Defining and validating chronic diseases

The principles in selecting the chamber or vessel for the injection are based primarily upon the knowledge that cardiac valves are normally unidirectional and blood pressures in the left atrium, left ventricle, and aorta normally exceed the pressures in corresponding right heart structures. In dogs with suspected valvular insufficiencies, injections are made into the vessel or cardiac chamber from which the contrast medium would regurgitate (i.e., immediately “down stream” from the affected valve). (2) These genetic factors have specific effects on cardiac morphogenesis, resulting in specific types of cardiovascular malformations. L Watkins, Jr, J A Burton, E Haber, J R Cant, F W Smith, A C Barger. Constriction of the pulmonary artery or thoracic inferior vena cava was maintained for 2 wk while daily measurements were made of plasma renin activity, plasma aldosterone, plasma volume, hematocrit, serum sodium and potassium concentrations, sodium and water balance, body weight, and arterial, caval, and atrial pressures. In selective angiocardiography, the contrast medium is injected through a catheter, the tip of which has been positioned into a specific vessel or cardiac chamber to visualize best a suspected abnormality based upon the clinical findings. On the basis of these observations, two hypotheses were made: (1) Genetic factors are determinants of certain types of congenital heart disease in the dog. Quote: "It was considered that the relationship between dp/dt and simultaneously developed pressure during the course of isovolumic contraction might afford a more accurate measure of contractility than the maximum rate of intraventricular pressure rise (peak dp/dt). In conclusion, the determination of dp/dt and intraventricular pressure throughout isovolumic contraction in the presence of variable arterial pressure and small changes of preload provides a useful, simple, and experimentally verified approach to the assessment of alterations of the contractile state of the heart in intact man." . Quote: "The role of the renin-angiotensin-aldosterone system in the development of congestive failure has been assessed in the conscious dog by use of the nonapeptide converting enzyme inhibitor.

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This is a list of citations and summaries of veterinary research journal articles which are applicable to mitral valve disease and cavalier King Charles spaniels. The pattern of inheritance of these defects was not consistent with any simple genetic hypothesis. In the days after moderate constriction plasma volume and body weight increased (with development of ascites and edema); blood pressure, sodium excretion, plasma renin acvitity, and plasma aldosterone returned to normal. Accurate measurement of volume was achieved by the use of a water-filled, thin latex balloon in the right ventricle connected to a special volume loading and transducing chamber.

This list is in chronological order, from 1965 to the current date, with the most recent additions added at the bottom of this page. Patent ductus arteriosus in dogs of poodle ancestry and fibrous subaortic stenosis in Newfoundlands were shown provisionally to be transmitted in a manner consistent with autosomal dominant inheritance. In animals in which blood pressure was not restored, plasma renin activity and plasma aldosterone remained elevated throughout the period of constriction. Pressure was measured with a miniature pressure transducer mounted within the balloon.

Thus the renin-angiotensin-aldosterone system plays an essential role in the maintenance of blood pressure during the genesis of congestive failure. Linear regression analysis applied to each of the isochronal pressure-volume data sets at 20-msec intervals from the onset of contraction showed a highly linear correlation between the pressure and the volume.

Initially, the restoration of blood pressure is dependent upon circulating angiotensin II; in the later stages, blood pressure is dependent upon the increase in plasma volume." . Both the slope and the volume intercept of the regression lines changed with time throughout the cardiac cycle.

Quote: "The prevalence rate for cardiovascular malformations in dogs presented to a large university veterinary clinic was 6..

Chronic infusion of the inhibitor in dogs with thoracic inferior vena caval constriction prevented the restoration of blood pressure and suppressed the rise in plasma aldosterone; sodium retention and volume expansion were less than in control experiments. The pressure and volume data were collected from multiple beats under a constant contractile state in the same mode of contraction while the left ventricle was vented to air.This suggests that congestive heart failure in these patients is due to severe regurgitation and subsequent volume overload of the left ventricle and atrium. Quote: Two-dimensional echocardiography was performed on 18 unanesthetized, normal dogs (4.5 to 30 kg).Heart failure secondary to mitral regurgitation can be due not only to myocardial failure, but also to severe regurgitation by itself or in combination with myocardial failure.” . Measurements of wall thickness, intracavitary dimensions, and cross-sectional area of the left atrium, left ventricle, and aorta were made.Ketanserin is a very effective antagonist of the mixture of vasoactive substances released by aggregating platelets. Following 20 min of Isc on cardiopulmonary bypass, dogs received either R (80m M) (n=S), A (20m M) and R (80m M)(n=5) or saline (NS)(n=6) for 24 hrs. The purpose of this study was to determine the effects of ribose infusion in a long-term model of global ischemia and attempt to identify the precursor which limits myocardial ATP regeneration in the intact animal.In experimental thrombosis, sustained ketanserin treatment prevents the impairment of blood flow and the associated organ deficiency. The end-systolic pressure-volume ratio CEmax• mm Hg/ml), d P/dt (mm Hg/sec) and diastolic circumferential stress (cr, dynes x 103/cm2)-strain (e:) relationships were determined from sonomicrometry and micromanometry data during transient vena caval occlusions. We conclude: (1) recovery of systolic function is essentially complete by 4 hrs. Global myocardial ischemia (20 min, 37°C) was produced in dogs on cardiopulmonary bypass.When deviations from normal hemorrheology are long-standing, as in aged spontaneously hypertensive dogs, acute ketanserin administration is distinctly antihypertensive and reduces hemorrheological abnormalities. Paraprase: 50% of Cavalier King Charles (CKC) spaniels have a murmur due to MR by the age of 5–6 years and at 10 years of age, the prevalence of murmurs approaches 100%. (2) Return of diastolic function is enhanced similarly to ATP recovery by R or A/R. With reperfusion either ribose (80 m M) in normal saline or normal saline alone was infused at 1 ml/min into the right atrium and the animals were followed for 24 hr.

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