Israel Medical Association Journal

Background: As the lowest natural site on earth (-415 meters), the Dead Sea is unique for its high pressure and oxygen tension in addition to the unparalleled combination of natural resources. Furthermore, its balneotherapeutic resorts have been reported to be beneficial for patients with various chronic diseases.

Objectives: To evaluate the safety, quality of life (QoL), exercise capacity, heart failure, and arrhythmia parameters in patients with systolic congestive heart failure (SCHF) and implantable cardioverter defibrillator (ICD) following descent and stay at the Dead Sea.

Methods: The study group comprised patients with SCHF, New York Heart Association functional class II-III after ICD implantation. The following parameters were tested at sea level one week prior to the descent, during a 4 day stay at the Dead Sea, and one week after return: blood pressure, O₂ saturation, ejection fraction (echocardiography), weight, B-type natriuretic peptide (BNP), arrhythmias, heart rate, heart rate variability (HRV), and QoL assessed by the Minnesota Living with Heart Failure questionnaire.

Results: We evaluated 19 patients, age 65.3 ± 9.6 years, of whom 16 (84%) were males and 18 (95%) had ICD-cardiac resynchronization therapy. The trip to and from and the stay at the Dead Sea were uneventful and well tolerated. The QoL score improved by 11 points, and the 6 minute walk increased by 63 meters (P < 0.001). BNP levels slightly increased with no statistical significance. The HRV decreased (P = 0.018). There were no significant changes in blood pressure, weight, O₂ saturation or ejection fraction.

Conclusions: Descent to, ascent from, and stay at the Dead Sea resort are safe and might be beneficial in some aspects for patients with sCHF and an ICD.
 

Background: Several murine models are susceptible to atherosclerosis, such as low density-lipoprotein receptor-deficient (LDLR^-/-) and apolipoprotein E-deficient (apoE^-/-) mice, and are used for studying pathophysiological mechanisms. Atherosclerotic lesions in the aortic valve and thoracic/abdominal aorta are commonly associated with hyperlipidemia. We recently demonstrated the development of large atherosclerotic plaques in Helicobacter pylori-infected heterozygous LDLR^+/- apoE^+/- mice.

Objectives: To measure novel biomarkers related to atherosclerosis, blood coagulation, and oxidative stress in order to investigate their possible pathogenic roles in atherosclerosis-prone mice.

Methods: Mice were fed with a normal chow diet or high-fat diet and sacrificed at different age intervals to measure aortic plaque size. Plasma cholesterol was enzymatically measured. Enzyme-linked immunosorbent assay was used to measure oxidized LDL (oxLDL)/beta-2-glycoprotein I (β2GPI) complexes, immunoglobulin M (IgM) antibodies against native LDL, oxLDL, or oxLDL/β2GPI, and urine 11-dehydro-thromboxane B₂ (11-dhTxB₂) or 8-hydroxy-deoxyguanosine.

Results: There was a parallel increase in plaque size, plasma cholesterol, and urinary 11-dhTxB₂ in atherosclerosis-prone mice. In contrast to atherosclerosis-prone strains, an elevation of urinary 11-dhTxB₂ with no significant plaque generation was observed in LDLR^+/- apoE^+/- mice. The atherogenic autoantigen oxLDL/β2GPI complex was detected only in LDLR^-/- mice. These levels seem to depend on plaque size. IgM antibodies against oxLDL in apoE^-/- mice were found, accompanied by atherosclerotic progression.

Conclusions: Progression of atherosclerotic lesions was associated not only with cholesterolemia but also with platelet activation and natural autoimmune-mediated regulatory mechanism(s) in murine models.
 

Background: Coronary CT angiography is an accurate imaging modality; however, its main drawback is the radiation dose. A new technology, the "step and shoot," which reduces the radiation up to one-eighth, is now available.

Objectives: To assess our initial experience using the "step-and-shoot" technology for various vascular pathologies.

Methods: During a 10 month period 125 consecutive asymptomatic patients (111 men and 14 women aged 25–82, average age 54.9 years) with various clinical indications that were appropriate for step-and-shoot CCTA[1] (regular heart rate < 65 beats/minute and body weight < 115 kg) were scanned with a 64-slice multidetector computed tomography Brilliance scanner (Philips, USA). The preparation protocol for the scan was the same as for the regular coronary CTA. All examinations were interpreted by at least one experienced radiologist and one experienced interventional cardiologist. The quality of the examinations was graded from 1 (excellent imaging quality of all coronary segments) to 4 (poor quality, not diagnostic). There were 99 patients without a history of coronary intervention, 13 after coronary stent deployment (19 stents), and 3 after coronary artery bypass graft.

Results: Coronary interpretation was obtained in 122 examinations (97.6%). The imaging quality obtained was as follows: 103 patients scored 1 (82.4%), 15 scored 2 (12%), 4 scored 3 (3.2%) and 3 scored 4 (2.4%). The grades were unrelated to cardiac history or type of previous examinations. Poor image quality occurred because of sudden heart rate acceleration during the scan (one patient), movement and respiration (one patient), and arrhythmia and bad scan timing (in one). Two patients were referred to percutaneous coronary intervention based on the CCTA findings, which correlated perfectly.

Conclusions: Step-and-shoot CCTA is a reliable technique and CCTA algorithm comparable to the regular CCTA. This technique requires the lowest radiation dose, as compared to other coronary imaging modalities, that can be used for all CCTA indications based on the inclusion criteria of low (> 65 bpm) and stable heart rate.

Background: Trans-aortic pressure gradient in patients with aortic stenosis and left ventricular systolic dysfunction is typically low but occasionally high.

Objectives: To examine the distribution of trans-aortic PG[1] in patients with severe AS[2] and severe LV[3] dysfunction and compare the clinical and echocardiographic characteristics and outcome of patients with high versus low PG.

Methods: Using the echocardiographic laboratory database at our institution, 72 patients with severe AS (aortic valve area ≤ 1.0 cm²) and severe LV dysfunction (LV ejection fraction ≤ 30%) were identified. The characteristics and outcome of these patients were compared.

Results: PG was high (mean PG ≥ 35 mmHg) in 32 patients (44.4%) and low (< 35 mmHg) in 40 (55.6%). Aortic valve area was slightly smaller in patients with high PG (0.63 ± 0.15 vs. 0.75 ± 0.16 cm² in patients with low PG, P = 0.003), and LV ejection fraction was slightly higher in patients with high PG (26 ± 5 vs. 22 ± 5% in patients with low PG, P = 0.005). During a median follow-up period of 9 months 14 patients (19%) underwent aortic valve replacement and 46 patients (64%) died. Aortic valve replacement was associated with lower mortality (age and gender-adjusted hazard ratio 0.19, 95% confidence interval 0.05–0.82), whereas trans-aortic PG was not (P = 0.41).

Conclusions: A large proportion of patients with severe AS have relatively high trans-aortic PG despite severe LV dysfunction, a finding partially related to more severe AS and better LV function. Trans-aortic PG is not related to outcome in these patients.

Background: An accurate preoperative definition of tumor and lymph node status is needed for reaching the correct decision regarding rectal cancer treatment. Transrectal ultrasonography is the most commonly used diagnostic modality for the local staging of rectal cancer.

Objectives: To determine the accuracy of TRUS[1] in the staging of rectal cancer.

Methods: We conducted a retrospective study on 95 patients evaluated by TRUS. The rectum was subdivided into two parts (lower and upper).

Results: Sixty patients underwent radical surgery. Of these, 34 received no preoperative chemo-irradiation owing to µT1, µT2 tumor or the patient’s choice (neo-adjuvant treatment was suggested to patients with adenocarcinoma that proved to be µT3). The overall accuracy rate was 80% for T stage. Overstaging was found in 13.3% and understaging in 6.7%.The N-stage was correctly assessed in 70%. The overall accuracy rate for tumors was 73.9% in the lower part and 90.9% in the upper. A trend towards a lower accuracy rate for low-lying tumors compared to high-located rectal tumors was found (P = 0.532), which did not reach statistical significance.

Conclusions: TRUS gave better results for T1 and T3 stage rectal tumors but was inaccurate for stage T2, indicating the possible need for local excision in order to base the final treatment for T2 tumors on pathologic staging.
[1] TRUS = transrectal ultrasonography
 

Background: High frequency oscillatory ventilation based on optimal lung volume strategy is one of the accepted modes of ventilatory support for respiratory distress syndrome in very low birth weight infants. In 1999 it was introduced in our unit as the primary ventilation modality for RDS[1].

Objectives: To evaluate if the shift to HFOV[2] influenced the outcome of ventilated VLBW[3] infants in the neonatal intensive care unit of Carmel Medical Center.

Methods: Data were obtained from the medical charts of VLBW infants born at Carmel Medical Center, and late mortality data were taken from the Israel Ministry of Internal Affairs records. A retrospective analysis and a comparison with a historical control group ventilated by the conventional method were performed.

Results: A total of 232 VLBW infants with RDS were mechanically ventilated, from 1995 to 2003: 120 were ventilated using HFOV during the period 1999–2003 and 102 infants using CV[4] during 1995–1999. The mean gestational age of survivors was 27.4 ± 2 weeks in the HFOV group and 28.4 ± 2 in the conventional ventilation group (P = 0.03). The sub-sample of infants with birth weights <1000 g ventilated with HFOV showed higher survival rates than the infants in the conventional ventilation group, 53 vs. 25 (64.6% vs. 44.6%) respectively (P < 0.05). A trend for lower incidence of pulmonary interstitial emphysema was observed in the HFOV group.

Conclusions: The introduction of HFOV based on optimal lung volume strategy proved to be an efficient and safe method of ventilation support for VLBW infants in our unit.

Background: Professional drivers have been found to be at high risk for developing low back pain. However, the exact reasons are poorly understood.

Objectives: To assess the prevalence of LBP[1] among Israeli professional urban bus drivers, and evaluate the association between LBP in drivers and work-related psychosocial and ergonomic risk factors.

Methods: A total of 384 male full-time urban bus drivers were consecutively enrolled to this cross-sectional study. Information on regular physical activity and work-related ergonomic and psychosocial stressing factors was collected during face-to-face interviews. The prevalence of LBP was assessed using the Standardized Nordic Questionnaire.

Results: From the total cohort, 164 bus drivers (45.4%) reported experiencing LBP in the previous 12 months. Ergonomic factors associated with LBP were uncomfortable seat (odds ratio 2.6, 95% confidence interval 1.4–5.0) and an uncomfortable back support (OR[2] 2.5, 95% CI[3] 1.4–4.5). In the group of drivers with LBP, 48.5% reported participation in regular physical activities vs. 67.3% in the group without LBP (P < 0.01). The following psychosocial stressing factors showed significant association with LBP: “limited rest period during a working day” (1.6, 1.0–2.6), “traffic congestion on the bus route” (1.8, 1.2–2.7), “lack of accessibility to the bus stop for the descending and ascending of passengers” (1.5, 1.0–1.5), and “passengers' hostility” (1.8, 1.1–2.9).

Conclusions: Work-related ergonomic and psychosocial factors showed a significant association with LBP in Israeli professional urban bus drivers. Prevention of work-related stress, organizational changes targeted to reduce stressful situations, improvement in seat comfort, and encouraging regular sports activity need to be evaluated as prevention strategies for LBP in professional bus drivers.

Background: The incidence of congenital heart defects, reported to be 5–8/1000 in term infants, is not well established in very low birth weight infants.

Objectives: To establish the incidence of congenital heart defects in VLBW[1] infants in the neonatal intensive care unit of our institution.

Methods: A retrospective analysis of the population in the NICU[2] at our institution was performed. VLBW (BW ≤ 1500 g) infants born between 2001 and 2006 who survived more than 48 hours were included in the study. Infants with clinical signs of heart disease underwent echocardiography.

Results: During the study period 437 VLBW live-born infants met the inclusion criteria. Of these, 281 (64.3 %) underwent echocardiography. CHD[3] was detected in 19 infants (4.4%, 95% confidence interval 2.4–5.4%), significantly higher than the incidence of 5–8/1000 in the general population (P < 0.0001). In the subgroup of 154 infants with BW < 1000 g there were 10 (6.5%) with CHD. In the subgroup of 283 infants with BW 100–-1500 g there were 9 (3.2 %, P = 0.19 vs. VLBW) with CHD.

Conclusions:  Our observations show an increased incidence of CHD in VLBW neonates, as compared to the general population. Since not all infants underwent echocardiography, and minor cardiac defects may have been missed in our VLBW infants, the true incidence may be higher than reported here.

Background: Low back pain is a common problem managed by primary care physicians and orthopedic specialists.

Objectives: To evaluate the outcome of new LBP[1] episodes in patients who chose to visit either an orthopedist or a general practitioner.

Methods: All patients visiting the orthopedist or physician during the study period were screened for a new complaint of LBP. After the initial visit the patients were interviewed by phone by means of a structured questionnaire, with a follow-up interview one month later. The study was performed at Clalit Health Services primary care and consultation clinics. A random sample of 125 GPs[2] and 17 orthopedists were chosen. Consecutively recruited were 166 patients who visited the GP and 75 the orthopedist. The main outcome measures evaluated were perceived complaint severity and degree of disturbance to everyday functioning, problem resolution, and health services utilization.

Results: Patients who decided to first visit the orthopedist indicated a higher disturbance to everyday functioning (75% vs. 70%, P < 0.01), were invited for further follow-up visits (6% vs. 51%, P < 0.05) and had more computed tomography and bone scans (20 vs. 3%, P < 0.001 and 9 vs. 2%, P < 0.05, respectively). Health status after one month showed that patients who chose the GP were more likely to have their problem solved (36 vs. 17%, P < 0.05).

Conclusions: Symptom resolution for a new LBP complaint was significantly higher in patients who decided on the GP, even when controlling for severity of illness and degree of disturbance to everyday functioning.

Background: Fat tissue mediates the production of inflammatory cytokines and oxidative products, which are key steps in the development of type 2 diabetes and atherosclerosis. Antioxidant-rich diets protect against chronic diseases, but antioxidants may interfere with pro-inflammatory signals.

Objectives: To investigate the effect of the potent tomato-derived antioxidant carotenoid, lycopene, on plasma antioxidants (carotenoids and vitamin E), inflammatory markers (C-reactive protein, interleukin-6, tumor necrosis factor-alpha), and oxidation products (conjugated dienes).

Methods: Eight obese patients (body mass index 37.5 ± 2.5 kg/m²) were compared with a control group of eight lean, age and gender-matched subjects (BMI[1] 21.6 ±  0.6 kg/m²), before and after 4 weeks of lycopene supplementation (tomato-derived Lyc-O-Mato) (30 mg daily).

Results: Plasma carotenoids were significantly reduced in the obese compared to control subjects (0.54 ± 0.06 vs. 0.87 ± 0.08 mg/ml, P < 0.01). CRP[2] levels were significantly higher (6.5 vs. 1.1 mg/L, P = 0.04) in obese vs. controls, as were IL-6[3] and conjugated dienes (3.6 and 7.9-fold, respectively). CRP, IL-6 and conjugated dienes correlated with BMI, while IL-6 and conjugated dienes correlated inversely with carotenoids (P < 0.05). Following lycopene treatment, a significant elevation of plasma carotenoids (1.79 vs. 0.54 ug/ml) and specifically lycopene (1.15 vs 0.23 ug/ml) (P < 0.001) occurred in the treatment vs. placebo group, respectively. Markers of inflammation and oxidation products were not altered by lycopene.
Conclusions: Obese patients showed abnormally higher markers of inflammation and oxidation products and lower plasma carotenoids. The lack of reduction of pro-inflammatory markers could be attributed to the short period of the study and the small number of participants. More studies are needed on the protective qualities of natural antioxidant-rich diets against obesity-related co-morbidities.

Background: The predictive value of electrophysiologic studies depends on the aggressiveness of the programmed ventricular stimulation protocol.

Objectives: To assess if non-inducibility with an "aggressive" protocol of PVS[1] identifies post-infarction patients with low ejection fraction (EF[2] ≤ 30%) who may safely be treated without implantable cardioverter defibrillator.

Methods: We studied 154 patients during a 9 year period. Our aggressive PVS protocol included: a) stimulus current five times the diastolic threshold (≤ 3 mA) and b) repetition of double and triple extrastimulation at the shortest coupling intervals that capture the ventricle.

Results: Sustained ventricular tachyarrhythmias were induced in 116 patients (75.4%) and 112 (97%) of them received an ICD[3] (EPS[4]+/ICD+ group). Of the 38 non-inducible patients, 34 (89.5%) did not receive an ICD (EPS-/ICD- group). In comparison to the EPS+/ICD+ group, EPS-/ICD- group patients were older (69 ± 10 vs. 65 ± 10 years, P < 0.05), had a lower EF (23 ± 5% vs. 25 ± 5%,  P < 0.05) and a higher prevalence of left bundle branch block (45.5% vs. 20.2%, P < 0.005). Follow-up was longer for EPS+/ICD+ patients (40 ± 26 months) than for EPS-/ICD- patients (27 ± 22 months) (P = 0.011). Twelve EPS+/ICD+ patients (10.7%) and 5 EPS-/ICD- patients (14.7%) died during follow-up (P = 0.525). Kaplan-Meier survival curves did not show a significant difference between the two groups (P = 0.18).
Conclusions: The mortality rate in patients without inducible VTAs[5] using an aggressive PVS protocol and who did not undergo subsequent ICD implantation is not different from that of patients with inducible arrhythmias who received an ICD. Using this protocol, as many as one-fourth of primary prevention ICD implants could be spared without compromising patient prognosis