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Biomedical subjects

L Agati

Publications and source records attributed to L Agati.

At least 55 records · Page 3Linked to original sources
PubMed1990

Usefulness of the dipyridamole-Doppler test for diagnosis of coronary artery disease.

Two-dimensional and Doppler echocardiographic studies and a hemodynamic investigation were performed during dipyridamole testing in 42 subjects (13 control subjects and 29 patients with coronary artery disease [CAD]), to evaluate the ability of dipyridamole Doppler echocardiography in identifying patients with ischemic left ventricular dysfunction. In the control group, after dipyridamole infusion, Doppler-derived parameters increased significantly from baseline (p less than 0.001). In patients with CAD, peak flow velocity, flow velocity integral and stroke volume failed to increase after dipyridamole infusion (0.89 +/- 0.21 to 0.85 +/- 0.18 m/s, difference not significant; 14 +/- 3 to 12 +/- 4 cm, difference not significant, and 56 +/- 13 to 50 +/- 14 ml/beat, p less than 0.05, respectively). Heart rate, rate pressure product, systemic vascular resistance and mean right atrial pressure had similar variations in the 2 groups. Changes in the 3 Doppler-derived parameters are closely related to the variations of peak positive dP/dt, stroke volume (thermodilution) and left ventricular end-diastolic pressure and are closely related to the coronary angiography jeopardy score and to the appearance of wall motion abnormalities. Thus, by combining Doppler and 2-dimensional echocardiography, dipyridamole-induced myocardial ischemia may be detected in a high percentage of CAD patients, providing a sensitive tool for identifying patients with high-risk coronary artery anatomy.

Adult↗
PubMed1989

Painless versus painful myocardial ischemia: different left ventricular dysfunction detected by echocardiography.

The mechanism responsible for the absence of anginal pain in patients who have episodes of both painless and painful myocardial ischemia, still remains unknown. Does the pain depend on an overstimulation of receptive structures or is this symptom the product of the excitation of a well-defined receptive system? The aim of this work is to test the first hypothesis: whether silent attacks are accompanied by the same degree of mechanical impairment as symptomatic ones. The authors compared the echocardiographic left ventricular functional behavior in the same patient (6 patients) during painful and painless myocardial ischemia. The echocardiographic changes observed during silent ischemic attacks were significantly different from those detected during symptomatic attacks. The latter were characterized by a larger extension of the ischemic myocardium and, as a consequence, by a larger functional impairment. Symptomatic and asymptomatic ischemic attacks were recorded echocardiographically in the same patient during repeated attacks on the same day, and were always clearly differentiated by the degree of wall motion abnormalities. The echocardiographic monitoring during the ischemic attack seemed to confirm that the greater functional impairment preceded the onset of pain leading to the occurrence of this symptom. Nevertheless, it was impossible to identify a threshold value above which the ischemic attack will be symptomatic. Our data seem to indicate a close relationship between painful ischemia and a higher degree of ischemic damage. Thus, in patients with predominantly painful myocardial ischemia, the extension and the severity of ischemia could play an important role in determining this symptom.

Adult↗
PubMed1987

Left ventricular filling pattern in hypertensive patients after reversal of myocardial hypertrophy.

After treatment with alpha-methyldopa a regression of left ventricular hypertrophy, due to hypertension, has been reported in spontaneously hypertensive rats. The reduction of left ventricular mass has been associated with an increase in hydroxyproline concentration, suggesting secondary functional changes. On this basis, 12 patients with essential hypertension and echocardiographic evidence of left ventricular hypertrophy have been studied before and after a 6-month alpha-methyldopa treatment. Ten normal subjects were used as a control group. Curves of changes in left ventricular diameter and velocity curves were obtained by digitation of the M-mode endocardial echoes and the diastolic patterns were studied. Before treatment all patients, as compared to normal subjects, showed: (a) prolongation of the isovolumetric relaxation time index, with increased diameter changes; (b) reduction of diameter changes and peak velocity during the rapid filling; and (c) marked compensatory increase of diameter changes and peak velocity of the filling due to atrial systole. Left ventricular hypertrophy was reduced in 5 patients (first group) after treatment. This group showed: (a) normalization of the isovolumetric relaxation time index; (b) slight increase of diameter changes during rapid filling; (c) increased peak velocity of the rapid filling; and (d) reduction of diameter changes and peak velocity during atrial systole. No changes of functional data were observed in the other 7 patients (second group) in whom left ventricular hypertrophy was unchanged after treatment. It is shown how the reduction of left ventricular hypertrophy, per se, could induce such an improvement of diastolic function, despite the biochemical changes probably caused by administration of alpha-methyldopa.

Blood Pressure↗
PubMed1983

[Morphologic and functional aspects of left ventricular hypertrophy evaluated by computerized echocardiography].

We have investigated the possible echocardiographic progression of left ventricular (LV) hypertrophy, in different stages of primary hypertension. Both morphological (LV mass and ratio of interventricular septal thickness to posterior wall thickness-IVST/PWT-, in M-mode) and functional data (parietal stress, duration, degree and velocity of filling in the four phases of diastole, obtained through computerised interpretation of M-mode tracings), were examined. We also tried to assess the morphofunctional differences between LV hypertrophy secondary to primary hypertension and LV hypertrophy secondary to renovascular hypertension, hypertrophic obstructive cardiomyopathy and physical training. Patients with primary hypertension were further subdivided in three groups: A) 14 patients with hypertension of less than one year's duration, B) 28 patients with long-lasting hypertension, and C) 5 patients with cardiomegaly. There was a progressive increase from controls to Group C patients of left ventricular mass (controls 171 +/- 25; Group A 168 +/- 72; Group B 253 +/- 83; Group C 439 +/- 117) and septal hypertrophy (controls IVST/PVT 1 +/- 0.1; Group A 1.2 +/- 0.2; Group B 1.4 +/- 0.3; Group C 1.5 +/- 0.1). The isovolumic relaxation period was prolonged only in Group C (controls 8.6 +/- 3.5 per cent of the diastole; Group C 15 +/- 3.5%) LV dimensions during slow filling and atrial contraction as well as filling velocity during this latter phase of the cardiac cycle were increased in Group A (7.8 +/- 2.3 and 7.3 +/- 2%; 1.2 +/- 0.6 cm/cm X sec respectively) and B (10 +/- 6 and 10.8 +/- 4%; 1.2 +/- 0.6 cm/cm X sec) compared to the controls (5 +/- 2.8 and 3.7 +/- 2%; 0.7 +/- 0.2 cm/cm X sec). The Vcf max was not significantly different in the three groups. The patients with renovascular hypertension (N = 14) could be differentiated from those with primary hypertension of Group B for a greater increase in LV mass, with concentric hypertrophy (IVST/PWT = 1.2 +/- 0.2), for a greater prolongation of IRP (16 +/- 0.6% of diastole), with increased diameter changes in this phase (displacement ratio = 3.3 +/- 2.3%, in Group B; 4.7 +/- 3.8%, in renovascular hypertension), for a normal displacement and velocity of slow and atrial filling, despite the impairment of rapid filling found in this group, too (% displacement and velocity, respectively: 19 +/- 5% and 1.8 +/- 0.6 cm/cm X sec).

Cardiomyopathy, Hypertrophic↗
PubMed1981

[Echocardiography during ergometric tests in subjects with stable effort angina (author's transl)].

The feasibility of echocardiography in detecting left ventricle wall motion abnormalities, their location and their spontaneous or therapeutic regression, was assessed performing monodimensional and two-dimensional echocardiography in 35 patients with stable effort angina, without previous AMI. A control group of 10 normal subjects was also studied. The Authors evaluated echocardiographic findings on subjects at rest, during supine bicycle exercise and after sublingual nitroglycerin administration, defining the quality of wall motion as normal, hypokinetic, akinetic or dyskinetic in M-mode, and normal or asynergic in 2-D. They also analyzed, in M-mode, some echocardiographic indices of regional left ventricle function (IVSE, PWE, VIVS, VPW, delta TS, delta TP), and, in 2-D, the percent of systo-diastolic endocardial outline changes versus standard references in 7 sectors of left ventricle (anterior, lateral, inferior, septal in short-axis, septal, postero-lateral in long-axis, and apical) by means of a HP 9845B Computer, interfaced to a Digitizer. The percentage of feasibility of exercise echocardiography has been 60% in M-Mode, and 70% in 2-D. Mono and two-dimensional findings were normal in all patients at rest, whereas, during exercise, 57% of them, in M-mode, and 88% in 2-D, showed segmental contraction abnormalities. The Authors conclude that exercise echocardiography, though technically difficult, is feasible, Both M-mode and 2-D involve peculiar advantages or disadvantages. They provide, however, a valuable tool in detecting the mechanical consequences of exercise-induced regional myocardial ischemia and may be applicable in patients with equivocal exercise test.

Adult↗