Israel Medical Association Journal

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.

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.

 

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.

 

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. 

Background: Atherosclerosis is a well-established inflammatory disease in which T helper 1 (Th1) cells play a key role. Regulatory T (Treg) cells drive a shift from Th1 to Th2 response and were shown to be reduced in atherosclerosis. ST2/interleukin (IL)-33 signal was found to promote Th2 response, attenuating atherosclerotic plaque progression.

Objectives: To evaluated the effect of IL-33 on Treg cell number.

Methods: We employed flow cytometry to determine Treg cell number, as well as ST2 levels, among splenocytes of C57BL/6J vs ApoE-/- mice. Soluble ST2 (sST2) levels were detected by enzyme-linked immunosorbent assay. 

Results: IL-33 contributed to an increase in Treg cells, but this association was attenuated in ApoE knockout (ApoE-/-) atherosclerotic mice. As a possible mechanism we demonstrated a reduction in the levels of CD4+ST2+ cells by flow cytometry, which is cotemporary to the previously described decrease in Treg cells in ApoE-/- mice. Additionally, the serum level of the soluble ST2 (sST2) decoy receptor was higher in ApoE-/- mice than in control animals.

Conclusions: Our results suggest that a repressed ST2/IL-33 signaling may contribute to the decrease in Treg cells observed in atherosclerosis.
 

Heart failure (HF) accompanied by renal failure, termed cardiorenal syndrome (CRS), encompasses both the development and worsening of renal insufficiency secondary to HF as well as the harmful effects of impaired renal function on the cardiovascular system, and remains a universal clinical challenge. CRS was recently classified into subtypes depending on the etiologic and chronologic interactions between cardiac and renal dysfunctions. The mechanisms underlying the CRS are multifactorial, including hemodynamic alterations, neurohormonal effects, and inflammatory components. However, despite enhanced understanding and awareness of CRS, further elucidation of the mechanisms involved and the appropriate treatment approaches are clearly warranted. CRS is a difficult condition to manage, as treatment to relieve congestive symptoms of HF is limited by a further decline in renal functions, itself a major independent predictor of long-term cardiac morbidity. In order to perform a proper clinical investigation and implement appropriate treatment that will minimize subsequent progression of heart and kidney injury, a comprehensive approach to these two pathologies is crucial. In the present review we discuss current theories behind the mechanistic evolution of the CRS as well as therapeutic issues regarding this multifaceted condition.
 

Background: Studies suggest that global semen quality is declining, but the debate remains open owing to geographic variation.

Objectives: To evaluate temporal trends of sperm parameters – namely concentration, motility and total motile sperm count – in sperm donated during the period 1995–2009.

Methods: In a retrospective longitudinal cohort study we analyzed the sperm count and motility of 2182 semen samples provided on a weekly basis by 58 young, healthy, fertile, university-educated, paid donors.

Results: Despite the lowering of criteria for sperm parameters satisfactory for donation that were implemented in 2004, 38% of applicants for sperm donation are now rejected based on semen quality as compared to a third of applicants 10–15 years ago (P < 0.001). If the old strict criteria were in place 88% of candidates would be rejected today (P < 0.0001). Over the study period, the average sperm parameters dropped from a concentration of 106 ± 25 million spermatozoa/ml with 79% ± 4.3% motility to 68 ± 14 million/ml with 66% ± 4.5% motile sperm (P < 0.0001, P < 0.0001, respectively). The total motile sperm count per ejaculate also decreased, from 66.4 ± 18.2 million to 48.7 ± 12 million (P < 0.005). When the previous criteria were implemented for the analysis of the latest group of sperm donors, only 18% of donors had an acceptable sperm quality, with an average concentration of 87 ± 12 million spermatozoa/ml, 73% ± 2.6% motile sperm and total motile sperm count of 53.1 ± 3.8 million per ejaculate – still significantly lower than 15 years ago (P = 0.01, P = 0.003, P = 0.058 respectively).

Conclusions: The rapid deterioration of sperm quality among fertile semen donors is alarming and may lead to cessation of sperm donation programs.