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F Ginés

Publications and source records attributed to F Ginés.

8 recordsLinked to original sources
PubMed2004

Smooth muscle role on pulmonary arterial function during acute pulmonary hypertension in sheep.

AIM: We determined the wall mechanical response of the pulmonary artery (PA) to acute pulmonary hypertension induced pharmacologically and by an occlusion maneuver, to study the vascular response of the local segment and its influence in the whole pulmonary circulation. METHODS: Pulmonary pressure and diameter were measured in six anaesthetized sheep under steady-state conditions. Transient hypertension in the PA was induced by phenylephrine (PHE) and a high pressure (HP) mechanical occlusion aimed at producing the same pulse and mean pressure responses. A viscoelastic arterial wall model was applied and the elastic (E(pd)) and viscous (micro) indexes were obtained. The micro/E(pd) ratio was adopted to quantify the damping performance of the arterial wall segment. The diastolic time constant was used as an indicator of the whole pulmonary buffering function. The systemic pressure was always measured. RESULTS: The pulmonary mean, systolic and pulse pressure increases (P < 0.05) were similar during PHE and HP, with respect to control. PHE also induced a systemic pressure rise (P < 0.05). The E(pd) elastic index increased during HP (P < 0.05) and tended to increase during PHE with respect to control. The viscous index micro only increased with PHE (P < 0.05) with respect to control and occlusion. The diastolic time constant increased with PHE with respect to control (P < 0.05). CONCLUSIONS: A pressure rise in the PA, induced by an occlusion maneuver, increased local stiffness. Similar pressure rises with smooth muscle activation (PHE), produced both a stiffness and viscous index increase. In PHE resistance increases more than compliance decreases so that the global net effect is a longer decay time. Smooth-muscle activation enhances the local damping effect (micro/E(pd)), concomitant with the buffering function improvement.

Acute Disease↗
PubMed2001

[Synchronization of the contraction of the right ventricle against an acute afterload increase. Left ventricle-like mechanical function of the right ventricle].

AIM: The aim of this study was to demonstrate right ventricular contraction synchronization during acute and moderate afterload increase. MATERIAL AND METHOD: Right and left ventricular pressures, pulmonary and aortic pressures, pulmonary flow, and ventricular volumes by sonomicrometry were measured in seven anesthetized sheep. Pulmonary arterial hypertension was induced by Escherichia coli endotoxemia. RESULTS: Acute increase of the right ventricular afterload, measured as the mean arterial pulmonary pressure (11.9 1.3 to 24 3.6 mmHg) produced the following changes in the right ventricle without preload and contractility changes: a) maximal elastance shifted towards the end of the ejection (127.5 18.5 ms) and the ejection time shortened (57.5 20.3 ms), so that the negative peak of the first ventricular pressure derivative occurred at the end of the ejection; b) the pressure-volume loop became rectangular, i.e.; the systolic and diastolic phases were isovolumic, and c) the ejection showed a single phase. CONCLUSIONS: Asynchronous and sequential right ventricular contraction with normal afterload changed to a synchronic contraction pattern as in the left ventricle during an acute and moderate afterload increase. This left ventricle-like mechanical property establishes a novel mechanical reserve mechanism of the right heart, since it allows the right ventricle to maintain its systolic function during an afterload increase, independently of the preload and contractility.

Adaptation, Physiological↗
PubMed1999

[The characteristics proper of the cardiac cycle phases of the right ventricle].

AIMS: The purpose of our study was to define at physiological conditions, the existence or not of an isovolumic relaxation phase in the right ventricle and its ejective phase properties. MATERIAL AND METHODS: Right and left ventricular pressures, pulmonary and aortic pressures, pulmonary flow and ventricular diameters by sonomicrometry were measured in nine anesthetized sheep. The first ventricular pressure derivative, ventricular volumes, and the right and left pressure-volume loops, were calculated "off line". An abrupt preload reduction was generated by a posterior vena caval occlusion. RESULTS: Right ventricle showed an ejection phase which can be subdivided in two phases (early and late). The end of the ejection phase was established by the temporal coincidence of the zero pulmonary flow, the minimum systolic value of the right ventricular volume and a right ventricular pressure of 0-4 mmHg. The time between the beginning of the ejection phase and: a) the end of systole; b) the negative peak of the first derivative of ventricular pressure and c) the end of ejection, were different for the right ventricle (67 +/- 15 ms, 274 +/- 30 ms, 412 +/- 33 ms, respectively), meanwhile the left ventricle showed the following values: 204 +/- 33 ms, 262 +/- 23 ms, 266 +/- 24 ms, respectively. CONCLUSIONS: Right ventricle exhibits a long lasting ejection phase which can be subdivided in two phases, spreading at the beginning of the next filling phase. This fact allows us to affirm that right ventricle does not show an isovolumic relaxation phase in comparison to left ventricle.

Animals↗
PubMedDate not supplied

[Study of the relaxation phase of the right ventricle].

The purpose of our study was to investigate the existence or not of an isovolumic relaxation period in the right ventricle in experimental animals with normal pressures in the pulmonary artery. Right and left ventricular pressures, pulmonary and aortic pressures (microtransducers), pulmonary flow, ventricular diameters (sonomicrometer), were recorded at the same time, in 10 sheep anesthetized intravenously with pentobarbital. We obtained "off line" the first ventricular pressures derivative, the ventricular volumes and the pressure-volume loops of both ventricles. The minimum systolic right ventricular volume coincided with 0 pulmonary flow, and both with a diastolic pressure value of 0-5 mmHg in that ventricle. Once the minimum systolic volume was reached, a rapid increase of the right ventricular volume started. The right ventricular pressure-volume loop, unlike the left ventricular one, adopted a non-rectangular shape. The right ventricular ejection period lasted until the beginning of the next filling phase. We concluded that there is no right ventricular isovolumic relaxation period.

Animals↗
PubMedDate not supplied

Human intramyocardial oxygen detected through chronic polarographic electrodes.

The intramyocardial PO2 was studied in 7 patients after cardiac surgery, by means of a long-term electrode implanted subepicardically in the free wall of the left or the right ventricle, utilizing the polarographic method. Inhalation of 100% O2 or 5% CO2 +95% O2 provoked maximal increases in the myocardial PO2. In most cases intense exercise, and the Valsalva manoeuvre caused a decrease in the PO2. Intravenous propranolol slightly increased the PO2 in one case. Other drugs used in coronary patients caused inconstant effects. Sleeping decreased the heart PO2 in one case. This technique appears to be a useful tool for studying the human intramyocardial PO2 during a period of several weeks.

Adolescent↗
PubMedDate not supplied

[Renoenterocolic fistula].

We present a case of reno-entero-colic fistula which is extremely rare and which, in the face of unspecific clinical pictures requires a detailed examination. Its physiopathology, the surgical problems which it poses and the means of solving these, are explained.

Adult↗
PubMedDate not supplied

[Retrovesical hydatid cyst].

This paper explains the clinical study and the resulting treatment carried out on a patient suffering from a retrovesical tumour which proved to be a cyst of hydatidic origin. Special mention is made of the course of study which should be followed in these cases, above all as far as radiological studies are concerned as well as the special features of the removal and in situ treatment of the cyst.

Aged↗