Efficacy of tilt training in the treatment of neurally mediated syncope. A randomized study.

Recurrent neurally mediated syncope represents a common clinical event and a therapeutic challenge. Recently tilt training has been proposed for the treatment of recurrent neurally mediated syncope. To evaluate the efficacy of tilt training in preventing tilt-induced syncope and its feasibility, this controlled, randomized study was undertaken. Sixty-eight consenting patients (25 males and 43 females, mean age 40 +/- 19) with recurrent neurally mediated syncope and 2 consecutive positive nitroglycerin-potentiated head-up tilt tests were randomized to tilt training (35 patients) or no treatment (controls, 33 patients). The tilt training programme consisted of daily 30-min sessions of upright standing against a vertical wall 6 days a week for at least 3 weeks, until a reevaluation tilt test (3 patients of both groups dropped out). On this third head-up tilt test, 19 (59%) of 32 tilt trained patients and 18 (60%) of 30 controls still had a positive test. Treated patients performed a mean number of 15 +/- 7 sessions (median 16) and only 11 patients (34%) did all the programmed sessions. Only 1 patient (3%) discontinued treatment because of intolerance, while all other patients did not perform tilt training adequately, because of poor compliance. Thus, in our study tilt training was not effective in reducing tilt testing positivity rate in patients with neurally mediated syncope. Because of poor compliance, tilt training appears to be a feasible treatment only for highly motivated patients, but not for the majority of patients with recurrent neurally mediated syncope.     

心房颤动介导的心肌病

心房颤动介导的心肌病(atrial fibrillation mediated cardiomyopathy,AMC)用于描述房颤导致的可逆性心力衰竭,随着导管消融和起搏技术的进展,房颤合并心衰患者中约有50％ ～60％ 的患者可能是"房颤介导的心肌病",其发病机制目前尚未完全阐明,心房功能缺损、快速心室率等因素并不能...     

Impact of parathyroidectomy on cardiovascular risk in primary hyperparathyroidism: A narrative review

AimsPrimary hyperparathyroidism (PHPT), one of the most frequent endocrine disorders, is not only associated with bone and kidney disorders but also with increased cardiovascular risk. This cardiovascular risk is not part of the indication for surgery owing to discordant evidence of the effects of parathyroidectomy (PTX), especially in mild PHPT which is the most common presentation of PHPT. This literature review focuses on the effects of PTX on the cardiovascular risk in PHPT. The MEDLINE database was searched via the PubMed interface, selecting relevant articles published after 1990 in English.Data synthesisIn the most recent series, PTX appeared to have a positive impact on cardiovascular morbidity and mortality. Surgery improves arterial hypertension, markers of glucose homeostasis, vascular and cardiac remodeling and electrocardiographic impairments due to classical PHPT. However, the results of surgery on mild PHPT are conflicting.ConclusionsPTX seems to improve cardiovascular risk in patients presenting the classical form of PHPT. This improvement is correlated with preoperative serum calcium and/or PTH level, depending on the cardiovascular risk factor. However, many aspects of this improvement are not fully understood. Future studies should assess the effects of PTX on nocturnal hypertension, cardiac morphology and functions. The results for mild PHPT are conflicting owing to the limited size of the cohorts included in studies and the lack of randomized trials. Surgery is not currently recommended for patients presenting mild PHPT based on the cardiovascular risk and more studies are needed to better understand the interest of PTX on cardiovascular outcomes.     

The Relation between the Color M‐Mode Propagation Velocity of the Descending Aorta and Coronary and Carotid Atherosclerosis and Flow‐Mediated Dilatation

Background: To improve clinical outcomes, noninvasive imaging modalities have been proposed to measure and monitor atherosclerosis. Common carotid intima‐media thickness (CIMT) and brachial artery flow‐mediated dilatation (FMD) have correlated with coronary atherosclerosis. Recently, the color M‐mode‐derived propagation velocity of descending thoracic aorta (AVP) was shown to be associated with coronary artery disease (CAD). Methods: CIMT, FMD, and AVP were measured in 92 patients with CAD and 70 patients having normal coronary arteries (NCA) detected by coronary angiography. Patients with acute myocardial infarction, renal failure or hepatic failure, aneurysm of aorta, severe valvular heart disease, left ventricular ejection fraction <40%, atrial fibrillation, frequent premature beats, left bundle branch block, and inadequate echocardiographic image quality were excluded. Results: Compared to patients with normal coronary arteries, patients having CAD had significantly lower AVP (29.9 ± 8.1 vs. 47.5 ± 16.8 cm/sec, P < 0.001) and FMD (5.3 ± 1.9 vs. 11.4 ± 5.8%, P < 0.001) and higher CIMT (0.94 ± 0.05 vs. 0.83 ± 0.14 mm, P < 0.001) measurements. There were significant correlations between AVP and CIMT (r =−0.691, P < 0.001), AVP and FMD (r = 0.514, P < 0.001) and FMD and CIMT (r =−0.530, P < 0.001). Conclusions: The transthoracic echocardiographic determination of the color M‐mode propagation velocity of the descending aorta is a simple practical method and correlates well with the presence of carotid and coronary atherosclerosis and brachial endothelial function. (Echocardiography 2010;27:300‐305)     

Possible roles of excess tryptophan metabolites in cancer

Tryptophan is metabolized through serotonin, indole, and kynurenine (KN) pathways. Uptake of an excess amount of tryptophan accompanied with vitamin B6 deficiency may result in the accumulation of higher concentrations of metabolites mainly from the KN pathways in the bladder. These metabolites could interact with nitrite to become mutagenic nitrosamines. They could be a promoter in the initiator–promoter model of carcinogenesis. They produced bladder cancer when implanted in the bladder. They also interact with transition metals copper or iron to form reactive radicals or reactive oxygen species (ROS). Some metabolites, 3‐hydroxy‐anthranilic acid, were autooxidized to mutagenic cinnabarinic and anthranilyl radical intermediates. These radical intermediates could also be ligands that interact with aryl hydrocarbon receptor (AhR) and induce xenobiotic metabolizing enzymes (XMEs) to metabolize contaminated carcinogens. When tryptophan is exposed to either visible or UV light, a photoproduct of 6‐formylindolo[3,2b]‐carbazole is formed, which has a very high affinity for the AhR that plays a role in carcinogenesis. This review gives an insight into various mechanisms through which tryptophan metabolites cause carcinogenesis. It could be concluded that tryptophan metabolites play a complementary role in promoting carcinogenesis along with carcinogens like aflatoxin, CCl₄, 2‐acetylaminofluorene, 4‐aminobiphenyl, 2‐naphthylamine, or N‐[4‐(5‐nitro‐2‐furyl)?2‐thiazolyl] formamide. The underlying mechanisms could be their autoxidation, exposure to either visible or UV light, interaction with nitrite or transition metals to form reactive intermediates, serving as ligands to interact with an AhR that is known to play a role in carcinogenesis through induction of XMEs. Further research is warranted.Environ. Mol. Mutagen. 52:81–104, 2011. © 2010 Wiley‐Liss, Inc.     

Is chronic ulcerative stomatitis a variant of lichen planus,or a distinct disease?

Chronic ulcerative stomatitis is an immune‐mediated mucocutaneous disorder characterized clinically by erosions or ulcers. Most cases are limited to the mouth. The histopathological features are non‐specific or mimic those of oral lichen planus, and studies by immunofluorescent microscopy are essential for definitive diagnosis. The defining immunopathogenic mechanism is the binding of IgG to the nuclear protein deltaNp63alpha of keratinocytes in the basal and parabasal cell layers of the oral stratified epithelium. DeltaNp63alpha functions as a regulator of epithelial stem cell activity and as an antiapoptotic agent and regulates the expression of cell‐to‐cell and cell‐to‐basement membrane adhesion molecules. The autoimmune IgG‐deltaNp63alpha interaction is thought to result in damage to the structural attachment of keratinocytes to one another and to the epithelial basement membrane zone and in dysregulation of the cell cycle and apoptosis of basal keratinocytes with the development of erosions or ulcers. The aims of treatment are to suppress the pathogenic immunoinflammatory responses, to prevent local infection and to promote healing. The purpose of this article is to provide a succinct review of the diagnostic, clinical and etiopathogenic features of, and treatment guidelines for chronic ulcerative stomatitis, and to argue that this disease should be regarded as a variant of oral lichen planus, rather than as a distinct entity.     

Association between Endothelial Function and Chronotropic Incompetence in Subjects with Chronic Heart Failure Receiving Optimal Medical Therapy

Objective: Impairment of flow‐mediated, endothelium‐dependent vasodilatation (FMD) of the brachial artery identifies peripheral endothelial dysfunction in subjects with chronic congestive heart failure (CHF) and is associated with increased morbidity and mortality. To further elucidate the interaction of peripheral and central mechanisms in the syndrome of CHF, we examined the association between endothelial function and chronotropic incompetence, an emerging prognostic marker in CHF. Methods: Thirty subjects with stable New York Heart Association (NYHA) functional class II–III CHF were studied. A vascular ultrasound study was performed to measure brachial artery FMD. The percentage of age‐adjusted maximal predicted heart rate (MPHR) reached during cardiopulmonary exercise tolerance testing (CPETT) was used to assess the degree of chronotropic competence. All patients received ACE inhibitors and β‐adrenoceptor blockers. Results: Brachial artery FMD averaged 1.3 ± 2.4% and age‐adjusted % MPHR 74.1 ± 11.7%. FMD correlated with % MPHR among all patients (r = 0.60, P = 0.01). FMD and resting heart rate (RHR) did not significantly correlate (r = 0.13, P = 0.55). Conclusions: FMD, a measure of peripheral endothelial dysfunction, and % MPHR, a central determinant of cardiac output, are moderately correlated in heart failure patients receiving optimal medical therapy. Whether a cause‐effect relationship underlies this association remains to be investigated. (Echocardiography 2010;27:294‐299)