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Biomedical subjects

P Alboni

Publications and source records attributed to P Alboni.

At least 19 recordsLinked to original sources
PubMed1999

Effect of etilefrine in preventing syncopal recurrence in patients with vasovagal syncope: a double-blind, randomized, placebo-controlled trial. The Vasovagal Syncope International Study.

BACKGROUND: Etilefrine is an alpha-agonist agent with a potent vasoconstrictor effect, which is potentially useful in preventing vasovagal syncope by reducing venous pooling and/or by counteracting reflex arteriolar vasodilatation. The present multicenter, randomized, placebo-controlled study was designed to evaluate the efficacy of this drug for the long-term management of patients with recurrent vasovagal syncope. METHODS AND RESULTS: In the 20 participating centers, 126 patients with recurrent vasovagal syncope (at least 3 episodes in the last 2 years) and a positive baseline head-up tilt response were randomly assigned to placebo (63 patients) or etilefrine at a dosage of 75 mg/d (63 patients) and were followed up for 1 year or until syncope recurred. The primary end-point of the study was the first recurrence of syncope. There were no differences between the 2 study groups in the patients' baseline characteristics. During follow-up, the group treated with etilefrine had a similar incidence of first syncopal recurrence to that of placebo group both in the intention-to-treat analysis (24% versus 24%) and in on- treatment analysis (26% versus 24%). Moreover, the median time to the first syncopal recurrence did not significantly differ between the 2 study groups (106 days in the etilefrine arm and 112 days in the placebo arm). CONCLUSIONS: Oral etilefrine is not superior to placebo in preventing spontaneous episodes of vasovagal syncope. Randomized controlled studies are essential to assess the real usefulness of any proposed therapy for patients with vasovagal syncope.

Adrenergic alpha-Agonists↗
PubMed1999

Modification of antegrade slow pathway is not crucial for successful catheter ablation of common atrioventricular nodal reentrant tachycardia.

We tested the hypothesis that in some patients affected by typical AVNRT, successful catheter ablation treatment may be achieved independently of specific measurable electrophysiological modifications of antegrade AV node conducting properties. Standard electrophysiological parameters and comparable antegrade AV node function curves were obtained, before and after successful ablation, in 104 patients (mean age 52 +/- 16 years; 69 women and 35 men) affected by the common form of AVNRT. The end point of the ablation procedure was noninducibility of AVNRT and of no more than one echo beat. For the purpose of this study, AV node duality was defined as an increase of > or = 50 ms in the A2H2 interval in response to a 10 ms decrease of the A1A2 coupling interval. Before ablation, AV node duality was present in 65 patients (62%) and absent in 39 patients (37%). Ablation caused measurable modifications of electrophysiological properties of the AV node in most patients with elicited AV node duality, but not in most patients without demonstrable AV node duality. After ablation, AV node duality persisted in 20 patients who had it before, whereas a new duality that could not be elicited before appeared in 5 patients. During 19 +/- 6 months of follow-up, clinical AVNRT recurred in 1 of 45 patients who had disappearance of AV node duality after ablation, in 1 of 34 patients who did not show AV node duality before and after ablation, and in 1 of 20 patients who had persistence of AV node duality after ablation. In conclusion, modifications of antegrade conduction properties of the AV node are not crucial for the cure of AVNRT in many patients.

Atrioventricular Node↗
PubMed1999

Atrial and ventricular pressures in atrial flutter.

The hemodynamic effects of atrial flutter (AF) are unknown. The purpose of the present study was to investigate the changes in atrial and ventricular pressures after induction of AF. In 23 patients with paroxysmal AF (age 59 +/- 9 years), a hemodynamic study was performed both during sinus rhythm and after induction of the tachyarrhythmia. During AF, 13 patients showed a fixed 2:1 AV conduction and 10 patients showed variable conduction. Mean right and left atrial pressures increased (P < 0.001) and right and left ventricular end-diastolic pressures decreased (P < 0.001) after induction of AF. Both the increase in mean atrial pressures and the decrease in ventricular end-diastolic pressures were present either in the patients with fixed 2:1 AV (heart rate: 133 +/- 15 beats/min) or in those with variable conduction (heart rate 96 +/- 15 beats/min), but were more marked in the former. AF produces an impairment of atrial function, as evidenced by the increase in mean atrial pressures and reduction in ventricular end-diastolic pressures in the absence of an elevated heart rate. The mechanisms responsible for the increase in mean atrial pressures are unknown; however, atrial contractions against closed AV valves seem to play an important role.

Atrial Flutter↗
PubMed1998

The natural course of untreated sick sinus syndrome and identification of the variables predictive of unfavorable outcome.

We performed a prospective study in 35 untreated patients aged > or = 45 years, who had a mean sinus rate at rest of < or = 50 beats/min and/or intermittent sinoatrial block, and symptoms attributable to sinus node dysfunction. The patients were followed up for up to 4 years (mean 17 +/- 15 months). During follow-up, 20 patients (57%) had cardiovascular events that required treatment: 8 had syncope (23%); 6 had overt heart failure (17%); 4 patients had chronic atrial fibrillation (11%); and 2 patients had poorly tolerated episodes of paroxysmal tachyarrhythmias (6%). Actuarial rates of occurrence of all events were 35%, 49%, and 63%, respectively, after 1, 2, and 4 years. At univariate analysis, age > or = 65 years, end-systolic left ventricular diameter > or = 30 mm, end-diastolic left ventricular diameter > or = 52 mm, and ejection fraction < 55% were predictors of cardiovascular events. At multivariate analysis, age, end-diastolic diameter, and ejection fraction remained independent predictors of events. Actuarial rates of occurrence of syncope were 16%, 31%, and 31%, respectively, after 1, 2, and 4 years. Both univariate and multivariate predictors of syncope were history of syncope and corrected sinus node recovery > or = 800 ms. A favorable outcome was observed in the remaining 43% of patients. Thus, clinical cardiovascular events occur in most untreated sick sinus syndrome patients during long-term follow-up, even though a favorable course can be expected in 43% of patients. The outcome can be partly predicted on initial evaluation. In the patients with a favorable outcome, treatment can safely be delayed.

Actuarial Analysis↗
PubMed1998

Anatomic M-mode: a new technique for quantitative assessment of left ventricular size and function.

To overcome the limitations of conventional M-mode echocardiography, a new technique referred to as anatomic M-mode has been recently developed. This technique is based on postprocessing of digitally acquired two-dimensional (2D) cineloops, and allows the operator to position one or multiple independent M-mode cursors freely on the 2D images. Initial clinical data show that anatomic M-mode can increase the reproducibility and accuracy of standard M-mode measurements of the left ventricle. Also, this quantitative technique has the potential to improve assessment of left ventricular wall motion and thickening, and could be particularly useful in providing objective measures during stress echocardiography.

Echocardiography, Doppler↗
PubMed1998

Three-dimensional echocardiographic reconstruction: description and applications of a simplified technique for quantitative assessment of left ventricular size and function.

A simplified system for three-dimensional (3D) reconstruction of the left ventricle and quantitation of its size and function is described. This system requires the acquisition of a minimum number of two-dimensional (2D) echocardiographic apical views, which are obtained by rotation of the probe about the initial imaging point. Traced endocardial borders are spatially reconstructed according to the common apex and longitudinal axis of the views and to the measured or assumed angular relation between scanned planes. This technique has been applied in vitro to regular and irregular ventricular phantoms, yielding excellent accuracy for volume calculation. Also, it has been applied clinically for left ventricular volume, stroke volume, and ejection fraction calculation in both normal subjects and patients with various cardiac diseases, providing good results compared with other independent imaging techniques and showing increased accuracy with respect to 2D echocardiographic methods. Because this is obtained without substantial increase in time, effort, or cost, this simplified technique for 3D reconstruction should therefore be of value in daily clinical echocardiographic practice.

Clinical Trials as Topic↗
PubMed1998

A simplified, practical echocardiographic approach for 3-dimensional surfacing and quantitation of the left ventricle: clinical application in patients with abnormally shaped hearts.

The goal of this study was to validate the quantitative accuracy of a system for 3-dimensional (3D) echocardiographic reconstruction of the left ventricle to assess its volume and function in human beings by using 3 apical views as a simplified technique to promote practical clinical application. End-diastolic and end-systolic volumes (EDV, ESV) and ejection fraction (EF) were obtained by 3D echocardiography in 50 patients with dilated or geometrically distorted left ventricles and compared with values from magnetic resonance imaging (20 consecutive patients), angiography (22 consecutive patients), and radionuclide imaging (8 consecutive patients). Three-dimensional results were also compared with 2-dimensional (2D) echocardiographic estimates. Three-dimensional left ventricular reconstruction provided values that correlated and agreed well with pooled data from the other techniques for EDV (y = 0.93x + 9.1, r = 0.95, standard error of the estimate [SEE] = 15.2 mL, mean difference = -0.5 +/- 15.4 mL), ESV (y = 0.94x + 4.3, r = 0. 96, SEE = 11.4 mL, mean difference = 0.4 +/- 11.5 mL), and EF (y = 0. 90x + 4.1, r = 0.92, SEE = 6.2%, mean difference = -0.9 +/- 6.4%) (all mean differences not significant versus 0), with greater errors by 2D echocardiography. Intraobserver and interobserver variabilities of 3D echocardiography were less than 6% for EDV, ESV, and EF. The overall time for image acquisition and 3D reconstruction was 5 to 8 minutes. Although this 3D method uses only a small number of apical views, it accurately calculates EDV, ESV, and EF in patients with dilated and asymmetric left ventricles and is more accurate than 2D echocardiography. The flexible surface fit used to combine the 3 views provides a convenient visual output as well as quantitation. This simple and rapid 3D method has the potential to facilitate routine clinical applications that assess left ventricular function and changes that occur with remodeling.

Coronary Angiography↗
PubMed1998

Short-term hemodynamic effects of DDD pacing from ventricular apex, right ventricular outflow tract and proximal septum.

Recently, short-term hemodynamic benefits of right ventricular outflow tract (RVOT) or proximal septum (His bundle area) pacing have been reported in comparison with traditional apical stimulation in preliminary investigations. The purpose of the present study was to compare the hemodynamics obtained during DDD pacing from ventricular apex, RVOT and proximal septum in patients with normal left ventricular function. A simultaneous hemodynamic and Doppler-echocardiographic study was performed in 21 patients (age 67 +/- 7 years) with sick-sinus syndrome (8 pts) or 2nd-3rd degree atrioventricular (AV) block (13 pts). The three stimulation sites were randomized and pacing was applied at an identical rate (84 +/- 5 beats/min) and at a constant AV delay (150 ms). Electrocardiographic, hemodynamic and Doppler-echocardiographic investigations were performed during stimulation from each site. The QRS duration did not show significant differences during DDD pacing from ventricular apex, RVOT and proximal septum. The hemodynamic measurements (systemic pressures, mean pulmonary wedge pressure, pulmonary pressures, right ventricular end-diastolic pressure, mean right atrial pressure, cardiac index, systemic vascular resistance and arteriovenous O2 difference) did not show significant differences during pacing from the three sites. Moreover, no significant differences were observed for the Doppler-echocardiographic measurements of systolic function (aortic stroke distance, left ventricular ejection fraction) and diastolic function (isovolumetric relaxion time, mitral E/A ratio, deceleration rate of the E wave). The results suggest that in patients with normal left ventricular function DDD pacing from RVOT or proximal septum does not improve cardiac function with regard to apical pacing.

Aged↗
PubMed1997

Assessment of atrioventricular junction ablation and DDDR mode-switching pacemaker versus pharmacological treatment in patients with severely symptomatic paroxysmal atrial fibrillation: a randomized controlled study.

BACKGROUND: The purpose of the study was to evaluate the effect of AV junction ablation and pacemaker implantation on quality of life and specific symptoms in patients with paroxysmal atrial fibrillation (AF) not controlled by drugs. METHODS AND RESULTS: We performed a multicenter, randomized, 6-month evaluation of the clinical effects of AV junction ablation and DDDR mode-switching pacemaker (Abl+Pm) versus pharmacological treatment in 43 patients with intolerable, recurrent paroxysmal AF of three or more episodes in the previous 6 months not controlled with three or more antiarrhythmic drugs. Before completion of the study, 3 patients in the drug group withdrew because of the severity of their symptoms and 1 patient assigned to the Abl+Pm group in whom the ablation procedure failed. At the end of the 6 months, the 21 patients of the Abl+Pm group who completed the study showed, in comparison with the 18 of the drug group, lower scores in the Living with Heart Failure Questionnaire (-51%, P=.0006), palpitations (-71%, P=.0000), effort dyspnea (-36%, P=.04), exercise intolerance score (-46%, P=.001), and easy fatigue (-51%, P=.02). The scores for rest dyspnea, chest discomfort, and NYHA functional classification were also lower (-56%, -50%, and -17%, respectively) in the Abl+Pm group, although not significantly. At the end of the study, palpitations were no longer present in 81% of the Abl+Pm group and in 11% of the drug group (P=.0000). AF was documented in 31 of 122 visits (25%) in the Abl+Pm group and in 9 of 107 examinations (8%) in the drug group (P=.0005); chronic AF developed in 5 (24%) and 0 (0%) in the two groups, respectively (P=.04). CONCLUSIONS: In patients with paroxysmal AF not controlled by pharmacological therapy, Abl+Pm treatment is highly effective and superior to drug therapy in controlling symptoms and improving quality of life. The discontinuation of drug therapy exposes patients to further recurrences of paroxysmal AF and the risk of developing permanent AF.

Aged↗
PubMed1997

Effects of permanent pacemaker and oral theophylline in sick sinus syndrome the THEOPACE study: a randomized controlled trial.

BACKGROUND: Pacemakers and theophylline are currently being used to relieve symptoms in patients with sick sinus syndrome (SSS). However, the impact of either therapy on the natural course of the disease is unknown. We conducted a randomized controlled trial to prospectively assess the effects of pacemakers and theophylline in patients with SSS. METHODS AND RESULTS: One hundred seven patients with symptomatic SSS (age, 73 +/- 11 years) were randomized to no treatment (control group, n = 35), oral theophylline (n = 36), or dual-chamber rate-responsive pacemaker therapy (n = 36). They were followed for up to 48 months (mean, 19 +/- 14 months). During follow-up, the occurrence of syncope was lower in the pacemaker group than in the control group (P = .02) and tended to be lower than in the theophylline group (P = .07). Heart failure occurred less often in patients assigned to pacemaker therapy and theophylline than in control patients (both, P = .05), whereas the incidence of sustained paroxysmal tachyarrhythmias, permanent atrial fibrillation, and thromboembolic events did not show any apparent difference among the three groups. Heart rate was higher in the theophylline group than in the control group. Both pacemaker therapy and theophylline improved symptom scores after 3 months of treatment; however, a similar improvement was observed in the control group. CONCLUSIONS: In patients with symptomatic SSS, therapy with theophylline or dual-chamber pacemaker is associated with a lower incidence of heart failure; pacemaker therapy is also associated with a lower incidence of syncope. The therapeutic benefits of pacemakers and theophylline on symptoms are partly a result of spontaneous improvement of the disease.

Administration, Oral↗
PubMed1997

Clinical usefulness of slow pathway ablation in patients with both paroxysmal atrioventricular nodal reentrant tachycardia and atrial fibrillation.

Some patients with atrioventricular (AV) node reentrant tachycardia (AVN RT) also presented with atrial fibrillation (AF). In this study we demonstrate that slow pathway ablation is able to suppress both AVN RT and AF in subjects without structural heart abnormalities, whereas in patients with structural heart abnormalities after ablation AF frequently recurs.

Adult↗
PubMed1997

Multiple mechanisms of successful slow-pathway catheter ablation of common atrioventricular nodal re-entrant tachycardia.

BACKGROUND: In patients with atrioventricular nodal re-entrant tachycardia, modifications of the antegrade atrioventricular nodal function curve caused by catheter ablation of the so-called slow pathway are heterogeneous, but have not yet been systematically evaluated. AIM: To test the hypothesis that successful treatment is independent of specific electrophysiological modifications of atrioventricular nodal conducting properties. METHOD: Standard electrophysiological parameters and comparable antegrade atrioventricular nodal function curves were obtained, before and after successful ablation, in 104 patients (mean age 52 +/- 16 years: 69 women) affected by the common form of atrioventricular nodal re-entrant tachycardia. RESULTS: Three different major patterns of antegrade atrioventricular nodal function curve were caused by ablation: downward shift of the curve with disappearance of atrioventricular nodal duality, suggesting the elimination of the slow pathway in 54 (52%) patients (type 1): absence of clear modifications of the curve (and of slow pathway ablation) in 33 (32%) patients (type 2); upward shift of the curve, suggesting a further slowing of conduction velocity through the slow pathway in 17 (16%) patients (type 3). Type-1 pattern was more frequent in patients < or = 45 years, whereas type-2 pattern was more frequent in those > 45 years. CONCLUSION: Successful ablation of atrioventricular nodal re-entrant tachycardia is independent of specific modifications of antegrade atrioventricular conduction and probably depends on critical nodal and perinodal tissue damage at different sites on the re-entrant circuit. The effects of ablation are influenced by patient age.

Adolescent↗