Biomedical subjects

O Visioli

Publications and source records attributed to O Visioli.

263 records · Page 15Linked to original sources

PubMedDate not supplied

Effect of prenalterol on contractility, relaxation, and filling phase in coronary artery disease patients with previous myocardial infarction.

Twelve postmyocardial infarction patients, with angiographically proven asynergic areas, but without overt cardiac failure, were treated with prenalterol intravenously, (a new cardioselective inotropic agent) at a dose of 30 micrograms/kg. The aim of this study was to test the usefulness and safety of this new drug in postmyocardial infarction patients, monitoring systolic and diastolic acute hemodynamic changes. Significant improvement in cardiac contractility was demonstrated by the increase of ejection fraction (+23%), stroke volume index (+22%), cardiac output (+41%), positive dp/dt (+82%), and Vmaxd (+39%). Left ventricular systolic, mean aortic, and mean right atrial pressure remained unchanged; a slight decrease in end-diastolic volume index (-2%) occurred. A significant increase in heart rate (from 66 +/- 7 to 85 +/- 14 beats/min), without electrocardiographic changes or subjective complaints of angina pectoris, was observed. Segmental wall motion analysis showed an improved systolic shortening in normal (from 34 to 44%) and in asynergic areas (from 10 to 18%), whereas no changes were observed in dyskinetic areas. The relaxation and filling phase also improved, as tested by negative dp/dt (+39%), time constant of relaxation (-36%), and by indices of ventricular compliance. Side effects consisted of a slight feeling of tension in two patients and a short episode of ventricular tachycardia (5 beats) in another patients. No episode of angina pectoris was observed. These results, with special emphasis on lack of exacerbation of pre-existing ischemia (although obtained in patients without evident heart failure), suggest the potential usefulness of prenalterol in acute cardiac failure, as well as postmyocardial infarction low-output syndrome.

Adrenergic beta-Agonists↗

PubMedDate not supplied

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↗

PubMedDate not supplied

[New findings on calcium antagonism].

The family of calcium antagonist substances is continuously increasing. Often it is difficult, if not impossible, to have clear, objective criteria to differentiate between the available molecules. We have considered some molecular aspects of calcium channels and of the effects of calcium antagonists which may be relevant for the clinical utilization of these drugs. In particular, differences between L and T type of calcium channels in the myocytes and between VOC and ROC calcium channels in the smooth muscle are described. Then we have considered the main differences in the mechanism of action and clinical use of the three prototypes of calcium antagonists: phenilalkilamines, dihydropyridines and benzothiazepines. Finally, we have synthetically depicted the characteristic of the second generation agents such as nisoldipine, amlodipine, felodipine, isradipine, lacidipine and gallopamil.

Animals↗

PubMedDate not supplied

Coronary revascularization and recovery of function: the ultimate target.

Recovery of contraction in the akinetic segments represents an important target of coronary revascularization, and the preoperative recognition of viable dyssynergic (hibernating) myocardium is a crucial point in the preoperative investigation of patients with chronically depressed left ventricular function. Dobutamine-echocardiography was utilized in 14 patients to study the contractile reserve retained by viable segments. Redistribution of thallium-201 after rest injection was also used to assess the viability of these areas. The wall motion response to dobutamine infusion predicted immediate postoperative improvement in 85 of 93 segments (sensitivity 91%) and identified 25 of 32 segments which did not exhibit early postoperative improvement (specificity 78%). Rest-redistribution of thallium-201 demonstrated high sensitivity (93%) but low specificity (44%) for predicting the early recovery of regional wall motion. When late recovery was also considered, the specificity of this method increased to 64%. Recovery of function following coronary revascularization can be predicted in patients in whom hibernating myocardium is recognized preoperatively.

Adult↗

PubMedDate not supplied