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Biomedical subjects

G Ferro

Publications and source records attributed to G Ferro.

At least 73 records · Page 4Linked to original sources
PubMed1985

Relation between heart rate and QT interval in exercise-induced myocardial ischemia.

The relation between heart rate and QT interval during dynamic upright exercise on a bicycle ergometer was investigated in control subjects (n = 18) and in patients with coronary artery disease (CAD), stable angina on effort, and angiographically documented significant coronary stenoses (n = 23). Both groups had a significant negative linear relation between heart rate and QT, with a higher correlation coefficient in control subjects (r = -0.78) than in patients with CAD (r = -0.64). This response may be a result of the nonhomogeneous response to ischemia in patients with CAD, particularly with regard to the different impact of exercise-induced ischemia. When the 2 regression lines were compared, a flatter slope was found in the CAD group (p less than 0.001) as a consequence of a faster decrease in the QT-increasing rate in control subjects. It is suggested that in control subjects exercise-induced increase in adrenergic tone causes a rapid and relevant decrease in QT-interval duration. In the CAD group, exercise-induced ischemia relatively prolonged the QT interval; this may have been the result of an impairment of myocardium in response to catecholamines release during exercise or the consequence of a direct effect of exercise-induced ischemia prolonging the duration of myocardial tension.

Adult↗
PubMed1985

Sperm antibodies and infertility in patients with testicular cancer.

The level of antisperm antibodies using the enzyme-linked immunosorbent assay (ELISA) in the serum of 48 patients with testicular cancer before and after therapy is reviewed. This is not a linear study of each patient, but some conclusions can be drawn: In a high percentage of testicular cancer patients serum antisperm antibodies can be detected: 73.3 per cent before orchiectomy and 43.7 per cent overall. The percentage of patients with antibodies decreases with adequate therapy. In patients with advanced disease there is a higher percentage of positivity (50%) for serum antisperm antibodies than in patients with low-stage disease (30%). The higher percentage of antibodies-positive patients among those with infertility patterns could be an important argument that supports the hypothesis that autoimmune pathology can play a role in oligo/azoospermia in testicular cancer patients.

Adolescent↗
PubMed1985

Non-invasive evaluation of the isovolumic relaxation period during dynamic and isometric exercise.

The purpose of the study was to evaluate non-invasively the response of the isovolumic relaxation period to different types of exercise--dynamic supine bicycle exercise (DSBE) and handgrip (HGP), in a selected healthy population. From simultaneous echo-polygraphic recordings, obtained in 30 young subjects at rest, during submaximal DSBE, during one minute of HGP (75% of maximal heart rate) and in the recovery period, the true isovolumic relaxation period (IRP) was determined. Systolic (SBP) and diastolic (DBP) blood pressure, aortic closing pressure (AoCP) and heart rate (HR) were also recorded. HR increased more markedly in DSBE (delta HR = +85% at peak load) than in HGP (delta HR = +29% at peak), while a greater rise of DBP (delta DBP = +25%) was observed in HGP. IRP shortened at both exercises as the workload progressively increased, with a maximum decrease by 54% in DSBE and by 42% in HGP. Moreover, at both exercises, an exponential correlation between IRP and HR was found. Correlating IRP with HR and AoCP by multiple regression analysis, it was found that IHP in HGP was equally affected by HR and AoCP, while during DSBE heart rate had a greater influence than AoCP.

Adolescent↗
PubMed1984

QT/QS2 ratio as an index of autonomic tone changes.

The effects of changes in sympathetic tone on QT/QS2 ratio were studied in 10 healthy subjects aged 21 to 24 years. The subjects underwent a bicycle ergometer exercise, a tilt test, a decrease in carotid transmural pressure induced by means of pneumatic neck chamber, an i.v. injection of phenylephrine. A phonocardiogram and ECG were simultaneously recorded at a paper speed of 100 mm/s to evaluate QT and QS2 intervals in each test. In basal conditions, the QT/QS2 ratio was less than 1, whereas it increased progressively during the physical exercise and became greater than 1 at peak exercise. Both the upright position and the increase in neck-tissue pressure induced a significant increase in the QT/QS2 ratio as compared with the basal values, whereas i.v. administration of phenylephrine reduced significantly the QT/QS2 ratio. These results demonstrate that those stimuli which induce a rise in adrenergic activity may increase the QT/QS2 ratio. In contrast, the reflex inhibition of the adrenergic activity induced by phenylephrine is accompanied by a reduction in QT/QS2 ratio. Therefore, the QT/QS2 ratio might represent a reliable index of sympathetic cardiac tone.

Adult↗
PubMed1984

Systolic and diastolic time intervals during spontaneous angina.

In 5 patients who suffered spontaneous angina during cardiac catheterization, aortic pressure and electrocardiographic lead (V5) were recorded at rest, at the onset of anginal pain, 5 and 10 min after 0.6 mg sublingual nitroglycerin (NTG). Heart rate, systemic arterial pressure, systolic, and diastolic time intervals were measured. Heart rate and systemic arterial pressure rose significantly immediately after the onset of angina and declined progressively within 10 min from NTG administration. Preejection period did not change during angina, while left ventricular ejection time and electromechanical systole lengthened. As a consequence, diastolic time, expressed as percent of cardiac cycle, shortened sharply. All parameters considered went back to basal values within 10 min from NTG administration, and were preceded by relief or reduction of anginal pain. We concluded that a fall in diastolic time, secondary to a prolongation of electromechanical systole occurring during angina, may further increase the degree of ischemia resulting in a vicious cycle than can be interrupted by NTG administration.

Angina Pectoris↗
PubMed1984

Water-path echotomography in differential diagnosis of scrotal masses.

Experience with Octoson water-path echotomography in examining 21 testicular masses is reported. Sonographic results were confirmed by surgical and pathologic findings in all cases. We believe this procedure to be of value in differential diagnosis of intrascrotal swellings.

Adolescent↗
PubMed1984

Diastolic time during exercise in normal subjects and in patients with coronary artery disease. A plethysmographic study.

Percent diastole (%D) was evaluated at rest and during effort (submaximal upright exercise) in 13 normal subjects and in 14 age-matched patients with coronary artery disease (CAD). Systolic time intervals were also simultaneously recorded by using the thermistor pulse transducer. At rest, in both groups, a positive linear regression was found between %D and cycle length (RR) (%D = 19.1 + 0.044RR, r = 0.83 in normals; %D = 21.2 + 0.044RR, r = 0.88 in CAD). During effort, while in normals no correlation was found between %D and RR values, in CAD patients %D and RR were linearly related (%D = -12.81 + 0.087RR, r = 0.67). These results prove that diastolic time is differently affected by the exercise in the two examined groups and that in CAD patients an abnormal reduction of %D occurs during stress test.

Adult↗
PubMed1984

Postural changes and isosorbide dinitrate. A polygraphic study in patients with coronary artery disease.

Sitting or orthostatic positions and trinitrine-like drugs reduce venous return. We focused on the non-invasive assessment of postural-induced cardiovascular stress and isosorbide dinitrate (IDN) induced changes in 8 male patients with coronary artery disease (CAD), using polygraphic recordings by means of a Thermistor Pulse Transducer. The pre-ejection period (PEP) is sensitive to reduced preload and to the positive inotropic state of the myocardium. In addition, the % diastole (RR interval--electromechanical systole/RR interval) has been recently demonstrated to be correlated to coronary perfusion in CAD patients. We observed that IDN in clinostatism and the sitting position reduced preload (longer PEP) with increased heart rate (HR) and did not affect % diastole. In orthostatism, while controls showed an increased HR and prolonged PEP, the HR was higher after IDN, with a fall in PEP and a significant decrease in % diastole. We ascribed this change to adrenergic stimulation by the hypotensive actions of IDN (lowered mean blood pressure) in orthostatism and with a fall in coronary perfusion. Caution should be taken in CAD patients when postural stress could occur during IDN treatment. Moreover, polygraphic studies can be useful to detect individual responses to nitrates and serial recordings could be employed to assess late responses to chronic management with IDN.

Analysis of Variance↗
PubMed1983

Two-dimensional echocardiography in idiopathic enlargement of the right atrium. Reliability and limitations.

A 36-year-old woman was admitted to our hospital with exertional dyspnea, palpitation and cardiac enlargement on standard chest X-ray. Physical examination did not reveal any significant abnormality and routine laboratory tests were normal. ECG showed atrial fibrillation and negative T waves in lead III and a VF, with a stiffened ST segment. M-mode echocardiography showed absence of pericardial effusion and normal size of both ventricular chambers. Two-dimensional echocardiography showed a large saccular dilation of the right atrium without significant enlargement of other cardiac chambers. A slight displacement of tricuspid valve leaflets was also present. Cardiac catheterization was effective in the diagnosis of idiopathic enlargement of the right atrium. Although two-dimensional echocardiography has some limitations in the diagnosis of this unusual malformation, it may prove useful in the noninvasive follow-up of these patients, in order to monitor the eventual increase of atrial size and to promptly detect late complications.

Adult↗
PubMed1983

Systolic time-interval evaluation by thermistor plethysmography during uninterrupted dynamic stress test in normals and in patients with coronary artery disease.

18 patients with coronary artery disease (CAD) and 21 normal subjects underwent a triangular bicycle exercise test. Systolic time intervals (STI) were calculated at rest and every 2 min during exercise. Under resting conditions, STI were similar in the two groups. During exercise, the ejection time index (ETI), i.e. left ventricular ejection time (LVET) corrected for HR, rose significantly more in CAD patients, as compared to normals. Pre-ejection period (PEP) was also differently affected by exercise in CAD patients, who showed a more shortened PEP (p less than 0.001) in the early stage of dynamic stress. PEP/LVET ratio, which in the control group decreased continuously, in CAD patients fell during exercise at lower work loads (p less than 0.001), whilst rose during strenuous exercise. Finally, significant differences (p less than 0.001) were found in the percent change (% delta) PEP/LVET ratio between the two groups during the early phase of exercise, in which no superimposition of single values was present. Therefore, this last parameter seems the most reliable to differentiate clearly CAD patients from normal subjects, but its use must be limited at early exercise.

Adult↗
PubMed1983

Intropic effects of several antiarrhythmic drugs.

The effects of intravenous administration of several quinidine-like antiarrhythmic drugs (bunaftine, monochloroacetyl ajmaline, lidocaine, mexiletine, disopyramide, aprindine, diphenylhydantoin, procainamide) on left ventricular performance, evaluated by systolic time intervals (STI), were studied in 100 patients with atherosclerotic heart disease. The STI were measured: the pre-ejection period (PEP), the isometric contraction time (ICT), the left ventricular ejection time (LVET), corrected LVET (LVETc), and the PEP/LVET ratio. The degree of impairment of left ventricular performance was maximal after aprindine and disopyramide administration. This was demonstrated by significant increases in the PEP, ICT, and PEP/LVET and by significant decreases in LVET and LVETc, in patients in both III-IV and I-II NYHA classes. Bunaftine, monochloroacetyl ajmaline, and lidocaine induced a less marked impairment of myocardial performance, since the PEP, ICT, and PEP/LVET increases were not significant compared to controls in patients in NYHA class I-II, and since no variation of LVET and LVETc were observed. Mexiletine effects on myocardial performance appear to be intermediate between these groups of drugs. Diphenylhydantoin and procainamide, considered separately because of their effects on heart rate and blood pressure which are not possessed by the other drugs, induced significant increases of PEP in NYHA class III-IV patients. However, the effects of these 2 drugs on myocardial performance may have been underestimated, due to the concomitant hemodynamic effect of these drugs.

Ajmaline↗
PubMed1982

Quantitative assessment of infarct size in isoproterenol-infarcted rats.

The authors performed a number of experiments aiming at quantifying the infarct size in Sprague-Dawley male rats. The experimental model employed was isoproterenol (ISP) induced, infarctlike myocardial lesions. In quantifying the extent of the infarct area they compared the cross reliability of enzymatic and histological methods. ISP was administered in two subcutaneous injections (50 mg/100 Gm body weight) at a 24 hour interval. At the peak of the necrotic process (48 hrs after the first injection), the heart was subjected to enzymatic or histological studies. Thus, a group of infarcted animals (n = 25) and their controls (n = 15) underwent the assessment of creatine kinase (CK) content in the homogenate of the myocardium. Another group of animals (n = 15) was used for histological observations, including measurement of infarct size by planimetry from histological sections. A good relationship was observed between the percentage of necrotic tissue calculated on the basis of CK values (69.11 +/- 2.39%) and the infarction area assessed by planimetry (72.37 +/- 2.69%) (mean +/- standard error of the mean [SEM]). Thus, the present study confirms that ISP-induced myocardial lesions are a simple and reliable model for experimental infarct. Moreover, the assessment of the CK content in the heart is correlated with histological studies by planimetry, and is suggested as a direct enzymatic method to quantify the extent of myocardial necrosis.

Animals↗