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Biomedical subjects

G Galanti

Publications and source records attributed to G Galanti.

At least 19 recordsLinked to original sources
PubMed1999

Cardiac growth factors in human hypertrophy. Relations with myocardial contractility and wall stress.

The aim of the present study was to investigate whether and which cardiac growth factors are involved in human hypertrophy, whether growth factor synthesis is influenced by overload type and/or by the adequacy of the hypertrophy, and the relationships between cardiac growth factor formation and ventricular function. Cardiac growth factor formation was assessed by measuring aorta-coronary sinus concentration gradient in patients with isolated aortic stenosis (n=26) or regurgitation (n=15) and controls (n=12). Gene expression and cellular localization was investigated in ventricular biopsies using reverse transcriptase-polymerase chain reaction and in situ hybridization. Cardiac hypertrophy with end-systolic wall stress <90 kdyne/cm2 was associated with a selective increased formation of insulin-like growth factor (IGF)-I in aortic regurgitation and of IGF-I and endothelin (ET)-1 in aortic stenosis. mRNA levels for IGF-I and preproET-1 were elevated and mainly expressed in cardiomyocytes. At stepwise analysis, IGF-I formation was correlated to the mean velocity of circumferential fiber shortening (r=0.86, P<0.001) and ET-1 formation to relative wall thickness (r=0.82, P<0. 001). When end-systolic wall stress was >90 kdyne/cm2, IGF-I and ET-1 synthesis by cardiomyocytes was no longer detectable, and only angiotensin (Ang) II was generated, regardless of the type of overload. The mRNA level for angiotensinogen was high, and the mRNA was exclusively expressed in the interstitial cells. Ang II formation was positively correlated to end-systolic stress (r=0.89, P<0.001) and end-diastolic stress (r=0.84, P<0.001). Multivariate stepwise analysis selected end-systolic stress as the most predictive variable and left ventricular end-diastolic pressure as the independent variable for Ang II formation (r=0.93, P<0.001). In conclusion, the present results indicate that the course of human left ventricular hypertrophy is characterized by the participation of different cardiac growth factors that are selectively related both to the type of hemodynamic overload and to ventricular function.

Aged↗
PubMed1999

Decreased baroreflex sensitivity assessed from phase IV of Valsalva maneuver in mild congestive heart failure.

Decreased sensitivity of cardiopulmonary and arterial baroreceptors has been hypothesized to sustain sympathetic activation in patients with heart failure. In the present investigation the relationship between the impairment of baroreflex sensitivity and clinical severity of congestive heart failure was investigated. The authors studied 58 patients with heart failure (14 in NYHA class I, 22 in NYHA class II, and 22 in NYHA class III), 38 women and 20 men, age range 28-65 years. Thirty-two patients suffered from idiopathic dilated cardiomyopathy and 26 from coronary heart disease. As control group they examined 21 age-matched subjects. Baroreceptor sensitivity was studied by using the Valsalva maneuver as stimulus. Arterial pressure and heart rate were measured noninvasively by Finapres instrument (Ohmeda) and signals were recorded and elaborated with a personal computer. A decrease of baroreflex sensitivity was already demonstrable in NYHA class I patients (4.72 +/- 3.31 vs 9.25 +/- 5.05 msec/mm Hg in control group) (p < 0.005). A further impairment of baroreceptor response was found in patients in NYHA class II (1.94 +/- 2.88 msec/mm Hg, p < 0.001) and class III (1.78 +/- 1.52 msec/mm Hg, p < 0.001). Baroreceptor response showed a significant correlation with functional NYHA class (r = 0.61, p < 0.001) and anaerobic threshold (r = 0.57, p < 0.001) while the correlation was less tight with left ventricular end-diastolic diameter, fractional shortening, left ventricular ejection fraction, pulmonary mean arterial blood pressure, cardiac index, distance at 6 minutes walk corridor test, and maximal oxygen consumption (VO2max). These results suggest that baroreceptor function may be impaired early in the clinical course of heart failure and may contribute to sympathetic activation.

Adult↗
PubMed1999

Partial anomalous venous return associated with intact atrial septum and persistent left superior vena cava: a case report and literature review.

Left-sided partial anomalous pulmonary venous return (PAPVR) with an intact atrial septum is a rare cardiovascular anomaly. This report deals with the case of a 22-year-old woman who was referred to our Institution because of resting palpitation and exertional dyspnea. Two-dimensional echocardiography revealed right heart volume overload and a dilated coronary sinus. A left-sided PAPVR draining into a persistent left superior vena cava which, in turn, entered a dilated coronary sinus, was correctly detected by magnetic resonance imaging. Diagnosis was confirmed by cardiac catheterization. The literature on this subject is reviewed.

Adult↗
PubMed1998

Cardiac troponin I and Q-wave perioperative myocardial infarction after coronary artery bypass surgery.

OBJECTIVE: To monitor cardiac troponin I (cTnI), a newly developed biochemical index for cardiac damage, in patients during and after coronary artery bypass surgery (CABS) to determine whether the measurement of the serum levels of this marker could be of value in formulating an early diagnosis of Q-wave perioperative myocardial infarction (PMI). DESIGN: Prospective study with sequential measurements of biological markers in a selected surgical patient group. SETTING: University research laboratory and general university hospital (Cardiac Surgery Unit and Anesthesiology and Reanimation Unit). PATIENTS: Forty-two patients undergoing elective CABS without concomitant valvular replacement. INTERVENTIONS: There were no interventions required for this study. However, patients entered into the study had CABS, sequential arterial blood samples, ECG recordings, and echocardiograms performed. MEASUREMENTS AND MAIN RESULTS: Pre-, intra-, and postoperative (up to 48 hrs) measurements of cardiac troponin I, MB-CK, and total creatine kinase, as well as serial electrocardiograms and echocardiograms. Perioperative infarction was assessed as the development of new persistent regional wall motion abnormalities in echocardiography together with electrocardiographic alterations and MB-CK increases. Eight patients had Q-wave PMI. All PMI patients had elevated peak cTnI values (all >9.2 ng/mL), whereas the 34 nonPMI patients had peak values <9.0 ng/mL; therefore, sensitivity and specificity (with a 9.0 ng/mL cut-off value) are 100%. MB-CK measurement peak values did not demonstrate such a high specificity and sensitivity. CONCLUSIONS: Because of its high specificity and sensitivity, serial measurements of cTnI provide a rapid and accurate method for confirming or excluding the diagnosis of perioperative myocardial injury. cTnI evaluation can therefore be used both as an independent prognostic marker for patients undergoing cardiac surgery and as a powerful tool for detecting smaller PMIs often missed with standard PMI diagnostic criteria.

Aged↗
PubMed1998

Relationship between depressed baroreflex function and exaggerated sympathetic response to exercise in patients with heart failure.

The relationship between impaired baroreflex sensitivity (BS) and the degree of sympathetic activation during exercise in patients with heart failure (HF) has not been studied in detail. For this purpose, we studied BS and measured plasma norepinephrine (NE) at rest, and during and after treadmill exercise in 15 patients and 10 controls. HF patients showed lower BS in comparison to controls (3. 51 +/- 3.62 vs. 9.74 +/- 4.56 ms/mm Hg; p < 0.001), and higher levels of plasma NE at rest (449.3 +/- 147.1 vs. 261.1 +/- 82.48 pg/ml; p < 0.001) and during exercise (1,542 +/- 361.2 vs. 524.6 +/- 92.61 pg/ml; p < 0.001). BS was directly related to pVO2 (r = 0.62; p = 0.0008) and inversely related to NE at peak exercise and to the increase in NE during exercise (r = 0.59, p = 0.005, and r = 0.53; p = 0.0058). Thus, during exercise, a marked sympathetic activation exists in patients with moderate HF. The relationship between increased plasma NE during exercise and decreased BS suggests that impaired baroreceptor function may be present in sympathetic activation in HF patients.

Adult↗
PubMed1998

Doppler echocardiography in suspected lone atrial fibrillation.

Echocardiography is frequently required in patients with atrial fibrillation (AF) to exclude underlying heart disease. In the present investigation the authors evaluated 56 patients with paroxysmal AF (PAF) (27 men, 29 women, mean age 54+/-11.3 years) in whom lone AF was suspected on clinical grounds. M-mode, B-mode, and Doppler examination were performed and measurements taken according to American Society of Echocardiography criteria. Left atrial diameter, left and right atrial volumes, left ventricular (LV) diameters, LV fractional shortening, and Doppler indexes of LV diastolic function were not different in patients with PAF in comparison with those of a control group of 56 age-matched subjects free from cardiovascular diseases. Echocardiographic examination results were entirely normal in 32/56 patients (57%) vs 39/56 of the control group (69%). Mitral valve prolapse was found in five patients (9%), but only one showed mild mitral regurgitation. Doppler examination disclosed a mild (+/++) mitral regurgitation in eight patients and a small aortic or pulmonary diastolic flow in four and two patients, respectively, in the absence of significant morphologic valvular abnormalities. In these patients the sizes of heart chambers were entirely normal. Aneurysm of the interatrial septum was found in one patient and an increased thickness of the epipericardial junction in another two patients. Finally two patients had a small increase of right atrial volume without demonstrable causes. The results suggest that lone AF can be correctly suspected on the basis of clinical findings (history, physical examination, and ECG) and that in these patients echocardiography rarely discloses organic heart disease.

Atrial Fibrillation↗
PubMed1997

Histological effect of (R)-alpha-methylhistamine on ethanol damage in rat gastric mucosa: influence on mucus production.

(R)-alpha-Methylhistamine, a selective agonist of histamine H3 receptors, prevents macroscopically visible gastric lesions by absolute ethanol in the rat. A further insight into its activity was the aim of our study. Rats were given saline or (R)-alpha-methylhistamine (100 mg/kg) intragastrically. After 30 min, absolute ethanol was given and gastric mucosa was sampled 60 min later. Histologic damage and intracellular and adherent mucus were quantified. Luminal surface and mucous cells were examined by scanning and transmission electron microscopy. (R)-alpha-Methylhistamine reduced the extent of lesions by ethanol from 96 to 18%. Surface mucous cells and mucous neck cells were increased in volume and number, packaging of intracellular mucus was modified, and the secretory processes were promoted by (R)-alpha-methylhistamine itself, although these modifications were mostly evident in stomachs subsequently exposed to ethanol. Adherent mucus layer thickness was increased by (R)-alpha-methylhistamine only after ethanol exposure. It is concluded that (R)-alpha-methylhistamine predisposes mucous cells to react to ethanol.

Animals↗
PubMed1997

Both plasma and renal endothelin-1 participate in the acute cardiovascular response to exercise.

Plasma endothelin (ET-1) and renal endothelin are two distinct functional systems involved in maintaining blood volume. To investigate whether plasma and renal ET-1 participate in the cardiovascular response to exercise-induced hypovolaemia, we studied changes in plasma and urinary ET-1 in healthy non-professional athletes after 2 h of jogging performed both without and with drinking isotonic fluids. After the run, which caused a 13% plasma volume (PV) reduction, plasma and renal ET-1 (+117% and +118%) increased significantly (all P < 0.01). Fluid loss restitution during the run significantly attenuated either the PV contraction (-1.2%) and plasma and renal ET-1 increase (+2 and +3%). At multiple regression analysis changes in AVP plasma concentration, and not in PRA or PV per se, were significantly related to ET-1 changes both in plasma and urine. The present findings indicate that both plasma and renal ET-1 participate in the cardiovascular response to hypovolaemia induced by long-lasting, dynamic exercise.

Adult↗
PubMed1996

Noninvasive evaluation of right ventricle systolic pressure during dynamic exercise by saline-enhanced Doppler echocardiography in progressive systemic sclerosis.

Progressive systemic sclerosis (PSS) is characterized in its first phases by vascular damage. Lungs are involved in two thirds of patients with initial progressive destruction of the capillary bed and consequent reduction of the functional reserve, which may lead to hypertension of the pulmonary circulation. For these reasons it is of great interest to have early information about the pressure of the pulmonary circulation, both at rest and during exercise, to follow the progression and the evolution of the illness independently from subjective symptoms. The aim of the study was to evaluate by a noninvasive method, saline-enhanced Doppler echocardiography, the behavior of the right ventricular systolic pressure in patients with PSS, at rest and during exercise, without clear instrumental or clinical signs of pulmonary involvement at rest. Nine patients (7 women and 2 men) with PSS, aged 55.7 +/- 8.7 years, and 9 control subjects were evaluated. All patients had normal pulmonary pressure at rest and negative history for effort dyspnea. Subjects underwent Doppler echocardiographic examination at rest and during exercise. Right ventricular systolic pressure was evaluated by saline-enhanced Doppler technique, at rest and throughout exercise. At rest the right ventricular systolic pressure was normal in all patients and controls. At the end of exercise, in 4 patients, values were still normal (40.7 +/- 2.2 mmHg); in the others pathologic values were recorded (59.8 +/- 3.9 mmHg). In the control group values were always normal (35.6 +/- 4.6 mmHg). In our study the saline-enhanced Doppler echocardiography has been demonstrated to be an important diagnostic tool for the noninvasive evaluation of right ventricular systolic pressure, both at rest and during exercise; it could be useful in monitoring the pulmonary vascular damage in patients with PSS.

Adult↗
PubMed1996

Left atrial size changes in patients with paroxysmal lone atrial fibrillation. An echocardiographic follow-up.

Left atrial enlargement has been demonstrated to occur as a consequence of the arrhythmia in patients with chronic atrial fibrillation (AF) in the absence of organic heart disease, whereas contrasting results have been reported in patients with paroxysmal lone AF. In the present investigation the behavior of left atrial size was followed up for an average period of 30.3 months in 20 patients with paroxysmal lone AF since their first arrhythmic episode. No significant changes in left atrial size were found at the end of the follow-up period. In 65% of patients the arrhythmia recurred at least once yearly. Left atrial size at enrollment was not significantly different in these patients from those without recurrences and did not change in either group during follow-up. The results suggest that in patients with lone AF left atrial dilatation occurs only after the arrhythmia becomes chronic. Early restoration of sinus rhythm may interrupt the vicious circle leading to atrial enlargement.

Adult↗
PubMed1996

[The fine structure of the gustatory cells of the circumvallate, foliate and fungiform papillae in hibernating bats].

The cells of vallate, foliate and fungiform papillae were studied in insectivore hibernating bats (Pipistrellus pipistrellus and Rhinolophus ferrumequinum) in the various epochs of the year in order to show cell types the seasonal changes. On the basis of the ultrastructural aspects and the relationships with nerve endings, besides the few basal cells, three types of sensorial cells can be identified: dark type I cells, light type II cells and light type III cells. All gustatory cells, long and narrow shaped, extend from the epithelial basal lamina to the gustatory canal, where they send long microvillous expansions of the apical cytoplasm. These expansions, except those of the fungiform papillae which never extend beyond the lower two thirds, usually reach the external opening of the taste pore, always completely void of dense substance. Dark type I cells are characterized by a developed RER and large granules. Light type III cells show peculiar dense core light vesicles, labelled protein A-gold particles immunoreactive to 5-HT. These cells only in the foliate and fungiform papillae also have bundles of microtubules whose function is still unknown. After comparative evaluation and discussion of topographical and ultrastructural aspects with those of other mammals and humans, the Authors states that bats are provided with a valid gustatory system and that all cell types are involved in taste transduction.

Animals↗
PubMed1993

Echocardiographic Doppler evaluation of left ventricular diastolic function in athletes' hypertrophied hearts.

It is well known that one of the most evident effects of prolonged and intense physical training is an increase of left ventricular mass. This increase could have a great influence on the diastolic properties of the heart, which can now be accurately evaluated by use of pulsed- and continuous-wave of Doppler echocardiography. The aim of this study was to evaluate the diastolic function of a group of superendurance athletes (professional bicyclists, exercising more than forty hours a week). Sixteen athletes (A), aged between twenty and thirty-one years, during the period of maximal training, and 16 age-matched controls (C) were studied. All subjects were evaluated at rest with mono-dimensional, two-dimensional, and Doppler echocardiography. Diastolic (DD) and systolic (SD) diameter, posterior wall (PW), and interventricular septum (IVS) thickness were also measured. The left ventricular mass (LVM) was calculated. Diastolic function was evaluated by calculating isovolumetric relaxation time (IVR) with continuous-wave Doppler, and deceleration time (DT), rapid filling flow peak (Ep), and atrial filling peak (Ap) were evaluated with pulsed Doppler echocardiography. The LVM (A: 354 +/- 47 g vs C: 170.6 +/- 33.4, p < 0.05), DD (A: 57.7 +/- 3.9 mm vs C: 50.5 +/- 2.7, p < 0.01), PW thickness (A: 11.9 +/- 0.7 mm vs C: 8.4 +/- 0.6, p < 0.05), and IVS thickness (A: 12.3 +/- 1 mm vs C: 8.2 +/- 0.9, p < 0.05) were significantly greater in the athletes than in the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Diagnostic accuracy of peak exercise echocardiography in coronary artery disease: comparison with thallium-201 myocardial scintigraphy.

To evaluate the accuracy of exercise two-dimensional echocardiography for the recognition of coronary artery disease, 53 patients (46 men and 7 women, age range 35 to 69 years) without either previous myocardial infarction or resting wall motion abnormalities, were studied. According to coronary angiography 26 had normal coronary arteries, 14 had one-vessel, seven had two-vessel, and six had three-vessel disease. After withdrawal of any therapy, all patients underwent a single exercise stress test with a stress table during which cine-loop digitized echocardiography was acquired and 74 MBq of thallium-201 (TI-201) were injected. Echocardiographic images were evaluated at rest and at peak exercise. Three-view planar scintigraphic images were collected immediately after exercise and 4 hours later. For the overall recognition of coronary artery disease, exercise electrocardiography had 77.8% sensitivity and 65.4% specificity; myocardial scintigraphy had 100% sensitivity and 92.3% specificity; and exercise echocardiography had 92.6% sensitivity and 96.2% specificity (both NS versus myocardial scintigraphy). Global accuracy was 71.7% for exercise electrocardiography, 94.3% for stress echocardiography, and 96.2% for myocardial scintigraphy. For the classification of the individual involved coronary arteries, the sensitivity of myocardial scintigraphy was 84.8% and that of exercise echocardiography was 63% (p less than 0.01); the related specificities were 98% and 98.2% respectively (NS). It may be concluded that exercise echocardiography is highly accurate for the recognition of coronary artery disease, whereas it appears less sensitive in the identification of the involved vessels, particularly in patients with multivessel disease.

Adult↗
PubMed1990

[The diameter of the common trunk of the left coronary artery and left ventricular mass in athletes. An echocardiographic study].

The feasibility of two-dimensional echocardiographic visualization of the coronary artery was re-evaluated in adults in the light of technological advances and development of new imaging planes. Athletes are a good model for this type of study. The aim of our study was to visualize in athletes the coronary arteries, particularly the left main artery, and to see if a correlation exists between left-ventricular mass and coronary diameter. Twenty-one endurance athletes, aged between 17 and 30 years, and 21 control subjects, matched for age, sex and body surface area, were examined. All the subjects were examined with mono- and two-dimensional echocardiography, with annular array (3.5 and 5 MHz), with parasternal and apical projections modified in order to visualize the left main coronary artery. Wall thickness, left ventricular internal dimension and left ventricular mass were calculated. Interventricular septum thickness was 10.8 +/- 1.5 mm for athletes (A) versus 8.2 +/- 0.9 mm for controls (C); p less than 0.01. Posterior wall thickness was 10.4 +/- 1.5 mm (A) versus 8.2 +/- 0.6 mm (C); p less than 0.01. The left ventricular diastolic diameter was 54.6 +/- 5.1 mm (A) versus 49.5 +/- 3.4 mm (C); p less than 0.01. The mean left ventricular mass was 278.2 +/- 85.2 g (A) versus 165.6 +/- 35.4 g (C); p less than 0.01. The mean diameter of the left main coronary artery was 4.9 +/- 0.8 mm (A) versus 3.1 +/- 0.4 mm (C); p less than 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1990

[Magnetic resonance imaging of aortic and mitral valve insufficiency. Comparison with Doppler echocardiography and angiocardiography].

Fourty-five subjects--10 normal volunteers and 35 patients with valvular insufficiency were examined with MRI and [20 of them with mitral (MI) and 15 with aortic (AI) insufficiency] were evaluated with MR imaging and with Doppler echocardiography (echo-Doppler); 22 of these patients were also studied with angiocardiography. The extent of regurgitation jet was classified as follows: minimal (1+), mild (2+), moderate (3+), and severe (4+), according to the max distance of regurgitant jet signal from valvular leaflets. In our series, MR imaging with FFE sequences always showed the regurgitant jet. High agreement was found between MR and echo-Doppler results (80% for MI, and 86% for AI). In 22 patients who underwent angiocardiography, we observed 73% agreement. Cine-MR imaging proved to be an accurate and sensitive technique to recognize and to evaluate severity of regurgitant valvular flow in patients with AI and MI. This technique may be useful in those patients in whom Doppler echocardiography is inadequate or impossible to perform.

Adult↗
PubMed1989

[Right ventricular thrombosis in association with dilated cardiomyopathy: diagnosis by echocardiography and nuclear magnetic resonance].

Thrombus formation in right chambers is an uncommon event which usually follows an acute right myocardial infarction or a thromboembolic disease. In subjects with dilated cardiomyopathy, thrombus formation is common in the left ventricle; so far right ventricular thrombosis has not yet been reported. In this report we describe a case of cardiomyopathy with right ventricular thrombosis as detected by echocardiography and nuclear magnetic resonance.

Cardiomyopathy, Dilated↗