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Biomedical subjects

G Ferro

Publications and source records attributed to G Ferro.

At least 91 records · Page 5Linked to original sources

Non-invasive evaluation by thermistor plethysmography of left ventricular performance during dynamic exercise. Comparison with echocardiography.

The purpose of this study was to evaluate the reliability of two non-invasive techniques (STI and echocardiography) in assessing cardiovascular response during exercise. STI were obtained using a new carotid pulse transducer (thermistor pulse) proved to be reliable in exercise recording. The study population included 12 male rowers (age 15-20 years), who performed supine bicycle exercise; STI and echocardiographic recording of left ventricle were simultaneously obtained at rest and continuously throughout the exercise period. A negative linear correlation (r=-0.782; p less than 0.001) was found between PEP (pre-ejection period) and %LVID (fractional shortening of left ventricle), reliable indexes of cardiac contractility measured by the two techniques. A lower, but significant correlation (r=0.643; p less than 0.001) was present between ETI (left ventricular ejection time corrected by heart rate) and SV (stroke volume) indexes of pump function. The present study shows that STI measured with this new technique, can be employed in evaluating left ventricular function in those patients in whom a good echocardiogram is difficult to record during exercise.

Adolescent↗

Severity of mitral regurgitation assessed by echocardiography. Reliability and limitations.

To assess whether echocardiography may represent a useful mean to evaluate the degree mitral regurgitation (DR), left ventricular diastolic internal dimension (LVIDd), left atrial dimension (LAD), and velocity of circumferential fiber shortening (Vcf) were compared to DR assessed by left ventriculography in 48 patients with primary (n = 21) and cardiomyopathic (n = 27) valvular incompetence. In patients with good left ventricular contractility, i.e. with Vcf values above 1.02, a significant positive linear correlation was found between LVIDd and DR (LVIDd = 5.38 + 0.45DR; r = 0.72; p less than 0.001). In contrast, in patients with depressed left ventricular function, i.e. with Vcf values below 1.02, LVIDd did not correlate to DR. In either group LAD and Vcf did not correlate to DR. Thus, echocardiography may provide useful semiquantitative information concerning DR only in patients with preserved left ventricular performance.

Cardiomegaly↗

Effects of intravenous disopyramide on myocardial function in patients with different degrees of cardiac failure.

The effects of intravenous disopyramide phosphate on myocardial function were evaluated by non-invasive indices of cardiac performance (systolic time intervals, STI) in 15 patients with atherosclerotic heart disease and different degrees of cardiac failure. Disopyramide (1.5 mg/Kg) was given intravenously over a period of 5 min. This drug induced in patients in I-II classes of NYHA a significant decrease of LVETc, while PEP, ICT, and PEP/LVET ratio rose significantly. STI were affected much more markedly in patients in III-IV classes of NYHA. Particularly affected were contractility indices (PEP, ICT, PEP/LVET), which were reduced significantly more in patients in III-IV classes as compares to patient in I-II classes. In contrast, LVETc, which correlates to stroke volume and cardiac output, was similarly worsened by the drug in the 2 groups of patients. Therefore, this study shows that disopyramide has relevant depressant effects on myocardial performance, simultaneously reducing stroke volume and contractility, and that the effect on contractility is more marked in patients with severe left ventricular impairment.

Arrhythmias, Cardiac↗

Myocardial hypertrophy in the rat. Correlation between two experimental models.

Two different conditions responsible for cardiac hypertrophy in the rat were investigated: the first one is isoproterenol-induced myocardial infarct, the second is exposure to hypoxia (0.42 atmospheres/24 h) in hypobaric chamber. To demonstrate that in both experimental models stimulation of protein synthesis is an absolute requirement to induce cardiac hypertrophy, a variety of techniques were employed including: evaluation of dry heart weight value, concentration of radiothallium (201T1) in the heart and effects of inhibitors of protein synthesis (Puromycin). Experimental results have showed: (A) a significant increase (p<0.001 as compared to control group) of dry heart weight values both in isoproterenol-treated and hypoxic rats; (B) a significant increase over control group (p<0.001) in myocardial 201T1 concentration in isoproterenol-treated rats; (C) total inhibition of cardiac hypertrophy in Puromycin treated group subjected to hypoxia. Finally, on the basis of different mortality observed in infarcted (85.0%) or hypoxic (5.0%) rats treated with Puromycin (40 mg/Kg body weight i.p.) a different role of cardiac hypertrophy in 2 experimental conditions is postulated: in the case of infarct-like lesions the cardiac hypertrophy has compensatory significance; under hypoxic stimulus is only due to increased cardiac work.

Animals↗

Relationship between systolic time intervals and heart rate during atrial or ventricular pacing in normal subjects.

Systolic time intervals (STI) are regarded as good indices of cardiac performance in many heart diseases. It must be considered, however, that they are temporally related to the cardiac contraction cycle and, therefore, may be modified by heart rate changes. Thus, it is necessary to define the possible relationship between STI and heart rate changes. In this study, changes in heart rate were induced by atrial and ventricular pacing. Tachycardia caused a proportional decrease of left ventricular ejection time (LVET) (y=275.142-1.0025 x, r=0.76, p less than 0.001 for atrial pacing and y=298.28-0.691 x, r=-0.75, p less than 0.001 for ventricular pacing, respectively), but did not modify the pre-ejection period (PEP) and the isometric contraction time (ICT) and the electromechanical interval (QS1). These results demonstrate that while LVET must be corrected for the changes in heart rate, no correction of PEP and ICT is necessary.

Adult↗

[Correlations between polygraphic and hemodynamic parameter changes induced by high concentrated oxygen administration in patients with mitral valvulopathy (author's transl)].

The goal of this study was to identify, utilizing apexcardiogram, other noninvasive parameters useful to evaluate the functional condition of the pulmonary vascular bed in patients with mitral stenosis and insufficiency. The patients of both sexes with mitral stenosis and insufficiency underwent left and right heart catetherization and simultaneously a polygraphic study was performed. Recordings of polygraphic as well as hemodynamic parameters were performed under control condition and after 5 min breathing of 100% Oxygen administered by facial mask. These results indicate that changes in rapid filling angle have a close relationship with changes in pulmonary capillary wedge pressure and variation of rapid filling interval are correlated with changes in pulmonary capillary wedge pressure and variation of rapid filling interval are correlated with changes in cardiac output.

Administration, Intranasal↗

[Effects of metoprolol on myocardial performance in hypertensive patients during exercise (author's transl)].

In this study the effects of metoprolol administration (200 mg daily per os) to 20 hypertensive subjects (WHO stage I and II), as a 20-days course, on heart rate (HR), systolic blood pressure (BP) and myocardial performance evaluated by systolic time intervals, were studied both at rest and during exercise. This treatment was able to reduce significantly HR and BP in all the patients, both at rest and during exercise. After the 20 days treatment, the left ventricular ejection time corrected for HR (LVETc) did not show any significant change both at rest and during exercise. On the other hand, the pre-ejection period (PEP) changed at rest in all the subjects studied after metoprolol treatment, but increased significantly during exercise only in patients in the I WHO class and only at the highest work load (at 70 watts, from 63 +/- 2 to 78 +/- 7 msec, P ¿ 0.05). Furthermore, in the same group of patients the maximal work load increased significantly after metoprolol treatment (from 67.5 +/- 6 to 85 +/- 8 watts, P < 0.05).

Adult↗

[Mondor's disease. Considerations on 5 cases].

The clinical, anatomical, topographical and pathological features of Mondor's disease are described, and five personal cases are presented. Their aetiopathogenetic characteristics reflect the doubts expressed in the literature. Stress is laid on the benign nature of the disease, the possibility of treating it at the out-patient level, and the complete remission of both subjective and objective symptoms obtainable in the space of a few weeks.

Adult↗

[The effects of intravenous mexiletine on cardiac performance (author's transl)].

The effects of intravenous Mexiletine (Kö1173) on cardiac performance has been studied in 20 patients affected by myocardiosclerosis (10 patients were classified in the 1st or 2nd NYHA classes, 10 cases in the 3rd or 4th ones. Mexiletine (1.5 mg/Kg) was given intravenously over a period of 1 minute. The effect on myocardial function has been evaluated by means of the systolic time intervals (STI). The drug caused non-significant changes of the left ventricular ejection time (LVET); on the contrary it caused a significant increases of the pre-ejection period (PEP), isometric contraction time (ICT) and the PEP/LVET ratio. These alteration became evident after 5--10 minutes and disappeared about 30 minutes after administration of the drug.

Adult↗

[Clinical and hemodynamic effects of disopyramide phosphate administered i.v. in cardiopathic subjects (author's transl)].

The antiarrhythmic action of disopyramide (1.5 mg/Kg) administered i.v. as a bolus was assessed in 30 patients with ischemic heart disease and different arrhythmias. In 75% of supraventricular parossistic tachycardia and in 75% of parossistic atrial fibrillation, arrhythmia was interrupted within few minutes from drug injection; in 90% with premature ventricular contractions (PVC) and in 100% of ventricular tachycardia, disopyramide was capable to interrupt the arrhythmias. The hemodynamic effects of the same dose of disopyramide were evaluated in other 17 patients, 9 of which in I-II class NYHA and 8 in III-IV class. We used STI's as parameters of cardiac performance. In all patients following the injection of disopyramide, a significant increase of PEP, ICT and PEP/LVET ratio and a significant decrease of LVETc were observed. Thus, the disopyramide impaired cardiac performance and its effect appeared more evident in patients in III-IV class NYHA. In conclusion, disopyramide showed to be effective in interrupting different arrhythmias; however, its depressant action on cardiac performance suggests that caution should be used in patients with severely impaired myocardial function.

Adult↗

[An unusual case of entero-vesical fistula caused by a foreign body].

The authors describe a rare case of sigmoidovesical fistula due to a foreign body and giving trouble 30 years after the causative surgical procedure, namely an oopheroctomy. The cause of the fistula was apparently some suture material that had not been reabsorbed. Surgical excision of the fistula produced a complete recovery.

Castration↗