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Biomedical subjects

R Bolognesi

Publications and source records attributed to R Bolognesi.

At least 19 recordsLinked to original sources

Effects of acute K-strophantidin administration on left ventricular relaxation and filling phase in coronary artery disease.

In 10 patients with coronary artery disease, preserved left ventricular (LV) performance and absence of previous myocardial infarction, the effects of an acute intravenous administration of k-strophantidin (0.005 mg/kg over 10 minutes) on selected parameters of both LV systolic and diastolic function, including relaxation, were evaluated. An increase in positive first derivative of LV pressure (dP/dt) and in the ratio between dP/dt and the pressure developed (dP/dt/P) (1,530 +/- 287) 1,600 +/- 329 mm Hg/s [p less than 0.05], and 30 +/- 6 to 34 +/- 8 s-1 [p less than 0.05], respectively) demonstrated the inotropic effect of k-strophantidin, whereas volumetric parameters of systolic function (end-systolic and stroke volume indexes, and ejection fraction) did not show any significant change. However, LV relaxation was impaired by k-strophantidin injection; in fact, mean values of T constant were significantly increased from 50 +/- 12 to 55 +/- 13 ms (p less than 0.01). Lowest LV and end-diastolic pressures increased from 8 +/- 4 to 11 +/- 4 mm Hg (p less than 0.05) and from 17 +/- 6 to 20 +/- 8 mm Hg (p less than 0.05), respectively. The end-diastolic volume and maximal rate of volumetric increase during the early and late filling phases were not modified by k-strophantidin. Mean aortic pressure increased from 110 +/- 10 to 120 +/- 12 mm Hg (p less than 0.001). Therefore, in patients with coronary artery disease and LV preserved performance, an acute intravenous administration of k-strophantidin appears to stimulate contractility and to worsen relaxation, and minimal LV and end-diastolic pressures.

Aged

Digitalis and heart failure: does digitalis really produce beneficial effects through a positive inotropic action?

Although digitalis was introduced to medicine long ago, the drug is still extensively used in clinical practice today. Opinions on its mechanism of action have undergone much change in the course of time, and the way in which cardiovascular effects are produced is still not completely clear. Limitations and contraindications for the use of digitalis substances are reported, especially in the treatment of ischemic heart disease. Preliminary data regarding the effects of digitalis on the diastolic phase are unfavorable, although the relationship between digitalis and diastolic function ought to be studied in greater depth in various clinical conditions. In spite of many recent trials, the old question of the usefulness of digitalis in the chronic treatment of patients in sinus rhythm and heart failure is still debated. An important clinical benefit in the chronic use of digitalis appears restricted to a relatively small proportion of patients with severe congestive heart failure, while in the majority of chronically treated subjects the effects of the drug are scanty or insignificant. The beneficial effect of digitalis used chronically is essentially believed to be due to its positive inotropic action. Since the vagomimetic and the antiadrenergic effects of digitalis have been demonstrated to be independent from its inotropic action, they could be considered determinants of the clinical benefits of digitalis. These indirect effects may be useful in the control of the negative neuroendocrine response developing during congestive heart failure. Thus the statement that digitalis is essentially an inotropic agent seems restrictive; its definition should reflect the favorable effects obtained in some cases of congestive heart failure rather than its various and contrasting underlying mechanisms of action.

Contraindications

Multivariate analysis of the variables affecting left ventricular filling in normal subjects.

Pulsed Doppler measurements of left ventricular filling (LVF), two-dimensional and M-mode echocardiograms were performed in 189 healthy subjects, in order to evaluate factors influencing LVF Doppler indexes in normal subjects. LVF Doppler indexes (peak E, peak A, peak E/peak A, deceleration rate of peak E (ED) were related by univariate and multivariate analyses with the following parameters: age, sex, heart rate, systolic and diastolic blood pressure, aortic root and left atrial dimensions, left ventricular mass index, left ventricular shortening fraction. The stepwise analysis showed that age by itself explained up to 18% of peak E variance, 50% of peak A variance, 61% of peak E/peak A variance and 25% of ED variance. The other variables entered into the regression, slightly improved the predictive power (less than 10%). In conclusion, age is the major independent factor affecting LVF in normal subjects, although other variables show significant correlation also after age adjustment.

Age Factors

The pharmacologic treatment of atrial fibrillation.

The pharmacologic treatment of atrial fibrillation (AF) is aimed at controlling the ventricular response, restoring sinus rhythm, and preventing or delaying relapses. In the control of ventricular response, digitalis maintains a primary role when the arrhythmia is accompanied by heart failure. In ischemic, hypertensive, and degenerative (whose number is increasing at present) cardiopathies without evident ventricular dilatation, treatments with calcium antagonists (such as verapamil, gallopamil, or diltiazem) or beta-blocking agents must be preferred. In order to control the ventricular response in patients with chronic AF during physical activity, the association of digitalis with beta-blocking agents or calcium antagonists seems to provide satisfactory results. The drugs of the IC class, especially flecainide, represent a certain therapeutical progress in the restoration of sinus rhythm in the treatment of paroxysmal atrial fibrillation affecting subjects without evident alterations of ventricular function, particularly in subjects with Wolff-Parkinson-White syndrome, with forms of vagal origin, or with atrial fibrillation alone. A therapeutic combination of digitalis and quinidine may produce resolution of the arrhythmia in the presence of altered ventricular function or when AF is of an uncertain onset. In patients with hypertensive, ischemic, and/or degenerative cardiopathy without evident ventricular or advanced heart failure, the verapamil-quinidine association may also be effective and even quicker. The combination of drugs of the I and III class for restoration of the sinus rhythm in particularly resistant forms of AF without evident structural heart alterations is promising but must be verified in a greater number of patients. In the prevention of relapses amiodarone appears to have the widest spectrum of advantages from an electrophysiologic point of view; however, because of its many side effects, amiodarone represents a late therapeutical choice. The promising results obtained with flecainide are disputed by the results of the CAST, which limit the possibilities of using this drug to a low number of cases (W.P.W. syndrome, AF of vagal origin, atrial fibrillation alone). In the past, quinidine and disopyramide have been the drugs most widely used in the prophylaxis of AF. These drugs have a similar efficacy, and both of them provided some positive results. However, because of untoward side effects (especially for quinidine) during chronic treatment, the use of these drugs has been questioned. Perhaps in the majority of patients, the less dangerous therapeutic choice after the termination of the fibrillation is a combination of drugs slowly down AV node activity (digitalis or calcium antagonists and beta blockers) with class IA antiarrhythmics.

Adrenergic beta-Antagonists

Different effects of acute intravenous administration of k-strophanthidin and prenalterol on the diastolic phase of left ventricular function in patients with coronary arterial disease.

In 21 patients with coronary arterial disease, and with maintained (or mildly depressed) systolic function, we studied the effects of two well-known inotropic agents, namely prenalterol and k-strophanthidin, on the diastolic phase. Selected variables of both systolic and diastolic function were assessed at controlled heart rate by cardiac catheterization and left ventriculography before and after acute intravenous administration of the beta 1 agonist prenalterol (35 micrograms/kg for 3 min) and of k-strophanthidin (0.008 mg/kg for 5-10 min). Ten patients received prenalterol, and 11 patients were injected with k-strophanthidin. Administration of prenalterol induced a remarkable diminution of end-systolic volume index (mean values from 41.8 +/- 11.9 to 32.2 +/- 10.4), while k-strophanthidin showed only a tendency towards a decrease (mean values from 43.4 +/- 13.2 to 40.7 +/- 15.1). After k-strophanthidin, we did not observe any significant changes in the peaks of maximal rate in volumetric increase during filling phase whereas, after prenalterol, a noteworthy increase of the first peak was accompanied by a significant decrease of the second peak. The lowest and end filling left ventricular pressures were decreased by prenalterol (mean values from -0.8 +/- 0.1 to -2 +/- 0.5 and from 10.6 +/- 4.6 to 4.1 +/- 1.1 respectively), whereas k-strophanthidin increased left ventricular end diastolic pressure (mean values from 11.6 +/- 4.3 to 17.1 +/- 9.1). Prenalterol induced a relevant increase of ejection fraction (mean values from 0.52 +/- 0.1 to 0.61 +/- 0.008), whereas k-strophanthidin produced only a nearly significant (P less than 0.06) mild increase (mean values from 0.51 +/- 0.06 to 0.54 +/- 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Diagnosis of an aorto-caval fistula by echo 2D color Doppler flow imaging and echocardiographic probe.

We describe a clinical case presenting two unusual features. The first was a spontaneous aorto-caval fistula which had developed from rupture of an atherosclerotic aortic aneurysm into the inferior vena cava. The second uncommon feature depended on the unusual method by which the diagnosis was performed. In fact, using an echo-Doppler color flow (HP 77020A ultrasound system) with a 2.5 MHz echocardiographic probe abdominal examination revealed an aneurysm of the abdominal aorta that communicated with a dilated inferior vena cava. Furthermore, flow study with pulsed color Doppler revealed a continuous turbolent, mixed (arterial and venous) blood flow into the vena cava.

Aorta, Abdominal

[Magnetic resonance in the study of Wilm's tumor and neuroblastoma].

Eleven patients suffering from neuroblastoma and Wilms' tumor were examined with MR imaging (25 examinations). The results were compared with those obtained with other diagnostic methods--e.g. CT--to verify MR reliability in locating and staging the lesions. Signal patterns were studied, as recorded on T1- and T2-weighted sequences using various repetition and echo times. An attempt was made to verify the presence of pathognomonic findings and to differentiate tumors from post-therapy fibroses. All findings were subsequently confirmed at biopsy or, in the patients who underwent surgery, by surgical findings. To carry out all the procedures, the patients had to be sedated or to be administered a general anesthetic. When possible, a brain or surface coil was used to obtain a clear, well-defined image in thin-section (7-8 mm) sequences. MR imaging allowed all lesions to be detected and located in the examined population. A large thrombus in the vena cava and local adenopathy were observed in a patients suffering from Wilms' tumor. Spread into the spinal canal was present in 2 cases of neuroblastoma. One of the main advantages of MR imaging is its multiplanarity which usually allows lesion extent to be demonstrated, together with the involved organs. The additional advantages of MR imaging over CT should not be underestimated. MR allows images of the abdomen to be obtained devoid of respiratory artifacts and provides a sharp contrast between pathological and healthy tissue without contrast medium administration. In all the patients who underwent it, MR imaging proved superior to CT in the evaluation of the intraspinal spread of paraspinal lesions. MR also allowed serial follow-up to be carried out, with no risk of subsequent proteximetric problems, thus helping distinguish tumor masses from fibrous tissue in all patients.

Abdominal Neoplasms

[The diagnosis by a Doppler color echocardiographic method of an aortocaval fistula following the rupture of an aortic aneurysm into the inferior vena cava].

We describe a clinical case presenting 2 rare features. The first was a spontaneous aortocaval fistula which had developed from rupture of an atherosclerotic aortic aneurysm into the inferior vena cava. The second infrequent feature depended on the unusual method by which the diagnosis was performed. In fact, using an echo-color Doppler flow imaging (HP 77020A ultrasound system) with a 2.5 MHz echocardiographic probe abdominal examination showed an aneurysm of the descending aorta that communicated to a dilated inferior vena cava. Furthermore, flow study with color Doppler showed a continuous turbulent, mixed (arterial and venous) blood flow into the inferior vena cava.

Aortic Aneurysm

Peak aortic blood acceleration: a possible indicator of initial left ventricular impairment in patients with coronary artery disease.

In 25 patients undergoing diagnostic cardiac catheterization, a catheter-tip electromagnetic velocity transducer was used to evaluate maximum velocity and acceleration of blood in the ascending aorta. All patients underwent a complete haemodynamic evaluation, including high-fidelity recording of intraventricular pressures and calculation of the derived indices, left ventriculography and coronary angiography. Nineteen patients with critical coronary stenoses were divided according to the presence of signs of left ventricular dysfunction, while the control group consisted of six subjects with chest pain, but without cardiac abnormalities detectable by cardiac catheterization. Maximum aortic acceleration was significantly lower in coronary patients (378 +/- 130 vs 562 +/- 82 in the control group P less than 0.01) and also in the selected subgroup of coronary patients with normal haemodynamic and angiographic indices of left ventricular systolic function (310 +/- 102 vs 562 +/- 82, P less than 0.01). No relationship could be observed between maximal blood acceleration and left ventricular peak systolic pressure, +dP/dt, left ventricular end-systolic volume index and ejection fraction. Our results suggest that maximal blood acceleration from the left ventricle may detect an initial myocardial impairment in patients with definite coronary artery disease but with normal conventional indices of left ventricular function. The clinical interest of this index, however, is limited by overlapping values in patients with and without coronary artery disease and the inability of a further separation of ischaemic patients in accordance with the severity of left ventricular impairment and the extension of coronary artery involvement.

Adult

Dynamic left-ventricular tract outflow obstruction: a late complication of mitral valve replacement.

The case presented is a 47-year-old woman with left-ventricular outflow tract obstruction which was the late complication of mitral valve replacement (4 years later). The diagnosis was made using two-dimensional Doppler echocardiography (echo-2D Doppler) and confirmed by cardiac catheterization. Protrusion of the prosthetic ring towards the intraventricular septum reducing the diameter of the outflow tract to 7-8 mm and creating a dynamic obstruction (30 mm Hg on cardiac catheterization, and 44 and 75 mm Hg on echo-2D Doppler basally and after isoamyl nitrite inhalation, respectively) was recorded. The echo-2D Doppler technique appears to be useful in detecting this postsurgical mitral complication.

Echocardiography, Doppler

[Effects of chronic administration of nifedipine on echo-Doppler parameters of left ventricular filling in hypertensive patients].

This study aimed determining the chronic effects of nifedipine (N) on left ventricular filling in 25 patients (mean age 55) with mild to moderate arterial hypertension. M-mode, B-mode and pulsed Doppler measurements were performed at baseline, after 30 min from administration of sublingual N (10 mg) and after 6 months of therapy with slow release N (max dose: 60 mg die). Acute and chronic N reduced significantly both systolic (p less than 0.001) and diastolic pressure (p less than 0.001). At the end of the treatment with slow release N, and septal wall thicknesses had a slight but significant decrease (p less than 0.01). Diastolic and systolic dimension were not modified. Left ventricular mass index decreased significantly from 141 +/- 34 to 130 +/- 31 g/m2 (p less than 0.05). The Doppler-derived diastolic filling indexes (peak E, ratio peak E/A,E deceleration) were abnormal at baseline, and had a significant increase after sublingual and chronic therapy. Changes in left ventricular mass index and diastolic filling indexes were not correlated. A significant correlation was found between peak E changes after acute and chronic N administration (r = 0.732 and p less than 0.001). The results of this study demonstrate that both acute and chronic administration of N modify transmitral flow velocity pattern, suggesting that, in hypertensive patients, left ventricular filling abnormalities are partly dynamic and reversible. Our findings also demonstrate that acute N effects may predict the chronic results.

Adult

[Effects of i.v. nicardipine in the treatment of hypertensive crisis].

The availability of i.v. nicardipine has urged us to prove this drug in the treatment of hypertensive attacks (SAP greater than or equal to 210 mmHg and/or DAP greater than or equal to 110 mmHg). Two groups of patients (each made up of ten subjects) were treated with 2 mg and 5 mg respectively of i.v. nicardipine injected for 4 min while mean systolic and diastolic arterial pressure and heart rate were registered until three hours. I.V. nicardipine administration induced in both groups of patients a decrease in systolic pressure from 20 to 30% while diastolic arterial pressure decreased from 15 to 18% in the first group and from 20 to 25% in the second one. Heart rate showed an initial mild increase following arterial vasodilator action of nicardipine whereas it decreased significantly from 120 min in the presence of an unchanged hypotensive effect of the drug. One patient did not respond to nicardipine while another felt chest pain and palpitations. In conclusion our results are satisfactory and argue for the inclusion of nicardipine among the drugs that may be considered useful for the treatment of hypertensive attacks.

Acute Disease

Electrophysiological evaluation of the sinus node in patients with atrioventricular and/or intraventricular conduction defects.

The authors evaluated retrospectively sinoatrial conduction time (SACT), sinus node recovery time (SNRT), and corrected sinus node recovery time (CSNRT) in 272 patients with atrioventricular and/or intraventricular conduction defects without evidence of overt sinus node dysfunction. The study was designed to determine the prevalence of electrophysiologic sinus node abnormalities in patients with overt atrioventricular and/or intraventricular conduction defects. One or more sinus node electrophysiological abnormalities were observed in 133 cases (48.9%). There was a significant prevalence of electrophysiologic sinus node abnormalities only in patients older than 71 years of age. The data suggest that the involvement of the specialized conduction system is much more diffuse than one might expect simply observing the single recorded ECG defect and that the prevalence of associated defects of the conduction system increases with increasing age of patients.

Adolescent

[Effects of intravenous flecainide in the treatment of paroxysmal or recent-onset atrial fibrillations].

Intravenous flecainide (2 mg/Kg for 15 min) was used in 30 patients (18 men and 12 women aged 23 to 85 years: mean 62) with recent or paroxysmal atrial fibrillation: 5 patients returned to sinus rhythm during flecainide administration while other 23 patients did it not later than 2 hours. Treatment with intravenous flecainide proved to be safe without significant side effects. Further investigations are required to define the effects of flecainide in the treatment of atrial fibrillation; at the moment it must be admitted that flecainide acetate is a useful, safe, fast acting drug for the conversion of paroxysmal or recent atrial fibrillation to sinus rhythm.

Adult

[Dynamic obstruction of the left ventricular outflow as a late complication of mitral valve replacement. Case report].

The obstruction of the left ventricular tract outflow following mitral valve surgery, as a late complication, is rarely reported in the literature. The case of a 47-yr-old woman, who, after mitral valve surgery, developed dynamic left ventricular tract outflow obstruction four years later is reported. This alteration was detected by 2D echo-Doppler. The echocardiographic findings were: 1) Normal function of the mitral prosthesis. 2) An equal pressure-gradient of 44 mmHg at rest and of 75 mmHg after amyl nitrite at three examined levels: below, above and at the level of the aortic valve. 3) A hyper-echo image in the peri-annular region, probably representing fibrous degeneration around the valve ring, which was the likely cause of the obstruction. Th data were confirmed by cardiac catheterization. The echocardiographic technique appears to be a useful tool to detect and study this complication of mitral valve surgery.

Echocardiography, Doppler