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Biomedical subjects

A Salvati

Publications and source records attributed to A Salvati.

At least 19 recordsLinked to original sources
PubMed2001

Atrial electroanatomic remodeling after circumferential radiofrequency pulmonary vein ablation: efficacy of an anatomic approach in a large cohort of patients with atrial fibrillation.

BACKGROUND: Circumferential radiofrequency ablation around pulmonary vein (PV) ostia has recently been described as a new anatomic approach for atrial fibrillation (AF). METHODS AND RESULTS: We treated 251 consecutive patients with paroxysmal (n=179) or permanent (n=72) AF. Circular PV lesions were deployed transseptally during sinus rhythm (n=124) or AF (n=127) using 3D electroanatomic guidance. Procedures lasted 148+/-26 minutes. Among 980 lesions surrounding individual PVs (n=956) or 2 ipsilateral veins with close openings or common ostium (n=24), 75% were defined as complete by a bipolar electrogram amplitude <0.1 mV inside the lesion and a delay >30 ms across the line. The amount of low-voltage encircled area was 3594+/-449 mm(2), which accounted for 23+/-9% of the total left atrial (LA) map surface. Major complications (cardiac tamponade) occurred in 2 patients (0.8%). No PV stenoses were detected by transesophageal echocardiography. After 10.4+/-4.5 months, 152 patients with paroxysmal AF (85%) and 49 with permanent AF (68%) were AF-free. Patients with and without AF recurrence did not differ in age, AF duration, prevalence of heart disease, or ejection fraction, but the LA diameter was significantly higher (P<0.001) in permanent AF patients with recurrence. The proportion of PVs with complete lesions was similar between patients with and without recurrence, but the latter had larger low-voltage encircled areas after radiofrequency (expressed as percent of LA surface area; P<0.001). CONCLUSIONS: Circumferential PV ablation is a safe and effective treatment for AF. Its success is likely due to both PV trigger isolation and electroanatomic remodeling of the area encompassing the PV ostia.

Atrial Fibrillation↗
PubMed2001

Electrical modulation of cardiac contractility: clinical aspects in congestive heart failure.

Heart failure is a highly prevalent disease in western society. Drug therapies aimed at increasing myocardial contractility have been associated with decreased survival. Several short and mid term clinical studies have suggested adjuvant or alternative therapies to congestive heart failure using modified pacing techniques that were aimed to increase contractility (e.g. Paired pacing) or restore synchrony of contraction (biventricular pacing). While delivery of paired pacing was abandoned during the early 70's, biventricular pacing has recently emerged as an adjuvant treatment to limited group of congestive heart failure patients with aberrant left ventricular conduction. In this brief review, we describe our initial safety and efficacy experience in patients with heart failure using a novel non-stimulatory electrical approach to the delivery of positive inotropic therapy to the failing myocardium. The study suggests that unlike modified pacing techniques, delivery of the signal to the left ventricle during the refractory period resulted in a rapid increase in myocardial contractility and improved hemodynamic performance. The near instantaneous contractility improvement achieved by this type of stimulus was shown to be safe and effective independently of the primary cause of heart failure or the function of the conduction system. Unlike pharmacologic treatments, which have a relatively constant effect, use of electrical stimuli may prove useful as a new therapeutic modality in the treatment of heart failure with which contractility can be improved when and as needed.

Cardiac Pacing, Artificial↗
PubMed2001

[Prospects of the treatment of atrial fibrillation. Circumferential radiofrequency ablation of pulmonary vein ostia].

The dominance of the left atrium (LA) in the pulmonary vein (PV) regions for triggering and maintaining atrial fibrillation (AF) is now widely recognized. Radiofrequency (RF) PV isolation with electroanatomical guidance has recently emerged as a promising approach for AF treatment. We report the clinical outcome of the procedure in 251 consecutive patients with paroxysmal (n = 179) or permanent (n = 72) AF. Circular RF lesions were deployed transseptally during sinus rhythm or AF at 5 mm from PV ostia. Procedural and mapping times were 112 +/- 32 min and 75 +/- 27 min, respectively, with 29 +/- 11 min of fluoroscopy. Complete lesions (peak-to-peak bipolar electrogram amplitude < 0.1 mV inside the line and no double potentials) were achieved in 85% of the veins treated. Sinus rhythm was restored during RF delivery in 52% and by DC shock in the remaining. Major complications (cardiac tamponade) occurred in 3%. Extent of ablated area was 4.9 +/- 0.5 cm2, accounting for 28 +/- 9% of the total LA map surface. After 11 +/- 5 months, procedure success rates (freedom from AF without antiarrhythmic drugs) were 85% for paroxysmal and 68% for permanent AF. No PV stenoses were detected. By univariate analysis, an increased risk of recurrence was predicted by LA dilation (diameter > 50 mm), AF duration, and a low ablated area (< 15% of total LA surface). After adjustment, only the latter variable continued to be significant (odds ratio 3.5, 95% confidence interval, 1.6-5.8). In conclusion, RF PV isolation is safe and effective in either paroxysmal or permanent AF. Patients with enlarged left atrium may require wider lesions to achieve AF suppression.

Atrial Fibrillation↗
PubMed2000

Circumferential radiofrequency ablation of pulmonary vein ostia: A new anatomic approach for curing atrial fibrillation.

BACKGROUND: The pulmonary veins (PVs) and surrounding ostial areas frequently house focal triggers or reentrant circuits critical to the genesis of atrial fibrillation (AF). We developed an anatomic approach aimed at isolating each PV from the left atrium (LA) by circumferential radiofrequency (RF) lesions around their ostia. METHODS AND RESULTS: We selected 26 patients with resistant AF, either paroxysmal (n=14) or permanent (n=12). A nonfluoroscopic mapping system was used to generate 3D electroanatomic LA maps and deliver RF energy. Two maps were acquired during coronary sinus and right atrial pacing to validate the lateral and septal PV lesions, respectively. Patients were followed up closely for >/=6 months. Procedures lasted 290+/-58 minutes, including 80+/-22 minutes for acquisition of all maps, and 118+/-16 RF pulses were deployed. Among 14 patients in AF at the beginning of the procedure, 64% had sinus rhythm restoration during ablation. PV isolation was demonstrated in 76% of 104 PVs treated by low peak-to-peak electrogram amplitude (0. 08+/-0.02 mV) inside the circular line and by disparity in activation times (58+/-11 ms) across the lesion. After 9+/-3 months, 22 patients (85%) were AF-free, including 62% not taking and 23% taking antiarrhythmic drugs, with no difference (P:=NS) between paroxysmal and permanent AF. No thromboembolic events or PV stenoses were observed by transesophageal echocardiography. CONCLUSIONS: Radiofrequency PV isolation with electroanatomic guidance is safe and effective in either paroxysmal or permanent AF.

Adult↗
PubMed2000

Cardiac pacing in heart failure patients with left bundle branch block: impact of pacing site for optimizing left ventricular resynchronization.

BACKGROUND: Acute left ventricular pacing has been associated with hemodynamic improvement in patients with congestive heart failure and wide QRS complex. We hypothesized that pacing two left ventricular sites simultaneously would produce faster activation and better systolic function than single-site pacing. METHODS: We selected 14 heart failure patients (NYHA functional class III or IV) in normal sinus rhythm with left bundle branch block and QRS > 150 ms. An 8F dual micromanometer catheter was placed in the aorta for measuring +dP/dt (mmHg/s), aortic pulse pressure (mmHg), and end-diastolic pressure (mmHg). Pacing leads were positioned via coronary veins at the posterior base and lateral wall. Patients were acutely paced VDD at the posterior base, lateral wall, and both sites (dual-site) with 5 atrioventricular delays (from 8 ms to PR -30 ms). Pacing sequences were executed in randomized order using a custom external computer (FlexStim, Guidant CRM). RESULTS: Dual-site pacing increased peak +dP/dt significantly more than posterior base and lateral wall pacing. Dual-site and posterior base pacing raised aortic pulse pressure significantly more than lateral wall pacing. Dual-site pacing shortened QRS duration by 22 %, whereas posterior base and lateral wall pacing increased it by 2 and 12%, respectively (p = 0.006). CONCLUSIONS: In heart failure patients with left bundle branch block, dual-site pacing improves systolic function more than single-site stimulation. Improved ventricular activation synchrony, expressed by paced QRS narrowing, may account for the additional benefit of dual- vs single-site pacing in enhancing contractility. This novel approach deserves consideration for future heart failure pacing studies.

Adult↗
PubMed1999

Vanadium inhibition of serine and cysteine proteases.

A study was made on the effect of vanadium, in both the tetravalent state in vanadyl sulphate and in the pentavalent state in sodium meta-vanadate, and ortho-vanadate, on the proteolysis of azocasein by two serine proteases, trypsin and subtilisin and two cysteine proteases bromelain and papain. Also the proteolysis of bovine azoalbumin by serine proteases was considered. An inhibitory effect was present in all cases, except meta-vanadate with subtilisin. The oxidation level of vanadium by itself did not determine the inhibition kinetics, which also depended on the type and composition of the vanadium containing molecule and on the enzyme assayed. The pattern of inhibition was similar for proteases belonging to the same class. The highest inhibition was obtained with meta-vanadate on papain and with vanadyl sulphate on bromelain.

Albumins↗
PubMed1991

Plasma catecholamine responses during a personalized physical stress as a dynamic characterization of essential hypertension.

High performance liquid chromatography (HPLC) with electrochemical detection proves to be a reliable method for determination of plasma catecholamines (CA) to assess the possible role of the sympathetic nervous system (SNS) in essential hypertension (EH). The present investigation in a group of 15 normotensive (N) and 13 stable EH patients, homogeneous for age and duration of hypertension, was carried out without treatment in the supine position, up-right position and during a personalized bicycle exercise. Mean blood pressure, mean heart rate, plasma renin activity and plasma aldosterone were also evaluated at the various exertion phases. Norepinephrine (NE) and epinephrine (E) showed a progressive increase in N and in EH patients, reaching the highest values at maximum effort. However, EH patients showed higher E plasma levels than N before maximum effort. Dopamine (DA) reached the highest values in N at maximum effort and in EH patients at recovery time. These findings allow us to foresee the possibility of a better characterization of the SNS role in EH.

Adult↗
PubMed1991

[Relations between ACE inhibition with captopril and atrial natriuretic factor during an acute hemodynamic study].

Aim of this study was to evaluate if captopril treatment may directly alter the trial natriuretic factor (ANF) concentration. Six patients (2 male and 4 female) aged 53 +/- 11 years, with mitral stenosis, and atrial fibrillation, underwent cardiac catheterization in our Institution. The following parameters were evaluated: heart rate, right atrial and pulmonary capillary wedge pressure, aortic and pulmonary pressure, cardiac index, pulmonary and systemic resistances and ANF concentration in coronary sinus, pulmonary, artery, aorta, peripheral vein. All these parameters were measured before and 30 and 60 min after captopril administration (50 mg orally). No hemodynamic changes occurred after captopril administration. No changes in ANF concentration occurred in comparison with baseline levels, after 30 and 60 min in coronary sinus (199.8 +/- 151.5 vs 181.9 +/- 102.5 fmol/ml; 178.4 +/- 95.2 vs 181.9 +/- 102.5 fmol/ml), in pulmonary artery (58.3 +/- 36.6 vs 51.4 +/- 48.8 fmol/ml; 35.5 +/- 16.9 vs 51.4 +/- 48.8 fmol/ml), in aorta (29.7 +/- 22.7 vs 37.5 +/- 26.3 fmol/ml; 25.2 +/- 9.8 vs 37.5 +/- 26.3 fmol/ml); and in peripheral vein (14.6 +/- 7.9 vs 17.3 +/- 9.7 fmol/ml; 16.2 +/- 12.2 vs 17.3 +/- 9.7 fmol/ml). In conclusion our data show that, providing no hemodynamic changes occur, captopril administration does not alter ANF concentration.

Adult↗
PubMed1987

Clinical, biological, and neuropsychological features associated with lateral ventricular enlargement in DSM-III schizophrenic disorder.

Clinical, historical, neuropsychological, and biological correlates of lateral ventricular enlargement on computed tomography (CT scan) were explored in a sample of DSM-III schizophrenics. Patients with enlarged ventricles, as compared with those whose ventricles were normal, presented a longer duration of illness and mean duration of hospitalization, and higher scores on the subscales alogia, affective flattening, and attentional impairment of the Scale for the Assessment of Negative Symptoms (SANS), on the scales self-care, participation in household activities, work performance, and behavior in crises and emergencies of the Disability Assessment Schedule, on the scales rhythm, writing, reading, arithmetic, and left hemisphere of the Luria-Nebraska Neuropsychological Battery, and on the subtests digit span, digit symbol and block design of the Wechsler Adult Intelligence Scale. Furthermore, on the computerized electroencephalogram, beta relative activity was significantly higher in patients with normal ventricles on the right frontal, left frontal, and right central leads. On stepwise discriminant function analysis, the patient groups with enlarged and normal ventricles could be separated statistically, and duration of illness and summary score on the SANS were found to be the best discriminators.

Adolescent↗
PubMed1985

Clinical and neuropsychological correlates of cerebral ventricular enlargement in schizophrenia.

A comprehensive assessment of computed tomography (CT) with respect to clinical, historical and neuropsychological variables has been carried out in a sample of DSM III schizophrenics fairly heterogeneous with respect to duration and severity of illness and in a normal control group matched for sex, age and educational level. The mean value of ventricular brain ratio (VBR) was significantly higher in schizophrenics than controls. Seven patients (21.2%) who had VBRs exceeding 2 SD of the control mean showed a significantly longer duration of illness than the other schizophrenics with significantly higher scores on the subscales alogia, effective flattening and attentional impairment of SANS, on the scales self-care and behaviour in crises and emergencies of DAS, on the scales rhythm, tactile, visual, reading, arithmetic, memory and left hemisphere of LNNB, and on the subtests arithmetic, digit span, digit symbol and block design of WAIS. These results confirm earlier reports of an enlargement of lateral cerebral ventricles in a subset of schizophrenics, and its association with a higher degree of cognitive and neuropsychological impairment, social maladjustment and defectual symptomatology. Moreover, they suggest that the neuropathological process likely to underlie the increase of cerebral ventricular size progresses during the course of the illness rather than predating its onset.

Adolescent↗
PubMed1985

Relationship between CSF noradrenaline levels, C-EEG indicators of activation and psychosis ratings in drug-free schizophrenic patients.

A significant increase of cerebrospinal fluid (CSF) noradrenaline (NA) levels, probably reflecting a rise of central noradrenergic activity, has been observed in a sample of acute schizophrenic patients as compared with a population of subjects without personal or family history of major psychoses. CSF NA levels have been found to be significantly correlated with computerized EEG (C-EEG) indicators of arousal (negative correlation with alpha relative activity and positive correlation with alpha barycentric frequency and beta relative activity in frontal and central leads). No significant relationship has emerged between CSF NA concentration and psychosis ratings on CPRS as well as platelet MAO activity. These findings seems to confirm the link between central noradrenergic hyperactivity and the condition of enhanced arousal of the schizophrenic patient, although the role of this condition in the pathophysiology of schizophrenia (primary phenomenon or non-specific consequence of the stress related to the illness?) remains to be elucidated.

Adolescent↗
PubMed1984

Platelet monoamine oxidase activity in schizophrenia: relationship to family history of the illness and neuroleptic treatment.

Platelet monoamine oxidase (MAO) activity was determined in a large population of drug-free and haloperidol-treated schizophrenic patients and healthy controls and, in a second study, in a sample of schizophrenics after a wash-out period and at different times during treatment with haloperidol. Enzyme activity was significantly decreased in both acute and chronic haloperidol-treated schizophrenics, but not in drug-free schizophrenics, compared with normal controls. No significant difference was observed between drug-free schizophrenics with a family history of the illness and those without such history, and between healthy relatives of schizophrenic patients and normal controls without a family history of schizophrenia. MAO activity was significantly reduced after 14 and 21 days of haloperidol treatment, and such reduction did not correlate with response to treatment. These data strongly support the idea that neuroleptic intake may, at least in part, explain low MAO values repeatedly reported in schizophrenics.

Adolescent↗