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Biomedical subjects

C Giusti

Publications and source records attributed to C Giusti.

At least 19 recordsLinked to original sources
PubMed1992

Normal ultrasonic myocardial reflectivity in athletes with increased left ventricular mass. A tissue characterization study.

BACKGROUND: Ultrasonic integrated backscatter of myocardial walls is directly related to the morphometrically evaluated collagen content. The integrated backscatter is also increased in hypertrophic cardiomyopathy, probably because of fiber disarray. The purpose of this study was to investigate myocardial tissue reflectivity in subjects with physiological hypertrophy caused by intense physical training and to assess the relation between the acoustic properties of myocardial tissue and left ventricular wall thickness assessed by conventional two-dimensional echocardiography. METHODS AND RESULTS: Twenty-four young male athletes (14 professional cyclists and 10 weight lifters, all in full agonistic activity) were studied together with 10 normal age-matched controls with sedentary life. By means of a commercially available two-dimensional echocardiograph, standard measurements were obtained according to the recommendations of the American Society of Echocardiography. With a prototype implemented in our Institute, an on-line radiofrequency analysis of ultrasound signals was also performed to obtain quantitative operator-independent measurements of the integrated backscatter of the myocardial walls. The integrated values of the radiofrequency signal were normalized for the pericardial interface and expressed in percent integrated backscatter (%IB). Compared with control subjects, athletes showed greater thickness values of septum (controls, 9 +/- 1; cyclists, 14 +/- 2; weight lifters, 15 +/- 1 mm, mean +/- SD; p less than 0.01) and posterior wall (9 +/- 1, 12 +/- 2, and 12 +/- 1 mm, respectively; p less than 0.01) but similar values of %IB for both septum (23 +/- 4%, 21 +/- 7%, and 23 +/- 8%, p = NS) and posterior wall (10 +/- 2%, 9 +/- 2%, and 11 +/- 2%, p = NS). In athletes, no correlation was found between septal and posterior wall thickness and the corresponding regional myocardial reflectivity (r = 0.23, p = NS and r = 0.01, p = NS, respectively). Furthermore, we compared the quantitative ultrasonic data between two subsets of 10 athletes and 10 patients with hypertrophic cardiomyopathy and similar degrees of septal thickness (16 +/- 1 versus 17 +/- 1 mm, respectively, p = NS). Septal and posterior wall %IB results were significantly higher in patients with hypertrophic cardiomyopathy (53 +/- 13% and 36 +/- 9%, respectively) than in athletes (21 +/- 7% and 10 +/- 3%, respectively; p less than 0.01 for both). CONCLUSIONS: We conclude that 1) endurance athletes show a normal pattern of quantitatively assessed ultrasonic backscatter despite of a marked left ventricular hypertrophy and 2) athletes and patients with hypertrophic cardiomyopathy and similar degrees of myocardial wall thickness can be differentiated on the basis of quantitative analysis of backscattered signal.

Adult↗
PubMed1991

Twenty-four-hour activity of felodipine extended release in chronic stable angina pectoris.

To investigate the antiischemic efficacy and duration of action of the dihydropyridine calcium antagonist felodipine, 15 patients with stable exertional angina were enrolled in a double-blind, crossover study comparing 2 doses (5 and 10 mg) of felodipine extended release (ER) and placebo given once daily for 1 week. Bicycle exercise tests were repeated at the end of each treatment period 4 and 24 hours after dosing. Four hours after dosing with both felodipine doses, only 5 patients discontinued the exercise test because of greater than 2 mm of ST-segment depression, whereas 10 continued until exhaustion (p less than 0.01 vs placebo). Compared with placebo, total exercise time was increased by 19% (p less than 0.001), with no difference between doses. After 24 hours, exercise duration was prolonged up to physical exhaustion in 6 patients taking felodipine 10 mg (p less than 0.05 vs both placebo and felodipine 5 mg); moreover, 11 patients taking 10 mg and 5 taking 5 mg increased time to 1 mm of ST depression greater than or equal to 15% compared with exercise time during the placebo test. Mean time to 1 mm of ST depression at 24 hours was increased by 8% with 5 mg and by 18% with 10 mg (p less than 0.001 vs placebo; p less than 0.01 between doses). Total exercise time at 24 hours was increased with both doses (p less than 0.001), with greater efficacy with the 10-mg dose (p less than 0.05 vs 5 mg).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Heparin anticoagulant activity: new knowledge and future prospects].

The present knowledge about the heparin molecular structure has been reported by current scientific literature and especially the relationship between structure and function. From the pharmacological point of view the authors suggest future lines of research in this field. The role of endothelial and the mechanisms of heparin removal from the circulation (saturation and desaturation) are analyzed. From the anticoagulation point of view the authors after the analysis of the anti-thrombin III and anti-factor Xa activity, evaluate the heparin biological action on the platelets, complement, white blood cells. They also evaluate the questions collected to heparin use in non classical clinical situations, alternative routes of administration and new therapeutic and anticoagulant procedure; the association of prostacyclin together with heparin.

Animals↗
PubMed1991

[Risk of disseminated intravascular coagulation in patients undergoing echo-guided transperineal prostatic needle biopsy with transrectal probe].

Disseminated intravascular coagulation (DIC) is a severe life-threatening acute bleeding disorder. Traumatized tissues, tumors, necrotic tissues, or bacterial endotoxines release similar material in the blood to the tissutal factors activating the coagulation cascade. This preliminary study was aimed at verifying the risk of DIC in patients undergoing US-guided transperineal prostatic biopsy with Chiba and Tru-Cut needles. To evaluate the activation degree of coagulation factors in the circulation, the authors measured the concentrations of urinary fibrin degradation products in 10 patients undergoing US-guided transperineal prostatic biopsy, both before and after biopsy, every second hour, for 24 hours. Every tube of urine sample contained soya bean trypsin inhibitor and bovine thrombin to prevent any further fibrin degradation during incubation period for the possible presence of blood in urine samples. The results showed that 7/10 patients had marked increase in urinary fibrin degradation product levels (up to 800 micrograms%), with a 3-phase trend: early peak after 2-6 hours, middle peak after 6-14 hours, and late peak after 18-24 hours, which proved the activation of the coagulation cascade.

Aged↗
PubMed1990

Fractional shortening/end-systolic stress correlation in the evaluation of left ventricular contractility in patients treated by acetate dialysis and lactate haemofiltration.

Fractional shortening/end-systolic stress (FS/ESS) correlation by echocardiography is a reliable index of left ventricular function. Acetate infusion or preload reduction due to water compartment re-equilibrium may induce ventricular derangements during dialytic treatment. In 13 patients on lactate haemofiltration (LHF) (mean age 56.8 +/- 11.9 years on regular dialytic treatment (RDT) for 75.3 +/- 56.5 months) and in seven patients on acetate haemodialysis (AHD) (mean age 48 +/- 10.7 years; on RDT for 43.9 +/- 49.2 months) fractional shortening/end-systolic stress was evaluated before and after single dialytic session. The following biochemical parameters were also studied: haematocrit (Htc), plasmatic osmolarity, ionised Ca, Na, K, and blood gases. In both groups the mean fractional shortening/end-systolic stress correlation maintained the same correlation coefficient before and after treatment (r = -0.68, P less than 0.001). Lactate haemofiltration and acetate haemodialysis by reducing the volume expansion and preload (mean interdialytic body-weight increase 2.5 +/- 0.8 kg in our patients), may decrease left ventricular contractility (Starling's law). Furthermore, acetate was postulated as a myocardial depressant. Dialysis-induced myocardial contractility variations plotted against fractional shortening/end-systolic stress correlation allowed the division of our patients into four different groups: (1) patients with increased fractional shortening and reduced end-systolic stress; (2) patients with unchanged fractional shortening and reduced end-systolic stress; (3) patients with reduced fractional shortening and increased end-systolic stress; and (4) patients with reduced fractional shortening and unchanged or reduced end-systolic stress. These groups include patients treated with either lactate haemofiltration or acetate haemodialysis. Our data cannot confirm the postulated acetate myocardial depressant activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMed1989

[Echocardiographic parameters and systolic times in arterial hypertension in the elderly].

In 40 subjects, 15 mean age 70.7 +/- 5.6 with systolic-diastolic hypertension, 15 mean age 75.5 +/- 6.8 years with systolic hypertension and 10 mean age 73.6 +/- 5.1 normotensive control group we have analyzed with M-mode 2D echocardiography and echophonocardiography the following parameters: diastolic--EDD--and systolic diameter--SD--of left ventricle, diastolic thickness of septum--SSD--and posterior wall--SPPD--of left ventricle, left ventricular ejection fraction--EF--(Theicholtr. formula), radius posterior wall thickness--R/SPPD--, left ventricular mass--LVM--(Devereux' formula), and systolic time intervals (Q-A2, LVET, PEP and PEP/LVET). The differences between groups are: systolic-diastolic hypertensive patients have increased EDD, SPPD and LVM, reduction of EF and increased PEP/LVET ratio in comparison with B and C groups; systolic hypertension doesn't increase EDD; SSD and PEP/LVET increase, while the EF remains within normal limits. In the healthy aged subjects SSD, SPPD and LVM are normal.

Aged↗
PubMed1987

Cardiovascular adjustments induced by training evaluated during semisupine isotonic exercise and recovery period: an echocardiographic study.

Two groups of subjects were examined: trained athletes (group A) and a sedentary control group (group B). The subjects performed submaximal bicycle exercise in the semisupine position to evaluate the differences between the two groups with regard to cardiovascular response during exercise and recovery and to point out all the changes due to training. During the first part of exercise, cardiac output increased contemporary with heart rate and myocardial contractility as shown by the trend of the ejection fraction, higher in group A, under the same level of total vascular peripheral resistances. Later there was an increase of cardiac output for a further increase of heart rate and cardiac inotropism due to the homeometric mechanism. During recovery the heart rate and peripheral vascular resistance reduction led to an increase of venous return which set up the Frank-Starling mechanism via an increase of left ventricular dimensions. These adjustments were more efficient in group A. During exercise and recovery the heart rate-pressure product was constantly lower in group A with a significant difference to group B. Therefore, trained athletes' myocardium is more efficient than that of the sedentary group because it performs an external work load with a lower oxygen consumption.

Adult↗
PubMed1987

Cardiac damage due to nonpenetrating trauma. Report of four cases.

Four examples of cardiac damage secondary to nonpenetrating trauma in road accidents are described. Two patients had interventricular septal defect and other two had tricuspid insufficiency. In all four cases the lesion was not recognized at the time of the accident but became clinically important later. The time interval between trauma and surgery was one month to thirteen years. After surgical treatment, all four patients have continued to be asymptomatic.

Accidents, Traffic↗
PubMed1978

[Effect of metoprolol on the exercise tolerance in patients with stable angina pectoris (author's transl)].

The effect on the exercise tolerance induced by a new selective beta1-receptor antagonist, metoprolol, given by a single administration per os, has been evaluated in 16 patients with stable angina pectoris. The study was a double blind cross-over between metoprolol 100 mg and placebo. Patients were hospitalized for the time required for the performance of the study; every cardioactive drug, except for trinitrine, was stopped 72 hours prior to the study period. Exercise testing was performed two hours after the intake of the drug, in a sitting position on a bicycle ergometer; the workload was increased by 25 Watts increments every two minutes. Compared to placebo, the total workload performed and duration of exercise increased after metoprolol (P less than 0.001), heart rate decreased (P less than 0.001) both in the resting state and during exercise test, systolic blood pressure didn't change in the resting state but decreased during exercise test (P less than 0.01), pressure-rate product, an useful index of changes in myocardial oxygen consumption decreased both in the resting state (P less than 0.001) and during exercise test (P less than 0.001). It is concluded that metoprolol induces a significant increase in exercise tolerance. This is due to a marked reduction in oxygen myocardial consumption resulting by both decreased heart rate and systolic pressure.

Adult↗
PubMed1978

[The diagnosis of myocardial infarction in the presence of disorders of ventricular activation for right endoventricular pacing and left bundle branch block (author's transl)].

The Authors have studied the vectocardiogram in left bundle branch block, right endoventricular pacing, myocardial infarction and right endoventricular pacing, myocardial infarction and left bundle branch block. Vectocardiographic loop analysis allows the diagnosis of myocardial infarction both in the presence of endoventricular pacing and in the presence of left bundle branch block.

Bundle-Branch Block↗