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Biomedical subjects

B Carù

Publications and source records attributed to B Carù.

11 recordsLinked to original sources
PubMed1992

Influence of thrombolysis on signal-averaged electrocardiogram and late arrhythmic events after acute myocardial infarction.

The influence of intravenous thrombolysis on both prevalence of ventricular late potentials and incidence of late arrhythmic events was evaluated in 174 consecutive patients surviving a first acute myocardial infarction; 106 patients (61%) received thrombolysis (group A) and 68 (34%) had conventional therapy (group B). In group A, 18 patients (17%) had late potentials compared with 23 (34%) in group B (p less than 0.05); mean left ventricular ejection fraction was not different (0.50 +/- 0.09 vs 0.50 +/- 0.10; p = not significant [NS]). Of 63 patients who underwent coronary arteriography because of postinfarction ischemia, 28 (44%) had a closed infarct-related artery; of these, 11 (39%) had late potentials compared with 3 of 35 (9%) with a patent artery (p less than 0.01). Mean left ventricular ejection fraction was not significantly different between the 2 groups (0.49 +/- 0.09 vs 0.53 +/- 0.09; p = NS). At a mean follow-up of 14 +/- 8 months, 8 of 161 patients (5%) had a late arrhythmic event; 6 of 8 (75%) with and 28 of 153 (18%) without events had late potentials (p less than 0.001). In group A, 4 of 99 patients (4%) had events compared with 4 of 62 (6%) in group B (p = NS, relative risk 1.6). Of 24 patients with anterior wall AMI and left ventricular dyskinesia, 6 events occurred. In this group of patients, a higher rate of events was observed (25%); 3 of 16 (19%) treated with thrombolysis had an event compared with 3 of 8 (37%) treated conventionally (p = NS, relative risk 2.6).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Functional evaluation 10 days and 3 weeks after acute myocardial infarction: comparative significance and prognostic value.

Early functional evaluation after non-complicated acute myocardial infarction (AMI) is widely recommended because of its prognostic value in the short term. In fact it seems to have a prognostic value within 15-20 days of the AMI, but in this period the patient is particularly controlled and is often still hospitalized. To evaluate the real significance of an early functional evaluation within 10 days of the AMI (mean 8.6 days +/- 1.2) as compared to an identical functional evaluation performed at 3 weeks after AMI (mean 20.16 days +/- 5.38) 25 patients with uncomplicated myocardial infarction were studied. Significant statistical differences were found between the first (ET1) and second (ET2) functional evaluations: they concern the maximal heart rate reached (P less than 0.001), the maximal pressure-rate product (P less than 0.05), the percentage increment of heart rate (P less than 0.01) and the total work performed (P less than 0.001). Agreement between ET1 and ET2 was found in 19 cases; 12 patients showed markers of ischaemia both at ET1 and ET2, while seven were free from ischaemia at both times. In six cases a disagreement between ET1 and ET2 was found: in particular, three cases had ischaemic ET1 and nonischaemic ET2; the reverse was seen in the other three. During follow-up (mean 215.4 days +/- 85.5), the total number of new events (reinfarctions, angina or surgery) among the 25 patients was eight; none occurred within the first 30 days after the AMI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Regional flow responses to exercise.

Both neural and humoral systems participate in the control of blood flow to various organs. Exercise places the greatest demands on the circulation. At rest, in humans, skeletal muscle receives somewhere between 15% and 20% of cardiac output, while during maximal exercise, this percentage reaches a value of 80% to 90%. The active human muscles have a high-flow capacity that exceeds the capacity of the heart to pump blood. Measurements in single human muscle have indicated that blood flow may be inhomogenous, that is, probably depending on variations of the vasomotor tone of the muscle mediated by humoral and neural factors. Exercise raises cardiac output and coronary blood flow, which rise linearly with increases in heart rate. In normal young men, coronary blood flow averages 280 ml/min/100 g of the left ventricle and reaches as high as 390 ml/min during moderately severe exercise, requiring about 85% of maximal heart rate. In nonexercising organs, the blood flow decreases at about 20% to 40% of the resting values, being the net result of competing vasoconstrictor and vasodilator drives.

Animals↗
PubMed1992

[The electrocardiographic anomalies and 2D-echocardiographic findings during the recovery phase of the stress test in the postinfarct patient].

BACKGROUND: The appearance or the increase of repolarization abnormalities in the EKG during post exercise (ET) recovery phase (R) is considered a marker of ischemia. METHODS: In order to evaluate the real meaning of these changes we compared the EKG data with eventual modifications of left ventricular kinesis analyzed by 2D-ECHO. 10 male patients with previous myocardial infarction, mean age 50 +/- 4.8 y, underwent exercise testing on a treadmill (Bruce's protocol) and continuous 2D-ECHO observation from the end of exercise along the whole R. Patients were divided in two groups: Group A (6 patients) and Group B (4 patients), all free of symptoms. RESULTS: Group A showed ischemic EKG markers during exercise which increased during R; Group B showed ischemic EKG markers only during R. The 2D-ECHO showed in Group A an impairment of left ventricular kinesis at peak exercise without increase or extension during R (WMSI at rest 1.32; peak ET 1.60; R 1.60); in Group B the kinetic alterations appeared only in R (WMSI at rest 1.33, peak ET 1.42; R 1.80), strictly related to EKG markers. CONCLUSIONS: The data suggest : 1) that the increase of EKG abnormalities already present during exercise do not seem to imply more severe ischemia; 2) that EKG changes appearing during R are markers of ischemia which occur in the R.

Echocardiography↗
PubMed1979

Comparative effects of nifedipine, verapamil, isosorbide dinitrate and propranolol on exercise-induced angina pectoris.

According to the experimental model of a 5 X 5 Latin square, 5 treatments were studied single blind in 5 patients, affected by stable-effort angina, by means of exercise tests. In the period of maximal supposed effect the following treatments were investigated: placebo (P), 1 tablet, orally; isosorbide dinitrate (ISDN), 5 mg, sublingually; propranolol (Pr), 40 mg, orally; nifedipine (N), 10 mg, orally; verapamil (V), 160 mg, orally. Placebo, compared with its own control tests, did not change any of the examined parameters. Comparison of the 'active' treatments with P showed the following results. All the treatments increased the duration of work before ECG positivity appearances. An increase in duration of work and total work performed before angina was seen after administration of ISIDN, N and V; the improvement observed after treatment with Pr was not significant. Comparison of treatments showed that work performance before angina was the same after administration of ISDN, N and V; these treatments were more effective than that with 40 mg Pr. Duration of work before ECG positivity was significantly longer after ISDN and N than after Pr. The changes in heart rate, maximal arterial pressure, ejection time index and triple product confirmed the activity of the administered doses. According to the observed effects on exercise tolerance, in comparison with P the same level of work was performed with the same triple product after Pr, and with lower triple products after ISDN, N and V.

Angina Pectoris↗
PubMed1979

[Ergometric evaluation of patients with WPW syndrome (author's transl)].

20 subjects affected by ventricular pre-excitation, without any other associated cardiac disorder, underwent to maximal exercise test on bicycle ergometer; the aim of the research is to analyse their maximum levels of aerobic power, to study their electrocardiographic behaviour during exercise, with a particular reference to the ventricular repolarization, and finally to evaluate the incidence of arrhythmias during exercise. The maximum aerobic power was slightly lower than the reference standards (on average 78.32%); the muscular work, in 1 patient only, gave rise to cardiac arrhythmias during exercise. In these patients we assume as non specific, the "like ischemic" variations of the ventricular repolarisation during exercise.

Adolescent↗
PubMed1977

[Effectiveness of nifedipine on exercise tolerance in patients with angina pectoris. Comparison with a nitroderivative and a beta-blocking agent].

The effect of nifedipine on effort angina was investigated by means of exercise tests with bycicle ergometer and compared, in the same patients, with the effects of a nitroderivative and a betablocking agent. Five patients with stable effort angina entered the study, after an hemodynamic and contrasto-graphic control. According to the protocol of a latin square 5 X 5, all the patients received in a random sequence the following treatments: placebo, 1 c. orally; isosorbide dinitrate, 5 mg sublingually; propranolol, 40 mg orally; nifedipine, 10 mg sublingually; nifedipine, 10 mg orally. No significant change of any of the considered parameters was observed after the placebo. Isosorbide dinitrate and nifedipine produced significant increases of the duration of work before appearance of pain and EKG positivity, and of total work performed before anginal pain. Only the duration of work before EKG positivity was improved by propranolol. The comparisons between treatments showed no significant difference of the effects of the administered doses of isosorbide dinitrate and nifedipine. The improvements observed after propranolol were significantly lower than that observed after isosorbide dinitrate and oral nifedipine. On the basis of the observed changes of cardiac rate, maximal arterial pressure, ejection time index and triple product, the authors evaluate the possible mechanism of action of nifedipine.

Adolescent↗
PubMed1977

[The significance of ventricular arrhythmias during muscular work: correlations with coronary heart disease (author's transl)].

The incidence of ventricular arrhythmias during muscular work in 400 patients hospitalized for clear or suspected coronary artery disease who underwent coronaroangiography and exercise test was studied. The correlations between the arrhythmias and some hemodynamic parameters and the coronaroangiogrphy patterns and left ventricle cineangiography were investigated. None of the factors that were supposed to be significant in the mechanism of the ventricular arrhythmias, such as high left ventricular end dyastolic pressure, modified myocardial contractility, previous myocardial infarct, or higher lesions of coronary arteries, gave significant correlations. In the present study, the ventricular arrhythmias during muscular work do not seem to be of diagnostic significance.

Angiography↗
PubMed1977

[The effort test in the diagnosis of typical stable effort angina (author's transl)].

Among 173 patients with typical effort angina (159 men and 14 women) which underwent exercise test and coronary angiography, significant stenosis (greater than or equal to 70%) of one or more of important coronary branches were present in 93,1% of the cases (96,3% among the males and 57% among the females). In the same group the exercise test sensitivity was 88,8%; when 3 coronary branches were involved the sensitivity rises to 94,3%. The 96,6% of patients with positive exercise test had coronary lesions too (true positives). We did not find any correspondence between the site of transient subendocardial ischemia occurred during the exercise test and coronary branch involved, when the stenosis was limited only one important coronary branch. Finally the researche of correlation between the entity of coronary disease (number of coronary vessels involved, entity of left ventricular contractility impairment) and behavior of patient during exercise test, evaluated with different parameters measured at the moment of stopping of exercise (heart rate and threshold work load, rate-pressure product, maximal downsloping of ST segment, different positivity criteria for exercise test) allowed us to show a good correlation only between the extent of coronary involvement and rate-pressure product or maximal downsloping of ST segment.

Adult↗
PubMed1976

[Comparative evaluation of the isometric test and of dynamic exercise in the diagnosis of coronary insufficiency (author's transl)].

Fifty patients with exertional coronary insufficiency performed an exercise test on a bicycle-ergometer and an isometric exercise with an instrument set up by the authors with the collaboration of the technical laboratory of the hospital. All cases had EKG positivity during dynamic exercise and only 2 patients had a positive EKG answer during isometric exercise. Angina occured in 70% of cases during dynamic exercise and in 12% of cases during isometric exercise. The difference in the increasing heart rate of the two types of exercise was statistically significant, as was the difference between absolute values of heart rate reached at the end of the exercise. The difference in the values of arterial pressure reached in the two types of exercise was also statistically significant. Moreover the comparison of product heart rate, time arterial pressure, time 10(-2) bordered on statistical significance. 31 of the 50 patients who underwent coronary angiography, demonstrated severe impairment. During isometric exercise a higher percentage of disturbances was observed. The authors came to the conclusion that isometric exercise is not advisable for the diagnosis of coronary insufficiency, either for the low specificity or the potential risk.

Adult↗