[Registry and studies of the German Competence Network on Atrial Fibrillation (AFNET)]. / Register und Studien des Deutschen Kompetenznetzes Vorhofflimmern (AFNET).

The German Competence Network on Atrial Fibrillation (AFNET) is a national interdisciplinary research network funded by the Federal Ministry of Education and Research (BMBF). AFNET was initiated in 2003 and aims at improving treatment of atrial fibrillation (AF), the most frequent sustained cardiac arrhythmia. AFNET has established a nationwide patient registry on diagnostics, therapy, course and complications of AF in Germany. The data analyzed to date demonstrate that patients with AF are likely to have multiple co-morbidities, such as hypertension, valvular heart disease, coronary artery disease, diabetes mellitus and advanced age. Oral anticoagulation is provided to the majority of patients in accordance with the recommendations given by guidelines. Further areas of research deal with the optimal duration of antiarrhythmic therapy following electrical cardioversion of atrial fibrillation and the value of strategies to prevent arrhythmogenic changes, such as fibrosis in the atria, for prevention of further episodes of atrial fibrillation. Additional registry projects were established for patients with catheter-based interventional therapy of atrial fibrillation and surgical ablation to define success, complications and long term results of these recently developed procedures more clearly. Data and insights gathered from these projects were used to further develop standards of care in two international conferences.

[Telemedicine in pacemaker therapy and follow-up]. / Telemedizin in der Schrittmachertherapie und Nachsorge.

Present-day remote systems for cardiovascular implantable electronic devices (CIEDs) provide, in contrast to previous solutions, a broad range of data about the patient and the implanted device ("remote control"). Telemedicine includes remote monitoring as well as remote follow-up: Remote monitoring is the continual interrogation of the device to detect patient- or device-related adverse events earlier than with standard follow-up visits. Remote follow-up aims to replace scheduled and unscheduled face-to-face follow-up visits due to the interrogation of the automatic pacemaker functions. Currently available remote systems, such as Home Monitoring, CareLink, Merlin.net, and Latitude, have in common that they interrogate the device, send these data to a server, and provide the data to the physician on a secured web site. Automatic wireless interrogation of the device is the preferred solution; however, the devices must have been equipped with a micro-antenna, which is usually restricted to more recent pacemaker models. Knowledge about remote control in pacemaker patients is limited, because most remote applications were evaluated in ICD and CRT patients. While the most frequently reported clinical event in pacemaker patients is atrial fibrillation, the impact in routine clinical follow-up still has to be evaluated in detail. Device-related adverse events are rare. Large, long-term, randomized trials are comparing remote and conventional approaches with the aim of demonstrating the benefits of telemedicine in this patient group.

[Training requirements for transvenous implantation of pacemakers and cardioverter-defibrillators]. / Empfehlungen zur strukturierung der herzschrittmacher- und defibrillatortherapie.

Therapy with implantable pacemakers, cardioverter defibrillators (ICD), and devices for cardiac resynchronization (CRT) is performed by various medical and surgical specialists. With the change from implantation by thoracotomy to the transvenous approach, an increasing number of devices are implanted by cardiologists. The purpose of this paper is to establish training requirements for transvenous device therapy, implantation and follow-up examinations, regardless of the implanting person, an internist, cardiologist, general surgeon, or cardiothoracic surgeon. Epicardial lead placement should be performed only by surgeons. Two levels of training topics are defined, level 1 for pacemakers and level 2 for ICD and CRT devices. Surgery that involves the implantation of foreign material should demand the highest standards of operating rooms design and environment. Catheter laboratories used for implantations should meet operating room standards. Complications need to be documented carefully for quality control.

Atrial fibrillation and heart failure comorbidity.

Atrial fibrillation and heart failure have in common that they mainly occur in older patients and the patients have similar underlying heart diseases. The prevalence of atrial fibrillation in heart failure patients varies from 10% to 30%. There are conflicting data whether the presence of atrial fibrillation is an independent predictor for an increased mortality in heart failure. Optimal medical heart failure therapy can improve outcome and may influence the relationship between atrial fibrillation and survival. Keystones for the management of atrial fibrillation in heart failure patients are the optimal treatment of heart failure, the use of oral anticoagulation, the case-adjusted decision of rhythm or rate control, and the primary prevention of sudden cardiac death. Heart failure patients with atrial fibrillation should receive long-term oral anticoagulation. The two options to treat atrial fibrillation are rhythm control and rate control. Given the findings of randomised trials, rhythm control of atrial fibrillation with the aim to improve survival is not justified in heart failure patients because of uncertainty about the role of atrial fibrillation as a predictor of worse outcomes and the safety of antiarrhythmic drugs. Rhythm control can be attempted, if rate control is chosen and symptoms persist. The indications for rhythm control are to control symptoms, including a deterioration of heart failure related to a loss of atrial contraction. Amiodarone seems to be the drug of choice to maintain sinus rhythm in patients with paroxysmal atrial fibrillation as well as in patients who returned to sinus rhythm after cardioversion. New non pharmacologic approaches for rhythm control such as catheter-based techniques seem to be highly effective. Rate control to prevent rapid atrial fibrillation is an acceptable approach in otherwise asymptomatic heart failure patients. Slowing of the ventricular rate often leads to a moderate improvement in left ventricular function in many patients. Standard therapy for rate control in heart failure patients consists of partial atrioventricular (AV) node blockade with digoxin and a beta-blocker. Amiodarone is also highly effective to reduce ventricular rate in patients with atrial fibrillation. When rate control remains refractory to medical therapy, rate control is achieved with AV node ablation and subsequent pacemaker implantation. Non pharmacological treatments for the primary prevention of sudden cardiac death are the implantation of a defibrillator.

Effects of bisoprolol treatment for chronic heart failure initiated and followed up by primary care physicians.

UNLABELLED: Primary care physicians prescribe beta-blockers for chronic heart failure infrequently. The aims of the study were to assess the effects of beta-blocker treatment in out-clinic patients with regard to NYHA class and frequency of adverse events. Beta-blocker treatment was initiated and followed up by primary care physicians. METHODS: Chronic heart failure patients already treated with ACE-inhibitors and diuretics were included. The 24-week follow-up consisted of a titration phase followed by a maintenance phase. The patients received the beta-blocker bisoprolol with an initial dose of 1.25 mg and a maximal dose of 10 mg. RESULTS: NYHA class II, III and IV had 174, 146, and one patient, respectively. Treatment duration lasted 189+/-73 days with a maximal bisoprolol dose of 7.2+/-3.2 mg. Sixty-one percent of the patients tolerated at least 7.5 mg bisoprolol. The NYHA class improved from 2.4+/-0.5 at baseline to 1.8+/-0.6 at week 24 (P<0.001). At final assessment, 74% of the patients showed an improvement. The number of permanent treatment withdrawals was 57 (17%). Death occurred in six patients and hospitalisation in 38 patients. CONCLUSIONS: Bisoprolol treatment in patients with chronic heart failure was effectively and safely carried out by primary care physicians.

Automatic analysis of pacemaker diagnostic data in the identification of atrial tachyarrhythmias in patients with no prior history of them.

AIMS: Modern pacemakers provide a large amount of diagnostic data. Given the limited time available during a pacemaker follow-up visit essential information may be overlooked. This registry was conducted to assess the utility of an expert system that analyses the diagnostic data collected by an implanted pacing device and notifies and advises the physician about suspected technical issues and arrhythmias that need further attention. METHODS: Patients with various standard indications for pacing were included in this registry and received single or dual chamber pacemakers. Data were collected and analysed by the expert system during at least two subsequent follow-up visits. The evaluation of this system focused on data obtained from patients with a dual chamber pacing device without prior history of atrial arrhythmias. RESULTS: A total number of 239 patients without prior history of atrial tachyarrhythmias were included in this analysis. Atrial tachyarrhythmias were detected in 73 (31%) of these patients. The highest incidence of newly detected arrhythmias occurred in the group of patients with high-degree AV block and VDD pacemakers. Furthermore, newly detected arrhythmias predominantly occurred in the period shortly after implantation. Device programming suggestions by the expert system were adopted in 30% of the cases. Following detection of atrial tachyarrhythmias by the expert system, pharmacological management was adjusted at 71% of the first follow-up visits and at 27% of later follow-up visits. CONCLUSION: Results of this registry show that this expert system provides a valuable tool for the detection of atrial tachyarrhythmias during pacemaker follow-up visits.

[Are the acute effects of transdermal estradiol in postmenopausal women with coronary disease related to changes of the autonomic tone?]. / Lassen sich die Akuteffekte transdermaler Ostradiolgabe bei Patientinnen mit koronarer Herzerkrankung durch Anderungen des autonomen Tonus miterklären?

The single application of estradiol in postmenopausal women with symptomatic coronary heart disease has an antiischemic effect, which seems to be mainly related to the relaxation of the vascular smooth muscle. Longterm replacement with estrogen in postmenopausal women reduces their increased sympathetic activity. The aim of the double-blinded study was to assess whether a single transdermal estradiol administration also has an effect on the sympathovagal balance and may additionally explain the acute effects of estradiol. Methods Fifteen women with symptomatic and angiographically proven coronary artery disease were cross-over randomized to two 100-microgram patches of estradiol or identical placebo. After one week the women received the opposite treatment. One day after patch application a 24-hour Holter-ECG recording was performed to assess the mean heart rate over 24 hours as well as time domain and frequency domain indices of the heart rate variability. Results The estradiol plasma concentration rose significantly from 354 +/- 176 pmol/l after placebo to 800 +/- 260 pmol/l after estradiol application. Heart rate during placebo was 74 +/- 15 bpm and during therapy 74 +/- 15 bpm. Heart rate variability was not different for time domain indices such as SDNN (estradiol: 64 +/- 31 ms; placebo: 65 +/- 33 ms) or for frequency domain indices such as LF (estradiol: 15.8 +/- 8.0 ms; placebo: 15.3 +/- 9.4 ms) and HF (estradiol: 12.1 +/- 8.5 ms; placebo: 12.9 +/- 9.9 ms). Conclusion A single transdermal application of estradiol did not modify heart rate or heart rate variability of women with coronary artery disease. The modulation of the autonomic tone does not seem to be a relevant mechanism of short-term estradiol effects.

[Evaluation of infrequent episodes of palpitations with a patient-activated hand-held electrocardiograph]. / EKG-Aufzeichnung bei Patienten mit seltenen Episoden von Palpitationen mit einem patienten-aktivierten Ereignisrekorder.

UNLABELLED: The disadvantage of most devices presently available for cardiac rhythm event monitoring is that they require either permanently attached electrodes or the subcutaneous implantation of the device. The aim of the study was to evaluate the feasibility and diagnostic yield of a hand-held, portable electrocardiograph for the evaluation of infrequent episodes of palpitations. In contrast to other devices, this electrocardiograph records and stores the electrocardiograms with integral electrodes, which makes long-term attached electrodes not unnecessary. METHODS: The study included 55 consecutive patients with palpitations less than once a week. The patients received the electrocardiograph Miniscope MS-3 with integral tripod electrodes (Schiller AG, Switzerland) to record a one-channel electrocardiogram during a recurrent episode. The frequency of device activation and the atrial rhythm during an episode was assessed. RESULTS: Forty-one (75%) patients had at least one episode within 38 +/- 22 days. The first episode occurred within the first week in 18 cases, during the 2nd in 9, during the 3rd in 9, during the 4th in 2 patients, and in 3 patients between the 4th and 12th week. All episodes could be properly analyzed: Twenty-three patients had sinus rhythm, 7 paroxysmal atrial fibrillation, 7 paroxysmal atrial flutter, and 4 an AV node reentry tachycardia. Eleven of the 23 patients with sinus rhythm additionally had premature atrial or ventricular contractions. Mean heart rate was 111 +/- 45 bpm. A second episode was recorded in 22 and a third episode in 12 patients. All patients had during the subsequent episode the same cardiac rhythm as during their first episode. CONCLUSIONS: Patients evaluated for their infrequent palpitations had during event monitoring a recurrent episode in 75% that occurred in 88% within the first 4 weeks. All patients were able to activate the electrocardiograph and could store an electrocardiogram with the integral electrodes. Patient-activated event monitoring reliably identified patients with an atrial arrhythmia who need further invasive evaluation and treatment, and ruled out patients with sinus rhythm and premature contractions.

[Preventive pacing in patients with paroxysmal atrial fibrillation: programming and follow-up of patients with dual-chamber pacemakers and triggered preventive pacing functions]. / Präventive Stimulation bei paroxysmalem Vorhofflimmern: : Überlegungen zur Programmierung und Kontrolle von Zweikammerschrittmachern mit getriggerten Algorithmen.

A treatment of patients with paroxysmal atrial fibrillation is the implantation of DDDRP pacemakers for preventive pacing. Atrial pacing with the aim for preventive pacing of atrial fibrillation can be classified as continuous constant pacing with a fixed manually programmed lower atrial pacing rate. The second approach is continuous dynamic overdrive pacing realized by new pacing algorithms, e.g., Pace Conditioning in the Vitatron DDDRP pacemakers. The third approach is discontinuous triggered pacing when specific pacing algorithms are activated by trigger events and temporally pace the atrium. The actual established indications for preventive pacing are patients with a conventional pacing indication and a history of paroxysmal atrial fibrillation. A possible indication are patients with a standard indication for cardiac pacing and a high risk to develop atrial fibrillation as well as patients with drug-refractory atrial fibrillation before AV-node ablation. After pacemaker implantation the pacemaker can be programmed individually according to the onsets of atrial fibrillation observed in the patient or the patient receives a standard programming and subsequently an individual adjustment of the pacing functions. The success of preventive pacing should be assessed a each follow-up visit by interrogation of the extended diagnostic pacemaker counters. There are at present no prospective studies concerning the effects of different pacemaker programming.

Multicenter experiences with a single lead electrode for dual chamber ICD systems.

Monitoring of atrial signals improves the accuracy in identifying supraventricular tachyarrhythmias to prevent inappropriate therapies in patients with implantable ICDs. Since difficulties due to the additional atrial lead were found in dual chamber ICD systems with two leads, the authors designed a single pass VDD lead for use with dual chamber ICDs. After a successful animal study, the prototype VDD lead (single coil defibrillation lead with two additional fractally coated rings for bipolar sensing in the atrium) was temporarily used in 30 patients during a German multicenter study. Atrial and ventricular signals were recorded during sinus rhythm (SR), atrial flutter, AF, and VT or VF. The implantation of the lead was successful in 27 of 30 patients. Mean atrial pacing threshold was 2.5 +/- 0.9 V/0.5 ms, mean atrial impedance was 213 +/- 31 ohms. Atrial amplitudes were greater during SR (2.7 +/- 1.6 mV) than during atrial flutter (1.46 +/- 0.3 mV, P < 0.05) or AF (0.93 +/- 0.37 mV, P < 0.01). During VF atrial "sinus" signals had significantly (P < 0.01) lower amplitudes (1.4 +/- 0.52 mV) than during SR. The mean ventricular sensing was 13.3 +/- 7.9 mV and mean ventricular impedance was 577 +/- 64 ohms. Defibrillation was successful with a 20-J shock in all patients. In addition, 99.6% of P waves could be detected in SR and 84.4% of flutter waves during atrial flutter. During AF, 56.6% of atrial signals could be detected without modification of the signal amplifier. In conclusion, a new designed VDD dual chamber lead provides stable detection of atrial and ventricular signals during SR and atrial flutter. Reliable detection of atrial signals is possible without modification of the ICD amplifier.

Psychiatric conditions in patients with recurrent unexplained syncope.

AIMS: The relationship between syncope and psychiatric disorders is little investigated. This study evaluated the prevalence of psychiatric diseases and prognostic outcome in patients with recurrent unexplained syncope. METHODS AND RESULTS: After an inconclusive standard diagnostic work-up for syncope, including head-up tilt testing, a psychiatric evaluation was offered to 50 consecutive patients with recurrent syncope. The evaluation was accepted by 26 patients (77% females, 36 +/- 16 years) and refused by 24 (63% females, 50 +/- 19 years). A psychiatric disorder was diagnosed in 21 (81%) patients: 12 had depression, four panic attacks, two general anxiety, and three a somatization disorder. Only five patients showed normal psychosocial function. Of the patients with psychiatric disorders four accepted psychiatric care, such as psychotherapy and/or pharmacotherapy; 17 patients refused treatment. During 6 months of follow-up no patient under psychiatric care had syncope, while all patients without psycho- or pharmacotherapy had recurrent syncopal events. In these patients the median of syncopal episodes was three in a 6 months interval before and after clinical assessment. Patients who refused both psychiatric evaluation and therapy continued to experience syncope as before. CONCLUSIONS: In patients with recurrent unexplained syncope psychiatric alteration is common. However, patients seldom accepted a psychiatric evaluation and treatment.

Autocapture compatibility in patients with the MembraneEX lead and Affinity pulse generators.

The first Autocapture generation worked well with all recommended leads. The newer Autocapture generation provides a more sensitive resolution for evoked response testing and its implementation in a dual-chamber device. The purpose of the study was to evaluate the performance of the Affinity SR/DR pacemaker with the new Autocapture algorithm in combination with the small surface area pacing lead MembraneEX in 129 patients. Autocapture ventricular threshold, sensing threshold, lead impedance, evoked response (ER) and polarization signals were determined at implantation and discharge, as well as after 1 and 3 months. Autocapture recommendation rate was based on the ER sensitivity test. The median pacing threshold was 0.38, 0.50, 0.75, 0.75 V at implant, discharge, 1 and 3 months post-implant, respectively. The respective data for median lead impedance were 744, 605, 649 and 691 ohms; median sensing threshold was 12.5 mV at all visits. The median ER amplitude was 9.0, 10.1, 9.9 and 10.1 mV and the median polarization signal 0.39 mV at all visits. The frequency of recommended Autocapture activation was 98.3%, 99.2%, 98.3% and 96.2% of all patients at implant, at discharge, 1 and 3 months post-implant respectively. In conclusion, the studied pulse generator enabled, in combination with this pacing lead, in >95% of all patients activation of Autocapture.

A randomized study on the effects of pacemaker programming to a lower output on projected pulse generator longevity.

The programmability of cardiac pacemakers enables the physician at follow-up to adjust the pacing pulse under consideration of the 100% safety margin with respect to the individual pacing threshold. The purpose of reducing the output is to prolong pacemaker longevity. The aims of this prospective, randomized trial were to compare the effects of nominal output versus a lower output on projected pacemaker longevity in single and dual chamber pacemakers. The secondary aim was to assess how many patients can be programmed to 2.5 V/0.4 ms instead of the nominal 3.5-V setting with > or = 100% safety margin. The patients received the same types of VVI or DDD pacemakers that were connected in the ventricle to the steroid-eluting, high impedance pacing lead. At the 3-month follow-up, patients with ventricular pacing thresholds < or = 0.15 ms at 2.5-V pulse amplitude were randomized to 3.5 V or 2.5 V amplitude at 0.4-ms pulse duration. Lead function and projected device longevity were assessed with the pacemaker's telemetry 6 and 12 months after implantation. Of patients implanted with a VVI pacemaker, at the 3-month follow-up, 3 patients had pacing thresholds > 0.15 ms at 2.5 V and 139 patients could be randomized. A reprogramming to a higher output was necessary in one patient. The mean percentage of ventricular pacing was about 40% throughout the study time. The programming to 2.5-V output resulted in an insignificant increase of device longevity from 117.9 +/- 18.7 months in the nominal group to 123.7 +/- 11.9 months at the 12-month follow-up (P = 0.16). Of patients implanted with a DDD pacemaker, 166 patients underwent randomization. The mean percentage of ventricular pacing was 85% in the ventricle and 35% in the atrium. The 2.5-V setting significantly prolonged pacemaker longevity from 98.1 +/- 21.3 to 112.0 +/- 13.6 months (P < 0.0001). In three (1%) patients a late increase of the pacing threshold was observed. Due to the low ventricular pacing thresholds, the 2.5-V/0.4-ms setting provided, 3 months after implantation, a > or = 100% safety margin in 99% of the patients. Programming to a lower output slightly increased projected pacemaker longevity compared to the nominal 3.5-V setting. Longevity increasedfor 5% in patients with single andfor 14% in dual chamber pulse generators.

Adjustment of the evoked response sensitivity after hospital discharge in pacemaker patients with automatic ventricular threshold tracking activated.

Automatic threshold tracking in cardiac pacemakers allows ventricular capture verification and self-adaptive pacing output regulation. The Autocapture algorithm detects the evoked response (ER) signal immediately after the pacing pulse to verify the efficacy of ventricular pacing. Before hospital delivery, the ER sensitivity must be programmed individually so that the pacemaker detects the ER signal adequately without sensing lead polarization. The aims of the study were to assess the frequency of patients in whom Autocapture could be activated and whether the ER sensitivity had to be adjusted after hospital discharge. The study included 44 patients who received the VVIR pacemaker Regency SR+ (St. Jude Medical) connected to the model 1450 T pacing lead. ER signal, lead polarization, and ER sensitivity were evaluated before hospital discharge and 1, 3, and 6 months after implantation. The system recommended activating Autocapture in 42 of 44 patients. The mean ER signal was 8.4+/-1.2 mV at discharge, 9.0+/-3.9 mV at month 1, 8.9+/-4.9 mV at month 3, and 9.3+/-4.5 mV at month 6. Polarization was 1.0+/-0.1 mV at discharge, 1.1+/-0.5 mV at month 1, 1.1+/-0.2 mV at month 3, and 1.1+/-0.5 mV at month 6. Mean ER sensitivity was 3.7+/-1.8 mV at discharge, 4.0+/-1.8 mV after 1, 4.1+/-2.2 mV after 3, and 4.1+/-1.8 mV after 6 months. ER sensitivity could remain unadjusted in 14 patients. Programming to a less sensitive ER setting from 2.9+/-1.2 mV to 4.3+/-1.5 mV was possible in 21 patients. Programming to a more sensitive ER setting from 4.1+/-1.1 mV to 2.5+/-0.9 mV was required in nine patients because of the decrease of the ER signal. The automatic threshold tracking algorithm Autocapture could be activated in 95% of patients. Programming to more sensitive ER settings was recommended in 21% of the patients after hospital discharge. Therefore, ER signal and polarization must be checked at each follow-up, as a decrease in ER signal amplitude can make reprogramming of the ER sensitivity necessary. There is no risk for the patient if the ER is not sensed, as high voltage backup stimulation is present.

The effects of local steroid-elution on high-performance pacing leads.

Pacing leads without the elution of dexamethasone from the electrode tip usually have an unpredictable increase of pacing threshold within the first few months after implantation. During follow-up, pacing thresholds remained significantly above the level at the time of implantation. The specific clinical effect of local steroid elution is to attenuate the increase of pacing threshold during lead maturation and to maintain low pacing thresholds during follow-up. With pacing thresholds less than 2.5V at 0.5ms pulse duration in more than 95%, patients with steroid-eluting leads rarely have a significant pacing threshold increase compared to patients with non-steroid leads. Steroid elution made the implantation of pacing leads with a small surface of 1.2mm(2) feasible. An advantage of these leads is a higher pacing impedance with values above 1000 ohms, in addition to constant pacing thresholds, which additionally reduces the pacing current. Steroid-elution also avoids in screw-in leads the postoperative threshold peaking, and long-term pacing thresholds were lower compared to non-steroid controls. The local steroid elution itself has no effect on pacing impedance or P/R-wave sensing.