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M Metra

Publications and source records attributed to M Metra.

76 records · Page 5Linked to original sources

Long-term changes in left ventricular mass, chamber size and function after valve replacement in patients with severe aortic stenosis and depressed ejection fraction.

We studied 21 patients undergoing valve replacement for severe aortic stenosis and marked left ventricular dysfunction (mean ejection fraction 27 +/- 7.9%) without significant coronary disease or other valve diseases. At 5-60 months (average 26 +/- 18) after surgery, the patients underwent a clinical history, physical examination and a complete M-mode, two-dimensional and Doppler transthoracic echocardiographic study. Thirteen patients were examined with cardiopulmonary exercise testing. Two patients with a low preoperative transvalvular pressure gradient (<50 mm Hg) died postoperatively. Nineteen patients were tested at follow-up. All patients showed an improvement in functional class, an increase in ejection fraction (EF), a normalization in left ventricular diameters, volumes and stress indices and a reduction in left ventricular mass which correlated with EF increase. Cardiopulmonary exercise testing showed a good exercise capacity. In conclusion, in patients affected by severe aortic stenosis and marked preoperative left ventricular dysfunction valve replacement induces a favorable remodeling of the left ventricle, as shown by a late postoperative examination. The regression of hypertrophy is a positive event which correlates with the improvement in EF.

Aged↗

[Lead and cardiopathy].

BACKGROUND: The studies dealing with the relationship between cardiovascular disease and exposure to environmental and occupational chemical risks are out-dated and insufficient. However, this is not true of studies on lead. OBJECTIVES: This paper aims to investigate in particular the etiopathogenesis of the relationship between lead exposure and hypertension. METHODS: The studies published in the last decade concerning both the general population and occupationally exposed subjects were reviewed. RESULTS AND CONCLUSION: The effects due to high levels of exposure to lead are well known and have been studied for over a century. Knowledge on the chronic effects deriving from low and long-term exposure is still very controversial but is currently the most interesting topic; in particular lead hypertension is the topic of an increasing number of studies. Chronic exposure to low levels of lead can cause hypertension via several mechanisms. The most important are: oxidative stress associated with functional NO deficiency, elevation of sympathetic activity coupled with depressed vascular and increased renal beta receptor densities, activation of the renin-angiotensin-aldosterone system, rise in endothelin production, reduction in vasodilatatory prostaglandins and elevation of vasoconstrictive prostaglandins.

Aldosterone↗