Biomedical subjects

S Dalla-Volta

Publications and source records attributed to S Dalla-Volta.

16 recordsLinked to original sources

PubMed1992

PAIMS 2: alteplase combined with heparin versus heparin in the treatment of acute pulmonary embolism. Plasminogen activator Italian multicenter study 2.

BACKGROUND: The effect of alteplase versus heparin in pulmonary embolism has not been studied extensively with serial pulmonary angiograms. OBJECTIVES: The aim of this randomized, open trial was to evaluate the efficacy and safety of alteplase followed by heparin, versus heparin alone, in 36 patients with angiographically documented pulmonary embolism. METHODS: Twenty patients were allocated randomly to a 2-h infusion of alteplase (10 mg bolus, then 90 mg over 2 h) followed by heparin; the other 16 patients were given intravenous heparin at a continuous infusion rate of 1,750 IU/h. RESULTS: The vascular obstruction, assessed by the Miller index at pulmonary angiography, decreased significantly in alteplase-treated patients (p less than 0.01) from a baseline of 28.3 +/- 2.9 to a value of 24.8 +/- 5.2 2 h after the start of infusion; in the heparin group there was no change (from 25.3 +/- 5.3 to 25.2 +/- 5.4). Mean pulmonary artery pressure decreased significantly from a baseline of 30.2 +/- 7.8 mm Hg to 21.4 +/- 6.7 in the alteplase group and increased in the heparin group (from 22.3 +/- 10.5 to 24.8 +/- 11.2 mm Hg). For a subset of patients, lung scans were performed at baseline and on days 7 and 30. There were no differences between the two groups in the follow-up lung scans, but there were significant decreases from the baseline values. Bleeding occurred in 14 of 20 alteplase-treated patients and in 6 of 16 in the heparin group (p = NS). There were three major bleeding episodes in the alteplase group and two in the heparin group. Two patients died after fibrinolysis (one of acute renal failure after cardiac tamponade and one of cardiac arrest after cerebral hemorrhage) and one patient in the heparin group died of recurrent pulmonary embolism. CONCLUSIONS: Alteplase resulted in a greater and faster improvement of the angiographic and hemodynamic variables compared with heparin. However, the high frequency of bleeding observed with alteplase in this trial suggests that patients should be carefully selected before thrombolytic therapy is given.

Acute Disease↗

PubMed1992

Reversible and irreversible left ventricular dysfunction after acute myocardial infarction.

Left ventricular function after acute myocardial infarction depends on several mechanisms leading to left ventricular remodeling: (a) infarct size and healing and (b) adaptive changes involving both the dysfunctioning but viable myocardium (hibernating and stunned myocardium) and the nonischemic myocardium. The prognosis after acute myocardial infarction is strongly related to regional and global left ventricular function and the loss of dysfunctioning viable myocardium is a main factor in the worsening in left ventricular function in survivors of the acute phase. Thus, medical strategies should exert their beneficial effect on the "mechanical instability" of ventricular myocardium by saving the viable myocardium. beta-Blocker therapy has been shown to be effective in improving the prognosis via anti-ischemic and antiarrhythmic actions. The combination of metoprolol and nisoldipine seems to be able to preserve the contractile function of viable myocardium in the first 6 months after acute myocardial infarction.

Adrenergic beta-Antagonists↗

PubMed1991

Exercise-induced left ventricular dysfunction in coronary heart disease. A model for studying the stunned myocardium in man.

The concept of myocardial stunning encompasses a wide variety of settings with major pathophysiological differences. Stresses, such as exercise-provoked myocardial ischaemia and dysfunction, are accompanied in most patients by a flow-limiting coronary stenosis, while contractile dysfunction persists in some with cessation of exercise. Twenty-six patients with proven coronary artery disease were studied by exercise echocardiography. Left ventricular (LV) volumes, wall motion and myocardial thickening were detected in apical four- and two-chamber views at rest and during upright bicycle exercise. All patients had an increase in total asynergy score and a decrease in ejection fraction (EF) during exercise. Myocardial dysfunction persisted after exercise in 22 patients (84%) as shown by the persistence of low values of LVEF on recovery up to 30 min. When compared to control, nisoldipine reduces total asynergy score and prevents the decline in LVEF during exercise by reducing the extent of myocardial ischaemia. The value of LVEF on recovery is normal. Thus, this particular form of myocardial stunning after exercise-induced ischaemia offers an interesting model for studying (1) the susceptibility of an individual patient and (2) to test the capability of a drug to prevent and to reverse myocardial stunning.

Adult↗

PubMed1990

Comparison of trimetazidine with nifedipine in effort angina: a double-blind, crossover study.

Trimetazidine has been shown to have an antianginal effect, increasing exercise capability without producing any significant change of heart rate or systolic blood pressure. The aim of this study was to compare trimetazidine efficiency to that of another classical antianginal drug. A double-blind crossover trimetazidine versus nifedipine trial was carried out in 39 male patients, mean age 58 years, with effort angina for 5 years on average, and a mean number of weekly attacks of 2.4. Thirteen patients had previous myocardial infarction. Nineteen patients received nifedipine (40 mg per day) then trimetazidine (60 mg per day), and 20 patients received the drugs in the opposite order. Each therapeutic period of 6 weeks was preceded by 1 week of washout with placebo. Drug efficacy was assessed by a bicycle exercise tolerance test, performed at the beginning and at the end of each therapeutic period, and by clinical symptoms observed with placebo or with treatment. The statistical analysis was performed according to a crossover design, with repeated measurements. The decrease of the number of weekly attacks was not significantly different with trimetazidine and nifedipine. Results on the exercise test showed no significant differences for maximum workload, the duration of exercise, ST-segment depression at peak exercise, and the time to 1-mm ST-segment depression. Heart rate and systolic blood pressure were not significantly different at rest and at peak exercise. However, the change in the rate-pressure product at the same workload differed significantly between the drugs: It decreased with nifedipine and remained unchanged with trimetazidine, indicating the difference to be in the mode of action of the drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Long-term nifedipine unloading therapy in asymptomatic patients with chronic severe aortic regurgitation.

Vasodilating agents acutely reduce regurgitant volume and improve left ventricular performance in aortic regurgitation, but more information is necessary about their long-term efficacy. To evaluate the effects of 12 months of therapy with nifedipine, a randomized, double-blind, placebo-controlled trial was performed in 72 asymptomatic patients with severe aortic regurgitation. At 12 months, patients receiving nifedipine had a significant reduction in left ventricular end-diastolic volume index (110 +/- 19 versus 136 +/- 22 ml/m2, p less than 0.01) and mass (115 +/- 19 versus 142 +/- 16 g/m2, p less than 0.01) measured by two-dimensional echocardiography. They also had a reduction in left ventricular mean wall stress (360 +/- 27 versus 479 +/- 36 kdyne/cm2, p less than 0.001) and an increase in ejection fraction (72 +/- 8% versus 60 +/- 6%, p less than 0.05). These data show that the long-term unloading action of nifedipine is able to reverse left ventricular dilation and hypertrophy and suggest that such therapy has the potential to delay the need for valve replacement in asymptomatic patients.

Adult↗

PubMed1990

The concept of preload and its evaluation in the intact left ventricle.

Preload affects left ventricular pump function through the Frank-Starling curve by changing sarcomere length. However, common indices of preload, such as end-diastolic volume, or pressure, or stress, do not necessarily reflect sarcomere length. Ultimately, this depends on the elastic stiffness constant (k) and end-diastolic stress (sigma), which are not in simple relation with the above mentioned indices. An index of preload is proposed, (k sigma)(1/k). This index has been evaluated in 148 patients with different degrees of hemodynamic overload, and in 24 normal subjects. The preload index was found to be 1.448 +/- 0.034 in normal subjects. However, in the other patients evaluated preload index increased in mitral insufficiency (1.490 +/- 0.035), in decompensated aortic insufficiency (1.490 +/- 0.89) and in dilated cardiomyopathy (1.52 +/- 0.125), and markedly decreased in aortic stenosis (1.367 +/- 0.039) and in hypertrophic cardiomyopathy (1.41 +/- 0.034). It was always positively related to the afterload, measured as peak systolic stress. No positive relationship was found with end-diastolic volume nor pressure. Therefore, preload as a compensatory mechanism is differently recruited in response to various degrees of hemodynamic overload and parallels the afterload, in agreement with the concept of preload-afterload mismatch.

Aortic Valve Insufficiency↗

PubMed1989

Contribution of cross-sectional echocardiography to the diagnosis of right ventricular dysplasia at the asymptomatic stage.

The value of cross-sectional echocardiography in the early diagnosis of right ventricular (RV) dysplasia in asymptomatic patients has been assessed. Criteria that defined RV dysfunction and structural abnormalities were developed from 38 normal subjects. Of 136 patients admitted into the study program, 40 (29.4%) had an echocardiogram suggestive of RV dysplasia using the following criteria: mild dilatation of the right ventricle (normal range defined as the 95% confidence limit of the values in the control group); localized bulge and dyskinesia of the infero-basal wall; structural changes of the moderator band; isolated enlargement of RV outflow tract; apical dyskinesia and trabecular disarrangement. Holter monitoring and a maximal exercise stress test at entry into the study and during the follow-up (mean 42, range 18-82 months) demonstrated serious ventricular arrhythmias, and RV endomyocardial biopsy confirmed the diagnosis of RV dysplasia in most of these patients, characterized by an electrical instability of RV myocardium (82.5%). During the follow-up, a marked enlargement of RV cavity appeared in three other patients, and RV endomyocardial biopsy demonstrated the typical findings in all patients.

Adolescent↗

PubMed1988

Myocardial function in heart failure.

Overt cardiac failure usually presents with constant clinical features as consequences of the reduced pump action, associated with an increased adrenergic drive, independent of the underlying disease. However, the study of left ventricular function, before and during the phase of cardiac insufficiency, shows that different pathophysiological mechanisms are responsible for the symptoms and signs of reduced cardiac action. It is possible to recognize that cardiac failure is caused primarily by: (1) early severe depression of the inotropic state, i.e. dilated cardiomyopathies; (2) late inadequate level of ventricular hypertrophy, with normal contractility, i.e. aortic stenosis; (3) early inadequate level of hypertrophy and slightly reduced inotropic state, i.e. mitral insufficiency, and (4) late inadequate level of hypertrophy and severe progressive reduction in contractility, i.e. aortic insufficiency. The possibility of an 'in vivo' assessment of the different determinant parameters of left ventricular function (contractility, afterload, preload, fiber and chamber compliance) through echocardiography enables a better understanding of the mechanisms leading to the cardiac failure and a more efficient therapeutic approach.

Echocardiography, Doppler↗

PubMed1988

Observations on the capability of the electrocardiogram to detect left ventricular function in chronic severe aortic regurgitation.

Echocardiographic parameters of left ventricular (LV) function were compared with the electrocardiographic findings in 40 patients with chronic severe aortic regurgitation. Total 12-lead QRS amplitude was linearly correlated with LV mass and its 'relative reduction' (less than 250 mm) indicated LV hypertrophy. Patients with an electrocardiographic 'strain' pattern had a marked increase LV stress (573 +/- 68 dyn). The association of high total 12-lead QRS amplitude and 'strain' indicate a moderately depressed ejection fraction (EF = 43 +/- 3). Finally, 'strain' and a 'relative reduction' of total 12-lead QRS amplitude were present in patients with a severe depression of EF and contractility. The predictive value of these electrocardiographic indices was confirmed during a mean follow-up of 49 months. In conclusion, the electrocardiogram remains an excellent, easy tool for anatomical and functional investigation of patients with aortic regurgitation.

Adolescent↗

PubMed1987

Effects of unloading and positive inotropic interventions on left ventricular function in asymptomatic patients with chronic severe aortic insufficiency.

The effect of an unloading (nifedipine, 20 mg sublingually) and of a combined unloading and positive inotropic intervention (nifedipine plus digoxin, 0.5 mg intravenously) on left ventricular performance was assessed in 48 patients with chronic severe aortic insufficiency. The left ventricular pump function-myocardial contractility relation (ejection fraction, EF vs. peak arterial pressure to end-systolic volume ratio, PAP/ESV), and the pump function-afterload relation (EF vs. mean systolic wall stress, MWS) were constructed by means of quantitative M-mode and two-dimensional echocardiography. In patients with normal control pump function (n = 14), nifedipine markedly decreased MWS, moving the patients to a new, more advantageous EF-MWS relation. In the 34 patients with abnormal pump function, the myocardial contractility level was the mean factor conditioning the response to pharmacological intervention. Patients with a value of PAP/ESV greater than 2.5 (n = 22) had normalization of EF after nifedipine and were upgraded to a more advantageous outlook for left ventricular mechanics EF-MWS and EF-PAP/ESV relations. Of the 12 patients without normalization of EF after nifedipine, only the 4 patients with PAP/ESV greater than 2 had normalization of pump function indices after combined administration of nifedipine and digoxin.

Adult↗

PubMed1987

Effects of amiodarone on oral and intravenous digoxin kinetics in healthy subjects.

The effect of amiodarone on oral and intravenous pharmacokinetics of digoxin was studied in healthy volunteers. A single 0.5-mg dose of digoxin was administered orally to three subjects both before and after 2 weeks of oral amiodarone (200 mg daily), while three subjects received a 0.5-mg intravenous dose of the glycoside under the same experimental conditions. Two other subjects were given both oral and intravenous doses of digoxin at different times, in the absence and in the presence of amiodarone. After oral digoxin treatment, amiodarone increased peak serum concentration, total area under the serum concentration-time curve (AUC), and 5-day urinary recovery of the glycoside, without changes in peak time and absorption rate constant. During the intravenous study, no significant change occurred in AUC and urinary recovery after amiodarone administration. Absolute bioavailability, for the two subjects who received both oral and intravenous digoxin, increased by 36 and 43%, respectively, after amiodarone treatment. Bioavailability derived from the mean values of oral and intravenous AUCs was 33% greater with amiodarone treatment. Apparent volume of distribution and systemic, extrarenal, and renal clearances of oral digoxin were not modified by amiodarone, when corrected for the bioavailability factor. Amiodarone had no effect on these pharmacokinetic parameters during the intravenous study with the glycoside. Our data indicate that increased oral bioavailability is the most relevant change in digoxin pharmacokinetics during the interaction with amiodarone and this can account for the increase in the glycoside concentrations.

Administration, Oral↗

PubMed1986

Ventricular development and function in complete transposition: angiocardiographic evaluation.

We studied 50 left ventricular cineangiograms and 41 right ventricular cineangiograms of 40 patients with usual atrial arrangement (situs solitus) together with concordant atrioventricular and discordant ventriculo-arterial connexions (complete transposition), catheterized between 1 day and 12 months of age. Our purpose was to evaluate ventricular development and function. The patients were subdivided on the basis of associated lesions into groups with intact ventricular septum; with ventricular septal defect; with ventricular septal defect together with pulmonary stenosis and with pulmonary stenosis in isolation. Each group was further separated according to age into those patients below and above 60 days. Ventricular volumes, ejection fraction and the ratio between systolic pressure and end-systolic volume were evaluated for both ventricles. The left ventricular mass, stress, and the ratio of stress to end-systolic volume were also calculated. A volume overload leads to increased left ventricular volume even at birth. With an intact ventricular septum, the left ventricle in patients with complete transposition is normal at birth and also during the first weeks of life. Myocardial mass, however, does not increase proportionately with increase in volume as the patient grows and it remains inadequate by the age of one year. The left ventricular mass is also inadequate in patients with associated anomalies when the left ventricular pressure is less than 60 mm Hg. Moreover, the left ventricle in presence of an intact ventricular septum presents a decrease in contractility during the first year of life despite the finding of a satisfactory arterial oxygen saturation. The right ventricle has a normal volume at birth which increases during the first year due to a greater diastolic filling following atrial septostomy. We noted a progressive decrease in ejection fraction, however, which is related to various factors including a reduction in contractility.

Angiocardiography↗

PubMed1986

Variability of positive inotropic response to acute amrinone administration in chronic cardiac failure.

To determine the factors conditioning the variability of positive inotropic response after intravenous acute amrinone administration, 14 patients with chronic cardiac failure were studied by quantitative M-mode and cross-sectional echocardiography. Six patients had idiopathic dilated cardiomyopathy and 8 patients had severe chronic aortic insufficiency. Myocardial contractility (evaluated as peak arterial systolic pressure/end-systolic volume ratio: PAP/ESV) did not change in patients with idiopathic cardiomyopathy, a significant increase of myocardial contractility occurred in patients with aortic regurgitation only if the control value of PAP/ESV was greater than 1. Mean systolic wall stress decreased significantly in all patients, independent of aetiology of cardiac failure and was the factor determining the improvement of left ventricular performance (evaluated as fractional shortening) in patients without changes in myocardial contractility. Maximum improvement in left ventricular performance occurred 10 minutes after amrinone administration. It is concluded that the possibility of detecting the positive inotropic properties of amrinone in man depends on the aetiology of the cardiac failure and on the basal level of myocardial contractility.

Adult↗

PubMed1985

Evaluation of the chronic antianginal effect of molsidomine.

The activity of molsidomine, a new antianginal drug, was investigated in 33 patients treated for 3 months with doses of 2 mg, three or four times daily. Exertional angina was present before treatment in 16 patients, spontaneous angina in 5, and mixed angina in twelve. Thirty patients completed the study, and three retired because of side effects. A reduction in the number of attacks of more than 75% in comparison to the pretreatment period was obtained in 20 cases, a diminution between 50% and 75% in 6, and a reduction below 50% in 6. Satisfactory increases in the duration (from 6 minutes 25 seconds to 11 minutes 40 seconds) and maximum load (89.6 to 139.3 W) were obtained in 80% of the cases of effort angina. A dramatic and statistically significant reduction of attacks was observed in the first 48 hours in 8 of 11 patients with spontaneous angina. Side effects were predominantly gastrointestinal and caused the interruption of treatment in 10% of the cases. Molsidomine seems to be a very promising drug for the treatment of effort and spontaneous angina.

Aged↗

PubMed1985

Natural and post-surgical history of mitral stenosis and mitral stenosis and insufficiency: an observational study.

Natural and post-surgical history has been investigated in 410 pts with mitral stenosis and 209 pts with mixed mitral stenosis and regurgitation. They had undergone cardiac catheterization in the years 1968-1980. Hemodynamic data and clinical status (NYHA class) have been statistically analyzed in order to obtain prognostically useful parameters. In mitral stenosis peak pulmonary artery pressure is the most important parameter for natural history, whereas cardiac index is the leading parameter in the operated patients. Commissurotomy has a very low surgical mortality, largely due to the better conditions of the patients undergoing this type of conservative surgery. Results are similar in mixed mitral stenosis and regurgitation. Surgery markedly improves survival in comparable patients. Therefore, intervention seems to be indicated especially in patients with elevated pulmonary artery pressure, because they can get the maximum advantage at a minimal risk.

Adult↗

PubMed1976

Aorto-pulmonary relationship, arterio-ventricular alignment, and ventricular septal defects in complete transposition of the great arteries.

A study of the conal anatomy of 36 specimens of complete transposition of the great arteries (TGA) is reported. The aim of the investigation was to verify if the two main anatomic features of the malformation, i.e. abnormal aorto-pulmonary and arterioventricular relationships, were strictly related to the maldevelopment of the conal structures. The findings indicate that in the cases with mitro-pulmonary fibrous continuity, there is a wide variation in subaortic conal development. and no correlation exists between the anterior position of the aorta and the length of the subaortic parietal conus. Therefore, differential conal absorption does not seem to play a role in the presumptive lack of rotation in TGA. TGA presenting with bilateral conus and biventricular pulmonary trunk origin are relatively frequent in this survey, but no correlation was observed between overriding of the pulmonary artery and development of the subpulmonary parietal conus. Consequently, in TGA the morphogenetic process of transfer of the pulmonary artery above the left ventricle does not seem to depend only on the absorption of the subpulomonary parietal conus. Ventricular septal defects (VSDs) in TGA are related frequently to conal pathology, either to some failure in conal septal growth or to malalignment of the normally developed conal and sinusal components of the ventricular septum.

Aorta, Thoracic↗