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Biomedical subjects

C Manca

Publications and source records attributed to C Manca.

At least 91 records · Page 5Linked to original sources
PubMed1986

Body surface potential mapping in ischemic patients with normal resting ECG.

Patients with ischemic heart disease frequently have a normal 12-lead electrocardiogram. We recorded body surface maps from 14 ischemic patients with normal (group A) and 5 with abnormal (group B) resting electrocardiograms. ST-T map data were compared with those of 36 normal subjects. In ischemic patients the following abnormalities were found: an anomalous location and/or trajectory of the potential minimum (lowest potential) on the chest in some; in others the instantaneous values of the time functions: Mxi (highest potential on the chest), delta Vi (highest potential difference) and integral of s/Vi/dS (integral of the absolute value of the potential function extended to the entire chest surface) were lower. In some ischemic patients, both abnormalities were observed. All changes were detectable during the first 200 msec of ST-T. The anomalous potential patterns were similar in group A and B patients, suggesting an ischemic origin of group A abnormalities. By submitting 10 properly selected variables, obtained from body surface maps, to Fisher's discriminant analysis, we succeeded in correctly classifying more than 90% of the cases. The efficacy of the method was validated by using one third of the cases as a test set, with correct allocation in 80.9% of the cases. We conclude that body surface maps at rest can reveal an altered cardiac electrogenesis induced by myocardial ischemia, not apparent in the 12-lead electrocardiogram.

Action Potentials↗
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

[Baseball during the growing years: repercussions on the cardiovascular system (echocardiographic evaluation)].

The influence upon the cardiovascular system of a period (21 months) of physical training program for baseball was studied in 40 normal children (aged 8 to 10 years) in an experimental (20) and control (20) group. The echocardiographic changes observed at the end of the period proved to be substantially alike in both groups. The physiopathological involvements linked to the baseball training in the prepubescent age are discussed.

Baseball↗
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

[The ambulatory ECG in the evaluation of coronary insufficiency].

To assess the diagnostic value of continuous ambulatory ECG in exercise angina pectoris, 49 males (mean age 52, 1 years), with exercise ischemic ECG changes and positive coronary angiography were evaluated. Ischemic ST-changes were detected by ambulatory ECG in 47% of those patients; most of these ST segment displacements were asymptomatic and a lot of them occurred at rest. In order to assess the specificity of ambulatory ECG, 90 healthy subjects (47 males and 43 females, mean age 43,6 years), were also evaluated 8.9% of these subjects developed ischemia like episodes of ST segment deviation. We conclude that in exercise angina pectoris the ambulatory ECG allows to recording silent ST segment changes, in spite of a poor diagnostic sensitivity. The low specificity of ST segment depression recorded by ambulatory ECG must be also emphasized.

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↗