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Biomedical subjects

F Fantini

Publications and source records attributed to F Fantini.

At least 145 records · Page 8Linked to original sources
PubMed1982

Effect of dextran infusion on left atrial size in normal subjects.

The purpose of this study was to evaluate left atrium dimension during acute volume loading. Low molecular weight dextran solution (1,000 ml) was continuously infused in 10 subjects without cardiac disease. Measurements of pulmonary arterial, capillary wedge, right atrial and systemic blood pressures, cardiac output, heart rate and M-mode left atrial maximum diameter were made in basal conditions and after 250, 500, 750 and 1,000 ml of dextran. In 4 subjects a two-dimensional echocardiogram was also obtained in the short axis and four-chamber views. Dextran produced the following changes (mean values +/- standard deviation) in haemodynamic variables: right atrial and wedge pressures increased from 3.2 +/- 1.55 to 12.3 +/- 3.08 mm Hg (p less than 0.001) and from 6.9 +/- 1.45 to 20.6 +/- 3.44 mm Hg (p less than 0.001), respectively. Stroke volume increased from 70.5 +/- 31.6 to 86.6 +/- 24.6 ml/beat (p less than 0.05). Heart rate increased from 81.0 +/- 15.8 to 95.0 +/- 12.3 beats/min (p less than 0.05). Left atrial maximum diameter showed a slight increase after 500 ml of dextran (from 39.5 +/- 4.1 to 43.6 +/- 5.0 mm, p less than 0.05). It did not further increase by continuing the infusion up to 1,000 ml despite the marked increase in wedge pressure. The results show that left atrial size is partly independent of haemodynamic changes and that the compliance of the left atrium is relatively low. This finding is consistent with the common clinical observation that the left atrium is only slightly enlarged in acute mitral insufficiency.

Adult↗
PubMed1982

[Evaluation of sinoatrial conduction time by recording the sinus node potential. Comparison with indirect methods of evaluation].

A method of recording the sinus node potential (SNP) has recently been introduced in clinical electrophysiology. The sinoatrial conduction time can now be measured directly (SACTD) as the interval between the onset of the SNP and the onset of atrial activation. We measured the SACTD in 16 normal subjects and in 7 patients with sinus node dysfunction. These values were compared with those obtained by the indirect methods of Strauss et al (SACTS) and Narula et al (SACTN). In normal subjects the SACTD ranged from 50 to 130 ms (average 84,4 +/- 22,35); the SACTS, from 55 to 160 ms (92,9 +/- 29,3), and the SACTN from 70 to 175 ms (113,2 +/- 28,8). In patients with sinus node dysfunction the SACTD ranged from 200 to 290 ms (227 +/- 32,5), the SACTS, from 52 to 198 ms (111,8 +/- 59,3) and the SACTN from 89 to 251 ms (142,3 +/- 63). No significant difference was observed between normal and pathological subjects using the indirect methods of evaluation. However, the SACTD method showed a very significant difference between the two groups (p less than 0,0005) with no overlap. No correlations were observed between the values obtained by the indirect and direct methods of measuring SACT.

Diagnosis, Differential↗
PubMed1982

Haemodynamic effects of carbochromen.

Carbochromen increases coronary flow and cardiac output. A previous study has advanced the hypothesis that the latter may be due to afterload reduction. Fourteen patients with coronary heart disease have now been studied by means of radionuclide angiocardiography. Gated blood pool angiocardiographic data were collected in basal conditions and, without moving the patient, 80 mg of carbochromen were administered i.v. Data were collected again, following infusion, during 3'-6'(1) and 7'-10'(2) periods. Changes in the following parameters have been evaluated: LV ejection fraction (EF), LV ejection rate (ER), system pressure (BP), heart rate (HR), cardiac output index (CO), stroke volume index (SV), LV end-diastolic volume index (EDV), systemic vascular resistance index (SVR), regional LV wall motion. During period 1 a significant decrease was observed in BP and SVR, the other parameters remaining unchanged. During period 2 there was a significant increase in CO, SV, EF, ER and a significant decrease in SVR. BP was unchanged. No changes were ascertained in HR and EDV. Eight patients, in basal conditions, showed asynergy in the LAO projection. Three of these patients showed improved wall motion during period 2. A possible central action of carbochromen should be pointed out. This conclusion can be drawn by observing the increase in the pump indexes, while BP and SVR show a decrease and EDV and HR no change. The left ventricular wall motion improvement observed in some of the cases confirms the possibility that carbochromen is capable of improving cardiac contractility. This effect may follow the regional myocardial perfusion increase.

Adult↗
PubMed1982

[Observations on prolapse of the aortic cusps].

The patterns of valve motion were analyzed in 14 patients with combined aortic and mitral valve prolapse by two-dimensional echocardiography. Four patients have also tricuspid valve prolapse. In one we could find evidence of a myxomatous pulmonic valve with prolapse of the posterior cusp. By two-dimensional echocardiography all patients had redundant aortic leaflets bulging into left ventricular outflow tract during diastole. M-mode examination of the aorta was normal in five patients; eccentricity of the diastolic aortic valve echo was found in two patients; seven showed multiple echoes from the valve leaflets, with diastolic fluttering. The aortic valve was visualized in the left ventricular outflow tract during diastole in one patient. The size of the aortic root was normal in all. Six patients had transient ischemic cerebral attacks and no evidence of extracranial or intracranial vascular disease by angiography. As polyvalvular prolapse as demonstrated by echo suggest a myxomatous degeneration of the valves, we hypothesize that there may be a causal relationship between TIA and this type of pathological process.

Adolescent↗
PubMed1981

Hemodynamic pattern following K-strophanthin in normal and coronary artery disease patients.

Hemodynamic effects of K-strophanthin (0.005 mg/kg i.v.) were evaluated in 7 normal and in 13 non-failing coronary artery disease patients (CAD). Volumetric parameters were obtained by single plane left ventricular angiography. The indexes of "pump" function, the end-systolic pressure-volume relationship and the ratio of peak pressure to systolic volume were also evaluated. Heart rate was maintained constant by atrial pacing. In normal subjects K-strophanthin exerted small effects without peripheral vasoconstriction. CAD patients showed different response to K-strophanthin in vascular tone: an increase (Group 1) or a decrease (Group 2) in total systemic resistance (TSR). No significant differences were found in basal values between the two CAD groups. In Group 2 the indexes of "pump" function increased after K-strophanthin and the end-systolic pressure-volume points shifted upward and to the left, while in Group 1 no improvement in cardiac function was observed and the end-systolic pressure-volume points shifted upward and to the right. Furthermore, we found a direct significant correlation between the percent changes of TSR and end-systolic volume index, and a negative significant correlation between the percent changes of TSR and stroke volume index. Our results show that K-strophanthin in CAD non-failing patients can have either a positive effect or a lack of improvement in ventricular performance. These effects correlate with changes in total systemic resistance.

Adult↗
PubMed1981

[Hemodynamic correlation of the systolic movement of the aortic root].

Factors influencing the anterior systolic movement of the aortic posterior wall (PAM) are complex and still controversial. Left atrial events seem to be more important that stroke volume or left ventricular function in determining PAM. Even if the reduction of systolic aortic movement is generally associated to a severe impairment of left ventricular function, very few studies correlate the changes in the amplitude of aortic systolic movement to the hemodynamic pattern. In 50 patients posterior aortic wall echocardiograms, right heart catheterization and 99mTc angiocardiography were performed within 24 h. According to hemodynamic and left ventricular wall motion parameters 18 patients resulted to have a normal (1st group) and 32 patients (2nd group) an impaired left ventricular function. In the 2nd group mean values of PAM were significantly lower than in the 1st group (7.4 +/- 2.9 mm vs 10.2 +/- 1.9 mm). A significant correlation was found between PAM and hemodynamic parameters, i.e. CPW (r = 0.58), EF (r = 0.58) and SV (r = 0.40), whereas no significant correlations were found between these parameters and left atrial dimensions and between PAM and left atrial dimensions. A high significant correlation was found between PAM and echocardiographically measured septal wall motion (r = 0.80). All patients with PAM Less Than 6 mm and echo septal wall motion Less Than 5 mm had an akinesis or a dyskinesis of septal wall quantitatively determined with 99mTc angiocardiography. These findings suggest that one of the main determinants of PAM is left ventricular wall motion and in particular left ventricular septal motion.

Aorta↗
PubMed1980

Pulsed Doppler echocardiography for diagnosis of ventricular septal defects.

In order to assess the performance of pulsed Doppler echocardiography and to examine the factors affecting its reliability for the diagnosis of ventricular septal defects, 51 patients, in whom angiographic studies had recently been performed, were investigated before and after operation by this technique. The diagnosis was correct in all cases with left-to-right shunt, when the defect was located either in the upper muscular or in the infracristal portion of the septum, even when pulmonary hypertension or additional cardiac malformations were present. Pulsed Doppler echocardiography did not differentiate between supracristal ventricular septal defects and obstruction of the right ventricular outflow. Apical muscular defects were never observed in our cases. Defects of the inlet portion were not localised by the method. In cases with bidirectional shunt, pulsed Doppler echocardiography failed to provide any diagnostic clue. When a right-to-left shunt was present, only in one case with membranous pseudoaneurysm could pulsed Doppler echocardiography provide an exact description of the haemodynamics before and after operation. In 12 of 22 patients with tetralogy of Fallot, pulsed Doppler echocardiography showed flow tracings possibly related to the septal defect. The site of defect and the extent and direction of intracardiac shunting seem to be the main factors affecting its diagnostic performance in ventricular septal defects.

Doppler Effect↗
PubMed1980

[Left ventricular kinetics in bundle-branch block. Analysis by different methods in patients without coronary artery diseases (author's transl)].

Radiological ventriculographic findings of twenty-three patients with left bundle branch block (LBBB) without valvular heart disease and without evident coronarographic lesions are studied by means of six differents methods for quantitative evaluation of wall motion analysis. The patients are subdivided into two subgroups on the basis of hemodynamic criteria, but the results of wall motion studies are similar in both, if the values obtained are normalized for election fraction (EF). End-diastolic images of left ventricle are similar in both subgroups too, but very different from those of normals because apical region is characterized by rounded contour of images. The modes of contractility in LBBB patients evidence, after normalization by the same EF, hypercinetic motility of anterior wall. The patterns of contractility, shaped by progressive simulated EF, show that low EF are obtained through contraction of anterior wall. Greater EF are obtained by further uniform contraction of all the explored regions. The apical zone in LBBB patients is affected by persistent hypokinesis.

Adult↗