Vester Eg

T Wave Alternans as a Risk Predictor in Patients with Cardiomyopathy and Mild-to-Moderate Heart Failure

The analysis oft wave alternans (TWA) was introduced to identify patients with an increased risk of ventricular tachyarrhythmias. The inducibility of ventricular tach‐yarrhythmias and the spontaneous arrhythmic events are correlated with a positive TWA in patients with a reduced left ventricular ejection fraction and survived myocardial infarction. In contrast, this study is the first to investigate the correlation of a survived sudden cardiac death and TWA in patients without coronary heart disease and only slightly decreased left ventricular function. Sixty patients were included in the study. The TWA analysis was performed using the Cambridge Heart system (CH2000). Patients were sitting on a bicycle ergometer and exercised with a gradual increase of workload to maintain a heart rate of at least 105 beats/min. The exercise test was stopped after recording 254 consecutive low noise level heart beats. The electrocardiographic signals were digitally processed using a spectral analysis method. The magnitude of TWA was measured at a frequency of 0.5 cycles/beat. A TWA was defined as positive if the ratio between TWA and noise level was > 3.0 and the amplitude of the TWA was > 1.8 μV. Twelve (20%) of the included 60 patients showed a positive TWA. The sensitivity concerning a previous arrhythmic event amounted to 65%, the specificity up to 98%, respectively. The alternans ratio was significantly higher in patients with a previous event (30.3 ± 53.2 vs 2.9 ± 5.9, P < 0.001) and cumulative alternans voltage (4.67 ± 3.55 vs 1.75 ± 1.88 μV, P < 0.001). In 19 patients, invasively investigated by an electro‐physiological study, a significant correlation between inducibility of tachyarrhythmias and a positive TWA result was found (Spearman R = 0.51, P = 0.01). In conclusion, the TWA analysis seems to identify patients with nonischemic Cardiomyopathy who are at an increased risk of ventricular tachyarrhythmias.

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 test group patient were set as follows: first shock at twice DFT plus, the second to fifth shocks at maximum output (34 J). In control group patients, all shocks were programmed at 34 J. The study population consisted of 166 consecutive patients (mean age 57.4 +/- 12.1 years, mean left ventricular ejection fraction 36.8 +/- 13.8%). Mean DFT plus was 9.6 +/- 3.2 J in test group patients and 10.1 +/- 3.5 J in control group patients (p = 0.36). During a mean follow-up of 24.2 +/- 9.6 months, 736 arrhythmia episodes were analyzed. The first shock efficacy was 98.3% in the test group patients versus 97.4% in the control group (p = 0.45). Total mortality was 6%, equally distributed in both study groups. The results of this study prove that the method of doubling the defibrillation energy at the DFT plus level provides an adequate safety margin in defibrillator therapy.

Defibrillation Energy Requirements with Single Endocardial (Endotak™) Lead

The need for thoracotomy in usually high risk patients has limited the use of the implantable cardioverter defibrillator. Initial clinical results with endocardial and subcutanous patch electrodes (SQPs) are en couraging. Using a single endocardial lead in the absence of a SQP for chronic implantation of the cardioverter defibrillator, the goal of the study was to obtain defibrillation thresholds (DFTs) of 15 Joules (J) or less and to investigate changes in DFT over time. We tested 19 consecutive patients (15 men, 4 women] age 62 ± 8.5 years with malignant ventricular arrhythmias (14 VT/5 VF). The underlying heart disease was coronary artery disease in 15 pafients, dilative cardiomyopathy in two patients, and primary electricaJ disease in two patients. Four patients had undergone previous cardiac surgery. Left ventricular ejection fraction ranged between 14% and 66% (39%± 12.6%). Pacing thresholds (0.54 ± 0.17 Vat 0.5 msec), R wave amplitude for pacemaker sensing (14.2 ± 7.0 mV), slew rate (2.12 ± 1.4 V/sec), and resistance (500.3 ± 73.9 W) were sufficient in all patients. Eighteen patients met our endocardial impiant criteria with a DFT ≤ 15 J (10.05 ± 4.03 J) using monophasic (14 patients) or biphasic (four patients) pulse wave forms. In the one remaining patient, with a DFT of 20 J, we implanted a SQP but there was no reduction of the DFT. All patients tested showed successful defibrillation prior to discharge. During follow‐up of 88 patient‐months (1–9 months), 114 spontaneous VT/VF episodes occurred in five patients and were all successfully terminated. Eleven patients with a minimum follow‐up of 2 months were reassessed. In seven out of 11 patients, termination of VF was achieved with the same minimal energy requirements obtained intraoperatively. In three patients, DFT increased by 5 J (one patient) and 10 J (two patients). In a further patient, X ray revealed dislocation of the endocardial lead. Our data suggest that effective defibrillation is feasible with a single endocardial lead for implantation of cardioverter defibrillator. In addition, we strongly recommend repetitive x‐ray control to detect asymptomatic lead dislocation. Despite stable DFTs in most of our patients, an energy difference of ≤ 15 J between acute DFT and cardioverter defibrillator energy rating seems to be currently desirable to ensure successful postoperative defibrillation.

Chemoreflexsensitivity in Patients with Survived Sudden Cardiac Arrest and Prior Myocardial Infarction

For evaluation of patients with an increased risk of sudden cardiac death, the analyses of ventricular late potentials, heart rate variability, and baroreflexsensitivity are helpful. But so far, the prediction of a malignant arrhythmic event is not possible with sufficient accuracy, For a better risk stratification other methods are necessary. In this study the importance of the ChRS for the identification of patients at risk for ventricular tachyarrhythmic events should be investigated. Of 41 patients included in the study, 26 were survivors of sudden cardiac arrest. Fifteen patients were not resuscitated, of whom 6 patients had documented monomorphic ventricular tachycardia and 9 had no ventricular tachyarrhythmias in their prior history. All patients had a history of an old myocardial infarction (> 1 year ago). For determination of the ChRS the ratio between the difference of the RR intervals in the ECG and the venous pO2 before and after a 5‐minute oxygen inhalation via a nose mask was measured (ms/mmHg). The 26 patients with survived sudden cardiac death showed a significantly decreased ChRS compared to those patients without a tachyarrhythmic event (1.74 ± 1.02 vs 6.97 ± 7.14 ms/mmHg, P < 0.0001). The sensitivity concerning a survived sudden cardiac death amounted to 88% for a ChRS below 3.0 ms/mmHg. During a 12‐month follow‐up period, the ChRS was significantly different between patients with and without an arrhythmic event (1.64 ± 1.06 vs 4.82 ± 5.83 ms/mmHg, P < 0.01). As a further method for evaluation of patients with increased risk of sudden cardiac death after myocardial infarction the analysis of ChRS seems to be suitable and predicts arrhythmias possibly more sensitive than other tests of neurovegetative imbalance. The predictive importance has to be examined by prospective investigations in larger patient populations.

Incidence and therapy of peripheral arterial vascular complications after heart catheter examinations

Wir analysierten die Inzidenz und Therapie aller in unserer Klinik aufgetretenen signifikanten lokalen Gefäßkomplikationen an der Punktionsstelle nach invasiver diagnostischer und interventioneller Herzkatheterisierung. Während eines 7jährigen Untersuchungszeitraums wurden 27387 Herzkatheteruntersuchungen durchgeführt, es handelte sich um 19581 diagnostische und 7806 interventionelle Herzkatheter. Insgesamt traten bei 114 der insgesamt 27387 Herzkatheterisierungen (0,42%) signifikante periphere lokale Gefäßkomplikationen auf. In 36 Fällen (0,13%) handelte es sich um arterielle Verschlüsse am Ort der Punktion, bei 34 Patienten (0,12%) um bedeutsame Hämatome an der Punktionsstelle (OP oder Bluttransfusion erforderlich), bei 32 Patienten (0,12%) um persistierende Pseudoaneurysmen, bei 9 Patienten (0,03%) um eine AV-Fistel und bei 3 Patienten (0,01%) um andere schwerwiegende Komplikationen. Lokale Gefäßkomplikationen waren deutlich häufiger bei Frauen als bei Männern nachweisbar, außerdem war nach interventioneller Kathetertherapie unter Verwendung großlumiger Schleusen mit der Notwendigkeit einer effektiven Heparintherapie die Häufigkeit von Komplikationen deutlich gegenüber rein diagnostischen Untersuchungen erhöht. Bei vorbestehender arterieller Verschlußkrankheit war die Häufigkeit eines lokalen Gefäßverschlusses erhöht. Eine operative Revision der Gefäßkomplikation war bei 62 Patienten (54%) notwendig, 34 Patienten (30%) wurden konservativ behandelt. Bei 18 Patienten (17%) konnte durch Kathetertechniken (PTA, lokale Lyse, Stent-Implantation) ein Gefäßverschluß eröffnet werden. Insgesamt ist die Inzidenz einer signifikanten lokalen Gefäßkomplikation nach Herzkatheteruntersuchung selten. Zukünftig werden diese vaskulären Komplikationen zunehmend auch durch konservative Maßnahmen (z.B. lolake Kompressionsbehndlung bei Pseudoaneurysmen) oder Kathetertechniken (vor allem zur Rekanalisation von arteriellen Verschlüssen) behandelt werden können. We analyzed the incidence and management of major vascular complications at the arterial puncture site following diagnostic or interventional cardiac catheterization. 27387 cardiac catheterization procedures were performed for diagnostic (n = 19581) or interventional (n = 7806) purposed at our institution during a 7-year study period. A total number of 114 major vascular complications (0.42%) were identified. In 36 (0.13%) patients an arterial occlusion at the puncture site was detected, 34 patients (0.12%) had severe hematoma (blood transfusion or surgical repair necessary), 32 patients (0.12%) developed false aneurysms, 9 patients (0.03%( with av-fistulas and 3 patients (0.01%) had other complications. The following factors were predictive for a significant increase in the incidence of major vascular complications: Female gender, interventional catheterization using larger introducer sheaths and necessitating effective perioperative doses of heparine, and peripheral vascular disease. Operative repair was necessary in 62 patients (54%), 34 patients (30%) were treated conservatively. In 18 patients (17%) acute vascular occlusion could be managed by percutaneous transluminal balloon dilatation and intravascular thrombolysis of the obstructionn, in 3 patients additional stent-implantation was necessary in the presence of a large occlusive dissection. Overall the rate of clinically significant major vascular complications is low. In the future a greater number of vascular complications at the entry site for cardiac catheterization will be treated with nonoperative methods (e.g. manual compression of pseudoaneurysms or catheter-based techniques for recanalization of acutely occluded vessels).

Gold vs. platinum-iridium tip catheter for cavotricuspid isthmus ablation: the AURUM 8 study.

AIMS Gold electrodes have the theoretical advantage of creating bigger lesions than platinum-iridium (Pt-Ir) electrodes. We performed a prospective randomized study to compare the clinical efficacy of standard 8 mm Pt-Ir tip catheter (control) and 8 mm gold-tip catheters in the ablation of the cavotricuspid isthmus (CTI)-dependent atrial flutter. METHODS AND RESULTS A total of 463 patients undergoing CTI ablation in 19 clinical centres were randomized to receive the treatment by gold-tip or control catheter. The primary endpoint was cumulative radiofrequency (RF) application duration until achieving bidirectional CTI block. It did not differ significantly for the two catheters. The gold-tip catheter was, however, associated with a higher ablation success rate (94.3 vs. 89.0%, P = 0.042) and a substantially lower incidence of char and coagulum formation (4.8 vs. 37.9%, P < 0.001), which required exchange of 1 gold-tip (0.4%) and 10 control catheters (4.6%, P = 0.005). The gold-tip catheter delivered more mean power (52 ± 12 W) than the control catheter (48 ± 13 W, P < 0.001). Both mean and maximum temperatures measured by the thermocouple integrated in the catheter tip were statistically significantly lower in the gold (mean: 53.2 ± 4.7°C, max: 68.7 ± 6.6°C) than in the control catheter (54.3 ± 5.2 and 70.2 ± 7.0°C, respectively, P < 0.05). Fluoroscopy time, procedure duration, procedural-related complications, and arrhythmia recurrence during 6 months of follow-up did not differ between the two catheters. CONCLUSION Owing to a higher primary ablation success rate and reduced incidence of char/coagulum formation, gold may be preferred over Pt-Ir as electrode material for 8 mm tip catheters for CTI ablation. ClinicalTrials.gov: NCT00326001 (http://clinicaltrials.gov/ct2/show/NCT00326001).

Etiology and Pathogenetic Mechanisms of Optic Disc Swelling with Visual Loss

A nonrandomized, prospective, interdisciplinary pilot study of 102 patients with noncompressive optic disc swelling with visual loss (ODSWVL) was performed in order to investigate etiologic and pathogenetic mechanisms. Forty-six patients suffered from underlying inflammatory disease. Seventeen patients suffered from highly probable cardiogenic embolization, 16 patients from multiple vascular risk factors. The remaining patients of the noninflammatory disease group suffered from leukemia, previously unknown or severely decompensated diabetes mellitus, acute arterial hypertension, different kinds of coagulopathies and others. Ninety-six of the 102 patients required medical treatment according to general medical standards. Inhomogeneity of the underlying disease processes explains the ineffectiveness of different monotherapies in previous studies. Interdisciplinary search for the underlying causes allows causative treatment. ODSWVL and anterior ischemic optic neuropathy in particular seem to be a common final pathway of various pathogenetic mechanisms due to different etiologies rather than a disease entity by itself.

Optimal method to achieve consistently low defibrillation energy requirements

Reduction of the defibrillation energy requirement offers the opportunity to decrease implantable cardioverter defibrillator (ICD) size and to increase device longevity. Therefore, the purpose of this prospective study was to obtain confirmed defibrillation thresholds (DFTs) of < or = 15 J in each patient with an endocardial dual-coil lead system incorporating an active pectoral pulse generator (TRIAD lead system: RV- --> SVC+ + CAN+). According to our previous clinical and experimental studies, we tried to lower DFTs that were > 15 J by repositioning the distal coil of the endocardial lead system in the right ventricle. A total of 190 consecutive patients requiring ICDs for ventricular fibrillation and/or recurrent ventricular tachycardia were investigated at the time of ICD implantation (42 women, 148 men; mean age 61.9 +/- 12.0 years; mean left ventricular ejection fraction 42.7 +/- 16.6%). Coronary artery disease was present in 139 patients; nonischemic dilated cardiomyopathy in 34 patients; and other etiologies in 17 patients; 47 patients had undergone previous cardiac surgery. Regardless of optimal pacing and sensing parameters, for patients having DFTs > 15, we repositioned the distal coil of the endocardial lead system toward the intraventricular septum to include this part of both ventricles within the electrical defibrillating field. In 177 of 190 patients, induced ventricular fibrillation was successfully terminated with < or = 15 J (group I) using the initial lead position. Repositioning of the endocardial lead was necessary in 13 patients whose DFT(plus) (DFT(plus) = second additional success at lowest energy level) were > 15 J (group II). In all patients, repositioning was successful within a 15 J energy level (100% success). The mean DFT(plus) was 7.3 +/- 3.5 J (group I) and 11.0 +/- 4.5 J (group II; p<0.005). The mean DFT(plus) of all patients enrolled in the study was 7.6 +/- 3.7 J (range: 2 to 15 J). In 87% of all patients, DFT(plus) of < or = 10 J was achieved. Repositioning of the endocardial lead in the right ventricle is a simple and effective method to reduce intraoperative high DFTs. As a result of this procedure, ICDs with a 20 J output should be sufficient for the vast majority (87%) of our patients. Furthermore, we were able to avoid additional subcutaneous or epicardial electrodes in all patients.

Myokardischämie und ventrikuläre Arrhythmien

Ein Zusammenhang zwischen akuter Myokardischämie und Arrhythmieauslösung läßt sich bei der koronaren Herzkrankheit im Gegensatz zu primär nicht ischämischen Herzerkrankungen durch kombinierte metabolisch-elektrophysiologische Untersuchungen (programmierte atriale und ventrikuläre Stimulation mit simultaner arterio-koronarvenöser Messung von Laktat, Pyruvat, freien Fettsäuren und Aminosäuren) nachweisen. Dabei zeigen sich signifikante metabolische Unterschiede zwischen beiden Erkrankungen unter Stimulationsbedingungen und z.T. auch in Ruhe. Bei Patienten, die im chronischen Postinfarktverlauf anhaltende ventrikuläre Tachyarrhythmien (VT/VF) entwickeln, finden sich häufiger als bei Patienten ohne VT/VF-Ereignisse Areale “hibernierenden” Myokards, szintigraphisch definiert als sog. Mismatchzonen mit reduzierter Perfusion und erhaltenem Stoffwechsel. Diese sind möglicherweise als bedeutsame Risikofaktoren für Arrhythmieereignisse und plötzlichen Herztod nach Herzinfarkt aufzufassen. Hierbei gewinnt das Konzept, daß die Interaktion zwischen akuter Ischämie und chronischer Ischämie bzw. Narbe zur Tachyarrhythmie, insbesondere polymorphen VTs und Kammerflimmern, führt, zunehmend an Bedeutung. Dagegen entstehen monomorphe Reentrytachykardien in der überwiegend durch Fibrose und vereinzelte vitale Inseln gekennzeichneten Narbenrandzone, die durch eine ausgeprägte gleichgerichtete Reduktion von Perfusion und Stoffwechsel gekennzeichnet ist. In diesen Fällen kann nur durch interventionelle Verfahren (Katheterablation, ICD-Implantation oder antitachykarde Operation) neben einer antiarrhythmischen medikamentösen Therapie eine Arrhythmiekontrolle erzielt werden. Eine antiischämische Kausaltherapie (PTCA oder ACB-Operation) stellt für maximal 40% der Patienten mit ischämischer Tachyarrhythmie in der Vorgeschichte eine allein ausreichende Therapieoption dar. Sie erscheint vor allem gerechtfertigt bei Patienten mit guter linksventrikulärer Funktion, funktionellem Ischämienachweis und postinterventioneller Arrhythmiesuppression bzw. prä- und postoperativer Nichtauslösbarkeit. In allen übrigen Fällen ist eine zusätzliche Absicherung durch Antiarrhythmika oder ICD-Implantation notwendig. A relation between myocardial ischemia and induction of ventricular arrhythmias can be demonstrated in patients with coronary heart disease – in contrast to patients with primary non ischemic cardiac diseases – using a combined metabolic-electrophysiological investigation protocol consisting of programmed atrial and ventricular stimulation with simultaneous measurement of the arterio/coronary venous difference for lactate, pyruvate, free fatty acids and amino acids. There are significant metabolic distinctions between both ischemic and non ischemic heart disease under pacing stress conditions as well as at rest. Areas of “hibernating myocardium” resp. “mismatch” zones in the myocardium showing reduced or abolished perfusion and preserved metabolism during scintographic SPECT/PET studies, may be found more often in patients with ventricular tachycardias (VT) or ventricular fibrillation (VF) in the chronic post myocardial infarction state than in patients without VT/VF. The proof of such zones may be considered a possible risk factor for arrhythmic events and sudden cardiac death after myocardial infarction. Hereby the concept of an interaction between acute and chronic ischemia triggering the onset of polymorphic VT or VF gaines increasing acceptance. In contrast, monomorphic reentrant VT are usually generated in the border zone of scarred areas where islands of vital fibers are surrounded by fibrotic tissue. These arrhythmogenic origin regions are characterized by a “match” pattern presenting a comparably severe reduction of perfusion and metabolism. Under those circumstances a control resp. suppression of the VT focus can only be provided by interventional techniques like catheter ablation, antitachycardiac surgery or implantation of a cardioverter/defibrillator beyond antiarrhythmic drug therapy. An antiischemic causal treatment (bypass surgery or angioplasty) represents for maximal 40% of patients with ischemically induced ventricular arrhythmias an adequate and sufficient therapeutic option. This pure antiischemic procedure seems to be justified especially in patients with preserved left ventricular function, proof of reversible ischemia and non inducibility of VT/VF following revascularization or non inducibility pre- and post intervention. In all other instances an additional treatment by antiarrhythmic drugs or preferably the implantable defibrillator is required.

Chemoreflex- und Baroreflexsensitivität bei Patienten mit überlebtem plötzlichem Herztod

Einleitung. Zur Untersuchung von Patienten mit einem erhöhten Risiko des plötzlichen Herztodes sind die Analyse ventrikulärer Spätpotentiale, der Herzfrequenzvariabilität und der Baroreflexsensitivität hilfreich. Jedoch gelingt die Vorhersage eines malignen arrhythmischen Ereignisses bislang nicht mit genügender Genauigkeit. Zur besseren Risikoabschätzung sind weitere Methoden notwendig. In dieser Arbeit soll die Wertigkeit der Chemoreflexsensitivität für die Vorhersage ventrikulärer Tachyarrhythmieereignisse untersucht werden. Methoden. Von 44 in die Studie eingeschlossenen Patienten waren 23 Überlebende des plötzlichen Herztodes. 7 Patienten hatten anhaltende monomorphe ventrikuläre Tachykardien, 14 Patienten keine anhaltenden ventrikulären Ereignisse in der Vorgeschichte. Die Untersuchung der Baroreflexsensitivität (BRS) wurde in standardisierter Form durch Anheben des systolischen Blutdruckes mittels Norfenefrin (Novadral) bei gleichzeitiger Erfassung der Zunahme der RR-Intervalle im Oberflächen-EKG durchgeführt. Zur Bestimmung der Chemoreflexsensitivität (ChRS) wurde das Verhältnis aus der Änderung der RR-Intervalle und des venösen pO2 nach fünfminütiger O2-Gabe über eine Nasenmaske gebildet. Ergebnisse. Die 23 bei Kammerflimmern erfolgreich reanimierten Patienten wiesen signifikant niedrigere Werte für die Chemoreflexsensitivität verglichen mit Patienten ohne ein Arrhythmieereignis in der Vorgeschichte auf (2,49 ± 1,86 vs. 6,75 ± 6,79 mm Hg, p < 0,001). Für die Baroreflexsensitivität zeigten sich dagegen keine signifikanten Unterschiede (5,23 ± 3,95 vs. 5,34 ± 3,10 mm Hg, p = n. s.). Patienten mit überlebtem plötzlichem Herztod, die in der elektrophysiologischen Untersuchung auslösbare Tachyarrhythmien boten, hatten signifikant niedrigere Werte für BRS und ChRS als solche Patienten ohne auslösbare Tachyarrhythmien. Schlußfolgerung. Als weitere Methode zur Erfassung von Patienten mit einem erhöhten Risiko des plötzlichen Herztodes scheint die Analyse der Chemoreflexsensitivität geeignet, und sie sagt eine Arrhythmiegefährdung sehr sensitiv voraus. Die prädiktive Bedeutung muß durch weitere prospektive Untersuchungen an großen Patientenkollektiven gesichert werden. Introduction. To evaluate patients with an increased risk of sudden cardiac death the analysis of ventricular late potentials, heart rate variability and baroreflexsensitivity is helpful. However, the prediction of malignant arrhythmic events cannot be performed with sufficient accuracy. For a better identification of high risk patients other methods are necessary. In this study the impact of the chemoreflexsensitivity for the prediction of ventricular tachyarrhythmias was investigated. Methods. Out of 44 patients included in the study, 23 were survivors of sudden cardiac death (SCD). Seven patients suffered from sustained monomorphic ventricular tachycardias, 14 had no arrhythmic events in their prior history. For the investigation of the baroreflexsensitivity (BRS) systolic blood pressure was augmented by Norfenefrin (Novadral) and the resulting increase of RR-intervals was measured in the surface-ECG. For determination of the chemoreflexsensitivity (ChRS) the ratio of the RR-interval-shift and the blood pressure shift during a 5-min inhalation of oxygen with a nose mask was formed. Results. Patients with aborted SCD showed significantly decreased values for the ChRS compared to those patients without an arrhythmic event in their priority history (2.49 ± 1.86 vs. 6.75 ± 6.79 mm Hg, p < 0.001). In contrast, for the BRS no significant differences could be found (5.23 ± 3.95 vs. 5.34 ± 3.10 mm Hg, p = n. s.). Patients with aborted sudden cardiac death and inducible tachyarrhythmias during the electrophysiologic study showed significantly lower values of BRS and ChRS compared to patients without inducibility. Conclusion. As a new method for identification of patients with an increased risk of sudden cardiac death the analysis of chemoreflexsensitivity seems feasable and indicates an increased arrhythmic risk with a high sensitivity. The predictive impact has to be corroborated in larger patient collectives by prospective studies.