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עמוד בית
Mon, 09.12.24

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August 2018
Yoav Michowitz MD, Jeremy Ben-Shoshan MD, Oholi Tovia-Brodie MD, Aharon Glick MD and Bernard Belhassen MD

Background: The incidence, characteristics, and clinical significance of catheter-induced mechanical suppression (trauma) of ventricular arrhythmias originating in the outflow tract (OT) area have not been thoroughly evaluated.

Objectives: To determine these variables among our patient cohort.

Methods: All consecutive patients with right ventricular OT (RVOT) and left ventricular OT (LVOT) arrhythmias ablated at two medical centers from 1998 to 2014 were included. Patients were observed for catheter-induced trauma during ablation procedures. Procedural characteristics, as well as response to catheter-induced trauma and long term follow-up, were recorded.

Results: During 288 ablations of OT arrhythmias in 273 patients (RVOT n=238, LVOT n=50), we identified 8 RVOT cases (3.3%) and 1 LVOT (2%) case with catheter-induced trauma. Four cases of trauma were managed by immediate radiofrequency ablation (RFA), three were ablated after arrhythmia recurrence within a few minutes, and two were ablated after > 30 minutes without arrhythmia recurrence. Patients with catheter-induced trauma had higher rates of repeat ablations compared to patients without: 3/9 (33%) vs. 12/264 (0.45%), P = 0.009. The three patients with arrhythmia recurrence were managed differently during the first ablation procedure (immediate RFA, RFA following early recurrence, and delayed RFA). During the repeat procedure of these three patients, no catheter trauma occurred in two, and in one no arrhythmia was observed.

Conclusions: Significant catheter-induced trauma occurred in 3.1% of OT arrhythmias ablations, both at the RVOT and LVOT. Arrhythmia suppression may last > 30 minutes and may interfere with procedural success. The optimal mode of management following trauma is undetermined.

September 2017
Jeremy Ben-Shoshan MD PhD, Ayman Jubran MD, Ran Levy PhD, Gad Keren MD and Michal Entin-Meer PhD

Background: Systemic CD11b+ cells have been associated with several cardiac diseases, such as chronic heart failure.

Objectives: To assess the levels of circulating CD11b+ cells and pro-inflammatory cytokines in cardiomyopathy induced by chronic adrenergic stimulation.

Methods: Male Lewis rats were injected with low doses of isoproterenol (isoprel) for 3 months. Cardiac parameters were tested by echocardiography. The percentage of CD11b+ cells was tested by flow cytometry. The levels of inflammatory cytokines in the sera were determined by an inflammation array, and the expression levels of cardiac interleukin-1 (IL-1) receptors were analyzed by real-time polymerase chain reactions. Cardiac fibrosis and inflammation were determined by histological analysis.

Results: Chronic isoprel administration resulted in increased heart rate, cardiac hypertrophy, elevated cardiac peri-vascular fibrosis, reduced fractional shortening, and increased heart weight per body weight ratio compared to control animals. This clinical presentation was associated with accumulation of CD11b+ cells in the spleen with no concomitant cardiac inflammation. Cardiac dysfunction was also associated with elevated sera levels of IL-1 alpha and over expression of cardiac IL-1 receptor type 2.

Conclusions: CD11b+ systemic levels and IL-1 signaling are associated with cardiomyopathy induced by chronic adrenergic stimulation. Further studies are needed to define the role of systemic immunomodulation in this cardiomyopathy.

 

June 2016
Einat Hertzberg-Bigelman MsC, Rami Barashi MD, Ran Levy PhD, Lena Cohen MSc, Jeremy Ben-Shoshan MD PhD, Gad Keren MD and Michal Entin-Meer PhD

Background: Chronic kidney disease (CKD) is often accompanied by impairment of cardiac function that may lead to major cardiac events. Erythropoietin (EPO), a kidney-produced protein, was shown to be beneficial to heart function. It was suggested that reduced EPO secretion in CKD may play a role in the initiation of heart damage. 

Objectives: To investigate molecular changes in the EPO/erythropoietin receptor (EPO-R) axis in rat cardiomyocytes using a rat model for CKD.

Methods: We established a rat model for CKD by kidney resection. Cardiac tissue sections were stained with Masson’s trichrome to assess interstitial fibrosis indicating cardiac damage. To evaluate changes in the EPO/EPO-R signaling cascade in the myocardium we measured cardiac EPO and EPO-R as well as the phosphorylation levels of STAT-5, a downstream element in this cascade.

Results: At 11 weeks after resection, animals presented severe renal failure reflected by reduced creatinine clearance, elevated blood urea nitrogen and presence of anemia. Histological analysis revealed enhanced fibrosis in cardiac sections of CKD animals compared to the sham controls. Parallel to these changes, we found that although cardiac EPO levels were similar in both groups, the expression of EPO-R and the activated form of its downstream protein STAT-5 were significantly lower in CKD animals.

Conclusions: CKD results in molecular changes in the EPO/EPO-R axis. These changes may play a role in early cardiac damage observed in the cardiorenal syndrome.

 

December 2015
May-Tal Rofe MD, Ran Levi PhD, Einat Hertzberg-Bigelman MSc, Pavel Goryainov MSc, Rami Barashi MD, Jeremy Ben-Shoshan MD PhD, Gad Keren MD and Michal Entin-Meer PhD
 

Background: Chronic kidney disease (CKD) is a prevalent clinical condition affecting 15% of the general population. Cardiorenal syndrome (CRS) type 4 is characterized by an underlying CKD condition leading to impairment of cardiac function and increased risk for major cardiovascular events. To date, the mechanisms leading from CKD to CRS are not completely understood. In particular, it is unclear whether the pathological changes that occur in the heart in the setting of CKD involve enhanced cell death of cardiac cells.  


Objectives: To assess whether CKD may mediate loss of cardiac cells by apoptosis. 


Methods: We established rat models for CKD, acute myocardial infarction (acute MI), left ventricular dysfunction (LVD), and sham. We measured the cardiac-to-body weight as well as kidney-to-body weight ratios to validate that renal and cardiac hypertrophy occur as part of disease progression to CRS. Cardiac cells were then isolated and the percent of cell death was determined by flow cytometry following staining with annexin-FITC and propidium iodide. In addition, the levels of caspase-3-dependent apoptosis were determined by Western blot analysis using an anti-cleaved caspase-3 antibody. 


Results: CKD, as well as acute MI and LVD, resulted in significant cardiac hypertrophy. Nevertheless, unlike the increased levels of cell death observed in the acute MI group, in the CKD group, cardiac hypertrophy was not associated with induction of cell death of cardiac cells. Caspase-3 activity was even slightly reduced compared to sham-operated controls. 


Conclusions: Our data show that while CKD induces pathological changes in the heart, it does not induce cardiac cell death. 


 

 
November 2013
O. Havakuk, M. Entin-Meer, J. Ben-Shoshan, P. Goryainov, S. Maysel-Auslender, E.l Joffe and G. Keren
 Background: Vitamin D has been shown to induce beneficial effects on cardiovascular and renal morbidity by regulating inflammation and tissue fibrosis.

Objectives: To evaluate the effect of vitamin D analogues on cardiac function and fibrosis in an animal model of cardiorenal syndrome.

Methods: Unilateral nephrectomy was performed and myocardial infarction induced in rats. Rats were treated with vitamin D receptor activator (VDRA, paricalcitol, 40 ng/250 g x 3/week) versus a vehicle. A third group of animals, which served as the control, underwent sham surgery and received no treatment. After 4 weeks of treatment, cardiac function and fibrosis were assessed by trans-thoracic echo and histology, respectively. As a parameter of systemic inflammation, previously shown to be altered in acute coronary syndrome, T regulatory (Treg) cell levels were measured by flow cytometry. Renal dysfunction was documented by standard laboratory tests.

Results: After 4 weeks of treatment, no significant improvement in cardiac function parameters was noted following VDRA administration. VDRA treatment did not significantly alter Treg cell systemic levels. Consistently, despite a trend toward less extent of myocardial fibrosis, we found no clear beneficial effects of VDRA on myocardial tissue inflammation and remodeling.

Conclusions: Vitamin D treatment showed no beneficial effects on cardiac function parameters and fibrosis in an animal model of cardiorenal syndrome. 

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