Energetic metabolism during acute stretch-related atrial fibrillation.

Background And Methods: Perturbations in energetic metabolism and impaired atrial contractility may play an important role in the pathogenesis of atrial fibrillation (AF). Besides, atrial stretch is commonly associated with AF. However, the atrial energetics of stretch-related AF are poorly understood.

Anti-arrhythmic effects of I (Na), I (Kr), and combined I (Kr)-I (CaL) blockade in an experimental model of acute stretch-related atrial fibrillation.

Introduction: Atrial dilatation is commonly associated with atrial fibrillation (AF), but the electrophysiological mechanisms and the implications for anti-arrhythmic therapy are poorly understood. In a model of acute stretch-related AF in isolated rabbit hearts, we evaluated the electrophysiological effects of three different anti-arrhythmic drugs: dofetilide, flecainide and BRL-32872 (associating I (Kr) and I (CaL) blocking properties).

Methods: After 30 min of sustained stretch-related AF, we perfused BRL 10-7 M, BRL 3.

[Pacemaker syndromes].

The pacemaker syndrome refers to symptoms and signs in pacemaker patients caused by inadequate timing of atrial and ventricular contractions. The lack of normal atrioventricular synchrony may result in decreased cardiac output and increased in atrial pressure which elicits a systemic hypotensive reflex response. These hemodynamic disturbances mostly occur in the presence of retrograde VA conduction is present.

[Buerger's disease and coronary disease].

The authors report the case of a 33 year old man with distal occlusive arterial disease diagnosed as Buerger's disease, with two previous transient ischaemic attacks and coronary disease resulting in myocardial infarction. Coronary angiography showed narrowing of the second segment of the left anterior descending artery, occluded distally and not suitable for revascularisation. The observation of coronary artery disease is very rare in Buerger's disease and data of coronary angiography are very sparse in this context.

Predictive factors of ventricular fibrillation triggered by pause-dependent torsades de pointes associated with acquired long QT interval: role of QT dispersion and left ventricular function.

Introduction: Death due to acquired torsades de pointes usually is caused by ventricular fibrillation (VF), but the contributing factors to VF triggered by pause-dependent torsades de pointes are not understood.

Methods And Results: We evaluated 91 patients who fulfilled four criteria: (1) pause-dependent torsades de pointes; (2) prolonged QT interval and/or corrected QT (QTc) (>0.44 sec); (3) long-short initiation sequence; and (4) conditions known to induce pause-dependent torsades de pointes.

[Hospital management of atrial fibrillation. Epidemiologic data and therapeutic strategy. Report of 100 consecutive patients].

Despite recent large scale trials, the management of atrial fibrillation remains very variable. The authors report the results of a prospective study of the management of atrial fibrillation in their department. One hundred consecutive patients admitted for atrial fibrillation were included in the study.

Continuous monitoring of an endocardial index of myocardial contractility during head-up tilt test.

Background: Previous studies suggest that vigorous myocardial contractions stimulate ventricular mechanoreceptors and lead to vasovagal syncope. We studied an endocardial index of myocardial contractility during the head-up tilt test in vasovagal patients and control patients, and we evaluated the effect of negative inotropic drugs on myocardial contractility and tilt test outcome.

Methods And Results: We investigated 19 patients with recurrent vasovagal syncope and positive tilt test (group 1) and 11 patients with no syncope and negative tilt test (group 2).

His-Purkinje system reentry as a proarrhythmic effect of flecainide.

We report a case of tachycardia due to reentry within the His-Purkinje system (HPS) occurring after introduction of flecainide. The patient presented with a mild mitral regurgitation and normal left ventricular function. He had incomplete left bundle branch block with left-axis deviation.

Near fatal electrical storm in a patient equipped with an implantable cardioverter defibrillator for Brugada syndrome.

A patient with Brugada syndrome experienced incessant ventricular fibrillation 7 years after implantation of an ICD. General anesthesia, fast ventricular pacing, bretylium, and atenolol infusion were ineffective; amiodarone infusion was started. After 190 defibrillation shocks over 36 hours, the electrical storm stopped.

Electrophysiological characterization of SCN5A mutations causing long QT (E1784K) and Brugada (R1512W and R1432G) syndromes.

Unlabelled: Familial long QT syndrome (LQTS) and Brugada syndrome are two distinct human hereditary cardiac diseases known to cause ventricular tachyarrhythmias (torsade de pointes) and idiopathic ventricular fibrillation, respectively, which can both lead to sudden death.

Objective: In this study we have identified and electrophysiologically characterized, in patients having either LQTS or Brugada syndrome, three mutations in SCN5A (a cardiac sodium channel gene).

Method: The mutant channels were expressed in a mammalian expression system and studied by means of the patch clamp technique.

Prolonged QT interval and altered QT/RR relation early after radiofrequency ablation of the atrioventricular junction.

This study evaluated the paced QT interval in the days after radiofrequency ablation of the atrioventricular junction in patients with chronic rapid atrial fibrillation. There is an abnormality in the dynamics of the paced QT interval until the second day after ablation, resulting in an increased duration when the paced heart rate is <75 beats/min.

A complication of pacemaker lead extraction: paradoxical embolism of a lead fragment in a leg artery.

Extraction of three chronically implanted pacemaker leads was performed via the implant vein in a 71-year-old man. One of the leads broke in the subclavian scar tissue. The lead fragment migrated into the left peroneotibial trunk artery.

Treatment of malignant primary vasodepressive neurocardiogenic syncope with a rate responsive pacemaker driven by heart contractility.

In a 41-year-old man suffering from frequent syncope, the tilt test reproducibly induced a primary vasodepressive neurocardiogenic syncope. Pharmacotherapy either failed to prevent the syncope induced at the tilt test or was poorly tolerated. In the minutes preceding the syncope, a dramatic increase in heart contractility was sensed by a microaccelerometer located at the tip of a right ventricular pacing electrode.

[Infections secondary to implantation of cardiac pacemakers].

Infectious complications of pacemaker implantation are not common but may be particularly severe. Localised wound infections at the site of implantation have been reported in 0.5% of cases in the most recent series with an average of about 2%.

Safety and tolerability of intravenous cibenzoline for acute termination of spontaneous sustained ventricular tachycardia. Cibenzoline and spontaneous VT.

Study Objectives: To evaluate prospectively, the tolerability and safety of intravenous cibenzoline therapy, for the cardioversion of spontaneous monomorphic ventricular tachycardia (VT).

Setting And Patients: Between February 1990 and December 1996, fifty-eight patients aged 59+/-10 years old (fifty-three males, five females), with spontaneous VT not causing cardiac arrest, received intravenous cibenzoline. Their underlying heart conditions were: ischemic heart disease [35], dilated cardiomyopathy [14], right ventricular dysplasia [3], hypertrophic cardiomyopathy [1], valvulopathy [2], Fallot's Tetralogy [1] and primary arrhythmogenic disease [2].

A sensor-based evaluation of heart contractility in patients with head-up tilt-induced syncope.

Studies using the head-up tilt test (HUT) suggest that a reflex increase in sympathetic activity resulting in vigorous myocardial contractions precedes neurally-mediated syncope (NMS). The aim of this study was to evaluate heart contractility changes during positive HUT. Ten patients with recurrent NMS and positive HUT were investigated.

Arrhythmic cardiac arrest due to isolated coronary artery spasm: long-term outcome of seven resuscitated patients.

Objectives: Our aim was to look at the clinical features and long-term follow-up of seven patients without coronary artery disease, who had a history of life-threatening ventricular arrhythmias due to coronary spasm.

Background: Arrhythmic cardiac arrest due to isolated coronary spasm is rare, and there is limited information on the patients affected by this entity alone.

Methods: The seven patients were recruited retrospectively from a cohort of survivors of cardiac arrest.