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.

High defibrillation threshold at cardioverter defibrillator implantation under amiodarone treatment: favorable effects of D, L-sotalol.

A 57-year-old man with primary dilated cardiomyopathy and obesity received an implantable cardioverter defibrillator because of recurrent, poorly tolerated ventricular tachycardia despite continuous treatment with amiodarone. When the device was implanted, assessment of the ability to defibrillate induced ventricular fibrillation showed high energy requirements, with a lack of conventional safety margin between energies effective at defibrillation testing and maximal device output. Treatment with oral amiodarone was withdrawn and substituted with oral sotalol.

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.

[Critical analysis of beta blockers in heart failure: certainty and incompleteness].

Heart failure is one of the commonest debilitating conditions of industrialized society, with mortality and morbidity comparable with that of the common neoplastic diseases. The role of beta-blockers in heart failure has been the subject of debate for many years. The results of recent prospective, placebo-controlled studies of the addition of beta-blockers to standard therapy in patients with chronic heart failure have confirmed a significant beneficial effect on ventricular function, clinical status, morbidity and mortality.

Evaluation of myocardial injury following repeated internal atrial shocks by monitoring serum cardiac troponin I levels.

Introduction: Electrical shocks delivered for atrial cardioversion (CV) may cause myocardial damage. The aim of this study was to assess the extent of myocardial injury caused by repeated intracardiac shocks delivered for low-energy internal atrial CV.

Methods And Results: Thirty-five patients with chronic persistent atrial fibrillation (AF) of different etiologies underwent CV with delivery of synchronized biphasic shocks (3.

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.

[Interventional or conservative approaches in acute coronary syndromes].

The past decade has witnessed a dramatic expansion in the scope of both mechanical and pharmacologic methods for treating patients with acute coronary syndromes. New device technologies, such as intracoronary stenting, more potent and more fibrin-specific thrombolytic agents, and new antithrombotic and antiplatelet drugs are now available. What is the best strategy to treat patients with acute coronary syndromes still remains a matter of debate.

Increasing plasma homocysteine during follow-up in heart transplant recipients: effects of folate and renal function.

Background: Hyperhomocysteinemia is a common finding in heart transplant recipients and may represent a risk factor for graft failure. However, the time-course, determinants and effects of medical therapy on total homocysteine plasma levels after heart transplantation remain undetermined. The aim of this study was to prospectively analyze 1) the time-course of total homocysteine in heart transplant recipients; 2) the effects of folate supplements and cyclosporine A on total homocysteine; 3) the relation among renal function, serum vitamin levels, and total homocysteine.

Evaluation of atrial refractoriness and atrial fibrillation inducibility immediately after internal cardioversion in patients with chronic persistent atrial fibrillation.

Objective: To prospectively evaluate right atrial refractoriness and sustained atrial fibrillation (AF) inducibility at programmed electrical stimulation in two groups of patient: a series of patients with chronic persistent AF, studied immediately after successful low energy internal atrial cardioversion, and a group of control patients without history of supraventricular arrhythmias.

Patients: Nineteen patients with chronic persistent AF (mean AF duration 11 +/- 10 months, range 2-61 months) submitted to successful internal low energy atrial cardioversion in fully conscious state and 11 control patients without history of supraventricular arrhythmias.

Methods: An electrophysiological evaluation was performed to measure atrial refractoriness and AF inducibility, by delivering single atrial extrastimuli in high right atrium, at decremental coupling, during spontaneous sinus rhythm and after 8 beats at 600, 500, 400 and 330 ms cycle length.

Transvenous internal cardioversion for atrial fibrillation: a randomized study on defibrillation threshold and tolerability of asymmetrical compared with symmetrical shocks.

Unlabelled: The aim of the study was to compare, according to a randomized cross-over design, two different biphasic waveforms (6.5/2.5 ms and 3.

Electrophysiological effects of flecainide and propafenone on atrial fibrillation cycle and relation with arrhythmia termination.

Objectives: (1) To investigate the electrophysiological effects of flecainide and propafenone during atrial fibrillation, and their relation to arrhythmia termination; (2) to investigate the effects of isoprenaline on atrial fibrillation in basal conditions and during treatment with class 1C drugs to evaluate the role of adrenergic stimulation on proarrhythmic events occurring during this treatment.

Design: Prospective, single centre study.

Setting: University hospital.

Long-term arterial patency after coronary reperfusion.

Coronary reocclusion is a frequent event after reperfusion and may be responsible for the deterioration of left ventricular function. It may occur early as well as in the chronic phase after hospital discharge. Current, evidence based, strategies to prevent reocclusion include antiplatelet and anticoagulant agents as well as the use of intracoronary stenting in those patients who are treated by PTCA.

Long-term follow-up of stent implantation versus stent-like angioplasty in unstable angina.

Stent-like plain old balloon angioplasty (POBA, < or = 30% residual diameter stenosis) in patients with stable angina resulted in a clinical and angiographic long-term outcome equivalent to stenting. In unstable angina POBA showed lower acute and long-term efficacy than in the stable setting. Data comparing stent-like POBA and coronary stenting in unstable angina are lacking in the literature.

Coronary stenting for unstable angina: predictors of 30-day and long-term clinical outcome.

Background: Unstable angina is usually caused by acute thrombosis superimposed on a fissured plaque. Coronary artery stenting has been shown to improve short- and long-term results of coronary angioplasty in mainly stable patients with one-vessel disease, but it is uncertain whether its use in an unstable clinical setting can be safe and useful. This study sought to evaluate the results of coronary stenting in unstable angina and to determine patient, lesion and procedure-related predictors of 30-day and long-term ischemic events.

Effects of wave reflection timing on left ventricular mechanics.

Unlabelled: The aim of this study was to evaluate how the timing of the pressure pulse produced by peripheral reflection affects the left ventricle (stroke volume, ventricular work, coronary driving pressure). Ten isolated perfused rabbit hearts were attached to rubber tubes of different lengths (0.5, 0.

A randomized placebo-controlled trial of fluvastatin for prevention of restenosis after successful coronary balloon angioplasty; final results of the fluvastatin angiographic restenosis (FLARE) trial.

Background: The 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors competitively inhibit biosynthesis of mevalonate, a precursor of non-sterol compounds involved in cell proliferation. Experimental evidence suggests that fluvastatin may, independent of any lipid lowering action, exert a greater direct inhibitory effect on proliferating vascular myocytes than other statins. The FLARE (Fluvastatin Angioplasty Restenosis) Trial was conceived to evaluate the ability of fluvastatin 40 mg twice daily to reduce restenosis after successful coronary balloon angioplasty (PTCA).

Low energy internal atrial cardioversion in atrial fibrillation lasting more than a year.

Unlabelled: The aim of this study was to evaluate the efficacy of low energy internal atrial cardioversion in restoring sinus rhythm (SR) in patients with chronic atrial fibrillation (AF) persisting > 1 year. Fifteen patients with chronic AF lasting > 1 year (from 13-48 months, mean 24 +/- 13 months) were studied. R wave synchronized 3/3 ms biphasic shocks were delivered between right atrial and coronary sinus (left pulmonary artery in five patients) electrodes.

Favorable effects of flecainide in transvenous internal cardioversion of atrial fibrillation.

Objectives: The aim of the study was to evaluate the effects of intravenous (IV) flecainide on defibrillation energy requirements in patients treated with low-energy internal atrial cardioversion.

Background: Internal cardioversion of atrial fibrillation is becoming a more widely accepted therapy for acute episode termination and for implantable atrial defibrillators.

Methods: Twenty-four patients with atrial fibrillation (19 persistent, 5 paroxysmal) underwent elective transvenous cardioversion according to a step-up protocol.

Conversion of recent-onset atrial fibrillation to sinus rhythm: effects of different drug protocols.

Unlabelled: In a population of 417 hospitalized patients, the efficacy and safety of different drug regimens administered to convert atrial fibrillation (AF) of recent onset (< or = 7 days duration) to sinus rhythm were evaluated. All patients were in NYHA Class < or = 2, and free of heart failure. They were randomly allocated to treatment with placebo in 121 patients; i.

Oral loading with propafenone: a placebo-controlled study in elderly and nonelderly patients with recent onset atrial fibrillation.

Unlabelled: The efficacy and safety of propafenone as an oral loading dose (600-mg single oral dose) in converting recent-onset atrial fibrillation (< or = 7 days duration) to sinus rhythm were evaluated in a single-blind, placebo-controlled study according to patients' age. Overall, 240 hospitalized patients, NYHA Class < or = 2 without signs or symptoms of heart failure were enrolled: among patients aged < or = 60 years, 55 were allocated to propafenone treatment and 59 to placebo, respectively, and among patients aged > 60 years, 64 were allocated to propafenone treatment and 62 to placebo, respectively.

Results: In each age group, the likelihood of conversion to sinus rhythm was significantly greater after propafenone compared with placebo at 3 and 8 hours.

Cardioverter-defibrillator oversensing due to double counting of ventricular tachycardia electrograms.

We report a case of a patient with idiopathic dilated cardiomyopathy and recurrent ventricular tachycardias refractory to antiarrhythmic treatment with amiodarone. A cardioverter defibrillator implantation was performed by the transvenous technique, but ventricular tachycardia detection resulted to be inappropriate because of constant double sensing of ventricular tachycardia electrograms (QRS width=250 ms). Device programmability didn't allow a satisfactory solution to this problem, therefore a more appropriate sensing system was considered.