Ist eine ICD-Programmierung auf eine Schockenergie der doppelten intraoperativen Defibrillationsschwelle im Langzeitverlauf sicher effektiv? Ergebnisse einer prospektiven randomisierten Multizenterstudie (Low Energy Endotak Trial – LEET)

Ziel dieser kontrollierten, prospektiven, randomisierten Studie war die Untersuchung der Effektivitat und der Sicherheit einer reduzierten Defibrillationsenergie mit biphasischer Schockform und einem endokardialem ICD-Sondensystem. 176 Patienten, die klinisch ein typisches ICD-Patientenkollektiv darstellten, wurden im Rahmen der Studie untersucht. Alle Patienten erhielten ein ICD-Aggregat mit der Moglichkeit der Episodenspeicherung (Ventak TM PRx II, PRx III) in Verbindung mit einem rein endokardialem Sondensystem (Endotak TM Serie 0070; 0090, CPI). Die intraoperative Defibrillationsschwelle (DFT) sollte ≤15 J betragen. Die DFT wurde in einem Protokoll mit absteigenden Energiemengen (15, 10…

Paroxysmal atrial fibrillation and high degree AV block: use of single-lead VDDR pacing with mode switching.

Dual chamber rate responsive pacing incorporating a mode switching option is increasingly used in patients with chronic paroxysmal atrial fibrillation and high degree AV block. Single-lead VDDR pacemakers have rarely used for this indication. The purpose of this study was to determine their reliability of atrial sensing during atrial fibrillation, the percentage of atrial synchronous ventricular pacing, and the behavior of the sinus rate outside the phases of atrial fibrillation. We studied ten patients with a single-lead VDDR pacemaker implanted for this indication. Follow-up visits were performed at predischarge and after 1, 3, 6, 12, 18, and 24 months. During the mean follow-up period of…

A simple method for preoperative assessment of the best fitting electrode length in single lead VDD pacing.

For single lead VDD pacing, electrodes with various distances between the lead tip and the floating atrial dipole (AV distance) are available. Using different AV distances allows positioning of the atrial dipole in the mid- to high right atrium, regardless of the size of the right heart. In this position, reliable atrial sensing and rejection of ventricular far-field potentials can be expected. A simple test for the preoperative assessment of the best fitting AV distance in the individual patient was tested. We studied 24 consecutive patients prior to implantation of a VDD pacemaker. With the patient in supine position, a test electrode with an AV distance of 13 cm was taped onto the thorax…

Is atrial sensing of ventricular far-field signals important in single-lead VDD pacing?

UNLABELLED In single-lead VDD pacing the atrial sensitivity frequently is programmed to sensitive values. Atrial sensing of ventricular far-field signals should be reduced by differential atrial sensing. The aim of the study was to evaluate the effectiveness of this approach. METHODS The study included 10 patients with a single-lead VDD pacemaker (Thera 8948, Lead 5032). The atrial sensitivity was set to its most sensitive value of 0.18 mV and the telemetered intraatrial EGM was continuously recorded. After atrial tracked ventricular pacing, VVI pacing was performed with pacing rates from 100 to 160 beats/min in steps of 10 beats/min and up to 165 beats/min. The peak-to-peak amplitudes of P…

Cardiac output in single-lead VDD pacing versus rate-matched VVIR pacing.

The importance of atrioventricular synchronous pacing compared with single-chamber rate-responsive pacing is still under discussion, especially for low-intensity workload representing daily life activities. We evaluated hemodynamics in single-lead VDD pacing versus VVIR pacing in 11 patients (8 men and 3 women, aged 58.6 +/- 13.8 years) with normal left ventricular function and a previously implanted single-lead VDDR pacemaker. A low-intensity steady-state treadmill test at 1 to 2.5 mph with a gradient of 2% to 4% was performed. Cardiac output was determined using a standard carbon dioxide rebreathing technique. Initially, the VDD mode was programmed, and after 5 minutes of exercise, cardia…

Die Spätpotentialanalyse in der Diagnostik nach akutem Myokardinfarkt:¶Risikomarker für den Arrhythmie-gefährdeten und klinisch symptomatischen Patienten (Late potentials in postinfarction patients: arrhythmogenic risk and clinical characteristics)

Ziel der prospektiven Studie ist die Korrelation ventrikularer Spatpotentiale mit klinischen Parametern bei Patienten nach akutem Myokardinfarkt. Es wurde die prognostische Wertigkeit dieser Methode hinsichtlich der Risikostratifizierung bezuglich des plotzlichen Herztodes in der spaten Postinfarktphase im Vergleich mit herkommlichen diagnostischen Moglichkeiten uberpruft. Zudem wurde untersucht, welche klinischen Symptome die potentiell gefahrdeten Patienten charakterisieren.

Kurzzeitmessung der Herzfrequenzvariabilität bei Postinfarktpatienten -

Hintergrund: In der Risikostratifizierung fur einen PHT bzw. das Auftreten eines arrhythmogenen Ereignisses nach AMI wurden bisher eine hohe Spezifitat und ein hoher negativ pradiktiver Wert durch Kombination mehrerer Methoden erreicht. Sensitivitat und positive Pradiktion sind jedoch weiterhin nicht ausreichend. Eine dieser Methoden ist die Messung der HRV, die als unabhangiger Pradiktor eines solchen Ereignisses gilt. Sie wird genutzt, um einen schnellen Uberblick uber den Zustand des autonomen Nervensystems zu bekommen, wird jedoch insbesondere in der Kardiologie bisher nur aus dem 24-Stunden-Langzeit-EKG bestimmt.¶   Studienziel: Die Kurzzeitmessung der HRV bei Postinfarktpatienten als …

How Can We Identify the Best Implantation Site for an ECG Event Recorder?

ZELLERHOFF, C., et al.: How Can We Identify the Best Implantation Site for an ECG Event Recorder? The aim of this study was to show how to find the preferable implantation site for an ECG event recorder (ECG-ER). We compared the quality of bipolar ECG recordings (4-cm electrode distance, vertical position) in 65 patients at the following sites: left and right subclavicular, left and right anterior axillary line (4th-5th interspace), left and right of the sternum (4th-5th interspace), heart apex, and subxyphoidal. The results were compared to the standard ECG lead II. In 30 patients, an additional comparison between vertical and horizontal ECG registrations was done using the same sites. ECG…

VDD(R)-Stimulation mit Mode-Switch bei paroxysmalem Vorhofflimmern und AV-Block: Verlauf über 2 Jahre

Safety and efficacy of implantable defibrillator therapy with programmed shock energy at twice the augmented step-down defibrillation threshold: results of the prospective, randomized, multicenter Low-Energy Endotak Trial.

Whether the safety and efficacy of implantable cardioverter defibrillator (ICD) therapy can be assured with lower output devices is an important question. The purpose of this study was to evaluate whether programming the device output at twice the augmented defibrillation threshold was as safe and effective as using the maximum energy. Patients indicated for ICD therapy, but without slow monomorphic ventricular tachycardia (MVT), who achieved an augmented defibrillation threshold (DFT plus)or = 15 joules (J) with a single endocardial lead system and a biphasic defibrillator were included in the study. Prior to ICD implantation, patients were randomized into 2 groups. The shock energies in t…

Ventilation and Heart Rate Response During Exercise in Normals: Relevance for Rate Variable Pacing

The observation of a close relationship of heart rate to oxygen uptake (HR-VO2) and heart rate to minute ventilation (HR-VE) has been shown to be of particular value in rate variable pacing. However, the impact of anaerobic threshold (AT) for the HR-VO2 and HR-VE slope has been studied less. Twenty-three male and 16 female subjects, mean age 52 +/- 7 years, were selected in whom complete heart catherization and extensive noninvasive studies excluded major cardiopulmonary disease. Semisupine bicycle exercise testing with analysis of respiratory gas exchange was performed using a ramping work rate protocol with work increments of 20 watts/min. At the respiratory AT, determined by the V slope …

Reproduzierbarkeit der Defibrillationseffektivität zur Terminierung von induziertem Kammerflimmern unter Verwendung der intraoperativ gemessenen Defibrillationsschwellenenergie bei Patienten mit implantierbarem Kardioverter-Defibrillator

Ziel vorliegender Untersuchung war es, die Reproduzierbarkeit der Effektivitat der nach einem modifizierten Protokoll intraoperativ bestimmten Defibrillationsschwellenenergie im Langzeitverlauf zu uberprufen. Hierzu wurden im Rahmen einer Substudie einer prospektiven, randomisierten Multizenterstudie (“Low Energy Endotak Trial” LEET)) zwischen Dezember 1993 und Januar 1996 83 Patienten, die im Rahmen einer Erstversorgung mit einem implantierbaren Kardioverter-Defibrillator (ICD) in Kombination mit einem transvenosen Einzelelektrodensystem eine intraoperativ bestimmte Defibrillationsschwelle (DFT) ≤15 J aufwiesen, eingeschlossen. Zur Bestimmung der DFT wurde ein Protokoll mit absteigenden En…

[Is ICD-programming for double intraoperative defibrillation threshold energy safe and effective during long-time follow-up? Results of a prospective randomized multicenter study (Low-Energy Endotak Trial--LEET)].

The aim of this prospective and randomized study was to evaluate the safety and efficacy of a reduced shock strength in transvenous implantable defibrillator therapy. So far clinical data concerning the safety margin of the shock energy in ICD therapy do not exist. The shock energy tested during long-term follow-up in this study was twice the intraoperatively measured defibrillation threshold (DFT). A total number of 176 consecutive patients representing a typical cohort of ICD patients were evaluated. All patients received a non-thoracotomy lead system (CPI, Endotak 0070, 0090) and a biphasic cardioverter-defibrillator with the ability to store episodes (Cardiac Pacemakers Inc., Ventac TM …

Experimentelle Untersuchungen zum Einsatz verschiedener atrialer Dipolkonfigurationen für die Vorhof-Stimulation mit VDD-Elektroden