Israel Medical Association Journal

Background: Idiopathic left ventricular tachycardia with a right bundle branch block configuration and left axis deviation, first described by Belhassen et al., is a rare electrocardiographic-electrophysiologic entity. Radiofrequency catheter ablation has been proposed as a good therapeutic option, but the best criteria for determining the optimal site of ablation are still under debate.

Objectives: To report the clinical features, electrophysiologic characteristics, results of RFA[1], and long-term outcome in 18 patients with "Belhassen's VT” treated in our laboratory during the last 10 years, stressing the best electrophysiologic criteria for determining the optimal site of ablation.

Methods: Eighteen consecutive patients with this specific VT[2] underwent RFA in our laboratory during the last 10 years. RFA was acutely successful in 17 patients after one or two procedures (15 and 2 patients, respectively) using 4.1 ± 2.2 RF pulses. The putative ablation sites were defined by good pace-mapping (3 patients), earliest recorded Purkinje spike prior to the QRS onset during VT or sinus rhythm (6 patients), earliest endocardial activation during VT (1 patient), and diastolic potential preceding the Purkinje spike during VT and/or late diastolic potential in sinus rhythm (7 patients). In the patients with a definite successful ablation, the ratio of successful to unsuccessful radiofrequency pulse delivery to the diastolic potential site was compared to that of other methods. The ratio of successful RFA at the diastolic potential site (5:8) was higher than in the other methods (8:31), and the difference was statistically significant (P = 0.05). Successful ablation sites were more basal when the diastolic potential site was chosen.

Conclusion: The results of the present study confirm the high success rate and safety of RFA using conventional techniques in the management of “Belhassen VT,” suggesting that this procedure can be proposed as a first-line therapy. Ablating at a site demonstrating a late diastolic potential is at least as effective as ablating at a ventricular exit site, although the use of combined electrophysiologic criteria may be the optimal approach.

Background: Hyperhomocysteinemia is a well-recognized risk factor for accelerated atherosclerosis in hemodialysis patients.

Objectives: To examine the effects of two doses of vitamins B6 and B12 and folic acid on homocysteine levels in hemodialysis patients and assess the functional impact of the methylenetetrahydrofolate reductase genotype on the response to treatment.

Methods: In a randomized prospective study, we assessed the effects of folic acid and two doses of B-vitamins in 50 hemodialysis patients with hyperhomocysteinemia. Patients were divided into two groups: 26 patients (group A) who received 25 mg of vitamin B₆ daily and one monthly injection of 200 µg vitamin B12, and 24 patients (group B) who received 100 mg of vitamin B6 daily and one monthly injection of 1,000 µg vitamin B12. In addition, both groups received 15 mg folic acid daily. Patients were evaluated for homocysteine levels as well as for coagulation and a thorough lipid profile. Baseline Hcy[1] levels were determined after at least 4 weeks washout from all folic acid and B-vitamins that were given. MFTHR[2] alleles were analyzed, as were activated protein C resistance, von Willebrand factor and lupus anticoagulant.

Results: Basal plasma Hcy levels were significantly elevated in hemodialysis patients compared with normal subjects (33.8 ± 4.3 vs. 4.5 to 14.0 mmol/L). Following treatment, Hcy levels were significantly reduced to 21.2 ± 1.6 in group A and 18.6 ± 1.4 mmol/L in group B (P < 0.01). There was no difference in Hcy reduction following the administration of either high or low dosage of vitamins B6 and B12 utilized in the present study. There was no correlation between Hcy levels or thrombophilia and high incidence of thrombotic episodes in hemodialysis patients. Genotypic evaluation of MTHFR revealed that the presence of homozygous thermolabile MTHFR (n = 5) was associated with higher Hcy levels and better response to treatment (Hcy levels decreased by 58%, from 46.2 ± 14.6 to 19.48 ± 4.1 mmol/L following treatment). In patients with heterozygous thermolabile MTHFR (n = 25), Hcy levels decreased by 34%, from 31.2 ± 3.7 to 18.1 ± 1.1 mmol/L following treatment. The efficacy of high and low doses of B-vitamins on the reduction of homocysteine levels was comparable.

Conclusions: Treatment with B-vitamins in combination with folic acid significantly decreased homocysteine levels in hemodialysis patients, independently of the tested doses. In addition, mutations in MTHFR were associated with elevated plasma levels of Hcy. Neither vascular access nor.

Background: Reports from Europe and North America indicate that significant changes have occurred in the practice of cardiac surgery in the last two decades.

Objectives: To examine the trends and case-mix in cardiac surgery in Israel and their relationship with changes in invasive cardiology.

Methods: We analysed data collected by the Ministry of Health from all cardiac centers in Israel from 1985 to 2002.

Results: Three periods were identified: the 1980s, when a relatively small number of operations were performed; 1990–1994, characterized by a dramatic rise in the number of operations; and 1994–present, characterized by a small decline and stabilization in the rate of operations. The percentage of valve procedures increased significantly from 15% of all cardiac surgeries in 1991 to 21% in 2002 (P = 0.002). In addition, the chance of a diagnostic coronary angiography being followed, in the same patient, by an interventional procedure such as percutaneous transluminal coronary angioplasty or by a coronary artery bypass graft increased dramatically from 42% in 1991 to 69% in 2002. At Rabin Medical Center, there was a constant decline in the percent of repeated CABGs[1] out of the total CABGs performed, from 6.7% in 1996 to 1.3% in 2002.

Conclusions: Despite the rise in the rate of percutaneous coronary interventions since 1991, there has been no significant decline in the rate of CABGs performed. However, there is a significant shift to more complex operations. The number of repeated CABG operations has significantly decreased and, in view of the growing use of arterial grafts and further improvements in invasive cardiology techniques, we expect this decline to continue.

Background: The highly tissue-specific trafficking of normal and malignant lymphocytes to particular organs is mediated by adhesion molecules, or “homing receptors.” Among our patients with B cell chronic lymphocytic leukemia 15% demonstrate predominantly splenic manifestations and are classified as stage II(S).

Objective: To investigate whether expression of cell surface adhesion molecules can distinguish stage II(S) patients from stage 0 or stage 0 and I CLL[1] patients.

Methods: Expression of adhesion molecules belonging to different families was studied in CD19-positive cells isolated from the blood of 42 patients by dual color flow cytometry. The families included: immunoglobulin superfamily (CD54, CD58), integrin family (β1, β2 and β3 chains, CD11a, CD11c CD49d), selectin family (L-selectin), and lymphocyte homing receptor family (CD44).

Results: The average percentage of leukemic cells expressing CD11c in the 23 patients with stage II(S) was 25.7 compared with 13.2% in the 14 patients with stage 0 disease (P = 0.047). The average percentage of leukemic cells expressing CD44 in patients with stage II(S) was 90.5 compared with 77.2% in patients with stage 0 (P = 0.007) and 80% in patients with stages 0 and I together (n=19, P = 0.008). Other adhesion molecules tested did not show a statistically significance difference in expression between the different disease stages.

Conclusions: The higher expression of CD44 and CD11c in cells of CLL patients with predominantly splenic manifestations may account for the tendency of their lymphocytes to home to the spleen.