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T Vinciguerra

Publications and source records attributed to T Vinciguerra.

5 recordsLinked to original sources
PubMed1988

Volume overload hypertrophy in a closed-chest model of mitral regurgitation.

Chronic volume overload hypertrophy as seen in mitral regurgitation in humans eventually may cause left ventricular dysfunction. Longitudinal study of the mechanisms leading to such dysfunction is difficult in humans and more easily performed in an animal model. In this study, we describe a canine model of volume overload hypertrophy produced by mitral regurgitation. An arterially placed grasping forceps was used to disrupt mitral chordae or leaflets; thus mitral regurgitation was produced without the need for thoracotomy. Eleven of 22 dogs had severe mitral regurgitation (regurgitant fraction greater than 0.50) and survived for greater than or equal to 3 mo (average 9.2 +/- 6 mo) after the production of mitral regurgitation. At 3 mo, end-diastolic volume increased from 48 +/- 9 to 85 +/- 19 ml, P less than 0.01. Left ventricular mass increased from 71 +/- 13 to 90 +/- 10 g, P less than 0.01. Left ventricular end-diastolic pressure increased from 9 +/- 3 to 19 +/- 6 mmHg, P less than 0.01. Cardiac output decreased from 2.3 +/- 0.61 to 1.80 +/- 0.64 l/min, P less than 0.05. The mass-to-volume ratio decreased from 1.44 +/- 0.17 to 1.09 +/- 0.13, P less than 0.01. We conclude that this closed-chest model of chronic mitral regurgitation produces significant eccentric cardiac hypertrophy. Despite a doubling of end-diastolic volume, there was a fall in cardiac output and a rise in left ventricular end-diastolic pressure, suggesting cardiac decompensation.

Animals↗
PubMed1985

Physiological limits in lifting.

Two different experiments were conducted to study the effects of frequency, height and load of lift on computed maximal oxygen uptake and to compare the data obtained to a standard bicycle ergometer. A progressive submaximal technique was used to predict maximal oxygen uptake. The results of the present study revealed that across all heights, an increase in either the frequency of lift or load of lift was accompanied by an increase in computed maximal oxygen uptake; however, all maximal oxygen uptake values reported showed a tendency to level off beyond the frequency of five lifts/min. The results also showed that combined arm and leg lifting recorded the highest maximal oxygen uptake followed by leg lifting then arm lifting, respectively. Maximal oxygen uptake values obtained for lifting tasks were much lower than those obtained for a bicycle ergometer. It is therefore recommended that limits for continuous work for a lifting task be based on the attainable maximal oxygen uptake for that particular task and not on a maximal oxygen uptake obtained from another task such as a bicycle ergometer test.

Adult↗
PubMed1975

Effects of metrizamide, a new nonionic contrast medium, on cardiac function during coronary angiography in the dog.

Metrizamide is a new non-ionic radiopaque agent with low osmolarity and low intravenous toxicity. Hyperosmolarity is one of the factors involved in the decrease of myocardial contracility, alterations of aortic pressure, and disturbances in the cardiac rhythm which contrast media induce during coronary angiography. Metrizamide has been compared to other commonly used contrast media and was shown to produce fewer changes on the cardiac functions recorded.

Aminoglycosides↗
PubMedDate not supplied

Cardiac function during coronary arteriography with calcium enriched diatrizoate and metrizamide.

Calcium was added to diatrizoate (Renografin 76) and metrizamide (Amipaque) to concentrations from 2.5 to 50 mEq/1. The solutions were injected into the left coronary artery in dogs with either the chest opened or closed. In open chest experiments contractile force and aortic pressures were recorded. In closed chest dogs, left ventricular pressure, first derivative of that pressure and aortic pressure were registered. The calcium ion concentration was linearly, inversely related to the effect of the contrast solutions on the recorded parameters. In these experiments the optimal amount of calcium is suggested to 40 mEq/1 added to the diatrizoate solution but only 10 mEq/1 added to the metrizamide solution. No ECG changes due to calcium addition could be registered. The cardiac toxicity of these contrast media seem to be due to an interference with the calcium flux across the cell membrane. The effect on contractility can be recorded with the same reliability in either closed or open chest experiments.

Angiocardiography↗