Effect of Positive End-Expiratory Pressure on Central Venous Pressure in Patients under Mechanical Ventilation.

Introduction: Finding the probable governing pattern of PEEP and CVP changes is an area of interest for in-charge physicians and researchers. Therefore, the present study was designed with the aim of evaluating the relationship between the mentioned pressures.

Methods: In this quasi-experimental study, patients under mechanical ventilation were evaluated with the aim of assessing the effect of PEEP change on CVP.

Myocardial hypertrophy is associated with inflammation and activation of endocannabinoid system in patients with aortic valve stenosis.

Aims: Endocannabinoids and their receptors have been associated with cardiac adaptation to injury, inflammation and fibrosis. Experimental studies suggested a role for inflammatory reaction and active remodeling in myocardial hypertrophy, but they have not been shown in human hypertrophy. We investigated the association of the endocannabinoid system with myocardial hypertrophy in patients with aortic stenosis.

Implantation of left ventricular epicardial leads in cardiosurgical patients with impaired cardiac function--a worthwhile procedure in concomitant surgical interventions?

Background: Cardiac resynchronization therapy (CRT) by means of multisite biventricular pacing is an effective therapeutic option for the treatment of severe heart failure. The present study estimates how many open heart-surgery patients could benefit from the implantation of permanent left ventricular (LV) pacing leads. After routine preoperative screening, epicardial electrodes were implanted in selected patients.

Prevalence of asymptomatic upper extremity venous obstruction in 302 patients undergoing first implantation of cardioverter defibrillator.

Background: Little is known about the prevalence of upper extremity vein obstruction or anomalies in patients before first implantation of implantable cardioverter defibrillator (ICD). It remains unclear in which patients contrast venography is warranted before implantation procedure.

Methods: Results of clinical data and contrast venography of 302 consecutive patients scheduled for first ICD implantation were analyzed.

Hybrid procedures can reduce the risk of congenital cardiovascular surgery.

Background: Minimally invasive operations and percutaneous interventions are well-accepted options in the treatment of congenital heart defects. However, percutaneous interventions may be associated with an increased risk due to limited vascular access or a very tortuous catheter course. In these cases, combining operative and interventional approaches with direct puncture of the heart or the great vessels may facilitate implantation of even large devices.

Emergent antegrade endovascular stent placement in a patient with perforated Stanford B dissection via right axillary artery.

We present a case of a ruptured chronic Stanford B dissection of the aorta which was successfully treated with a tapered endoprosthesis using the right axillary artery for access. Challenges to endovascular strategies for thoracic aortic pathology include relatively restricted endoprosthesis configurations and problems associated with endovascular access. Especially in younger patients the right axillary artery should be considered as a possible and safe access for antegrade stent placement.

Incidence and characteristics of appropriate and inappropriate therapies in recipients of ICD implanted for primary prevention of sudden cardiac death.

Background: We evaluated the number of appropriate and inappropriate therapies for ventricular tachyarrhythmias and trigger mechanisms in 55 MADIT II (MII)-like (group 1) and 86 SCD-HeFT-like (group 2) patients.

Methods And Results: We analyzed 399 appropriate episodes in 31 patients with implantable cardioverter defibrillators (ICD) implanted according to the MII trial indications, and 502 appropriate episodes in 47 patients matching the SCD-HeFT trial criteria (mean follow-up in both groups = 33 +/- 19 months). In group 1, 39 treated episodes were inappropriate (9% of all episodes), while in group 2, 76 episodes were treated inappropriately (15% of all episodes).

Identification of "substrate fibrillators" and "trigger fibrillators" by pacemaker diagnostics.

Background: The population of patients likely to respond to selected pacing algorithms for maintenance of sinus rhythm is unknown.

Objectives: The purpose of this study was to identify patients with specific onset patterns of paroxysmal atrial fibrillation (AF).

Methods: Dual-chamber pacemakers with advanced diagnostic functions were implanted in 112 patients with conventional indications for antibradycardia pacing and a history of paroxysmal AF.

Individualized selection of pacing algorithms for the prevention of recurrent atrial fibrillation: Results from the VIP registry.

Objectives: The VIP registry investigated the efficacy of preventive pacing algorithm selection in reducing atrial fibrillation (AF) burden.

Background: There are few data identifying which patients might benefit most from which preventive pacing algorithms.

Methods: Patients, with at least one documented AF episode and a conventional antibradycardia indication for pacemaker therapy, were enrolled.

Early stereological changes in liver of Sprague-Dawley rats after streptozotocin injection.

Background: Diabetes mellitus is associated with biochemical, physiological and pathologic alterations in the liver. We measured changes in structure of rat liver after streptozotocin injection, using stereology.

Methods: Livers of 36 streptozotocin-injected rats were removed after 4, 8 and 12 weeks.

Potential device interaction of a dual chamber implantable cardioverter defibrillator in a patient with continuous spinal cord stimulation.

Spinal cord or thalamic deep brain stimulation with a pacemaker is becoming more important in the treatment of drug refractory pain due to peripheral vascular disease, angina pectoris and intractable tremor in patients with neurologic disorders such as Parkinson's disease. An additional indication for a cardiac pacemaker or implantable cardioverter defibrillator raises concerns about possible interactions between the implanted electrical devices. We report on a patient with existing spinal cord stimulation who survived sudden cardiac death and received a dual chamber cardioverter defibrillator capable of delivering tiered therapies in both the atrium and ventricle.

Transit time flow measurement in on-pump and off-pump coronary artery surgery.

Objective: Transit time flow measurement is frequently used during coronary artery bypass with and without cardiopulmonary bypass to detect graft dysfunction resulting from technical errors.

Methods: Intraoperative transit time flow measurement measurements of 896 patients requiring surgery for double- or triple-vessel disease were reviewed retrospectively. Six-hundred and ninety-five patients were operated on-pump (Group A: coronary artery bypass with cardiopulmonary bypass), and 201 patients off-pump (Group B: coronary artery bypass without cardiopulmonary bypass).

Incidence and rate characteristics of atrial tachyarrhythmias in patients with a dual chamber defibrillator.

Atrial tachyarrhythmias play an important role in the treatment of patients with malignant ventricular tachyarrhythmias not only with respect to inappropriate discharges but also to left ventricular function and stroke risk. A combined dual chamber defibrillator provides separate therapies for atrial and ventricular tachyarrhythmias. To assess the incidence of atrial tachyarrhythmias in patients with this dual chamber implantable defibrillator, 40 patients with ventricular tachyarrhythmias and concomitant atrial tachyarrhythmias and/or AV conduction disturbances were included in a prospective study.

Advanced pacemaker diagnostic features in the characterization of atrial fibrillation: impact on preventive pacing algorithms.

Pacing algorithms to prevent PAF are mainly based on the suppression of premature atrial complexes (PACs), which play an important role in its initiation. In contrast to 24-hour ambulatory electrocardiograms, advanced pacemaker (PM) diagnostic features are capable of recording AF episodes during long follow-up periods and of characterizing AF in a detailed fashion. For the specific use of these algorithms, a detailed characterization of AF was performed in 91 dual chamber PM recipients with histories of AF.

An unusual case of pacemaker failure: complete disconnection of connector block and battery of a subpectorally implanted dual chamber pacemaker.

Local trauma to patients with implanted pacemaker devices may result in lead fracture or breakage of the lead socket with leakage of fluid into the connector system. This report describes an unusual case of complete entrance and exit block in a subpectorally implanted dual chamber pacemaker due to total disconnection and dislodgement of header block and battery part. Damage may be caused by an interaction of machine fatigue/manufacturing defective and fixation of the header with unusual movability of the battery, leading to breakage with intermittent malfunction and consecutive bradycardia and syncope.

Hospital readmission after transvenous cardioverter/defibrillator implantation; a single centre study.

Aims: Hospital readmission after implantation of cardioverter/defibrillators has a major impact on quality of life and cost-effectiveness in defibrillator patients. Rehospitalization has not been studied in large patient populations with modern transvenous defibrillation systems.

Methods And Results: We report on incidence, reasons, time in follow-up, duration and predictors of hospital readmission in 180 patients after transvenous implantation of a cardioverter/defibrillator during a follow-up period of 25+/-18 months.

Clinical experience with implantable atrial and combined atrioventricular defibrillators.

Unlabelled: The high prevalence of atrial fibrillation (AF) and its clinical complications, the poor efficacy of medical therapy for preventing recurrences, and dissatisfaction with alternative modes of therapy stimulated interest in implantable atrial and combined atrioventricular defibrillators. In a multicenter study, the safety and efficacy of a stand alone implantable atrial defibrillator, the Metrix system, were evaluated. The device was implanted in 51 patients with highly symptomatic episodes of AF refractory to pharmacological treatment.

[Clinical experience with the implantable atrial defibrillator (atrioverter) in patients with atrial fibrillation. Metrix Investigators].

Due to the limited efficacy of drug therapy in atrial fibrillation and the high rate of recurrence, strong efforts were made to find non-pharmacological strategies. For three years now, the implantable atrial defibrillator Metrix from InControl has been available as an alternative therapy. From October 1995 to the present the atrial defibrillator was implanted in 179 patients worldwide.

Inappropriate implantable defibrillator discharge caused by a retained pacemaker lead fragment.

Introduction: Inappropriate discharge is still a major issue of implantable cardioverter defibrillator therapy. The diagnostic options of modern devices facilitate classification of the underlying abnormality.

Methods And Results: A 65-year-old woman with depressed left ventricular performance received spurious shocks from an ICD, implanted for ventricular tachycardia.

Prospective evaluation of the quality and long-term stability of atrial signals in non-thoracotomy defibrillation electrodes: comparison of four different endocardial electrograms.

Unlabelled: Documentation of atrial signals in stored endocardial electrograms of modern implantable cardioverter-defibrillators (ICD) is a useful tool to classify the underlying arrhythmia leading to device therapy. Newest generations of ICD provide near- and far-field electrograms derived between various endocardial electrodes. The aim of this prospective study was to assess the quality and long-term stability of atrial signals in different far-field configurations including the active can housing.

Specific considerations with the automatic implantable atrial defibrillator.

Introduction: Internal atrial defibrillation has been evaluated as an alternative approach to the external technique for more than two decades. Previous studies in animals and humans have shown that internal atrial defibrillation is feasible with relatively low energies. The promising results achieved with internal atrial defibrillation have facilitated the development of an implantable atrial defibrillator (IAD).

Prospective evaluation of shoulder-related problems in patients with pectoral cardioverter-defibrillator implantation.

Background: The pectoral approach to implantation of cardioverter defibrillators (ICDs) has become a standard in defibrillator therapy because of reduced generator size, weight, and volume. But the size of these devices is still comparable to the size of the early conventional antibradycardia pacemakers that were associated with a number of significant pocket- and shoulder-related problems after implantation in the pectoral region. In a prospective, single-center study of 50 patients with subpectoral implantation of a fourth-generation ICD, the ipsilateral shoulder joint was evaluated regarding active shoulder motility, shoulder-related pain, shoulder function, shoulder elevation, insertion tendinitis, and morphologic alterations of the shoulder.

A new classification algorithm for discrimination of ventricular from supraventricular tachycardia in a dual chamber implantable cardioverter defibrillator.

Introduction: The high incidence of inappropriate therapies due to supraventricular tachycardia remains a major unsolved problem of implantable cardioverter defibrillators. We report a new detection formula for discrimination of ventricular tachycardia from supraventricular tachycardia in a patient with a dual chamber implantable cardioverter defibrillator and a new atrioventricular classification algorithm.

Methods And Results: The enhanced detection algorithm performs a stepwise arrhythmia analysis.