpulmonary gradient (r = 0.26; P < 0.05) and pulmonary vascular resistance (r = 0.30; P < 0.05) were weaker. Subgroup analysis revealed that in patients with left ventricular systolic dysfunction (n = 31), RV strain showed no correlation with any hemodynamic variable. In patients with normal left ventricular systolic function (n = 39), correlations were significant between RV strain and mean pulmonary artery pressure (r = 0.59; P < 0.001), pulmonary vascular resistance (r = 0.60; P < 0.001), and cardiac index (r =−0.67; P < 0.001). Conclusions: RV myocardial strain correlates significantly with pulmonary hemodynamics in patients with pulmonary hypertension and normal left ventricular function. However, there is no correlation with RV performance in patients with left ventricular dysfunction.     

Patent foramen ovale in a large population of ischemic stroke patients: diagnosis, age distribution, gender, and race

BACKGROUND: Patent foramen ovale (PFO) is a well-recognized risk factor for ischemic strokes. The true prevalence of PFO among stroke patients is still under debate. Transesophageal echocardiography (TEE) is the "gold standard" in diagnosing PFO but the physiology requires right-to-left atrial shunting. In this report, we evaluate the prevalence of PFO in a diverse group of ischemic stroke patients studied by TEE. METHODS: TEE of 1,663 ischemic stroke patients were reviewed for cardiac source of embolism, including PFO and atrial septal aneurysm (ASA). Agitated saline bubble injection was performed to look for right to left atrial shunting. Success of maneuvers to elevate right atrial pressure (RAP) was noted by looking at the atrial septal bulge. RESULTS: Among 1,435 ischemic stroke patients analyzed, the presence or absence of PFO could not be determined in 32.1% because bulging of the septum could not be demonstrated in patients with negative contrast study despite aggressive maneuvers to elevate RAP. Of the remaining 974 patients, 294 patients (30.2%) had a PFO. The mean age was 61.5 years in both groups, with a bimodal distribution of PFO and the highest prevalence occurring in < or =30-year-old group. Prevalence of PFO was similar in men (32.4%) and women (28.15%, P = 0.15); and in Caucasian (32.1%) and African American (27.7%; P = 0.15). ASA was present in 2.02% and hypermobile septum in 2.49% of the 1,435 patients. PFO was seen in 79.3% of the patients with ASA. CONCLUSION: Successful elevation of RAP cannot be achieved in a significant number of patients undergoing TEE and determination of PFO may be difficult. In our series, the true prevalence of PFO among ischemic stroke patients was 30.2% taking into account only those patients who showed no shunting despite bulging of the atrium septum into the left atrium (PFO absent group) during the contrast study. There was no gender or racial difference in the prevalence of PFO, but there was a bimodal distribution in prevalence with age.     

Is Echo‐Determined Left Ventricular Geometry Associated with Ventricular Filling and Midwall Shortening in Hypertensive Ventricular Hypertrophy?

BACKGROUND: The correlation between left ventricular (LV) geometry, mass, diastolic function, and midwall fractional shortening (MFS) in hypertensive patients with left ventricular hypertrophy (LVH) is not well established owing to limited diffusion of MFS evaluation. The aim of the study was to evaluate this correlation in 1887 consecutive hypertensive patients, all affected by LVH (mean age 66 years, 924 males), with LV ejection fraction (LVEF) >45% for early detection of ventricular dysfunction rather than LVEF and diastolic function impairment. METHODS AND RESULTS: All patients underwent M-B mode echocardiography and PW-Doppler evaluation. LV geometry and mass were compared with Doppler-determined mitral flow and tissue velocities. LV geometry was eccentric (E) for 1018 subjects (53.9%) and concentric (C) for 869 (46.1%). There was no difference concerning LV diastolic dysfunction (P: n.s.) between 576 (30.6%) of the ELVH and 368 (19.4%) of the CLVH patients. The following parameters showed significant statistical differences: LV MFS impairment (P < 0.01) between 86 (4.6%) of the ELVH and 177 (9.4%) of the CLVH patients. LV MFS impairment rate was higher in 171 patients without LV diastolic dysfunction (9.1%), than in 92 patients affected (4.9%, P < 0.02). In CLVH patients, a higher prevalence of LV MFS impairment was observed in 143 without LV diastolic dysfunction (7.6%), than in 34 patients affected (1.8%, P < 0.01). In ELVH patients, a lower prevalence of LV MFS impairment was observed in 28 without diastolic dysfunction (1.5%), than in 58 patients affected (3.1%, P < 0,03). CONCLUSION: Midwall LV impairment, an independent predictor of cardiac death and morbidity in hypertensive patients, can allow early identification of patients with LV dysfunction even when LVEF or assessment of diastolic function are normal. LV MFS impairment rate is higher in CLVH patients, and even higher when considering only those CLVH patients with no diastolic dysfunction. These results suggest that the ventricular dysfunction with normal LVEF is not always due to diastolic dysfunction, but often to systolic dysfunction as assessed by MFS impairment, an important early sign of ventricular dysfunction in hypertensive patients, even when diastolic function is normal.     

Multicenter evaluation of SonoVue for improved endocardial border delineation

OBJECTIVES: Two multicenter studies were conducted to evaluate the safety and efficacy of SonoVue as a contrast agent for enhanced left ventricular endocardial border delineation (LVEBD), and to compare the efficacy of SonoVue and Albunex in adult patients with a suboptimal, nonenhanced echocardiogram. BACKGROUND: The use of contrast to enhance echocardiographic assessment of LVEBD is well-established. SonoVue is a new microbubble contrast agent that contains sulfur hexafluoride. METHODS: Patients were randomized to receive four injections of SonoVue (0.5, 1, 2, and 4 ml), or two injections of Albunex and two injections of hand-agitated saline (0.08 and 0.22 ml/kg). Echocardiographic images were evaluated at the study centers and by four blinded, offsite reviewers for degree of left ventricle opacification (LVO), duration of contrast enhancement, and LVEBD. RESULTS: LVO scores were significantly higher for all doses of SonoVue. Patients with complete LVO ranged from 34%-87% for SonoVue and from 0%-16% for Albunex. The mean duration of useful contrast effect ranged from 0.8-4.1 minutes for SonoVue and < 15 seconds for Albunex. Mean increases in LVEBD scores ranged from 3.8-18.2 for SonoVue and 0.1-4.3 for Albunex. SonoVue (cumulative 7.5 ml dose) was well-tolerated, with a safety profile similar to that observed in the control group. CONCLUSIONS: SonoVue is superior to Albunex for improving visualization of endocardial borders in patients with suboptimal noncontrast echocardiograms. Optimal increases in LVEBD, LVO, and duration of useful contrast effect were observed at the 2.0 ml dose of SonoVue.     

Transesophageal three-dimensional echocardiographic assessment of left ventricular pseudoaneurysm

We report an adult patient with a left ventricular pseudoaneurysm following an acute myocardial infarction in whom three-dimensional (3-D) transesophageal echocardiography (TEE) delineated clearly not only the location but also the size and shape of the rupture site. The size of the rupture site measured by 3-D TEE correlated well with the surgical measurements. Three-dimensional images also showed a localized superior distortion of the lateral aspect of the mitral annulus and left atrial wall produced by the pseudoaneurysm. The resulting severe mitral regurgitation practically disappeared after repair and decompression of the pseudoaneurysm.     

Live/Real Time Three‐Dimensional Transthoracic Echocardiographic Assessment of Inferior Vena Cava and Hepatic Vein Thrombosis in Sickle Cell Disease

We describe the value of live/real time three‐dimensional transthoracic echocardiography (3DTTE) over two‐dimensional transthoracic echocardiography (2DTTE) in the assessment of inferior vena cava (IVC) and hepatic vein (HV) obstruction in a patient with sickle cell disease. 3DTTE provided additional information when compared to 2DTTE by (1) identifying the obstructing lesion as a likely thrombus, (2) by providing assessment of anatomical severity of IVC lumen obstruction since the thrombus could be visualized en face also, and (3) identifying an area of increased mobility of a portion of the thrombus suggesting greater risk of embolization. (Echocardiography 2010;27:594‐596)     

Three‐Dimensional Transthoracic Echocardiography in Identification of Aorto‐Right Atrial Fistula and Aorto‐Right Ventricular Fistulas

We report the case of a 72‐year‐old woman who developed new onset right ventricular failure after redo aortic valve replacement. The diagnosis of left to right shunt was initially made using two‐dimensional transthoracic echocardiography (2DTTE) and 2D transesophageal echo with color Doppler (TEE). Definite diagnosis of aorto‐right atrial and aorto‐right ventricular fistula was made using thee‐dimensional transthoracic echocardiography (3DTTE) with color flow Doppler imaging. Early recognition and diagnosis of this rare surgical complication is imperative for prompt surgical repair of this lethal defect. 3DTTE should be utilized in cases of new onset heart failure with unclear etiology to diagnose unusual causes of this potentially fatal condition. (Echocardiography 2010;27:E105‐E108)     

Live/Real Time Three‐Dimensional Transesophageal Echocardiographic Findings in Caseous Mitral Annular Calcification

We describe a 77‐year‐old female with hypertrophic cardiomyopathy in whom live/real time three‐dimensional transesophageal echocardiography (3DTEE) provided incremental value over two‐dimensional transthoracic and transesophageal echocardiography (2DTTE, 2DTEE) and three‐dimensional transthoracic echocardiography (3DTTE) in making a more comprehensive assessment and a more confident diagnosis of caseous mitral annular calcification. 3DTEE revealed a portion of the mass to consist of small, multiple, highly echogenic discrete band‐like and punctate areas within a relatively much less echogenic stroma and surrounded by a well defined highly echogenic border. This appearance correlated with the pathological findings of calcific granules/strands located in a liquefied or semiliquefied interior providing a typical toothpaste like appearance. The highly echogenic outer border represented the residual outer portion or rim of the calcific mass which did not undergo liquefaction. These findings on 3DTEE which correlated with the toothpaste like appearance seen at surgery were not visualized on 2DTTE, 2DTEE, and 3DTTE. (Echocardiography 2010;27:1147‐1150)