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Biomedical subjects

F Prati

Publications and source records attributed to F Prati.

50 records · Page 3Linked to original sources
PubMed1995

Three-dimensional reconstruction of coronary arteries with intravascular ultrasound.

Three-dimensional (3D-) reconstruction of intravascular ultrasound (IVUS) images is a recently introduced technical method which has rapidly grown in science and clinical practice. In the catheterization laboratory it is particularly important to obtain the 3D-reconstruction on-line, since the dimensions measured and the plaque attributes displayed may guide the therapeutic decision. Off-line reconstruction, however, provides very accurate and reproducible area and volume measurements of lumen and plaque and is thus exceptionally qualified for studying progression/regression of atherosclerosis or restenosis after catheter-based interventions. Complementary 3D-reconstruction methods, revealing specific advantages and limitations, meet the requirements by slightly different technical approaches, but each 3D-reconstruction of two-dimensional IVUS images requires some basic procedural steps. The IVUS images can be acquired during continuous or ECG-gated withdrawals of the IVUS imaging catheter. The latter permits even to visualize the cyclic pulsation of the reconstructed arteries. As an alternative approach a sensing device recognizes the insertion depth of the IVUS catheter and permits reliable measurements even during manual handling of the IVUS catheter. A discrimination between the blood-pool and structures of the vascular wall, performed in the digitized images, can be achieved by the application of different techniques. This processing step which is called segmentation and the image acquisition are particularly crucial with regards to the final quality of the 3D-reconstruction. Currently there are still limitations of 3D-IVUS, but a new approach combining data obtained from 3D-IVUS and biplane angiography offers a promising potential to solve most of the remaining problems in the future. Thus, three-dimensional IVUS offers a great clinical and scientific potential since it provides spatial visualization of vascular pathology, longitudinal and volumetric measurement of luminal and plaque dimensions, and facilitated guidance of catheter-based interventions. Assuming a technical development similar to the progress of the previous years. 3D-IVUS has a realistic chance to gain significant importance and to become a routine technique in the future.

Computer Graphics↗
PubMed1994

Value of low-dose echodobutamine in the diagnosis of patency of the infarct related coronary artery.

The resumption of contractility of asynergic segments in survivors after acute myocardial infarction (AMI) may be detected in viable myocardial areas. We have correlated the detection of viable myocardium, assessed with low dose dobutamine testing, with coronary angiography and clinical outcome in 66 consecutive survivors of AMI using the echocardiographic evidence of left ventricular wall motion abnormalities. The test enabled the identification of two groups: group A, comprising 32 patients (pts) demonstrating wall motion recovery at dobutamine infusion and group B, comprising 34 pts without wall motion recovery. The mean basal asynergy score index was 5.8 +/- 4.2 in group A and 6.0 +/- 4.2 in group B (p = ns). With dobutamine testing the score decreased to 2.8 +/- 3.6 in group A (p < 0.001 with respect to basal value), while it did not change significantly in group B. Left ventricular end diastolic volume (ml) was similar in the two groups (114 +/- 35 vs 107 +/- 79, p = NS). The infarct related artery (IRA) patency rate was 87.5% in group A, vs 26.5% in group B (p < 0.001). After a mean follow-up of 11 +/- 5 months, group A pts had basal asynergy score improvement (2.6 +/- 3.1, p < 0.001) and mild left ventricular end diastolic volume (ml) reduction, (108 +/- 32, p = NS), while group B pts had left ventricle end diastolic volume enlargement (130 +/- 38, p < 0.05), without score asynergy modification. Moreover all pts who experienced heart failure at follow-up were in group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[The 24-hour hemodynamic changes after percutaneous mitral valvuloplasty].

Hemodynamic studies were performed immediately before, within 1/2 hour and 24 hours after percutaneous mitral valvuloplasty in 31 patients with severe mitral stenosis and pulmonary hypertension. Single rubber-nylon balloon (Inoue balloon) technique was used in all the procedures. Mean transmitral gradient fell from 12.7 +/- 5.4 mmHg to 6.1 +/- 3.1 mmHg (p < 0.001). Mitral valve area increased from 0.9 +/- 0.2 cm2 to 1.8 +/- 0.3 cm2 (p < 0.001). Mean pressure in the left atrium decreased from 21.8 +/- 7.1 mmHg to 16.9 +/- 5.1 mmHg (p < 0.001). After 24 hours there was a significant further drop in left atrial pressure (or pulmonary capillary wedge pressure), that decreased to 11.5 +/- 5 mmHg (p < 0.001). Mean cardiac output increased from 4.1 +/- 0.8 l/min to 4.5 +/- 0.9 l/min immediately after successful valvuloplasty and after 24 hours was significantly higher (5.4 +/- 1.2 l/min; p < 0.001). Mean pulmonary pressure immediately decreased from 29.2 +/- 9.7 mmHg to 26.5 +/- 6 mmHg (p < 0.05) and after 24 hours was 19.4 +/- 6 mmHg (p < 0.001). Left ventricular end-diastolic pressure increased from 9.9 +/- 3.8 mmHg to 13.8 +/- 5 mmHg (p < 0.001). In conclusion, pulmonary hemodynamic and cardiac output improve immediately after percutaneous mitral valvuloplasty and get progressively better up to 24 hours from the procedure.

Adult↗
PubMed1991

Percutaneous transluminal coronary angioplasty of the very proximal left anterior descending artery lesions: immediate results and follow-up.

In order to assess the results of percutaneous transluminal coronary angioplasty of the proximal (before the first septal branch) left anterior descending artery lesions, we analyzed the results in 206 consecutive patients, aged 56 +/- 12 years. The distance of the lesion from the origin of the left anterior descending artery was measured in the right oblique angiogram. The location of the lesions proved to be very proximal (less than 0.5 cm from the origin) in 22 patients, intermediate (0.5-1 cm from the origin) in 26 patients and distal (greater than 1 cm from the origin) in 158 patients. The initial angiographic success rate was similar among the 3 groups of patients: 95.8% in those with very proximal and intermediate lesions and 98.1% in those with distal lesions. Occlusive dissection of the left anterior descending artery without involvement of the mainstem occurred in 3.8% of the patients with intermediate lesions and in 1.9% of those with distal lesions. No complications occurred in any patient with very proximal lesions. The clinical follow-up was 25.2 +/- 12 months; angina recurred in 15.5% (31 out of 206 patients). Coronary angiography was performed in 103 patients. Restenosis occurred in 42.3% of the patients with very proximal and intermediate lesions (11 out of 26) and 31.2% of those with distal lesions (24 out of 77). In conclusion, in most patients with very proximal and intermediate lesions of left anterior descending artery, coronary angioplasty can be performed with low risk. The location of the lesion in the proximal portion of left anterior descending artery does not affect the overall success rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1990

[The clinical evaluation of the severity of chronic heart failure: a comparison between the NYHA functional class and the Goldman scale].

Controversies exist about the functional evaluation of chronic heart failure; aim of this study has been the assessment of the feasibility of the Goldman classification, based on the metabolic cost of various daily physical activities, in a cohort of patients with mild to moderate heart failure, its relation to NYHA class and to the main clinical parameters currently used. We evaluated 114 patients (mean age 61 years) with mild to moderate heart failure due to idiopathic cardiomyopathy (78%), ischemic heart disease (14%) and others (8%). Based on the Goldman classification there were 82 patients (72%) in second and 28 (24%) in third class while 83 (73%) were in NYHA II class and 31 (27%) in NYHA III class. The concordance rate between Goldman second and NYHA II class was 84% and 64% between Goldman third and NYHA III class. The cardiothoracic ratio was statistically different in all 3 Goldman classes while this happened only in NYHA IIM and III versus IIS. Double product and duration of exercise were statistically different in all Goldman classes but only in NYHA II and III class. No relation was observed with ejection fraction on echocardiogram. In the subgroups analysis there was a linear positive relation between duration of exercise versus double product and cardiothoracic ratio versus cardiac volume. We conclude that Goldman class is a feasible method to assess quality of life in chronic heart failure and is more helpful and objective than NYHA class in determining the functional class of the patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Negative post-ischemic T waves in variant angina].

The clinical and prognostic significance of negative T waves on the basal electrocardiograms of patients with unstable angina has been recently investigated with controversial results. Moreover, there is little data regarding this phenomenon in patients with variant angina. In order to evaluate the significance of negative post-ischemic T waves in patients with variant angina, 72 patients underwent Holter recording and coronary angiography. Negative T waves were present in 38 out of 72 patients (53%): they were anterior in 24 cases and inferior in 14 cases. The negative T-wave phenomenon was present in 29 patients on admission and showed up in 9 patients during hospitalization. Holter recording showed no significant differences between patients with or without negative T waves with regards to: 1) the proportion of symptomatic transient myocardial ischemic attacks; 2) the frequency of arrhythmias during transient myocardial ischemic attacks; 3) the maximum duration of transient myocardial ischemic attacks; 4) the maximum degree of ST elevation during transient myocardial ischemic attacks. Negative T waves on the anterior leads showed a moderate sensitivity (54%) and total predictive accuracy (52%), as well as a lower specificity (43%) and negative predictive accuracy (15%) for a significant stenosis of the left anterior descending coronary artery. This was due to the presence of several patients with left anterior descending artery stenosis and without negative T waves. On the other hand, negative T waves on the inferior leads were characterized by high sensitivity (85%), specificity (80%) and total predictive accuracy (82%) for a significant stenosis of the right coronary artery and/or the circumflex artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris, Variant↗
PubMedDate not supplied

[Use of diverse diagnostic techniques in the study of silicosis].

This study would examine the efficiency of different diagnostic tools, imaging and functional, in the study of pulmonary system of workers exposed to silicotigen dusts. 24 male miners were examined with chest H.R.T.C., spirometry with study of DLCO and of total lung capacity. 13 of 24 miners were submitted to pulmonary ventilatory scintigraphy (99mTcDTPA). All 24 miners were previously yet submitted to two follow-up by means of chest radiography in conformity with ILO guidelines. The chest radiography, even evaluated in conformity with ILO guidelines, is subject to remarkable differences when performed and reported by different operator. Useful data are provided by functional studies. H.R.T.C. is necessary to evaluate the degree of parenchymal involvement and for medicolegal porpoises. Scintigraphy with 99mTc DTPA need of further studies in the evaluation of exposure to silicotigen dusts.

Adult↗