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Biomedical subjects

S Betocchi

Publications and source records attributed to S Betocchi.

At least 55 records · Page 3Linked to original sources
PubMed1991

Assessment of left ventricular diastolic function: comparison of contrast ventriculography and equilibrium radionuclide angiography.

Twenty-two patients with coronary artery disease were studied first by radionuclide angiography (RNA) and then by contrast ventriculography. Cardiac medications were discontinued at least 72 hr before study. The patients were studied during atrial pacing at heart rates close to their spontaneous sinus rhythm. Contrast ventriculography was performed at 50 frames/sec in the 30 degrees right anterior oblique projection using 40 ml of a nonionic contrast medium (iopamidol) at a flow rate of 10-12 ml/sec. The contours of the left ventricular silhouette at contrast ventriculography were traced, frame by frame, on a graphic table with a digitizing penlight. Equilibrium 99mTc RNA was performed in the best septal 45 degrees left anterior oblique projection, acquiring 150,000 cts/frame, at 50 frames/sec and with a 5% gate tolerance. Time-activity curves from both end-diastolic and end-systolic ROIs were built and interpolated. Both RNA and contrast ventriculography volume curves were filtered with Fourier five harmonics. A close relationship was found between RNA and contrast ventriculography measurements of peak filling rate normalized to end-diastolic cps (r = 0.87, p less than 0.001) and stroke count (r = 0.87, p less than 0.001), ejection fraction (r = 0.94, p less than 0.001). Thus, in patients with coronary artery disease, LV filling can be accurately assessed using RNA.

Algorithms↗
PubMed1991

[Ventricular hypertrophy as an expression of hypertensive damage].

Although left ventricular hypertrophy is an adaptative mechanism to increased load, its development represents a pathological state which can affect patients' health in many ways. Systemic hypertension is often associated to left ventricular hypertrophy; a correlation exists between ambulatory blood pressure monitoring daytime mean blood pressure values and left ventricular mass. Left ventricular hypertrophy is an independent risk factor for cardiovascular events, and the pattern of concentric left ventricular hypertrophy is associated with higher morbidity and mortality. The mechanism by which left ventricular hypertrophy impair life expectancy is not completely known; arrhythmias and ischemia may often develop in patients with secondary left ventricular hypertrophy and can contribute to worsen prognosis. Left ventricular mechanics is also affected by hypertrophy. Systolic function is usually normal at rest, but its response to exercise can be blunted when hypertrophy develops. Diastolic dysfunction is often present in patients with hypertension, even before left ventricular hypertrophy occurs, and it can impair systolic function by hampering filling resulting mostly in an impairment in the adjustment to exercise. Effective antihypertensive therapy leads to a decrease in left ventricular hypertrophy and an improvement in diastolic mechanics.

Cardiovascular Diseases↗
PubMed1990

Effects of intravenous verapamil on left ventricular relaxation and filling in stable angina pectoris.

Left ventricular (LV) diastolic function is often impaired in coronary artery disease (CAD). To assess whether verapamil could improve LV diastolic properties, 12 patients with CAD undergoing right- and left-sided cardiac catheterization, as well as simultaneous radionuclide angiography, were studied before and during intravenous administration of verapamil (0.1 mg/kg as a bolus followed by 0.007 mg/kg/min). The heart rate was kept constant by atrial pacing in both studies. LV pressure-volume relations were obtained. Verapamil decreased LV systolic pressure (130 +/- 22 to 117 +/- 16 mm Hg, p less than 0.01) and the end-systolic pressure/volume ratio (2.4 +/- 1.3 to 1.6 +/- 0.5 mm Hg/ml, p less than 0.05), and increased LV end-diastolic (13 +/- 4 to 16 +/- 4 mm Hg, p less than 0.02) and pulmonary capillary pressures (10 +/- 5 to 12 +/- 5 mm Hg, p less than 0.005). Despite such negative inotropic effects, cardiac index increased (3.4 +/- 0.7 to 3.9 +/- 0.6 liters/min/m2, p less than 0.02). The time constant of isovolumic relaxation shortened (63 +/- 14 to 47 +/- 9 ms, p less than 0.02); peak filling rate increased (370 +/- 155 to 519 +/- 184 ml/s, p less than 0.001; 2.6 +/- 1.1 to 3.3 +/- 0.9 end-diastolic counts/s, p less than 0.02; and 4.1 +/- 1.6 to 5.5 +/- 1.5 stroke counts/s, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Quantitation of left ventricular asynchrony on radionuclide angiography phase images.

Quantitation of left ventricular (LV) asynchrony is relevant in clinical cardiology, as well as in evaluating LV mechanical properties. Radionuclide angiography (RA) phase images are extensively used, and asynchrony is usually assessed by computing the standard deviation of phase angle distribution (SD). However, SD is dependent on count statistics and does not take into account the spatial distribution of asynchrony. In this study a new index to evaluate asynchrony on phase images is presented (differential uniformity parameter, DUP). DUP is based on the frequency analysis of phase images. Diagnostic accuracy and reproducibility of either SD or DUP were tested. Reproducibility was evaluated in 15 patients studied by RA twice within a few minutes. DUP showed a better reproducibility than SD. Diagnostic accuracy was estimated in 84 patients, divided into four subgroups on the basis of coronary arteriography and contrast ventriculography findings: (a) 25 control subjects, (b) 16 patients with coronary artery disease (CAD) and normal LV wall motion, (c) 23 patients with CAD and LV hypokinesia and (d) 20 patients with CAD and LV dyskinesia. Relative diagnostic ability was assessed by comparing the areas under receiver-operating characteristic curves. DUP's area was larger than SD's when group D was tested against all the other groups (DUP's area = 87% +/- 5%, SD's area = 76% +/- 7%; P less than 0.01). Thus, our study indicates that DUP is more reproducible and more accurate than SD in identifying patients with CAD and LV dyskinesia.

Coronary Disease↗
PubMed1990

Phase analysis of radionuclide angiography in acute myocardial infarction.

Standard deviation of the histogram of left ventricular phase distribution (SDP-LV) obtained by radionuclide angiography (RNA) was studied in 75 acute myocardial infarction (AMI) patients, 37 with anterior or anteroseptal (Group A) and 38 with inferior, inferolateral or posterior necrosis (Group I). In order to evaluate sensitivity, specificity and accuracy of SDP-LV compared to ejection fraction (EF) and peak filling rate (PFR), 16 controls and 29 patients with coronary artery disease with normal kinesis proved by angiography were studied. Patients were also compared according to normal or abnormal EF and PFR. Sensitivity of PFR was better than those of EF and PFR (86.6% vs 38.7% and 70.6%, respectively). Specificity of SDP-LV was 89.6%, better than that of PFR (58.6%), but just less than that of EF (93.1%). The accuracy of SDP-LV turned out to be better than those of EF and PFR (87.5% vs 53.8% and 67.3%, respectively). Ejection fraction correlated with SDP-LV in the total study population (r = -0.54, P less than 0.001), and in Groups A (r = -0.44, P less than 0.01) and I (r = -0.43, P less than 0.05); SDP-LV correlated with PFR in the total population (r = -0.35, P less than 0.05), but not in Group A or I. Mean SDP-LV was higher in Group A than I and in patients with lower EF; no difference was found among patients with different PFR values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Improvement of diastolic function after reversal of left ventricular hypertrophy induced by long-term antihypertensive treatment with tertatolol.

In 15 previously untreated hypertensive subjects with left ventricular (LV) hypertrophy who responded favorably (supine blood pressure less than or equal to 140/90 mm Hg) to antihypertensive treatment with a nonselective beta-blocking agent, tertatolol, the effects of reversal of LV hypertrophy on systolic and diastolic function were assessed. Patients underwent echocardiographic and radionuclide studies in control conditions (phase 1), after 1 month of blood pressure normalization (phase 2), after reversal of LV hypertrophy or at least a 20% reduction of LV mass compared to basal value (phase 3) and finally, after a 1-month washout (phase 4). In phase 2, blood pressure (130 +/- 2/85 +/- 1 vs 148 +/- 4/104 +/- 1 mm Hg) and heart rate (59 +/- 1 vs 76 +/- 2 beats/min) decreased (both p less than 0.01); LV mass remained unchanged. There were improvements in peak filling rate (end-diastolic volume/s) (2.4 +/- 0.1 vs 2.0 +/- 0.1), ejection fraction (65 +/- 1 vs 61 +/- 1%) and their ratio (stroke counts/s) (3.7 +/- 0.2 vs 3.2 +/- 0.1) (all p less than 0.05). In phase 3, blood pressure and heart rate were unchanged and reversal of LV hypertrophy was accompanied by a further increase in peak filling rate (2.9 +/- 0.1), ejection fraction (69 +/- 1%) and their ratio (4.1 +/- 0.1) compared to phase 2 (all p less than 0.01). Finally, in phase 4 blood pressure and heart rate returned to the basal value, but peak filling rate (2.7 +/- 0.1) and ejection fraction (65 +/- 1%), although reduced compared to phase 3, were still higher than phase 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1989

Assessment of left ventricular function using radionuclide angiography after dipyridamole infusion.

Thirty-six patients with significant coronary artery stenosis and no previous myocardial infarction and 25 subjects with normal coronary arteries underwent 99mTc RNV before and after coronary vasodilatation induced by dipyridamole, 0.75 mg/kg, given IV over 10 min. In subjects with normal coronary arteries, dipyridamole induced an increase in LVEF (from 66 +/- 8 to 76 +/- 8 percent; mean +/- SD; p less than 0.001); in patients with significant coronary artery stenosis (greater than or equal to 75 percent narrowing of at least one major vessel), dipyridamole injection did not affect LVEF (from 63 +/- 12 to 62 +/- 12 percent). In ten patients a complete, successful PTCA was performed and the RNV with the dipyridamole test repeated. The EF did not change with the dipyridamole test before PTCA (63 +/- 7 to 65 +/- 9 percent), but increased significantly after PTCA (62 +/- 11 to 70 +/- 9 percent; p less than 0.01). Sensitivity and specificity of EF changes after dipyridamole infusion were 75 and 76 percent, respectively. The test produced no major side effects or complications. Radionuclide angiography with dipyridamole helps to detect coronary artery stenosis and might be used to assess the effects of angioplasty on coronary flow reserve.

Adult↗
PubMed1988

Influence of left ventricular asynchrony on filling in coronary artery disease.

To evaluate whether the extent of left ventricular (LV) asynchrony plays a role in the impairment of LV rapid filling in patients with coronary artery disease (CAD), 48 patients underwent both radionuclide angiography and cardiac catheterization. Patients were divided into group I (n = 33), with normal LV kinesis or only mild hypokinesia, and group II (n = 15), with LV dyskinesia or akinesia. Radionuclide ejection fraction was higher in group I than in group II (62 +/- 12 vs 44 +/- 20%; p less than 0.001). Peak filling rate was significantly lower in group II (1.9 +/- 0.8 vs 2.6 +/- 0.9 end-diastolic counts/s; p less than 0.01). Time to end-systole coefficient of variation, an index of the extent of LV asynchrony, was significantly higher in group II than in group I (43 +/- 10 vs 35 +/- 6; p less than 0.0002). In group I, a highly significant inverse relation was found between this index of asynchrony and peak filling rate (r = 0.71; p less than 0.0001). This correlation was found even when time to end-systole coefficient of variation was normalized to the RR interval (r = 0.49; p less than 0.01) and when peak filling rate was expressed in stroke counts (r = 0.57; p less than 0.001). The correlation between peak filling rate and index of asynchrony was maintained up to an end-systole coefficient of variation value of approximately 35. In group II patients (most with an asynchrony value greater than or equal to 35) no relation was found between time to end-systole coefficient of variation and peak filling rate.

Adult↗
PubMed1988

Relation between serum nifedipine concentration and hemodynamic effects in nonobstructive hypertrophic cardiomyopathy.

The relation between nifedipine concentration and hemodynamic effects after sublingual administration of 10 or 20 mg was examined in 13 patients with nonobstructive hypertrophic cardiomyopathy (HC). Serum nifedipine concentrations were determined by gas chromatography and were not related to dose. Peripheral vascular resistance decreased as a function of nifedipine concentration (r = -0.63, p less than 0.001); this was associated with a concentration-related increase in heart rate (r = 0.56, p less than 0.001) and in cardiac index (r = 0.50, p less than 0.001). However, evidence for a pure vasodilator effect of nifedipine was inconsistent, in that the change in stroke volume index with nifedipine was not significant. Although stroke volume index increased at nifedipine concentrations between 60 and 120 ng/ml (38 +/- 6 to 42 +/- 4 ml/m2, p less than 0.01), it decreased at concentrations greater than 120 ng/ml (40 +/- 3 to 38 +/- 4 ml/m2, p less than 0.01). Moreover, pulmonary artery wedge pressure increased at nifedipine concentrations greater than 120 ng/ml (11 +/- 2 to 16 +/- 4 mm Hg, p less than 0.001), suggesting either depressed left ventricular (LV) systolic function or reduced LV filling. To investigate these possible mechanisms, LV systolic and diastolic function was studied during catheterization with a nonimaging scintillation probe in 6 of the 13 patients. In these subjects, heart rate was held constant by atrial pacing.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Diastolic function in acute myocardial infarction: a radionuclide study.

We studied left ventricular diastolic function by equilibrium gated radionuclide angiography in patients as follows: 75 with acute myocardial infarction (AMI), 35 with anterior or anteroseptal necrosis (Group A) and 40 with inferior, inferolateral, or posterior necrosis (Group I). The ejection fraction (EF) was lower in Group A than Group I (41.9 +/- 2.5 vs. 57.1 +/- 2.0%, p less than 0.001), as was peak diastolic filling rate normalized to end diastolic volume (PDFR-EDV/sec) (1.9 +/- 0.1 vs. 2.4 +/- 0.1 EDV/sec, p less than 0.05). PDFR normalized to stroke volume was similar in both groups. An excellent linear correlation was found between EF and PDFR-EDV/sec in the total study population. Isovolumic relaxation period (IRP) was beyond our upper normal value of 94 msec in 64% of patients and it was shorter in Group A than I (95.8 +/- 12.7 vs. 147.0 +/- 13.6 msec, p less than 0.05). The presence of shorter IRP in Group A than in I is probably a result of an earlier mitral valve opening as a consequence of higher left atrial pressure.

Adult↗
PubMed1987

Effects of intravenous verapamil administration on left ventricular diastolic function in systemic hypertension.

The effects of intravenous verapamil administration (0.1 mg/kg as a bolus followed by an infusion of 0.007 mg/kg/min) were studied using high-temporal-resolution radionuclide angiography in 27 patients with hypertension. Verapamil administration increased heart rate from 69 +/- 11 to 75 +/- 12 beats/min (p less than 0.001) and decreased systolic, diastolic and mean blood pressures (BPs) from 155 +/- 21/102 +/- 12 mm Hg (mean 119 +/- 14) to 142 +/- 19/95 +/- 12 mm Hg (mean 109 +/- 13) (p less than 0.001 for all). Ejection fraction decreased significantly (from 65 +/- 10% to 60 +/- 11%, p less than 0.005); peak filling rate, however, increased significantly only in patients in whom it was subnormal in the basal study (from 2.2 +/- 0.4 to 3.0 +/- 0.6 end-diastolic counts/s, p less than 0.001). These latter patients had significantly higher values of left ventricular (LV) mass index than patients with normal or increased peak filling rate (129 +/- 22 vs 112 +/- 22 g/m2, respectively, p less than 0.05). The isovolumic relaxation period changes were inversely related to the baseline values (r = 0.83, p less than 0.001). In the subgroup of patients in whom isovolumic relaxation period lengthened, time to end systole decreased (from 360 +/- 31 to 329 +/- 30 ms, p less than 0.025) and time to onset of rapid filling increased (from 420 +/- 31 to 451 +/- 34 ms, p less than 0.025), whereas these 2 intervals had opposite patterns in patients in whom isovolumic relaxation period decreased or did not change.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Isovolumic relaxation period in hypertrophic cardiomyopathy: assessment by radionuclide angiography.

Left ventricular isovolumic relaxation and the relation between relaxation and filling were studied in 90 patients with hypertrophic cardiomyopathy and 29 control subjects using radionuclide angiography. The isovolumic relaxation period was determined automatically on left ventricular time-activity curves as the interval between minimal volume and onset of rapid filling. In 17 patients, M-mode echocardiography performed simultaneously with radionuclide angiography demonstrated that onset of mitral valve opening correlated well with onset of rapid filling (r = 0.84, p less than 0.001). The isovolumic relaxation period was longer in patients with hypertrophic cardiomyopathy than in control subjects (95 +/- 44 versus 50 +/- 23 ms, p less than 0.01) and was longer in patients without an outflow tract gradient at rest than in patients with a gradient (109 +/- 37 versus 86 +/- 35 ms, p less than 0.05). In these patients without obstruction, a weak linear relation between duration of the isovolumic period and peak filling rate was found (r = 0.48, p less than 0.02). Filling was impaired in patients with hypertrophic cardiomyopathy, as assessed by lower peak filling rate (3.2 +/- 1.2 versus 3.5 +/- 0.5 end-diastolic volume/s, p less than 0.05) and prolonged time to peak filling rate (185 +/- 44 versus 145 +/- 20 ms, p less than 0.01) compared with values in control subjects. The delay in time to peak filling rate was caused primarily by the prolonged isovolumic period, because the interval from onset of rapid filling to peak filling rate was similar in patients with hypertrophic cardiomyopathy and control subjects (87 +/- 31 versus 95 +/- 25 ms, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Effects of sublingual nifedipine on hemodynamics and systolic and diastolic function in patients with hypertrophic cardiomyopathy.

The hemodynamic effects of sublingual nifedipine were examined in 36 patients with hypertrophic cardiomyopathy. Twenty-one patients were initially given 20 mg and 15 patients were given 10 mg of the drug; 30 min after this first dose 26 patients received 10 mg and one patient 20 mg as a second dose. Hemodynamic findings in patients who received different doses of the drug were similar. Peak effects included an increase in heart rate from 79 +/- 12 to 91 +/- 14 (mean +/- 1 SD) beats/min (p less than .01), and a decrease in mean blood pressure from 89 +/- 12 to 77 +/- 10 mm Hg (p less than .01). Cardiac index increased after nifedipine (2.8 +/- 0.6 to 3.3 +/- 0.8 liters/min/m2; p less than .01); stroke volume index, however, did not change (36 +/- 7 to 36 +/- 8 ml/beat/m2; NS). Peripheral vascular resistance index fell significantly from 822 +/- 261 to 610 +/- 197 dynes X sec X cm-5 (p less than .01). Overall, left ventricular outflow tract gradient (LVOTG) did not change in patients with significant (greater than or equal to 30 mm Hg) basal LVOTG (75 +/- 22 to 83 +/- 22 mm Hg; NS), but it increased significantly in those six patients in whom peripheral vascular resistance fell by 25% or more (73 +/- 28 to 99 +/- 22 mm Hg; p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Systolic and diastolic time intervals during spontaneous angina.

In 5 patients who suffered spontaneous angina during cardiac catheterization, aortic pressure and electrocardiographic lead (V5) were recorded at rest, at the onset of anginal pain, 5 and 10 min after 0.6 mg sublingual nitroglycerin (NTG). Heart rate, systemic arterial pressure, systolic, and diastolic time intervals were measured. Heart rate and systemic arterial pressure rose significantly immediately after the onset of angina and declined progressively within 10 min from NTG administration. Preejection period did not change during angina, while left ventricular ejection time and electromechanical systole lengthened. As a consequence, diastolic time, expressed as percent of cardiac cycle, shortened sharply. All parameters considered went back to basal values within 10 min from NTG administration, and were preceded by relief or reduction of anginal pain. We concluded that a fall in diastolic time, secondary to a prolongation of electromechanical systole occurring during angina, may further increase the degree of ischemia resulting in a vicious cycle than can be interrupted by NTG administration.

Angina Pectoris↗
PubMed1983

Two-dimensional echocardiography in idiopathic enlargement of the right atrium. Reliability and limitations.

A 36-year-old woman was admitted to our hospital with exertional dyspnea, palpitation and cardiac enlargement on standard chest X-ray. Physical examination did not reveal any significant abnormality and routine laboratory tests were normal. ECG showed atrial fibrillation and negative T waves in lead III and a VF, with a stiffened ST segment. M-mode echocardiography showed absence of pericardial effusion and normal size of both ventricular chambers. Two-dimensional echocardiography showed a large saccular dilation of the right atrium without significant enlargement of other cardiac chambers. A slight displacement of tricuspid valve leaflets was also present. Cardiac catheterization was effective in the diagnosis of idiopathic enlargement of the right atrium. Although two-dimensional echocardiography has some limitations in the diagnosis of this unusual malformation, it may prove useful in the noninvasive follow-up of these patients, in order to monitor the eventual increase of atrial size and to promptly detect late complications.

Adult↗