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In a subset of patients with pacemaker models Assurity® and Endurity® (Abbott, Sylmar, California, USA; worldwide outside the USA approximately 83,000 devices), a mistake during production may have occurred resulting in insufficient adhesion between the pulse generator header and device housing which in turn may allow moisture to enter the header. This may cause loss of telemetry, switch to back-up mode, reduced battery longevity, or in worst case loss of pacing. Until June 2022, these malfunctions were reported for 128 devices worldwide (0.15%); no permanent harm to patients due to this issue has been reported. The nucleus of the AGEP suggests the following recommendations: (1) Patients with a device under safety advisory should be informed. (2) The risks for the patient in case of loss of stimulation should be assessed. Patients should be categorized into "likely pacemaker-dependent" (e.g., indication permanent atrioventricular [AV] block, no intrinsic rhythm at the last follow-up, percentage of ventricular pacing in the device memory 90%), "unknown", or "likely not pacemaker-dependent" (e.g., indication sick sinus syndrome, intrinsic rhythm 50 bpm at the last follow-up, percentage of ventricular pacing in the device memory 1%). (3) In likely pacemaker-non-dependent patients, information about this issue should be provided together with an unchanged follow-up or a follow-up with shortened intervals (e.g., every 3 months) and/or remote monitoring. (4) In patients with unknown risk if stimulation failure occurs, at least follow-up intervals should be shortened to, for example, 3 months and/or remote monitoring should be initialized. In addition, risks and benefits of a device exchange should be weighed against each other. (5) In patients who are likely pacemaker-dependent, device exchange is recommended.Bei einer Untergruppe von Schrittmachern der Modelle Assurity® und Endurity® (Fa. Abbott, Sylmar, Kalifornien, USA; weltweit ca. 83.000 Geräte) kann es bei der Herstellung zu einem Verarbeitungsfehler der Verbindung zwischen Konnektorblock („header“) und Metallgehäuse gekommen sein, wodurch Feuchtigkeit eindringen kann. Dies kann zu Verlust der Telemetriefähigkeit, Umstellen in den Back-up-Modus, verkürzter Batterielaufzeit oder im schlimmsten Fall zu einem Stimulationsverlust führen. Bis Juni 2022 wurden solche Ausfälle bei 128 Geräten weltweit (0,15 %) gemeldet, gesundheitliche Schäden durch einen Ausfall wurden bis zu diesem Zeitpunkt nicht gemeldet.Der Nucleus der AGEP empfiehlt hierzu folgendes Vorgehen: 1. Patienten, bei denen ein betroffenes Gerät implantiert wurde, sollten informiert werden. 2. Die Risiken für den Patienten im Fall eines Ausfalls des Schrittmachers sollten abgeschätzt werden und die Patienten in „vermutlich schrittmacherabhängig“ (z. B. Indikation: permanenter AV-Block, bei letzter Kontrolle kein Eigenrhythmus, Anteil ventrikulärer Stimulation im Speicher 90 %), „unklar“ und „vermutlich nicht schrittmacherabhängig“ (z. B. Indikation: Sick-Sinus-Syndrom, bei letzter Kontrolle Eigenrhythmus 50/min, Anteil ventrikulärer Stimulation im Speicher 1 %) kategorisiert werden. 3. Bei vermutlich nicht schrittmacherabhängigen Patienten genügt eine Information zusammen mit unveränderter Nachsorge, ggf. können die Nachkontroll-Intervalle auf z. B. 3 Monate verkürzt und/oder eine Fernnachsorge initiiert werden. 4. Bei Patienten mit unklarem Risiko im Fall eines Schrittmacherausfalls sollten zumindest die Nachkontroll-Intervalle auf z. B. 3 Monate verkürzt und/oder ein Fernnachsorge initiiert werden und individuell Nutzen und Risiken eines Geräteaustauschs abgewogen werden. 5. Bei vermutlich schrittmacherabhängigen Patienten wird ein Geräteaustausch empfohlen.

Programming of implantable cardiac devices, especially dual-chamber pacemakers, can be challenging in daily clinical practice. Precise knowledge of programmable parameters is important; furthermore, one should also be familiar with the specific algorithms of each manufacturer. During programming, the patient's individual requirements should be taken into account, but out-of-the-box programming should be avoided. Another important goal of programming should be to stimulate as much as needed but as little as possible to provide the patient good exercise capacity while not being aware of the pacing. Manufacturers' algorithms can help reach these aims but need to be understood and-in case of inappropriate behavior-to be deactivated.Die Programmierung von Schrittmachersystemen, insbesondere von Zweikammerschrittmachersystemen kann die untersuchenden Ärzte vor große Herausforderungen stellen. Eine genaue Kenntnis der zu programmierenden Parameter sowie der herstellerspezifischen Algorithmen ist essentiell. Bei der Programmierung sollte darauf geachtet werden, die Programmierung den individuellen Bedürfnissen der Patient:innen anzupassen und „Out-of-the-box“-Programmierungen zu vermeiden. Ein weiteres wichtiges Ziel der Programmierung ist es, unnötige Stimulation im rechten Ventrikel zu vermeiden und dem Patienten eine gute Belastbarkeit zu ermöglichen sowie zu vermeiden, dass er eine Stimulation wahrnimmt. Algorithmen der Hersteller können hierbei helfen, müssen jedoch verstanden und bei inadäquatem Verhalten ggf. deaktiviert werden.

Cardiac pacemakers are an extremely effective treatment for bradycardia but can, however, cause desynchronization of ventricular contraction leading to cardiomyopathy. Pacing of the conduction system can prevent and even reverse desynchronization, which is impressively visible in echocardiography with speckle tracing. His' bundle and left bundle branch pacing requires a specific implantation technique, sheaths and leads which can achieve successful stimulation of the conduction system in up to 98% of cases. Data on conduction system pacing have been acquired in numerous studies but only a few randomized outcome studies. Therefore, in the current European guidelines His' bundle and left bundle branch pacing only have a low level recommendation. The guidelines recommend His' bundle pacing in patients in whom a coronary sinus lead cannot be implanted and in patients with permanent atrial fibrillation and planned atrioventricular (AV) node ablation for heart rate control. Additionally, conduction system pacing appears to be meaningful in patients with an AV block who require pacing of the ventricle for ≥20% of the time or who already show a slightly or moderately reduced left ventricular ejection fraction (36-50%). Even in patients scheduled for generator replacement who have developed a cardiac pacemaker-induced cardiomyopathy, the opportunity should not be missed to upgrade the system by implantation of a His' bundle electrode.Herzschrittmacher stellen eine extrem effektive Therapie von Bradykardien dar, können jedoch über eine Desynchronisation der ventrikulären Kontraktion eine Kardiomyopathie verursachen. Die Stimulation des Leitungssystems kann diese Desynchronisation verhindern und rückgängig machen, was echokardiographisch im „speckle tracking“ eindrucksvoll sichtbar wird. His-Bündel- und Linksschenkelstimulation erfordern eine spezielle Implantationstechnik, Schleusen und Elektroden, wodurch eine erfolgreiche Stimulation des Leitungssystems in bis zu 98 % der Fälle erreicht werden kann. Bislang liegen zahlreiche Studiendaten, jedoch nur wenige randomisierte Outcome-Studien vor. In den aktuellen europäischen Leitlinien ist die His-Bündel‑/Linksschenkelstimulation daher nur mit einem geringen Empfehlungsgrad versehen. In den Leitlinien wird die His-Bündel-Stimulation für Patienten, bei denen keine Koronarsinuselektrode implantiert werden kann, und für Patienten mit permanentem Vorhofflimmern, bei denen eine Atrioventrikular(AV)-Knoten-Ablation zur Frequenzkontrolle geplant ist, empfohlen. Darüber hinaus erscheint sie sinnvoll für Patienten mit AV-Blockierungen, bei denen die Notwendigkeit besteht, den Ventrikel für 20 % der Zeit oder länger zu stimulieren, oder die bereits eine leicht- bis mittelgradig reduzierte linksventrikuläre Ejektionsfraktion (36–50 %) zeigen. Auch bei Patienten, bei denen sich zum Zeitpunkt des Aggregatwechsels eine schrittmacherinduzierte Kardiomyopathie zeigt, sollte die zusätzliche Implantation einer His-Bündel-Elektrode erwogen werden.

His bundle pacing (HBP) allows ventricular excitation through the entire cardiac conduction system, resulting in a better synchronicity and efficacy of contraction compared to myocardial pacing. Due to better, dedicated implantation tools and exact practical implantation recommendations, HBP has developed into a form of stimulation that can be successfully applied with reasonable time and effort in90% of patients. The rate of lead dislodgement and threshold increase is similar to conventional pacemaker systems. Despite a rather weak data base and a paucity of randomized trials, HBS represents an alternative to conventional right or biventricular pacing in the following conditions: (1) high-degree atrioventricular (AV) block with expected ventricular pacing20% of the time, (2) AV block 1st degree with long PQ (alone or in combination with intermittent 2nd to 3rd degree AV block or sick sinus syndrome), (3) AV node ablation due to refractory atrial fibrillation, and (4) upgrade in pacing-induced cardiomyopathy. Moreover, HBP may be useful in context with cardiac resynchronization therapy (CRT). Left bundle branch block below the level of His represents a limitation of HBP. Therefore, more recently left bundle branch pacing (LBBP) has been introduced to correct left bundle branch block. LBBP seems to be possible in a wider anatomic area and may be easier to implant. However, LBBP requires active screw-in of the lead deep into the ventricular septum. Experience with this new technique is limited, particularly regarding long-term performance.

Long-term right ventricular apical pacing is known to be deleterious for left ventricular function leading to the clinical picture of heart failure with all the possibly associated complications, ranging up to death of the affected patient. This led to the ambition to find alternative pacing sites such as pacing at the right ventricular outflow tract or septal pacing. An attractive alternative is selective His bundle pacing with the goal to use the physiologic His-Purkinje system in order to enable intrinsic conduction and physiologic myocardial contraction. To find and identify the His bundle poses a challenge for operators. For exact endocardial mapping, knowledge of the anatomic landmarks is as important as the ability to evaluate local electrocardiograms. The goal of this review is to characterize the anatomic landmarks to help physicians to identify these precise targets for His bundle pacing.

The 75 year old patient was hospitalized because of vertigo, exertional dyspnea and clamminess. Based on ischemic heart disease with sick sinus syndrome a pacemaker was implanted 5.5 years ago. In consequence of non-permanent atrial fibrillation Dronedaron was added to medication 8 months ago.The patient presented unstable. The ECG showed a second-degree atrioventricular block with wenckebach periodic and a frequency of 29 bpm. The pacemaker survey showed primary a proper atrial function but ineffective ventricular stimulation.After initial external pacing the pacemaker was reprogrammed and in this way the ventricle stimulated effectively. Dronedaron was ceased after checking trigger factors and the patient left hospital after 3 days free of complaints. The pacemaker survey 18 days later showed a proper function with stabilized pacing threshold close to the old level.In patients with dysfunction of a permanent pacemaker an increased pacing threshold should be excluded and if any the current medication needs to be controlled. Caution should be exercised to Dronedaron here.Der 75-jährige Patient wurde mit Schwindel, Belastungsdyspnoe und Kaltschweißigkeit eingeliefert. Bei ischämischer Herzkrankheit mit Sick-Sinus-Syndrom erfolgte vor 5,5 Jahren die Schrittmacherimplantation. Aufgrund eines nicht permanenten Vorhofflimmerns wurde die Medikation vor 8 Monaten um Dronedaron erweitert.Im Status präsentierte sich ein instabiler Patient. Das 12-Kanal-EKG zeigte einen AV-Block 2. Grades mit Wenckebach-Periodik und einer Frequenz von 29/min. In der Schrittmacherabfrage fand sich primär bei regelrechter atrialer Funktion eine ineffektive ventrikuläre Stimulation.Nach initial externer Stimulation erfolgte die Umprogrammierung des Schrittmachers und damit die effektive Ventrikelstimulation. Dronedaron wurde nach Prüfung auslösender Faktoren pausiert, und der Patient konnte nach 3 Tagen beschwerdefrei entlassen werden. In der Schrittmacherabfrage 18 Tage später fand sich eine regelrechte Funktion bei Stabilisierung der Reizschwelle nahe dem alten Niveau.Bei Patienten mit permanentem Herzschrittmacher sollte als Ursache einer Fehlfunktion eine Reizschwellenerhöhung ausgeschlossen und bei Vorliegen die aktuelle Medikation hinterfragt werden. Dabei ist auch bei einer Dronedaron-Einnahme Vorsicht geboten.

The therapy for heart failure in patients with uncompromised systolic ventricular function (HfpEF) is still challenging because there is an obvious lack of effective therapy options. Several of these particular patients are additionally presenting atrioventricular (AV) block. In these patients HIS bundle pacing could be a hopeful therapy strategy due to the option of an AV resynchronisation as illustrated in the following case.

In 2016, there were 77 293 pacemakers and 28 953 ICDs implanted in Germany. This makes pacemaker- and ICD-implantations part of the most frequently performed operations in Germany. This article addresses questions of correct indication and patient selection.

In der Schrittmacher- und ICD-Therapie wird die Vorhofelektrode meist im rechten Vorhofohr („right atrial appendage“, RAA) implantiert. Dies ist zwar einfach, birgt jedoch das Risiko negativer hamodynamischer und elektrophysiologischer Effekte. Atriale Erregungsausbreitung, atriale Kontraktion und atrioventrikulare Uberleitung konnen durch RAA-Stimulation verzogert und desynchronisiert werden. Dies kann zu Vorhofflimmern, einem stimulationsinduzierten langen AV-Block I°, unnotiger rechtsventrikularer Stimulation und Entwicklung einer Herzinsuffizienz fuhren. Eine hochseptale Stimulation nahe dem Vorhofdach, auf dem das Bachmann’sche Bundel verlauft, kann die negativen Folgen einer atrialen Stimulation aus dem Vorhofohr vermeiden und die atriale Erregung synchronisieren, wie die Verkurzung von PQ-Zeit und P‑Wellen-Dauer unter Bachmann-Bundel-Stimulation nahelegt. Einige Techniken zur Implantation atrialer Elektroden am Bachmann-Bundel werden hier vorgestellt, die abgesehen von einer Durchleuchtung in linksanterior obliquer Projektion im Vergleich zur RAA-Stimulation keinen zusatzlichen Implantationsaufwand benotigen. Klinische Studien zur hochseptalen und speziell zur Bachmann-Bundel-Stimulation sind rar. Eigene Daten zeigen einen positiven Effekt bei Patienten mit Sick-Sinus-Syndrom und paroxysmalem Vorhofflimmern, die mindestens 50 % der Zeit atrial stimuliert werden. Die Bachmann-Bundel-Stimulation stellt eine interessante und einfache Option zur optimierten Vorhofstimulation dar. Es ware wunschenswert, wenn diese Technik zur atrialen Elektrodenpositionierung weitere Verbreitung erfahren und zusatzliche Daten uber den klinischen Nutzen generiert wurden.

The pacemaker is the treatment of choice for symptomatic bradycardic arrhythmias. However, pacemaker patients may develop further bradycardial arrhythmias, often due to a pacemaker dysfunction. The possible causes range from lead problems to complete system failure. The Nanostim

This article gives an update on the management of acute ST-segment elevation myocardial infarction (STEMI) according to the recently released European Society of Cardiology guidelines 2017 and the modifications are compared to the previous STEMI guidelines from 2012. Primary percutaneous coronary intervention (PCI) remains the preferred reperfusion strategy. New guideline recommendations relate to the access site with a clear preference for the radial artery, use of drug-eluting stents over bare metal stents, complete revascularization during the index hospitalization, and avoidance of routine thrombus aspiration. For periprocedural anticoagulation during PCI, bivalirudin has been downgraded. Oxygen treatment should be administered only if oxygen saturation is90%. In cardiogenic shock, intra-aortic balloon pumps should no longer be used. New recommendations are in place with respect to the duration of dual antiplatelet therapy for patients without bleeding events during the first 12 months. Newly introduced sections cover myocardial infarction with no relevant stenosis of the coronary arteries (MINOCA), the introduction of new indicators for quality of care for myocardial infarction networks and new definitions for the time to reperfusion.

Der Begriff „valvuläres Vorhofflimmern“ wird in der Leitlinie nicht mehr verwendet. Die Klassifikation von paroxysmalem und persistierendem Vorhofflimmern hat sich geringfügig geändert. Ein regelmäßiges, zufälliges Screening auf Vorhofflimmern nach dem 65. Lebensjahr sowie die Suche nach asymptomatischen atrialen Hochfrequenzepisoden bei Herzschrittmacherpatienten wird empfohlen. Die Beeinflussung kardiovaskulärer Risikofaktoren (u. a. Blutdruckeinstellung, Gewichtsreduktion) wird besonders betont. Für die Einteilung der Symptomatik hat sich die EHRA-Klassifikation geringfügig geändert. SCHLAGANFALLPRäVENTION: Eine orale Antikoagulation wird für alle Männer mit einem CHA Digoxin sowie Diltiazem/Verapamil werden zur Frequenzregulation gleichwertig empfohlen. Eine Kardioversion kann unter einem NOAK ebenso wie unter einer VKA-Therapie erfolgen. Nach jeder medikamentösen/elektrischen Kardioversion ist unabhängig vom CHA

The first European Society of Cardiology (ESC) guidelines on atrial fibrillation (AF) developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS) were published in August 2016. These guidelines replace the revised guidelines from 2012 and contain some interesting new aspects. The topics range from the pathophysiology through diagnostics, therapy and stroke prevention up to special clinical situations, such as atrial fibrillation in cardiopathy, sport and pregnancy. Early screening, patient informed consent, individualized therapy and the modification of factors promoting atrial fibrillation are of particular importance. The guidelines recommend the establishment of AF heart teams, containing specialists from various disciplines. The guidelines also underline the importance of non-vitamin K‑dependent oral anticoagulants (NOAC) for stroke prevention compared to standard anticoagulants with vitamin K antagonists. For symptomatic and especially paroxysmal atrial fibrillation, the guidelines emphasize the importance of an antiarrhythmic treatment with catheter ablation and/or pharmaceutical antiarrhythmic therapy in addition to a frequency regulating therapy.

We describe the case of a 78-year-old patient who presented for ablation of a wide complex tachycardia with right bundle branch block (RBBB) morphology. A pacemaker spike at the QRS onset indicated supraventricular tachycardia with AV synchronous ventricular pacemaker activation.Correct positioning of the ventricular lead in the right ventricular apex was confirmed by fluoroscopy and echocardiography, excluding malpositioning of the right ventricular lead.In the electrophysiological study we diagnosed atrial tachycardia with 1:1 AV stimulation by the pacemaker. The ECG, however, presented negative concordance in the precordial leads. Only after shifting the precordial leads V1 and V2 from the 4th to the 2nd intercostal space were all 12 ECG leads in accordance with the clinical tachycardia.Thus, it is suspected that malpositioning of the ECG electrodes generated an apparent RBBB morphology of the clinical tachycardia. Malpositioning of ECG electrodes switches the lead characteristics from horizontal (anterior-posterior) to frontal (cranial-caudal) plane properties. In this situation, the precordial leads V1 and V2 with positive vector in V1 and V2 imitate aVL (V2) and aVR (V1) and can produce an apparent RBBB morphology.

Little is known about the incidence and risk factors for progression to pacemaker dependency or the need for cardiac resynchronization in typical patients with an implanted defibrillator with regard to an alternative implantation of a subcutaneous ICD (S-ICD).After retrospective analysis of 291 patients with first implantation of a transvenous single chamber ICD (VVI-ICD) from 2010-2016 and excluding those with an indication for pacemaker or lack of follow-up data, 121 patients were included and investigated with regard to the following endpoints: need for pacemaker stimulation, upgrade for cardiac resynchronization (CRT), and secondary occurrence and effectiveness of antitachycardia pacing (ATP). We compared the results with those of fundamental S‑ICD studies and tried to determine risk factors on the basis of medical history and pre-implant data.The study population and the rate of endpoints were significantly different to those of fundamental S‑ICD studies. Within a 2.2-year follow-up, 14.9 % of the patients developed a need for pacemaker stimulation and 0.8 % the need for cardiac resynchronization. Excluding patients who at implantation were already at high risk for pacemaker dependency, 7.4 % remained with a reached endpoint. We identified atrial fibrillation and bundle-branch-block as risk factors. All episodes of ventricular tachycardia (VT) could be terminated by ATP in 9.9 % of the patients. They more often had ischemic heart disease and a secondary prophylactic indication for an ICD.The low rate of conversions from S‑ICD to a transvenous ICD in case of pacemaker-dependency as stated in fundamental S‑ICD studies should not be transferred to other typical collectives of ICD recipients. The latter group is at significantly higher risk for developing pacemaker-dependency.

Atrial fibrillation is the most common form of persistent cardiac arrhythmia with a greatly increasing prevalence due to an aging population and increasing cardiovascular risk factors. Apart from impairment of the quality of life atrial fibrillation is associated with a high morbidity, most importantly stroke and heart failure. The therapy is complex and aims at improving symptoms as well as the prevention of thromboembolic complications, heart failure and aggravating comorbidities. Based on individual patient characteristics and symptoms therapy is mainly based on heart rate control by pharmacological means or therapy for maintaining sinus rhythm. This treatment includes antiarrhythmic drugs and catheter ablation. Current research is aimed at the investigation of the electrophysiological mechanisms of recurrent therapy refractive atrial fibrillation and the question whether the maintenance of sinus rhythm can improve the prognosis of atrial fibrillation.

Cardiac contractility modulation (CCM) is a stimulation therapy by an implantable impulse generator, which enhances ventricular contractile performance by delivering CCM impulses to the right ventricle during the absolute refractory period. The CCM signals mediate increased inotropy by prolonging the duration of the action potential, which leads to an enhanced influx of calcium into cardiomyocytes and a greater release of calcium by the sarcoplasmic reticulum. The increase of cardiac contractility is not associated with increased oxygen consumption. Several small studies have shown that CCM therapy can safely improve symptoms of heart failure and peak oxygen consumption in patients with moderate to severe heart failure who are not eligible for resynchronization therapy. Therefore, CCM is a novel potential therapy for patients with heart failure, an ejection fraction ≤ 35 % and a normal QRS duration 130 ms. However, apart from selecting appropriate patients for CCM therapy there are still unanswered questions, such as the impact of CCM therapy on established clinical endpoints. At present no data are available which have shown that CCM therapy leads to reduction of hospitalization for heart failure or mortality.

The latest guidelines of the European Society of Cardiology (ESC) on cardiac pacing and cardiac resynchronization therapy were presented and published in June 2013. Compared to the last guidelines from 2007 several substantial changes have been made. The new guidelines are much more clinically oriented with a special focus on practicability. The intention is a better usefulness not only for electrophysiologists but also for cardiologists, internists and general practitioners.

Bradycardic arrhythmias are classified into disorders of impulse formation and conduction. Impulse formation disorders are diseases of the sinus node. Conduction disturbances are the sinoatrial (SA), atrioventricular (AV) block and bundle branch block. The conduction disturbances are also subdivided in different grades (grade I to III). Clinical manifestations of bradycardic arrhythmias are usually syncope, Morgagni-Adam-Stokes seizures, dizziness, palpitations, or heart failure. The investigation of syncope as the most visible clinical manifestation of bradycardic arrhythmias, is performed in three steps with the goal of risk stratification for sudden cardiac death or major adverse cardiac events. If symptomatic bradycardia is present, there is usually an indication for pacemaker implantation. Prior to a definitive pacemaker implantation reversible or preventable causes must be investigated and treated.

Bradyarrhythmias are caused by a disturbed impulse formation in the sinus node and/or a disturbed impulse conduction and can be subclassified clinically as sinus node dysfunction, atrioventricular (AV) block, or functional bradycardia. Persistent bradycardia can be diagnosed by standard ECG. For diagnosis of intermittent bradycardia, often long-term ECG monitoring and/or additional testing is necessary. Symptomatic bradycardias are the standard indication for cardiac pacing after exclusion of reversible causes. Since sinus node dysfunction is associated with a good prognosis, pacing in this condition is only indicated in the presence of bradycardia-related symptoms. For prognostic reasons, pacemaker implantation is indicated in third degree AV block and second degree AV block Mobitz Type II, even if asymptomatic. Cardiac pacing for recurrent unpredictable neurocardiogenic syncope due to a cardioinhibitory reflex should be considered in certain circumstances. The implantation of cardiac pacemakers has been performed for more than half of a century. Due to the enormous technological progress, pacemaker implantations can nowadays be performed under local anesthesia in an outpatient setting. However, complications of pacemaker therapy are still not uncommon.Bradykarde Rhythmusstörungen haben ihre Ursache in einer gestörten Impulsbildung im Sinusknoten und/oder in einer gestörten Erregungsleitung. Klinisch lassen sich Bradyarrhythmien subklassifizieren als Störungen der Sinusknotenfunktion und atrioventrikuläre (AV)-Blockierungen sowie funktionelle Bradykardien. Während anhaltende Arrhythmien mittels Standard-EKG zu diagnostizieren sind, sind zur Diagnose von intermittierenden Arrhythmien häufig Langzeit-EKGs und/oder Zusatztests erforderlich. Symptomatische bradykarde Rhythmusstörungen sind nach Ausschluss reversibler Ursachen die Standardindikation für die Herzschrittmachertherapie. Da die Sinusknotendysfunktion mit einer günstigen Prognose assoziiert ist, ist bei dieser Erkrankung eine Schrittmacherimplantation nur bei Symptomen gerechtfertigt. Bei AV-Blockierungen 3. Grades und 2. Grades Mobitz Typ II ist aus prognostischen Erwägungen auch bei asymptomatischen Patienten die Schrittmachertherapie indiziert. Rezidivierende unvorhersehbare neurokardiogene Synkopen auf der Basis eines kardioinhibitorischen Reflexes stellen in speziellen klinischen Situationen eine Schrittmacherindikation dar. Herzschrittmacherimplantationen werden seit über einem halben Jahrhundert durchgeführt und können heutzutage dank der enormen technologischen Entwicklung in Lokalanästhesie ambulant durchgeführt werden. Allerdings sind Komplikationen der Schrittmachertherapie weiterhin nicht selten.

Early repolarization, involving infero-lateral ST segment elevation and prominent J waves at the QRS-ST junction has been considered a normal ECG variant for more than 80 years. More recent studies suggest that this phenomenon is not as benign as earlier believed and may represent a risk for subsequent ventricular fibrillation in patients with and without structural heart disease. However, based on current data it seems unjustified to consider these often accidental ECG findings a marker for high risk of sudden cardiac death. The concept of a reduced repolarization reserve developed for the Long QT syndrome can be transformed to early repolarization syndrome. In general a "fibrillation reserve" is relatively high but if triggers such as a genetic background, age, gender, influences of the autonomous nervous system, changes in body temperature, or an acute coronary syndrome act together ventricular fibrillation may occur. A combination of an "early repolarization ECG" with syncope and/or a positive family history of sudden cardiac death may justify defibrillator therapy just on an individual basis. This review intends to summarize actual aspects of early repolarizations syndrome and focuses on the dilemma of risk stratification.