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Biomedical subjects

L Libero

Publications and source records attributed to L Libero.

14 recordsLinked to original sources
PubMed2001

Long-term follow-up of right ventricular monomorphic extrasystoles.

OBJECTIVES: The purpose of this study was to verify in a long-term follow-up whether frequent monomorphic right ventricle extrasystoles may progress to arrhythmogenic right ventricular dysplasia (ARVD). BACKGROUND: Frequent monomorphic right ventricle extrasystoles are generally considered benign. However, in patients with this pattern, cardiac magnetic resonance (MR) has recently shown anatomical and functional abnormalities of the right ventricle. METHODS: Sixty-one patients who had been classified by noninvasive examinations as having frequent idiopathic right ventricle ectopy were contacted after 15 +/- 2 years (12 to 20) and submitted to clinical examination, electrocardiogram (ECG), Holter monitoring, stress test, signal averaged ECG, echocardiography and, in 11 patients, cardiac MR. The primary end point was to ascertain the presence of cases of sudden death or progression to ARVD. RESULTS: At the end of the follow-up, 55 patients were alive; six died, none of sudden death; eight stated to be well but refused further examinations. The 47 patients examined had normal ECG; in 24 patients (51%), extrasystoles were no longer present at Holter monitoring; late potentials were present in up to 15% of the patients; the right ventricle was normal at echocardiography. In 8 of 11 patients (73%), cardiac MR showed focal fatty replacement and other abnormalities of the right ventricle. CONCLUSIONS: In this long-term follow-up study, no patient died of sudden death nor developed ARVD; two-thirds of the patients were asymptomatic, and, in half of the patients, ectopy had disappeared. Focal fatty replacement in the right ventricle was present in most.

Adolescent↗
PubMed2001

Comparison of defibrillation thresholds using monodirectional electrical vector versus bidirectional electrical vector.

BACKGROUND: Currently, two main lead configurations are used for implantable cardioverter-defibrillators (ICD). One generates a monodirectional electrical vector by using the can surface as an active part (hot can) together with a right ventricular defibrillation coil. The other one (TRIAD) produces a bidirectional electrical vector by adding a proximal defibrillation electrode on the same lead. The purpose of this prospective study was to determine whether there is a difference between these configurations in terms of the acute defibrillation threshold (DFT). The secondary objective was to evaluate the possible sequential effect of successive arrhythmia induction and defibrillation shocks on the final DFT value. METHODS: In 44 patients (37 males, 7 females, mean age 59.18 +/- 12.05 years; mean ejection fraction 35.21 +/- 11.69%), a Hot Can Ventak family ICD (Guidant, St. Paul, MN, USA) was implanted in a left pectoral pocket. During the implant procedure, step-down to failure DFT testing was performed twice in each patient using the two different above-mentioned configurations: the bidirectional and the monodirectional. The first configuration to be tested was determined by a 1:1 randomization by center. RESULTS: The step-down DFT protocol was followed in 35 patients. The average DFT was 8.6 +/- 4.0 J for TRIAD and 10.4 +/- 4.3 J for the monodirectional (p = 0.009) lead configuration; this represents a 16.3% decrease in the DFT using a bidirectional configuration. Furthermore, no relationship between the final DFT and the number of ventricular fibrillation inductions and shocks received was observed, confirming the secondary objective. CONCLUSIONS: Compared to the monodirectional electrical vector, the bidirectional electrical vector is clearly more beneficial for the patient.

Adult↗
PubMed1996

Italian experience with AutoCapture in conjunction with a membrane lead. Pacesetter Automatic Control of Energy and Membrane Automatic Threshold Evaluation (Pacemate) Study Group.

AutoCapture is a programmable feature of the Pacesetter Microny SR + 2425T VVIR pacemaker, which provides for the automatic capture verification, increase in output in the presence of noncapture and threshold searching, with adjustment of output settings. The effectiveness of this unit in conjunction with the Membrane models 1400T and 1401T bipolar endocardial leads was studied in 54 patients followed at 19 Italian Centers. The patients were randomized at the time of implantation to receive either the model 1400T or the 1401T lead. The electrodes in these leads are covered by a Nafion membrane, which was either impregnated (model 1400T) or not-impregnated (model 1401T) with steroid. This paper reports the data collected over the first six weeks postimplantation. The results of the automatic capture function was compared to the capture threshold measured using the Vario technique at the time of predischarge evaluations, and weeks 1,2, and 6 of postimplant follow-up. The reliability and effectiveness of the pulse generator-lead system allowed for consistent pacing at very low outputs and safety preserved at a programmed output only 0.3 V above the capture threshold.

Aged↗
PubMed1995

[Idiopathic ventricular tachycardia with onset in the verapamil-sensitive left ventricle: the clinical characteristics and long-term follow-up of 37 patients].

BACKGROUND: Idiopathic verapamil-responsive left ventricular tachycardia (IVRLVT) is a rare, well known form of ventricular tachycardia. Issues concerning long-term prognosis, drug prophylaxis and non-pharmacological therapy are rarely reported in the literature. We report the long-term follow-up, the efficacy of various drugs in the prophylaxis and the role of catheter ablation in a large group of patients with IVRLVT. METHODS AND RESULTS: This retrospective study involves 37 patients with a mean age of 28.3 +/- 14.8 years at first IVRLVT episode. The tachycardia morphology was typically with a right bundle-branch block configuration in all cases, with left axis deviation in 33 and right axis deviation in 5 (one patient had the 2 morphologies). Four patients had a mitral valve prolapse; the remaining 33 patients had neither clinical nor echocardiographic signs of heart disease. Only sporadic ventricular extrasystoles were detected at Holter monitoring in 73% of cases; 30% of patients had positive criteria for the presence of late potentials at signal averaged ECG. During electrophysiologic study, the tachycardia could be easily induced in 91% of patients. Mean follow-up is 7.3 +/- 4.7 years; all patients are alive at the end of follow-up. A mean of 2.3 +/- 1.2 drugs was prescribed in 35 patients (94.6%); betablockers were effective in 66% of the cases, verapamil in 20%, class I drugs in 22%, class III drugs in 15%. Both the 2 patients, who never received prophylaxis, and the 4 who stopped medication, utilize verapamil in case of recurrences. Eight patients were submitted to catheter ablation, with DC shock the first 2 patients, with RF energy from the third on; all but one (with DC shock) were successfully cured. CONCLUSIONS: Long-term follow-up confirmed the good prognosis of this form of ventricular tachycardia; a new insight that has been addressed about prophylaxis is the high efficacy of betablockers in preventing relapse and the poor efficacy of verapamil per os in chronic prophylaxis. Radiofrequency catheter ablation is effective and safe, using the earliest ventricular potential and the pace-mapping reproducing the same morphology of the tachycardia in all the 12 leads as a marker to identify the site of RF application, and may be proposed to all patients suffering from frequent episodes of IVRLVT.

Adolescent↗
PubMed1994

Idiopathic verapamil-responsive left ventricular tachycardia: clinical characteristics and long-term follow-up of 33 patients.

Long-term prognosis, pharmacological prophylaxis and transcatheter ablation in a large group of patients with idiopathic verapamil-responsive left ventricular tachycardia (IVRLVT) are reported in this study. Thirty-three patients with a mean age of 27 +/- 16 years at their first IVRLVT episode, were studied retrospectively. Ventricular tachycardia was of the right bundle branch block morphology in all cases, with left axis deviation in 29 and right axis deviation in five (one patient had the two morphologies). Mitral valve prolapse was present in four patients; no heart disease was found in the remaining 29. Ventricular tachycardia could be electrophysiologically induced in 90% of the patients; Holter monitoring showed only sporadic ventricular extrasystoles in 76%; late potentials were found in 33% of the cases. At the end of a follow-up of 5.7 +/- 4.7 years, no patient had died. Thirty-one patients (94%) received a mean of 2.5 +/- 1.2 drugs; beta-blockers were effective in 71% of the cases, verapamil in 25%, class 1 drugs in 22%, class 3 drugs in 18%. Two patients who never received prophylaxis and four in whom it was stopped, were controlled with verapamil in case of recurrence. Six patients underwent catheter ablation; two with DC shock in whom it was successful in one, and four with radiofrequency energy, with a total success rate. The good prognosis of IVRLVT has been confirmed in a long-term follow-up; a new finding is the high efficacy of beta-blockers for prophylaxis. Radiofrequency transcatheter ablation is an effective and safe therapy for patients with symptoms not controlled by drug treatment.

Adolescent↗
PubMed1993

Associated cardiac lesions in patients with radiation-induced complete heart block.

We investigated the clinical, electrophysiological, haemodynamic and angiographic aspects of four patients (two men and two women, aged 31-46 years) who developed complete heart block 13-20 years after therapeutic irradiation of the chest for Hodgkin's disease. The initial cardiac symptom was syncope in three, effort intolerance in one. The electrocardiogram recorded third-degree atrioventricular block in three patients, right bundle branch block and posterior fascicular block in one. The electrophysiological study, performed in three cases, showed that the block was infranodal in two. Three patients had significant coronary arterial stenoses, that involved the ostia in two. All patients had mild-to-moderate aortic and mitral regurgitation. One patient had haemodynamic signs of constriction. Another patient had recurrent pericardial effusions. All had echocardiographic evidence of a thickened pericardium. Cardiac involvement can be extensive in patient with radiation-induced heart block. Because coronary artery disease can be particularly severe, coronary angiography appears to be warranted in such patients.

Adult↗
PubMed1992

Catheter ablation of accessory pathways in patients with Wolff-Parkinson-White syndrome.

PATIENTS: Fifty-two patients with Wolff-Parkinson-White syndrome underwent transcatheter ablation. All patients were symptomatic. Eighteen had documented episodes of atrial fibrillation, 14 of which also had reentrant tachycardias; the remaining 34 had only episodes of reentrant tachycardias. Forty-nine patients had both anterograde and retrograde conduction through the accessory pathway; 3 had retrograde conduction alone; 2 patients had 2 accessory pathways and 1 had 3. All patients were resistant or intolerant to at least 2 antiarrhythmic drugs. METHODS: All patients were treated with radiofrequency current. Ablation was considered successful if the anterograde and retrograde conduction were completely abolished. Ablation was considered unsuccessful if ablation of only 1 pathway in patients with 2 or more accessory pathways and/or modification of the accessory pathway conduction without interruption was achieved. RESULTS: Accessory pathway ablation was successfully performed in 46 out of 52 patients (88%). Fifty out of 56 accessory pathways were effectively ablated (89%). Thirty-eight required a single session of ablation and 8 additional patients were successfully ablated during a second session. The number of radiofrequency current applications ranged from 2 to 13 (mean 4.1 +/- 2.5). The mean duration of the sessions was 4.30 +/- 1.50 hours (range 2.30 to 9). The mean radiation exposure for session was 55 +/- 25 minutes (range 20 minutes to 2.30 hours). Complications were observed in 2 out of 52 patients. One patient had a transient II degree type 1 atrioventricular block; another patient with severe arterial hypertension had a mild hemorrhagic stroke with complete neurological remission. FOLLOW-UP. Forty-five out of the 46 patients in whom ablation was successful were asymptomatic for arrhythmias during a mean follow-up of 8 months (range 4 to 16), without antiarrhythmic treatment, and without reappearance of preexcitation. One patient showed reappearance of preexcitation at electrocardiogram one month after the ablation, followed by an episode of reentrant tachycardia; this patient underwent a second successful ablation session. CONCLUSIONS: Our results show that ablation techniques have high success rates with no serious complications.

Adolescent↗
PubMed1991

[Nonpharmacological therapy of supraventricular arrhythmia].

Between 1985 and 1990, 1242 patients with supraventricular arrhythmias were followed-up at our Institution. Six hundred and twenty patients had atrial fibrillation or flutter; 7 of them (1%) underwent modulation of atrioventricular conduction. Four hundred and twenty-eight patients had ventricular preexcitation; in 23 (5%) surgical or transcatheter ablation of an accessory pathway were performed. Atrioventricular node reentrant tachycardias were diagnosed in 111 patients; 8 patients (7%) underwent antitachycardia pacemaker implantation. Surgical and catheter ablative techniques eliminate the substrate of the tachycardia; death and complete A-V block (paraseptal pathways) are at this moment rarely reported. Antitachycardia pacemakers do not offer a definitive therapy. For their safeness and effectiveness they are still indicated in patients with A-V node reentrant tachycardias, until technological development will reduce the risks of ablative techniques.

Arrhythmias, Cardiac↗
PubMed1989

No evidence of platelet activation during atrial pacing in subjects with stable angina.

Platelet behaviour (activation) in ischemic heart disease (stable angina) during pacing-induced tachycardia was studied. ECG was recorded during the trial. Ischemic heart disease (IHD) subjects had 75% or more narrowing of the luminal diameter of a coronary artery, demonstrated by coronary angiography. Eight subjects needing cardiac catheterism because of supraventricular rhythm disturbances with no evidence of IHD were studied as controls. Beta-thromboglobulin (beta-tg) and platelet factor 4 (PF4) were studied as platelet activation markers; beta-tg and PF4 were evaluated before atrial pacing in peripheral venous blood and, by catheterism, before and at maximum pacing rate in coronary venous sinus (CVS) and in ascending aorta (AA). Catheterism and blood withdrawals were performed in order to reduce platelet activation in vivo. No significant difference in platelet activation between IHD patients and control group in peripheral venous blood were found. No trans-myocardial gradient neither in IHD subjects nor in controls were observed. In conclusion, no platelet activation in IHD patients during pacing-induced tachycardia could be observed.

Adult↗
PubMed1989

[A case of pericarditis in acute brucellosis].

A case of brucellosis pericarditis in a patient affected with acute brucellosis hospitalized in the Infectious Disease Department of Asti Hospital is described. During the hospitalization, the patient revealed (in addition to the classical symptoms and signs), a modest shooting pain in the chest and typical electrocardiographic alterations confirmed by an echocardiography that revealed slight pericardial effusion at both front and rear, subsequently and by steroid and specific antibiotic therapies. The real possibility of finding this complication, considered so rare in the literature, in cardiovascular brucellosis is pointed out as is the capacity of modern echocardiographic research to confirm and reinforce diagnosis and consequently also the description of modest pericardial effusions with unclear symptoms and electrocardiographic signs that were once practically ignored when the pericardial involvement often escaped a clinical identification, being concealed by the most important signs of the primary infection.

Acute Disease↗
PubMed1988

Platelet arachidonic acid metabolism in patients with cardiovascular disorders.

There is increasing evidence that prostaglandins (PG) and thromboxane (Tx) play a major role in the pathogenesis of coronary artery disease. The regulation of arachidonic acid (AA) metabolism through cyclooxygenase (COx) pathway and the AA-dependent Ca2+ influx were investigated in platelets from 10 patients with unstable angina and 10 controls. The activation of the hexose monophosphate shunt (HMS), a sensitive index of the flux through the PGG2 to PGH2 step of the COx pathway, in response to AA was significantly enhanced in platelets from patients. AA-induced malonyldialdehyde (MDA) production as well as AA-evoked Ca2+ flux and glutathione-dependent peroxidase activity resulted significantly increased. Moreover, platelet sensitivity to prostacyclin (PGI2), measured as inhibition of Ca2+ flux, was highly decreased. Thus far, evidence is presented for intrinsic platelet hyperactivity (at the PG-peroxidase reaction of the COx pathway) in patients with unstable angina: the resulting increase in PGH2 and TxA2 synthesis, alone or in combination with decreased PGI2 sensitivity, may account for a facilitated thrombus formation.

Angina Pectoris↗
PubMed1984

Severe electrocardiographic abnormalities during arfonad administration.

Severe and reversible electrocardiographic abnormalities (first degree atrioventricular block, left bundle branch block, ventricular fibrillation), were induced by the administration of Arfonad in a patient with type III acute aortic dissection previously chronically treated with alpha-methyl-dopa. Any other possible cause of the electrocardiographic changes was excluded on the basis of clinical findings and laboratory studies. The explanation of the electrocardiographic abnormalities induced by Arfonad are not readily apparent, also on careful review of the literature. We suggest a strict electrocardiographic monitoring during Arfonad administration especially in patients with cardiac conduction defects and previous administration of cardiac cathecholamines depleting drugs.

Adult↗