Ablation of the ability to control the right-to-left cardiac shunt does not affect oxygen uptake, specific dynamic action or growth in the rattlesnake Crotalus durissus

The morphologically undivided ventricle of the heart in non-crocodilian reptiles permits the mixing of oxygen-rich blood returning from the lungs and oxygen-poor blood from the systemic circulation. A possible functional significance for this intra-cardiac shunt has been debated for almost a century. Unilateral left vagotomy rendered the single effective pulmonary artery of the South American rattlesnake, Crotalus durissus, unable to adjust the magnitude of blood flow to the lung. The higher constant perfusion of the lung circulation and the incapability of adjusting the right-left shunt in left-denervated snakes persisted over time, providing a unique model for investigation of the long-term consequences of cardiac shunting in a squamate. Oxygen uptake recorded at rest and during spontaneous and forced activity was not affected by removing control of the cardiac shunt. Furthermore, metabolic rate and energetic balance during the post-prandial metabolic increment, plus the food conversion efficiency and growth rate, were all similarly unaffected. These results show that control of cardiac shunting is not associated with a clear functional advantage in adjusting metabolic rate, effectiveness of digestion or growth rates. © 2013. Published by The Company of Biologists Ltd.

Diastolic function is associated with quality of life and exercise capacity in stable heart failure patients with reduced ejection fraction

Exercise capacity and quality of life (QOL) are important outcome predictors in patients with systolic heart failure (HF), independent of left ventricular (LV) ejection fraction (LVEF). LV diastolic function has been shown to be a better predictor of aerobic exercise capacity in patients with systolic dysfunction and a New York Heart Association (NYHA) classification >II. We hypothesized that the currently used index of diastolic function E/e' is associated with exercise capacity and QOL, even in optimally treated HF patients with reduced LVEF. This prospective study included 44 consecutive patients aged 55±11 years (27 men and 17 women), with LVEF,0.50 and NYHA functional class I-III, receiving optimal pharmacological treatment and in a stable clinical condition, as shown by the absence of dyspnea exacerbation for at least 3 months. All patients had conventional transthoracic echocardiography and answered the Minnesota Living with HF Questionnaire, followed by the 6-min walk test (6MWT). In a multivariable model with 6MWT as the dependent variable, age and E/e' explained 27% of the walked distance in 6MWT (P=0.002; multivariate regression analysis). No association was found between walk distance and LVEF or mitral annulus systolic velocity. Only normalized left atrium volume, a sensitive index of diastolic function, was associated with decreased QOL. Despite the small number of patients included, this study offers evidence that diastolic function is associated with physical capacity and QOL and should be considered along with ejection fraction in patients with compensated systolic HF.

Avaliação bioquímica, morfológica e funcional do músculo estriado esquelético de ratos na insuficiência cardíaca

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Loss of the Ability to Control Right-to-Left Shunt Does Not Influence the Metabolic Responses to Temperature Change or Long-Term Fasting in the South American Rattlesnake Crotalus durissus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Adaptive morphology of the heart of Southern-Fur-Seal (Arctocephalus australis - Zimmermamm, 1783)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Heart Failure-Induced Diaphragm Myopathy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mensuração das dimensões cardíacas pelo método VHS (Vertebral Heart Size) em cães

It is imortant to be able to evaluate the cardiact size . In 1995, was proposed by Buchanan and Bücheler a new way to measure the dimensions of the cardiac silhouette. This study aims to gather several studies of the cardiac dimensions by VHS method in the right lateral recumbency of of different breeds of dogs in a single work, facilitating the assess to information. Deep chest breeds have a smaller mean VHS value than the barrel chest breeds, showing that there is a variation of the VHS values acoording to the thoracic conformation of each breed, which indicates that there is a need to recognize the specific VHS values according to the breed standard to not to interpret the cardiac measurement in a wrong way through not compatible reference values for the animal. There is the individual variation that should be taken into accont at the time of measurement. The VHS is a helper method to a radiographic evaluation of the heart, and the ultrasonography remains the gold standard for the evaluation of the cardiac chambers and other changes of the heart

Temperature effects on baroreflex control of heart rate in the toad, Rhinella schneideri

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)