Sympathetic Nerve Activity and Baroreflex are Strongly Altered in a Context of Severe Hypertension Using the Spontaneously Hypertensive Rat Model Associated with Chronic Reduction of Nitric Oxide.

The aim of our study is to investigate the sympathetic output and baroreflex via renal sympathetic nerve activity (RSNA) recording in a model of severe hypertension which exhibits arterial, cardiac, and renal damages, the spontaneously hypertensive rat (SHR) under lowered NO bioavailability. SHR are treated from 18 to 20 weeks of age with a low dose of L-NAME, a NO synthase inhibitor, in drinking water (SHRLN) and compared to SHR and normotensive Wistar Kyoto (WKY) rats. After the two-week treatment, rats are anesthetized for RSNA, mean blood pressure (MBP), and heart rate (HR) recording.

Concomitant systolic and diastolic alterations during chronic hypertension in pig.

The mechanical and cellular relationships between systole and diastole during left ventricular (LV) dysfunction remain to be established. LV contraction-relaxation coupling was examined during LV hypertrophy induced by chronic hypertension. Chronically instrumented pigs received angiotensin II infusion for4weeks to induce chronic hypertension (133 ± 7 mmHg vs 98 ± 5 mmHg for mean arterial pressure at Day 28 vs 0, respectively) and LV hypertrophy.

Ivabradine improves left ventricular twist and untwist during chronic hypertension.

Background: Left ventricular (LV) dysfunction develops during LV hypertrophy and particularly during tachycardia. Thus we investigated the effects of heart rate (HR) reduction with ivabradine, an I-channel blocker, on LV twist and untwist which represents myocardial deformation occurring during the overall systole and diastole and therefore provide valuable evaluation of global LV systolic and diastolic function.

Methods: Eight chronically instrumented pigs receiving continuous angiotensin II infusion during 28days to induce chronic hypertension and LV hypertrophy.

Metabolic Considerations in Atrial Fibrillation - Mechanistic Insights and Therapeutic Opportunities.

Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice and is associated with morbidity and mortality. Over the past 2 decades, there have been major advances in understanding AF pathophysiology, but important knowledge gaps, particularly about targetable basic mechanisms, remain. Recent metabolomic and proteomic studies have shown changes in the expression of molecules involved in metabolic pathways in human and experimental AF, indicating a role for metabolic alterations in AF pathophysiology.

Improvement of left ventricular filling by ivabradine during chronic hypertension: involvement of contraction-relaxation coupling.

Chronic hypertension is associated with left ventricular (LV) hypertrophy and LV diastolic dysfunction with impaired isovolumic relaxation and abnormal LV filling. Increased heart rate (HR) worsens these alterations. We investigated whether the I f channel blocker ivabradine exerts beneficial effects on LV filling dynamic.

The value of basic research insights into atrial fibrillation mechanisms as a guide to therapeutic innovation: a critical analysis.

Atrial fibrillation (AF) is an extremely common clinical problem associated with increased morbidity and mortality. Current antiarrhythmic options include pharmacological, ablation, and surgical therapies, and have significantly improved clinical outcomes. However, their efficacy remains suboptimal, and their use is limited by a variety of potentially serious adverse effects.

Ivabradine improves left ventricular function during chronic hypertension in conscious pigs.

During chronic hypertension, increases in heart rate (HR) or adrenergic stimulation are associated with maladaptive left ventricular responses as isovolumic contraction and relaxation durations failed to reduce, impeding filling. We, therefore, investigated the effects of acute selective HR reduction with ivabradine on left ventricular dysfunction during chronic hypertension. Accordingly, chronically instrumented pigs received angiotensin II infusion during 4 weeks to induce chronic hypertension.

Impaired left ventricular function in the presence of preserved ejection in chronic hypertensive conscious pigs.

Systolic function is often evaluated by measuring ejection fraction and its preservation is often assimilated with the lack of impairment of systolic left ventricular (LV) function. Considering the left ventricle as a muscular pump, we explored LV function during chronic hypertension independently of increased afterload conditions. Fourteen conscious and chronically instrumented pigs received continuous infusion of either angiotensin II (n = 8) or saline (n = 6) during 28 days.

Guidelines for treatment of open fractures and infected pseudarthroses by external fixation.

There are three phases in the treatment of open fractures and infected pseudarthroses by the Hoffmann external fixator. During the initial phase a careful surgical debridement is performed in the bony tissues, and the external fixator is applied in a manner appropriate to the type and level of the lesion site (double- or triple-frame mounting; additional anchorages; neutralization, compression, or distraction; ligamentotaxis). During the intermediate phase both the nursing of the patient and care of the apparatus are critical for the avoidance of complications; it is during this period that granulation tissue must develop and bone infections must be controlled.

[Tibio-fibular graft as a treatment of non-union of the tibia (author's transl)].

The authors have reviewed 47 cases of septic non-union of the tibia treated by tibio-fibular graft, Bone union was obtained in 31 cases, 2 limbs were amputated and 13 tibiae were united after another procedure. In 17 cases the grafts were performed in the presence of a discharging sinus. These cases did as well as any others.

Experimental evaluation of microarterial grafts in rats and rabbits: long-term histological studies.

This experimental study was done to compare the fate of microarterial grafts versus microvenous grafts. Based on morphological aspects, patency rates, and histological features, the arterial grafts gave better long-term results than the venous grafts--due mainly to an absence of subintimal fibrotic changes in the microarterial grafts.