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Biomedical subjects

A Branzi

Publications and source records attributed to A Branzi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Interplay between methylenetetrahydrofolate reductase gene polymorphism 677C-->T and serum folate levels in determining hyperhomocysteinemia in heart transplant recipients.

BACKGROUND: Homocysteine metabolism is often impaired in heart transplant recipients, and increased total homocysteine plasma levels may constitute a risk factor for the development of heart allograft vascular disease. Although 677C-->T transition in methylenetetrahydrofolate reductase (MTHFR) is associated with increased homocysteine levels in the general population, it is unclear whether MTHFR polymorphism influences homocysteine metabolism after heart transplant. METHODS: Homocysteine, serum folate, renal function, concentrations of cyclosporine and its metabolites, and MTHFR genotype were determined in 57 heart transplant recipients (age, 55 +/- 11 yr; 21% women; time from transplant, 48 +/- 42 months). RESULTS: Forty nine percent of the study population presented with hyperhomocysteinemia. Homocysteine was 17.1 +/- 5.9 micromol/liter, 19.4 +/- 4.9 micromol/liter, and 26.3 +/- 14.2 micromol/liter for genotypes CC, CT, and TT, respectively (p = 0.028, Kruskal-Wallis test). At multivariate analysis, MTHFR genotype was independently associated with homocysteine (p = 0.005). When the study population was divided into 2 groups accordingly to serum folate levels (above/below the median value of 6.1 ng/ml), MTHFR genotype remained a significant predictor of homocysteine only in patients with low serum folate (p = 0.048). CONCLUSIONS: This study demonstrates that hyperhomocysteinemia is frequent in heart transplant recipients and that the 677C-->T transition in the MTHFR gene independently and unfavorably influences homocysteine metabolism in this group of patients. Adequate folate intake may overcome genetic predisposition to hyperhomocysteinemia.

Adult↗
PubMed2001

Neurocardiogenic syncope in selected pediatric patients--natural history during long-term follow-up and effect of prophylactic pharmacological therapy.

OBJECTIVE: The natural history of pediatric patients with severely symptomatic neurocardiogenic syncope is poorly defined respect to the likelihood of remission or symptomatic recurrence along time. We undertook this study to investigate the likelihood of clinical relapse, and to assess the effect of prophylactic pharmacological treatment in the most symptomatic patients. METHODS: Twenty-nine patients with neurocardiogenic syncope were studied at our Institution: 14 (12 +/- 3.6 years) highly symptomatic received prophylactic therapy with beta-blockers guided by head up tilt (HUT), whereas 15 (12.2 +/- 2.7 years) moderately symptomatic received only education to avoid triggering of the vasovagal reflex and to abort forthcoming syncope. Patients were then followed respectively for 33.7 +/- 9.0 and 33.3 +/- 8.7 months (p = NS). RESULTS: The average duration of symptoms before HUT was 9.0 +/- 4.3 months (range 3-17) for treated patients, and 6.2 +/- 2.5 months (range 2-11) for those untreated (p < 0.05). Treated patients had also a greater number of symptomatic events: 6 +/- 2 vs. 2 +/- 1 (p < 0.001). During follow up, 9/15 untreated and 6/14 treated patients had at least 1 recurrence, with an odds ratio of 2 (95% CI 0.72-5.49). Clinical events were greatly reduced in both groups at follow up, but treated patients had a significantly greater reduction either of syncopal (p < 0.001) or near syncopal events (p < 0.02). Time to the first recurrence, syncope or near syncope, was shorter for untreated vs treated patients: 5 +/- 2 vs. 25 +/- 12 months (p < 0.001). Looking at the time course of all clinical recurrences, 23/26 occurred in untreated patients, whereas 7/10 occurred in treated patients within 24 months. An attempt to therapy discontinuation was made after 30 months in 4 patients, and resulted in half of them being asymptomatic, and half with a single minor recurrence. CONCLUSIONS: Spontaneous reduction of symptoms occurs along time in pediatric patients with neurocardiogenic syncope, so that recurrences are very unlikely after 24 months from first diagnosis. Tiered prophylactic therapy may be guided by HUT in selected highly symptomatic patients; beta-blockers appear a very effective intervention. Larger, prospective controlled studies are required to investigate the role of any intervention in moderately symptomatic patients.

Cardiotonic Agents↗
PubMed2001

Transvenous low energy internal cardioversion for atrial fibrillation: a review of clinical applications and future developments.

Low energy internal atrial cardioversion can be performed by delivering biphasic shocks between transvenous catheters positioned within the cardiac chambers or great vessels. Delivery of shocks results in effective cardioversion at energies < 6-10 J and the procedure can be effective even when external cardioversion has failed. Shock induced discomfort varies from patient to patient, but the procedure can be usually performed without general anesthesia and eventually under mild sedation. Nevertheless, tolerability has to be improved by obtaining a substantial reduction in defibrillating thresholds. With regard to safety, delivery of shocks for defibrillating the atria implies a potential risk of inducing ventricular fibrillation; to minimize this risk, shock delivery must be synchronous to the QRS and should be avoided during rapid RR cycles (< 300 ms). Presently, transvenous low energy cardioversion is an investigational procedure, but a widening of indications is expected in the near future. The cost of the procedure, which remains invasive and requires a brief hospital stay, must be balanced with the benefit of restoring sinus rhythm and the possibility of maintaining sinus rhythm for the medium- to long-term. Experimental and clinical investigations of low energy internal cardioversion have resulted in the development of devices for atrial defibrillation whose clinical role and cost-benefit ratio is currently under evaluation.

Atrial Fibrillation↗
PubMed2001

Clinical evaluation of morphology discrimination: an algorithm for rhythm discrimination in cardioverter defibrillators.

The aim of this study was to test the new morphology discrimination diagnostic algorithm for ICDs that differentiates supraventricular tachycardias (SVTs) from VTs by analysis of ventricular depolarization complexes morphology. Twenty-five patients implanted with a St. Jude Ventritex single chamber ICD were studied during electrophysiological evaluation at predischarge and were followed for 7 +/- 4 months. Sensitivity and specificity for VT detection and overall diagnostic accuracy of the morphology discrimination algorithm were calculated on 326 detected events. At electrophysiological evaluation, the algorithm was tested during 67 episodes of right atrial pacing, during 119 episodes of RV pacing (at basal interventricular septum and RV apex) and during 27 episodes of sustained AF: specificity was 98%, sensitivity was 66%, and diagnostic accuracy was 80%. All episodes of AF were correctly diagnosed as SVT. Exclusion of detections related to pacing at the basal interventricular septum, resulted in a specificity of 98%, a sensitivity of 85%, and a diagnostic accuracy of 93%. During follow-up, evaluation of the morphology discrimination algorithm on 113 spontaneous episodes (31 VTs, 31 AF, 7 SVTs, and 44 sinus tachycardias) exhibited a specificity of 89%, a sensitivity of 100%, and a diagnostic accuracy of 92%. In conclusion, the morphology discrimination algorithm exhibits a high specificity in discriminating VTs from SVTs, although with a corresponding reduction in sensitivity. The preliminary experience on spontaneous episodes is promising. To correct for the reduction in sensitivity, it is advisable to use this algorithm in parallel with other algorithms for rhythm discrimination (sudden onset, stability) coupled with extended high rate.

Adult↗
PubMed2001

Internal low energy atrial cardioversion: efficacy and safety in older patients with chronic persistent atrial fibrillation.

BACKGROUND: Low-energy internal atrial cardioversion is a relatively new technique based on delivery of intracardiac shocks through transvenous catheters placed into the atria or the vessels. OBJECTIVE: The aim of this study was to assess in older and younger patients with chronic persistent atrial fibrillation (AF) the efficacy and safety of transvenous low-energy internal atrial cardioversion performed without routine administration of sedatives or anesthetics. DESIGN: A prospective longitudinal study. SETTING: A cardiological university hospital. PARTICIPANTS: 82 patients, divided into older (> or = 60 years) (n = 49) and younger (n = 33) subjects. MEASUREMENTS: Atrial defibrillation threshold for internal cardioversion, measured as leading edge voltage (V) and delivered energy (J) of effective shocks, percentage of patients maintaining sinus rhythm at short-term (within 3 days) and at long-term follow-up. METHODS: Patients with chronic persistent AF, treated with oral anticoagulants for at least 3 to 4 weeks, were admitted to hospital. Following a clinical work-up, patients were subjected to low-energy internal atrial cardioversion with shock delivery according to a step-up protocol. RESULTS: Internal cardioversion was effective in restoring sinus rhythm in 90% (44/49) of the older patients and in 94% (31/33) of the younger patients. Shocks were effective at a mean energy between 6 and 8 joules (range 0.9-23) and administration of sedatives or anesthetics was required during the procedure in 22% (11/49) of older and in 48% (16/33) of younger patients (P = .026 at chi-square). No major complications occurred during the procedure. Pharmacological prophylaxis of AF recurrences was instituted immediately following the procedure. During inhospital stay and during the follow-up (mean 12 +/- 9 months for older patients and 15 +/- 10 months for younger patients), AF recurred in 39% (17/44) of older patients and in 16% (5/31) of younger subjects (P = .064 at chi-square). CONCLUSIONS: Internal low energy cardioversion is a very effective procedure for restoring sinus rhythm in patients with AF; it can be performed in older patients, and administration of sedatives or anesthetics can be avoided or minimized in a substantial proportion of subjects. Recurrences of AF in the long term tend to be higher in older subjects and intensive prophylaxis with antiarrhythmic drugs is required.

Aged↗
PubMed2001

Left superior vena cava persistence in patients undergoing pacemaker or cardioverter-defibrillator implantation: a 10-year experience.

OBJECTIVE: The persistence of a left superior vena cava (LSVC) has been observed in 0.3% of the general population as established by autopsy. In the adult population, it is an important anatomic finding if a left superior approach to the heart is considered. The aim of the study was to evaluate the prevalence of a LSVC in patients undergoing pacemaker (PM) and cardioverter-defibrillator (CD) implantation. DESIGN: We observed the prevalence of LSVC during a 10-year period; each patient undergoing PM or transvenous CD implantation received a left cephalic/left subclavian venous approach to the heart. With this technique, LSVC persistence is easily diagnosed during lead placement. RESULTS: A total of 1,139 patients consecutively underwent PM implantation during 10 years: 4 patients had persistent LSCV (0.34%). Among 115 patients undergoing CD implantation, 2 patients with LSVC (1.7%) were observed. Overall LSVC persistence was found in 6 of 1,254 patients (0.47%). Two patients, one of whom had no right superior vena cava (RSVC), received a left-sided PM, whereas two other patients received right-sided devices. Both CD patients received a left-sided active-can device: the first patient with a right-sided lead tunneled to the left pectoral pocket, as a result of poor catheter handling through the LSVC and coronary sinus, and the second patient with a screw-in lead from LSVC. Long-term follow-up of these patients (average +/- SD, 41 +/- 26 months) revealed absence of lead dislodgment and appropriate device function regardless of lead implantation site. CONCLUSIONS: Persistence of LSVC in adults undergoing PM/CD implantation is similar to that of the general population (0.47% in our study). The left-sided implant can be achieved by stylet shaping and by use of active fixation leads in most patients, with a reliable outcome at short term in addition to appropriate device performance at follow-up. Assessment of the RSVC is advisable when planning a right-sided implantation, since a minority of patients lacks this vessel.

Defibrillators, Implantable↗
PubMed2001

A semi-automatic algorithm for reducing the time spent on routine follow-up of cardioverter defibrillators.

BACKGROUND: The routine follow-up of cardioverter defibrillators (CD) is a time-consuming procedure. AIM of the STUDY and METHODS: The present study was a prospective randomized cross-over evaluation on the clinical usefulness of a specific semi-automatic software algorithm (Quick Check) for CD follow-up, available in CPI Guidant systems (CD and programmer). Time-saving, while ensuring all the required data and patient safety, was evaluated in a large group of patients (105), recruited in different centers. In the same session and under a physician's supervision all patients underwent a follow-up with the aid of Quick Check or a standard follow-up, in a randomized sequence. Each patient served as his own control. RESULTS: In the overall population of 105 patients, the time spent for follow-up was reduced by Quick Check from 186+/-105 sec to 106+/-67 sec (p<0.0001) (43% reduction). The reduction in time spent for follow-up with Quick Check was the same (43% reduction) in patients with detected episodes (n=38) (from 241+/-144 sec to 138+/-95 sec (p<0.0001)) and in patients without detected episodes (n=67) (from 154+/-52 sec to 88+/-34 sec (p<0. 0001)). No adverse events or deletion of potentially useful data was detected by the supervising physician. CONCLUSIONS: Use of a specific software algorithm for routine follow-up of implanted CDs allows a significant shortening of the time spent on routine follow-up, thus reducing costs. The supervision of a physician is a guarantee of patient safety.

Algorithms↗
PubMed2001

Ultrasound-assisted stent implantation in small size coronary arteries: a pilot study.

BACKGROUND: Many studies have indicated that a small lumen size is one of the most important predictors of acute events and of late restenosis after balloon angioplasty or stent implantation. In the last few years many studies have shown that intravascular ultrasound (IVUS) guidance makes it possible to optimize stent implantation. The aim of this pilot study was to evaluate the feasibility and safety of IVUS imaging of small vessels. Secondary endpoints were the immediate and long-term results of IVUS-guided elective BeStent implantation in small vessels. METHODS: Fourteen symptomatic patients with small coronary vessel (mean angiographic reference diameter 2.3 +/- 0.2 mm) disease underwent IVUS-guided BeStent implantation. IVUS success was defined as the achievement of a final minimal intrastent cross-sectional area (CSA) > 90% of the smaller reference lumen CSA. RESULTS: IVUS evaluation was feasible in all patients without any clinical or angiographic adverse events. Procedural success was achieved in all patients with implantation of a BeStent 15 mm. No major complication (death, myocardial infarction, stent acute or subacute thrombosis, coronary artery bypass, re-coronary angioplasty) occurred during the in-hospital phase. Two non-flow-limiting, asymptomatic coronary dissections were detected after stent expansion. The post-stenting lesion stenosis rate decreased from 72.9 +/- 12.9% to 0.75 +/- 11.7% with an acute gain of 1.8 +/- 0.4 mm. The final IVUS minimal stent CSA was 5.6 +/- 1.1 mm2. The IVUS criteria of adequate stent expansion were reached in 11 (78.6%) patients. At 6 months of follow-up, the rate of angiographically diagnosed in-stent restenosis was 30.7%; the 6-month late loss in stent diameter was 1.1 +/- 0.6 mm. No patient died or presented with a myocardial infarction. The target lesion revascularization rate was 30.7%. CONCLUSIONS: Coronary IVUS-guided stenting can be performed in small vessels with a high success rate and low incidence of in-hospital complications. However, despite these encouraging short-term results, the long-term clinical and angiographic outcome is less favorable. Further larger and randomized IVUS studies, probably employing more aggressive IVUS criteria, are needed to clarify the true role of IVUS guidance in this particular field.

Aged↗
PubMed2001

[Familial predisposition to ischemic cardiopathy: role of homocysteine and genetic polymorphism of methylenetetrahydrofolate reductase].

Homocysteine represents a risk factor for coronary artery disease determined not only by nutritional habits, but also by the genetic polymorphism of the enzymes involved in its metabolism (i.e. methylenetetrahydrofolate reductase - MTHFR). However, recent prospective studies questioned the initial evidence of a clear epidemiological and pathogenetic link between homocysteine levels and coronary artery disease. Moreover, the relationships between MTHFR polymorphism and coronary artery disease remain unclear. In this paper, the recent literature analyzing the role of homocysteine and MTHFR polymorphism as a risk factor for coronary artery disease has been reviewed.

Causality↗
PubMed2001

[Late-appearing cholestatic icterus after a month of treatment with ticlopidine].

A 65-year-old man was submitted to coronary angioplasty and stent implantation for stable angina. The treatment included a 30-day therapy with ticlopidine (in addition to aspirin, metoprolol, ramipril, amlodipine and nitrates). One month after ticlopidine withdrawal a progressive cholestatic jaundice took place. Viral, immunogenic as well as nutritional causes were ruled out. The abdominal echography disclosed a normal biliary tree and the liver biopsy showed a centrolobular cholestasis pattern. Drug-induced cholestatic reaction was diagnosed and attributed to ticlopidine. There was a progressive improvement in clinical and laboratory findings 4 months after steroid treatment. The clinical picture was normalized after 6 months. When considering the option ticlopidine, even for a short time after coronary angioplasty, the possibility of drug-induced hepatotoxicity should be kept in mind. Consequently, markers of liver toxicity should be monitored carefully.

Aged↗
PubMed2001

Management of patients with atrial fibrillation: different therapeutic options and role of electrophysiology-guided approaches.

At present the approach to atrial fibrillation treatment is based on the electrophysiological patterns of atrial fibrillation (on the basis of multiple intra-atrial recordings or sophisticated new mapping techniques) only in a restricted minority of patients, those who are candidate to ablation of the substrate and/or of the triggers. Atrial fibrillation has a broad spectrum of clinical presentations and a heterogeneous electrophysiological pattern. The treatment of this arrhythmia, both with drugs and non pharmacological treatments, has been based, classically, on empirical basis and on a clinically-guided staged-approach. The limitations of pharmacological treatment led in recent years to the development of a wide spectrum of non pharmacological treatments. This implies a change in the approach to atrial fibrillation and the need to identify potentially ideal candidates to complex and expensive treatments. In this view it is currently under investigation the possibility to identify potential responders to a definitive treatment or a combination of treatments (both pharmacological and non-pharmacological) on the basis of the electrophysiological pattern.

Anti-Arrhythmia Agents↗
PubMed2000

DDD and single-lead VDD pacing: evaluation of atrial signal dynamic changes.

BACKGROUND: Single-lead VDD pacing systems are an alternative to conventional DDD pacemakers in patients with atrioventricular (AV) block and normal sinus function. HYPOTHESIS: The aim of this study was to assess changes of P-wave amplitude occurring in dynamic conditions in two groups of patients with a single-lead VDD and with a DDD pacing system, respectively. METHODS: Twenty-eight patients with second- or third-degree AV block and normal sinus function were enrolled prospectively into the study. Seventeen patients were implanted with a single-lead VDD pacing system and 11 with a DDD pacemaker. Patients were evaluated at 3 months (all patients) and at 6 months (26 patients) at supine and in dynamic conditions (postural changes, hyperventilation, and during exercise). RESULTS: Mean P-wave values at supine were 1.92 +/- 1.10 mV at 3 months and 1.76 +/- 1.01 mV at 6 months for VDD systems, and 4.63 +/- 2.18 mV at 3 months and 4.58 +/- 2.80 mV at 6 months for DDD pacemakers. In dynamic conditions, P-wave amplitude changes compared with supine condition ranged between -74 and +226% in VDD, and between -53 and +138% in DDD; however P-wave amplitudes showed no significant changes compared with baseline. Moreover, changes in atrial signal amplitudes did not occur randomly, and in both systems P-wave amplitudes remained significantly correlated with supine values. CONCLUSIONS: A wide range of P-wave amplitude variations occurs in different postural conditions or during exercise, both with single-lead VDD and DDD pacing systems. However, with appropriate programming of atrial sensitivity based on supine values, constant atrial tracking can be maintained.

Aged↗
PubMed2000

Role of statins in the management of dyslipidemia after cardiac transplant: randomized controlled trial comparing the efficacy and the safety of atorvastatin with pravastatin.

BACKGROUND: Cardiac transplant patients are at increased risk of dyslipidemia, a known pathogenetic factor in chronic rejection. The aim of this study was to compare the efficacy and the safety of treatment with atorvastatin (AT) and treatment with pravastatin (PV) in a population of dyslipidemic transplant patients. METHODS: Thirty-nine transplant patients were randomized to receive a 4-month cycle of therapy with AT or PV, in a cross-over sequence. We analyzed the effects on their lipid profiles using Student t-test for paired data. RESULTS AND CONCLUSION: Atorvastatin was significantly more effective than PV in reducing total cholesterol (33% vs 21%, p < 0.001), LDL cholesterol (45% vs 30%, p = 0.001), and triglycerides (24% vs 7.7%, p < 0.001), at lower doses and with comparable tolerability and safety.

Adult↗
PubMed2000

Benefits in projected pacemaker longevity and in pacing related costs conferred by automatic threshold tracking.

The aim of this study was to calculate the battery current drain of different VVI-VVIR pulse generators, with and without automatic adjustment of stimulation output, from the same manufacturer, and obtain projections on pacemaker longevity and pacing related costs. Twenty-five patients who had received a VVIR pacemaker (Microny SR+ 2425T) with Autocapture function, an algorithm able to provide automatic adaptation of device output coupled with continuously monitored capture threshold, were analyzed. Calculations of current drain and projections of device longevity were based on diagnostic data retrieved from device memory and on comparisons of multiple programmed settings of the same device (Microny SR+ 2425T with Autocapture, Low Output [output = 2 x Autocapture threshold, but not less than 2.4 V] versus Standard Output [5 V]). In addition, devices with Autocapture but with different battery capacities (0.35 Ah and 0.79 Ah, Microny and Regency, respectively) were compared to a standard device (battery capacity = 0.78 Ah) at 2.5-V and 5-V output settings. According to a series of assumptions, Autocapture increased device longevity by 53% (Microny) and by 245% (Regency) over a 15-year follow-up with a consequent reduction in pacing related costs of 25% (Microny) and of 57% (Regency) compared to the standard settings of a VVIR device from the same manufacturer. In conclusion, pacing with constant adaptation of generator output coupled with continuous monitoring of stimulation threshold has the potential to increase generator longevity and to reduce pacing related costs as compared to a standard device from the same manufacturer.

Aged↗