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Biomedical subjects

O Visioli

Publications and source records attributed to O Visioli.

At least 145 records · Page 8Linked to original sources
PubMed1985

Hemodynamic advantage of combined administration of oral ibopamine and nitroprusside in patients with ischemic and idiopathic congestive cardiomyopathy.

The hemodynamic effects of combined administration of ibopamine (Ib) (150 mg orally) with nitroprusside (NP) (50-150 micrograms/min intravenously) were compared with those of NP alone in 17 patients with severe congestive heart failure due to coronary artery disease (7 patients) or idiopathic cardiomyopathy (10 patients). Hemodynamic measurements were obtained using a Swan-Ganz thermodilution catheter and a bedside thermodilution cardiac output computer. Nitroprusside alone produced a significant decrease (-12.4%) in mean arterial pressure, mean pulmonary arterial pressure (-28.3%), and systemic vascular resistance (-22.6%), and a significant increase in stroke volume index (23.1%). The administration of combined NP and Ib produced a further significant increase of stroke volume index (20.1%) with a concomitant and significant reduction of systemic vascular resistance (-19.4%); heart rate, mean systemic and pulmonary arterial pressures did not change significantly from the values observed with NP alone. Moreover, stroke work index, although not significantly modified with the vasodilator alone, was significantly increased over control values with NP + Ib association. Although NP alone induced similar effects in both the ischemic and idiopathic cardiomyopathies, the association of Ib gave a more favorable, though not significant, hemodynamic response in the subjects with primitive cardiomyopathy than in the ischemic ones. Thus, the association of Ib to NP therapy, in patients with congestive heart failure, further increases stroke volume index and stroke work index with a concomitant reduction of systemic vascular resistance, without any significant change in mean systemic and pulmonary arterial pressures, or heart rate. These results point out the possibility of associating Ib with other orally active vasodilators in the chronic treatment of congestive heart failure.

Adult↗
PubMed1985

Oxygen-mediated myocardial damage during ischaemia and reperfusion: role of the cellular defences against oxygen toxicity.

The possibility that myocardial ischaemia alters the defence mechanisms against oxygen toxicity has been investigated. Ischaemia was induced in isolated, perfused rabbit hearts by reducing coronary flow from 25 ml/min to 1 ml/min for 90 min. Two different degrees of ischaemic damage have been achieved using either spontaneously beating or electrically stimulated hearts. The effects of post-ischaemic reperfusion were also followed for 30 min. Tissue activity of superoxide dismutase (SOD), glutathione peroxidase and reductase (GPD and GRD) have been determined together with tissue content of reduced and oxidized glutathione (GSH and GSSG) and of protein SH groups. The changes in myocardial ATP and CP content and release of CPK and of GSH and GSSG were also determined. Systolic and diastolic pressures were continuously monitored. In the spontaneously beating hearts ischaemia induced a reduction of tissue GSH and protein SH groups. On reperfusion there was a recovery of mechanical function, a transient release of GSH into the coronary effluent and an increase of tissue GSH. In the paced hearts, ischaemia resulted in 50% reduction of mitochondrial SOD activity together with a reduction of tissue GSH and protein SH groups. Reperfusion induced a massive release of CPK and of GSH and GSSG, a further reduction of tissue GSH concomitant with an increase of GSSG and no recovery of mechanical function. GPD and GRD activity were not affected by ischaemia and reperfusion. These data indicate that severe ischaemia induces a reduction of the protective mechanisms against oxygen toxicity.

Adenosine Triphosphate↗
PubMed1985

Syncope and tumours in the neck: carotid sinus or glossopharyngeal syndrome?

Three patients with syncope, lateral cervical metastasis and/or carotid sinus hypersensitivity are described. The initial diagnosis in these patients was carotid sinus syndrome (CSS). Further investigations, including computerized tomography, showed in all the patients a malignant tumour localized in the epipharynx or nearby. We think that the symptomatology in our patients can be attributed to the epipharyngeal tumour. The mechanism of the attacks could be similar to that which operates in the glossopharyngeal neuralgia-asystole syndrome, but does not involve pain pathways. The clinical picture in our patients was quite different from the classic CSS; the vaso-vagal attacks were more prolonged, severe, and relapsing and were mainly vasodepressor. Symptoms were not improved by demand ventricular pacing, but A-V sequential pacing achieved a moderate improvement in two patients.

Aged↗
PubMed1985

Pre-operative sinus node function in adult patients with atrial septal defect (ostium secundum type).

The authors studied, pre-operatively, the sinus node function in adult patients with secundum atrial septal defect and large left-right shunts, using Holter ECG and electrophysiological tests. Sinus node electrophysiological tests were found abnormal in 17 out of 26 patients; on the contrary, Holter monitoring was always within normal limits. The authors believe that concealed sinus node dysfunction existing before surgical correction may be a cause of early, acute, and reversible, post-operative sick sinus syndrome.

Adolescent↗
PubMed1985

[Hypotension during ventricular pacing. A study of the vagal reflex component].

It has been suggested that hypotension during ventricular pacing (V) could be caused by a parasympathetic vasodilating reflex. In order to evaluate this hypothesis, we studied 10 patients who had wide fluctuations of arterial pressure during V. Intra-arterial pressure, right atrial pressure, EKG and cardiac index (thermodilution) were determined in the following conditions: basal rhythm (B), V, atrioventricular pacing (A-V) and ventricular-atrial pacing (V-A). The same investigations have been carried out in the same conditions (B,V,A-V,V-A) after atropine 0.03 mg/Kg intravenously. The arterial blood pressure during V decreased markedly simultaneously with the appearance of cannon waves in the right atrial pressure tracing. During A-V the arterial pressure remained stable at the highest level observed during V. The start of V-A pacing induced a marked drop of arterial pressure, which, however, gradually increased to a level slightly lower than during A-V pacing. After atropine the arterial blood pressure during V decreased again in all patients concomitantly to the appearance of cannon waves in the atrium as before atropine. The values of arterial blood pressure during B, A-V and V-A were not different from those measured before atropine. Therefore, an increase of parasympathetic activity during V is not responsible for the wide fluctuation of arterial blood pressure. A possible role of sympathetic failure must be considered.

Adult↗
PubMed1985

[T-wave changes in intermittent left bundle branch block. Pathogenesis and clinical significance].

In patients with intermittent left bundle branch block (LBBB) it is common to observe T wave abnormalities in the right precordial leads during normally conducted beats. These changes have usually been interpreted as a result of anteroseptal ischemia. More recently it has been suggested that they may be the consequence of an electric phenomena secondary to the abnormal ventricular activation. However, the "benign" character of these abnormalities has never been confirmed by clinical studies. We have studied a group of 10 pts (3 males and 7 females), aging between 23 and 66 years (mean 41 +/- 8) with atypical precordial pain admitted to our institution, because of intermittent LBBB and T wave inversion in the right precordial leads during the normally conducted beats. All patients had normal left ventriculography and coronary angiograms. During the follow-up period (20 to 102 months, mean 4.7 years) they were subjected to serial clinical examinations, 24 hours ECG Holter monitoring echocardiogram and exercise thallium 201 scintigraphy. Within this period of observation, no patient developed symptoms or signs of cardiac involvement while all but three developed a stable LBBB (these three patients have been followed only for a limited period of time). Exercise thallium 201 scintigraphy showed in 4 patients a reversible septal perfusion defect during LBBB. We conclude that T wave abnormalities observed in the normally conducted beats in patients affected by intermittent LBBB have a favourable prognostic significance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

The metabolical effects of L-carnitine in angina pectoris.

We determined the effects of L-carnitine on myocardial metabolism in 18 patients with angiographically-proven coronary artery disease, subjected to two rapid coronary sinus pacing evaluations. L-Carnitine converted lactate production to extraction and increased the percentage of free fatty acid extraction. These results suggest that L-carnitine may be of use to improve the metabolism of coronary artery disease patients.

Angina Pectoris↗
PubMed1984

Value of purinic compounds in assessing sinus node dysfunction in man: a new diagnostic method.

The purpose of this paper is to investigate whether the inhibitory action of purinic compounds (striadyne: STR) on the sinus node is quantitatively different on a pathological sinus node in comparison to a normal one and thus whether it is possible, as suggested by other authors, to use STR as a pharmacological test in the diagnosis of sick sinus syndrome (SSS). With this aim we investigated 55 patients, divided into 3 groups according to ECG and sinus function evaluation tests: 1--normal; 2--SSS (2a: flagrant SSS; 2b: latent SSS); 3--excess vagotonia and/or abnormal response to vagal stimulation. In all patients after a prophylactic insertion of a temporary pacemaker, 30 mg of STR were rapidly injected i.v. and the surface and intracavitary ECG continuously recorded until the basal state was regained; the following parameters were evaluated: average baseline sinus cycle (SC), minimum and maximum SC after the drug. In all patients STR caused first a slowing, then an acceleration of the sinus rate. SC lengthening was moderate in groups 1 and 3 [max SC was respectively 740-1820 ms (1198 +/- 290.9 ms) and 720-1440 ms (1157.5 +/- 223.3 ms)], but it was severe in patients with SSS [max SC in group 2a 2500-11880 ms (5398.3 +/- 2687.4 ms) in group 2b 1620-11140 ms. (4470.7 +/- 3660.6 ms)]. The difference between the max post STR SC of SSS patients, and the control group was highly significant P less than 0.001). Assuming as upper limit of the normal a value of 2071 ms. (corresponding to the mean + 3 standard deviations of the response of the control group) we recorded abnormal responses in 100% in group 2a and in 85.7% in group 2b, whereas there were no abnormal responses in group 3. In addition, nodal atrioventricular block occurred frequently. The authors believe this test could be useful in the diagnosis of SSS, but it is essential to insert a ventricular pacing catheter prophylactically if this test is used.

Adenosine Triphosphate↗
PubMed1984

Comparative evaluation of exercise ST response in healthy males and females. A computer study.

In order to evaluate both quantitatively and qualitatively exercise ST response in females, we have studied 232 healthy subjects (age range 35-59 years): 82 women (mean age 45.8 years) and 150 men (mean age 46.1 years). All subjects had performed a maximal treadmill exercise in 1976 and were followed up for 6 years in order to exclude the presence of subclinical coronary artery disease. Exercise ST segment responses were evaluated in a single bipolar lead (CB5) and were classified as 'positive' by visual interpretation when a 1.0-mm or greater 'ischemic' ST depression occurred. A computer system was employed to evaluate exercise ST changes quantitatively. The following ST parameters were evaluated: ST depression at R + 80 ms point (ST2); mean ST depression (STmean), and ST time-voltage integral (STarea). Computer analysis of resting ECG has shown lower ST voltages in females than in males. ST2, STarea, and STmean changes from basal to maximal exercise values were not significantly different in men and women. A similar prevalence of 'positive' responses in males and females was also found by ECG visual interpretation. In conclusion, our data show that in healthy subjects exercise ST segment response is comparable in males and females and indirectly suggest that the lower predictive value of exercise ECG in women is likely to be related to different coronary artery disease prevalence.

Adult↗
PubMed1984

Ejection phase indexes with apexcardiography. Comparison with echocardiographic and angiographic parameters.

The reliability of a new noninvasive method for evaluating ejection fraction and the mean velocity of circumferential fiber shortening by apexcardiography and carotid pulse tracing has been evaluated. Three groups of subjects were considered. Group 1: 30 normal subjects (mean age 43 years); Group 2: 34 patients with aortic valve disease (mean age 51 years); Group 3: 76 patients with coronary artery disease (mean age 50 years). The mechano-cardiographic tracing points were acquired by an ultrasonic digitizing system and compared with the same indexes measured from the ventriculogram. In 53 patients M-mode echocardiographic evaluations also were performed. The correlations between the apexcardiographic derived ejection phase indexes and the angiographic measurements were highly significant in all subjects and in each group of patients. The correlations between the ejection phase indexes determined by echocardiography and the same angiographic data were also significant, but the r-values were somewhat lower than those found between the apexcardiographic and angiographic parameters in the same patients. Our results have assessed the reliability of this new method and demonstrated that this noninvasive technique can be applied not only in coronary disease but also in aortic valve disease and in normal subjects. It can be concluded that the apexcardiographic evaluation of cardiac performance appears applicable to patients in whom a means of assessing and sequentially following ventricular function is indicated.

Adolescent↗