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G Tommasini

Publications and source records attributed to G Tommasini.

At least 19 recordsLinked to original sources
PubMed1999

A deterministic approach to automated stenosis quantification.

We developed a new approach to quantitative coronary angiography (QCA), which overcomes several limitations of available programs, such as dependence on operator input; limited tracking ability; fixed correction of the point spread function (PSF); and different calibration on empty vs. contrast-filled catheters. The program (Intelligent Images QCA, version 1.4) provides absolute reproducibility by deterministic, operator-independent identification of the skeleton and the edges of the coronary tree. The algorithm works as follows: application of a matched filter to emphasize selectively the coronary arteries; adaptive threshold binarization; binary thinning and skeletonization; perpendicular resampling with sub-pixel interpolation; derivative filtering; minimal cost edge detection; and automatic identification and quantification of the stenosis. Operator's interaction is restricted to definition of a region of interest; editing of either skeleton or edges is not allowed. PSF correction is fine-tuned to the actual frequency response of the imaging chain by calibration on a contrast-filled conical lucite phantom. Catheter calibration is carried out by a second derivative-based edge detection much less sensitive to the presence of contrast. In vitro phantom analysis (0. 5 to 5.0 mm) showed accuracy of 0.028-0.031 mm and precision of 0. 054-0.062 mm on nonmagnified images from the angio TV chain and the cine projector, respectively. In vivo evaluation on a series of consecutive diagnostic angiograms yielded correct contour detection of 70/73 stenoses (96%); interobserver intraframe MLD variability 0. 00 mm; correct tracking of catheter edges 100%; interobserver variation coefficient of catheter calibration 3.3%; and mean difference of calibration factor on contrast-filled vs. empty catheters 2.7%. This new approach significantly improves reproducibility with respect to conventional QCA, maintaining high accuracy, precision, and applicability. Cathet. Cardiovasc. Intervent. 48:435-445, 1999.

Algorithms↗
PubMed1999

[Nephrotic syndrome refractory to conventional therapy].

BACKGROUND: Prednisone is the choice medicine in Nephrotic Syndrome (NS) treatment, possibly associated with immunosuppressor medicines (cyclophosphamide or chlorambucil), either in case of NS resistance at cortisone therapy or with frequent relapses. Cyclosporin A (CyA) use has been recently proposed, due to its inhibitory effect on the IL2 and lymphokine release, with a permeabilizing effect on the glomerular membrane. The purpose of this study is to evaluate the CyA antiproteinuric effectiveness with NS conventional therapy refractory patients. METHODS: Six patients (3 females and 3 males) have been treated with CyA (4 +/- 0.5 mg/Kg/die) associated with low corticosteroid dosages. RESULTS: During the treatment, proteinuria reduced in 5 patients, at less than 1/3 of pre-treatment values, for 4 patients this happened starting from the 2nd month of therapy, while after the 12th for the fifth patient. The sixth patient has now a 2/3 reduction compared to the initial one and he is at the 3rd month of therapy. During the CyA treatment, further to the proteinuria reduction, a total proteinemia values increase and a cholesterolemia and tryglyceridemia reduction has been observed, while creatinine and PA have not changed. CONCLUSIONS: Four out of the six treated patients have been respectively under therapy for 2,3,12,30 months. Two stopped CyA therapy: one after 18 months due to clinical stability, still present after 2 years from interruption; one after 9 months with a stable clinical picture for just three months, since she was longing for a pregnancy, achieving a quick proteinuria relapse.

Adolescent↗
PubMed1998

Panoramic coronary angiography.

OBJECTIVES: We describe a new imaging technique for coronary angiography. BACKGROUND: The conventional approach to coronary angiography exploits static perspective imaging over multiple cardiac cycles, using a limited number of empirically selected views. This approach entails both lack and redundancy of information and may result in suboptimal visualization of the individual lesion, contributing to diagnostic inaccuracy. METHODS: We developed a new imaging technique exploiting dynamic perspective, obtained by transverse 180 degree rotation of the C arm of a conventional angiographic unit during standard selective coronary opacification and filming. This technique yields a picture of the coronary tree isocentrically rotating around the longitudinal axis and conveying complete three-dimensional information. RESULTS: A complete diagnostic run for both coronary arteries, including two 25 degree cranial and two 25 degree caudal scans is accomplished with a total cine time of 16 s and 45 ml of contrast medium, about half of that required by conventional angiography. In a series of 129 consecutive patients studied by both the conventional and the new technique with quantitative measurements of the severity of the stenoses, the final diagnosis was identical in 65. In no case was a stenosis detected only by the conventional approach. However, in 31 patients the new technique permitted identification of 34 critical stenoses (79+/-8% [mean +/- SD]) either underestimated (61+/-3% n = 24, p < 0.001) or undetected (21+/-22%, n = 10, p < 0.001) in the standard projections. In a further 28 cases, 33 subcritical lesions (60+/-5%) were visualized in the rotational images but were insignificant (24+/-22% p < 0.001) in the standard projections. In five additional patients, distinct laminar plaques were clearly visualized only by the panoramic approach. CONCLUSIONS: This new technique can be easily implemented on conventional angiographic equipment at no additional cost. It provides complete, operator-independent exploitation of the angiographic information, resulting in enhanced diagnostic accuracy.

Coronary Angiography↗
PubMed1998

Stent implantation versus balloon angioplasty in chronic coronary occlusions: results from the GISSOC trial. Gruppo Italiano di Studio sullo Stent nelle Occlusioni Coronariche.

OBJECTIVES: In this multicenter, randomized trial we evaluated whether stent implantation after successful recanalization of a chronic coronary occlusion reduced the incidence of restenosis. BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) in chronic total occlusions is associated with a higher rate of angiographic restenosis and reocclusion than PTCA in subtotal stenoses. Preliminary reports have suggested a decreased restenosis rate after stent implantation in coronary total occlusions. METHODS: We randomly assigned 110 patients with recanalized total occlusion to Palmaz-Schatz stent implantation, followed by 1 month of anticoagulant therapy versus no other treatment. The primary end point was the minimal lumen diameter (MLD) of the treated segment at follow-up, as determined by quantitative angiography at a core laboratory. RESULTS: Repeat coronary angiography was performed 9 months after the procedure in 88% of patients. The MLD (mean +/- SD) at follow-up was 1.74 +/- 0.88 mm in patients assigned to stent implantation and 0.85 +/- .75 mm in patients assigned to PTCA (p < 0.001). Stent implantation was associated with a lower incidence of restenosis (defined as diameter stenosis > or =50% at follow-up) (32% vs. 68%, p < 0.001) and reocclusion (8% vs. 34%, p = 0.003) than balloon PTCA. Likewise, stent-treated patients had less recurrent ischemia (14% vs. 46%, p = 0.002) and target lesion revascularization (5.3% vs. 22%, p = 0.038), but experienced a longer hospital stay. CONCLUSIONS: Palmaz-Schatz stent implantation after successful balloon PTCA of chronic total occlusions improves the midterm angiographic and clinical outcome and could be the preferred treatment option in selected patients with occluded vessels.

Adult↗
PubMed1994

Atrial natriuretic peptide response is blunted in patients with acute myocardial infarction and mild left ventricular dysfunction.

Neurohumoral parameters in 45 asymptomatic patients with acute myocardial infarction were measured. In patients with mild left ventricular dysfunction (ejection fraction < or = 45% and/or left ventricular end-diastolic pressure > or = 15 mm Hg), atrial natriuretic peptide levels differed significantly from those in patients with normal left ventricular function (127 +/- 74 pg/ml vs. 79 +/- 71 pg/ml; p < 0.001). After stimulus an increase in atrial natriuretic peptide levels (79 +/- 71 to 118 +/- 86 pg/ml; p < 0.001) was found only in patients with normal hemodynamic parameters. These data show that in patients with left ventricular dysfunction, the atrial natriuretic system is activated; however, atrial natriuretic peptide response to stimulus is present only in patients with normal hemodynamics.

Adult↗
PubMed1993

Selective activation of atrial natriuretic peptide in patients with myocardial infarction and mild left ventricular dysfunction.

The purpose of this study was to investigate whether neurohumoral activation occurs in asymptomatic patients with acute myocardial infarction (AMI) and without clinical signs of heart failure. During the early phase of AMI (mean 8 days), the neurohumoral profiles of 60 patients (mean age 59 range 37 to 70) were examined. Blood levels of the following humoral parameters were measured: atrial natriuretic peptide (ANP), plasma renin activity, aldosterone and vasopressin. All patients underwent cardiac catheterization during hospitalization. Baseline hemodynamic characteristics identified left ventricular dysfunction (ejection fraction < or = 45% and/or left ventricular end-diastolic pressure > or = 15 mmHg) in 32 patients; the remaining 28 patients had normal hemodynamic parameters. In patients with AMI, plasma ANP levels differed significantly from control subjects (111 +/- 74 pg/ml vs. 53 +/- 18 pg/ml; P < 0.001). In patients with AMI and mild left ventricular dysfunction ANP levels were significantly increased when compared to patients with AMI and normal left ventricular function (129 +/- 73 pg/ml vs. 82 +/- 69 pg/ml; P < 0.001). The hemodynamic data showed a significant correlation with ANP only in patients with AMI and left ventricular dysfunction (EF% r = 0.42; LVEDP r = 0.44; P < 0.001). These data show that in patients with myocardial infarction and without heart failure, the atrial natriuretic peptide is the only neurohumoral system activated out of all neurohumoral systems tested in this population and its circulating levels are strictly related to the degree of left ventricular dysfunction.

Adult↗
PubMed1993

[Pulmonary valvuloplasty].

The aim of this study was to present the experience of 2 Institutions (Department of Cardiology in Bergamo and Department of Pediatric Cardiology, Apuano Pediatric Hospital in Massa) in performing the balloon dilatation of the pulmonary valve. From January 1985 to August 1993 the balloon pulmonary valvuloplasty was performed in 220 patients, age ranging from 1 day to 60 years (mean age 5 years), 55 (25%) in the first year of life, 17 (8%) in the first week of life. The systolic gradient across the pulmonary valve fell from 78 +/- 31 mmHg (range 40-160) to 20 +/- 16 mmHg (range 0-70) immediately after the procedure (p < 0.001). In-hospital mortality happened in 3 cases (1.3%); 2 of them were neonates with critical pulmonary stenosis. In 7 cases (3%) the balloon valvuloplasty was repeated afterwards, because of inadequate relief of the gradient after the first dilatation. During the mean follow-up period of 4 years the other 210 patients (95%) did not need any further treatment and remain in stable clinical conditions. The balloon valvuloplasty gives excellent early and intermediate term results and should be considered the first choice procedure in the treatment of pulmonary stenosis at all ages.

Adolescent↗
PubMed1992

Prevention of life-threatening arrhythmias by pharmacologic stimulation of the muscarinic receptors with oxotremorine.

The potential antiarrhythmic efficacy of pharmacologic parasympathetic activation is still controversial. This study assessed the antiarrhythmic effect of saline solution (n = 9) and of the muscarinic agonist oxotremorine (1.5 micrograms/kg administered intravenously) (n = 17) in a feline animal model in which malignant arrhythmias were reproducibly elicited by the combination of acute myocardial ischemia and left stellate ganglion stimulation. Although saline solution had no effect, oxotremorine significantly decreased heart rate, blood pressure, the incidence of ventricular fibrillation from 47% to 0% (p = 0.004), and the incidence of malignant arrhythmias (either ventricular tachycardia or ventricular fibrillation) from 88% to 12% (p less than 0.001). When reduction in heart rate was prevented by means of atrial pacing (n = 15), the incidence of malignant arrhythmias was still significantly reduced from 87% to 27% (p = 0.001). Arrhythmias were also graded as follows: 0 = no premature ventricular contractions; 1 = 1 to 10 premature ventricular contractions; 2 = 11 to 50 premature ventricular contractions; 3 = ventricular tachycardia; 4 = ventricular fibrillation. Arrhythmia severity was 3.29 +/- 0.16 (SEM) in the control trials and was reduced to 0.76 +/- 0.26 (p less than 0.001) by oxotremorine and to 1.53 +/- 0.34 by oxotremorine and pacing (p = 0.002). Therefore a muscarinic agonist can significantly reduce malignant arrhythmias during acute myocardial ischemia and may represent a novel approach to the prevention of sudden cardiac death.

Animals↗
PubMed1991

Coeliac disease, folic acid deficiency and epilepsy with cerebral calcifications.

Two cases of focal occipital epilepsy with cerebral calcifications poorly responsive to antiepileptic treatment are described. In both cases coeliac disease was diagnosed and folic acid deficiency documented. A gluten-free diet and a brief supplementation with folic acid lead to a complete EEG and clinical normalization in one case and to a significant improvement of EEG and seizure control in the other.

Adult↗
PubMed1990

Radiological anatomy of the kidney revisited.

In recent years some structures or features such as the "inter-renuncular septum", the "echogenic triangle" and the "echogenic line" have been described to support the concept of a kidney resulting from the fusion of two masses or renunculi. To clarify this concept and to understand the meaning of the above echographic features better, the authors have examined prospectively by sonography the kidneys of 50 children, 200 adults with a single collecting system, 25 adults with a duplicated collecting system and 32 cadavers. Furthermore, to help explain the sonographic features, we have examined 32 cadaver kidneys with sonography and 10 cadaver kidneys with magnetic resonance imaging (MRI). The sonographic, MRI and anatomical correlations have shown that the "echogenic triangle" and the "echogenic line" are not renuncular residuals, but simply an extension of the hilar fat visible when the renal sinus is rather deep. The intermediate cortical mass is not a septum dividing the kidney into an upper and lower renunculus, but a column of parenchymal tissue crossing the renal sinus, which, from an anatomical point of view, is an accessory renal lobe. The presence of two renunculi, suggested in a previous study with cortical nephrotomography, has not been confirmed.

Adolescent↗
PubMed1989

High frequency of empty sella syndrome in children with growth hormone deficiency.

Computer-assisted tomography (CT) with 2 mm axial sections and reconstructions was carried out in 31 children affected by GH deficiency (GHD): 18 with idiopathic complete isolated GHD, 3 with idiopathic partial isolated GHD, 2 with idiopathic panhypopituitarism, 4 with isolated acquired GHD and 4 with acquired panhypopituitarism. Density in the intrasellar area on CT corresponded to that of cerebrospinal fluid in 13/20 cases with idiopathic hypopituitarism and in 2/8 cases with acquired hypopituitarism. The overall incidence of primary empty sella syndrome (PESS) in the GH deficient patients studied was thus over 48%, while in children without endocrine dysfunction, it was only 5/213 (2.4%). It is concluded that PESS is more frequent in childhood than assumed until now and that it is frequently associated with GHD.

Adolescent↗
PubMed1984

[Isolated straddling tricuspid valve. Presentation of 2 cases operated on successfully].

During the period May 1977-September 1983 in the Department of Cardiac Surgery of Massa Hospital two patients with isolated straddling tricuspid valve were studied with cardiac catheterization and selective angiocardiography and subsequently underwent surgical correction. The first patient, a 38-month-old white boy presented with "complete straddling" according to Bharati and Lev classification; the second, a 39-month-old white boy presented with "peripheral straddling". In both cases at surgery the ventricular septal defect was closed with a Teflon patch, sparing the chordae tendinae and the "straddling" papillary muscle. Both patients survived operation. The first one developed a complete atrioventricular (A-V) block with a ventricular rate which never was below 80 beats/min, during the 30 days of in-hospital observation. No permanent pacemaker was therefore inserted. The follow-up controls (39 and 79 months respectively) shows both patients to be hemodynamically and functionally well.

Child, Preschool↗
PubMed1983

Direct determination of distribution volume and disappearance rate of native creatine kinase in humans.

Distribution volume (DV) and disappearance rate (Kd) of native creatine kinase (CK), parameters needed for enzymatic estimation of infarct size, have not been characterized in humans. Values for these parameters have been determined in experimental models and extrapolated for use in humans. During hemodynamic monitoring, 100 to 150 ml of enzyme-rich plasma was collected from 10 patients with acute myocardial infarction, stored at -30 degrees C for a maximum of 6 days, and then rapidly reinfused back to the same patient after return of CK serum activity to baseline levels. After reinfusion, blood samples were obtained at 5- to 15-minute intervals for 2 hours and at 30- to 60-minute intervals for an additional 10 hours. In each specimen, total CK activity and MM-CK and MB-CK concentrations were determined by spectrophotometry and radioimmunoassay. Data were analyzed by either nonlinear least-squares approximation or the noncompartmental approach after baseline subtraction. Concentration of immunologically active molecules appeared to decline in parallel to enzymatic activity. In three patients a double exponential decay was demonstrated. All others exhibited single exponential decay, with a Kd of 0.0023 +/- 0.00057 (SD) min-1. DV averaged 3284 +/- 693 (SD) ml, 5% of body weight. There was no correlation between Kd estimated from terminal portions of CK time-activity curves following infarction and Kd calculated after reinfused plasma. It was concluded that a one-compartment model using values for Kd and a DV compatible with plasma volume is suitable for clinical application, and that true Kd cannot be determined from the terminal portion of CK time-activity curves after acute infarction.

Blood Transfusion, Autologous↗
PubMed1982

Assessment of atrioventricular septal defects by two dimensional echocardiography.

Ninety-six patients with an atrioventricular septal defect were assessed by two dimensional echocardiography. Forty-eight patients were judged as having two discrete valve orifices. In this group, 37 had an intact ventricular septum and 11 a ventricular septal defect. Two patterns of attachment of the valve leaflets to the interventricular septum were noted. Forty-eight patients had a common valve orifice. In 29 patients there was absence of tethering of the anterior bridging leaflet to the interventricular septum. A further 19 had varying degrees of tethering of the anterior bridging leaflet. A ventricular septal defect was identified under the anterior bridging leaflet in all cases. In 58 cases where the posterior bridging leaflet was identified, a ventricular septal defect was visualised in eight and missed in two. Seventy-eight patients had an ostium primum defect, 12 a common atrium, and a further six an intact interatrial septum. Two dimensional echocardiography provides in depth morphological information about the type of atrioventricular defect and can correctly identify the presence of a ventricular septal defect beneath the anterior or posterior bridging leaflet, unless it exists between short crowded chordae.

Child↗
PubMed1982

Tricuspid atresia: analysis of coronary artery distribution and ventricular morphology.

There is still disagreement concerning the precise nature of the anterior ventricular chamber in "tricuspid atresia". Some argue that it is a right ventricle, while our own previous studies have suggested it is comparable to the outlet chamber seen in classical "single ventricle". We have compared the morphology of the anterior ventricular chambers in 48 examples of tricuspid atresia (absent right atrioventricular connection), 24 hearts with double inlet to the left ventricular chamber, and 15 hearts with pulmonary atresia and intact ventricular septum. Since there is further disagreement concerning the nature of the coronary artery which delimits the posterior extent of the ventricular septum in these hearts, we analysed the position of this vessel relative to external reference points on the atrioventricular junction. No significant difference was found with respect to the morphometry of hearts with tricuspid atresia (absent right atrioventricular connection) and those with double inlet. In both groups, however, significant differences were shown between hearts with ventriculoarterial concordance and discordance. Coronary artery disposition was the same in both groups and different from that found in hearts with pulmonary atresia and intact septum. We conclude that the ventricular morphology is comparable in hearts with tricuspid atresia (absent right atrioventricular connection) and those with double inlet to a left ventricular chamber. The lesions are distinguishable by their atrioventricular connection which is nevertheless univentricular in both.

Coronary Vessels↗
PubMed1982

[Ostium secundum type of interatrial septal defect associated with cleft mitral valve].

Eight patients (7 females and one male) ranging in age from 6 to 30 years (mean 11.2 years), with secundum-type atrial septal defect (o.s. ASD) and cleft mitral valve (CVM) were surgically corrected at the Cardiac Surgery Department of Massa Hospital (Massa-Italy) from 1974 to 1981. All patients were studied with non invasive diagnostic techniques and with cardiac catheterization and angiography. All had mitral regurgitation of variable degree. On the ECG, there were P and QRS wave abnormalities but no superior quadrant QRS axis deviation suggestive of endocardial cushion defect. At operation the cleft(s) was found in variable positions: on the anterior leaflet in 4 cases and on the posterior leaflet in four. In two cases there was a double cleft. Correction was accomplished in 5 cases with direct repair of CVM, associated with various types of anuloplasty and in 2 cases anuloplasty only was done, without suturing the cleft. The septal defect was closed by direct suture in one case and with a Dacron patch in the remaining seven. There was one early death in the first 24 hour post-operatively. The seven surviving patients have been followed for a period of time ranging between 2 and 93 months (mean 29 months). No survivor has been re-evaluated by cardiac catheterization and cineangiography. No patient shows clinical or non-invasive evidence of residual mitral regurgitation behind grade I (slight). We conclude that: 1) the CVM associated with o.s. ASD cannot be securely diagnosed preoperatively with the common diagnostic techniques, even when producing severe mitral regurgitation, except perhaps by B-mode echocardiography; 2) the CVM (part of the spectrum of endocardial cushion defect malformations) in no cases was associated with the typical ECG or angiocardiographic abnormalities; 3) the CVM associated with o.s. ASD should always be repaired because, compared to the CVM that occurs with endocardial cushion defects, its site and regurgitation characteristics are variable, and simple ASD closure may not be sufficient.

Adolescent↗