Septal Myectomy in Hypertrophic Cardiomyopathy: National Outcomes of Concomitant Mitral Surgery

Objectives

To assess the frequency and implications of mitral valve (MV) surgery at the time of septal myectomy (SM) for hypertrophic cardiomyopathy (HCM) in a national cohort.

Rabies vaccine is associated with decreased all-cause mortality in dogs

Evidence suggests that rabies vaccine may have non-specific protective effects in animals and children. We analyzed four years of data (2012–2015) from an observational study of the health and demographics of a population of owned, free-roaming dogs in a low-income community in South Africa. The objective of this analysis was to assess the association between rabies vaccine and all-cause mortality in dogs, stratified by age group (0–3 months, 4–11 months, and 12 months and older), and controlling for the effects of sex and number of dogs in the residence. Rabies vaccination reduced the risk of death from any cause by 56% (95% CI = 16–77%) in dogs aged 0–3 months, by 44% (95% CI = 21–60%) in dogs aged 4–11 months and by 16% (95% CI = 0–29%) in dogs aged 12 months and older. We hypothesize that the protective association between rabies vaccination status and all-cause mortality is due to a protective effect of rabies vaccine against diseases other than rabies. Existence of a strong non-specific protective effect of rabies vaccine on mortality in dogs would have implications for the design of dog rabies control programs that aim to eliminate dog-mediated human rabies cases. Further, we propose that owned domestic dogs in high mortality settings provide a useful animal model to better understand any non-specific protective effect of rabies vaccine in children, due to dogs’ high numbers, high morbidity and mortality rates, relatively short lifespan, exposure to a variety of infectious and parasitic diseases, and shared environment with people.     

Thirst and vasopressin secretion following central administration of angiotensin II in rats with lesions of the septal area and subfornical organ

Various dipsogenic stimuli, including peripheral and central administration of angiotensin II, have been shown to be capable of releasing vasopressin from the neurohypophyseal system. Studies were carried out in the rat to investigate whether the septal area, which contains a high concentration of angiotensin-sensitive cells and has neural connections with hypothalamic vasopressin-secreting neurons, mediated the stimulatory effect produced by angiotensin II on vasopressin release. Rats with electrolytic lesions in the region of the septal area had increased daily water consumption and urine output when these lesions included the medioventral or lateral nuclei of the septal forebrain, but not when the lesion involved the subfornical organ. No difference was observed in drinking responses following water deprivation or intracerebroventricular injection of angiotensin II in all experimental groups. In addition, the impaired ability to maintain water homeostasis (polyuro-polydipsic syndrome) of septal-lesioned rats was associated septal-lesioned rats was associated with decreased levels of circulating radioimmunoassayable vasopressin. Furthermore, the vasopressin release which occurred in response to intracerebroventricular angiotensin II in normal controls, sham-lesioned and subfornical organ-lesioned rats was significantly attenuated in rats with electrolytic lesion of the medioventral or lateral septal area. Since cells in the lateral septal area are excited by iontophoretic application of angiotensin II, the present data might be consistent with the hypothesis that the stimulatory effect produced by central administration of angiotensin II on vasopressin release rests upon the integrity of the lateral septal area.     

Biatrial maze procedure versus pulmonary vein isolation for atrial fibrillation during mitral valve surgery: New analytical approaches and end points

Objective

To use novel statistical methods for analyzing the effect of lesion set on (long-standing) persistent atrial fibrillation (AF) in the Cardiothoracic Surgical Trials Network trial of surgical ablation during mitral valve surgery (MVS).

Anatomy of membranous ventricular septum in the human heart

One of the most common congenital abnormalities of the human heart is a defect in the development of the membranous part of the ventricular septum which, in this study, is designated the MVS. The WS is a thin fibrous membrane, about 1 cm long, which extends upward and to the right from the muscular ventricular septum to the adjacent part of the aortic fibrous annulus that also gives attachment to the right posterior (noncoronary) and anterior (right coronary) aortic valve cusps. It is of considerable clinical importance that there lies between the muscular ventricular septum and the MVS the atrioventricular (AV) bundle of the cardiac conduction system. The MVS has an irregular quadrangular form and has right and left surfaces. This study is based on macroscopic and histological sections of more than 30 normal and abnormal hearts. © 1994 Wiley-Liss, Inc.