Change of sensing vector in the subcutaneous ICD during follow-up and after device replacement.

BACKGROUND: The subcutaneous implantable cardioverter defibrillator (S-ICD) has been established as a valuable alternative to transvenous ICD for prevention of sudden cardiac death. The system automatically chooses the optimal sensing vector. However, during follow-up and especially after device replacement we observed a change of the suggested sensing vector in automatic setup. Therefore, we analyzed frequency and reasons of vector change and its impact on inappropriate shocks (IAS). MATERIAL AND METHODS: Between June 2010 and December 2017, a total of 216 patients with S-ICD® were included in this analysis. In all patients sensing vectors at the time of implantation, during follow-up, and after device replacement were investigated. Median follow-up time was 27.3 ± 25.3 months. RESULTS: A change of the initial vector was seen in 77 patients (35.7%). The most frequent reason for vector change was the postoperative setup in supine and erect position in 54 patients (70.1%). In 12 patients (15.5%), the vector was manually changed due to inappropriate sensing and/or therapies. Routine setup during follow-up led to automatic vector change in 10 cases (13.0%). In only 1 patient the vector was manually changed due to oversensing in an exercise treadmill test. In 27 patients, the device was replaced due to battery depletion and in 6 of these patients the sensing vector was changed by the automatic setup. Vector change did not have an impact for inappropriate therapies in the follow-up; only 1 patient received an IAS due to an inadvertent vector change after device replacement. CONCLUSION: In the present study, a significant number of S-ICD® patients had a manual or automatic vector change during follow-up and after device replacement. The study underlines the importance of a thoroughly performed screening and at least two valuable sensing vectors preimplant. Further studies are needed to evaluate the necessity of a routine automatic setup during follow-up.

Sensitive Detection of Atrial Fibrillation in Acute Stroke Patients by Short-Term Bedside Electrocardiography Monitoring Software Analysis.

BACKGROUND: Atrial fibrillation (AF) is an important cause of stroke. Continuous electrocardiography (ECG) monitoring with software-based analysis algorithms has been suggested to enhance the AF detection rate. We investigated the ability of stroke risk analysis (SRA) in the detection of AF in acute stroke patients. METHODS: Consecutive stroke patients numbering 1,153 were screened. Patients with cardioembolic stroke related to AF (n = 296, paroxysmal n = 63, persistent n = 233) and patients with cryptogenic stroke (n = 309) after standard diagnostic work-up (bedside ECG monitoring, ultrasound, transesophageal echocardiography, 24 h Holter ECG) received SRA during their stay at the Stroke Unit. Determination of AF risk by SRA in the patients with AF and in the patient group with cryptogenic stroke was assessed and compared. RESULTS: Median SRA monitoring analysis time was 16 h (range 2-206 h, interquartile range 10-36). In AF patients, SRA also detected a possible or definitive AF in 98%. The overall sensitivity of SRA to detect possible or definitive AF in patients with proven AF by standard diagnostic work up and cryptogenic stroke was 98%, specificity 27%, positive predictive value 56%, and the negative predictive value (NPV) was 92%. Area under ROC curve was 0.622. CONCLUSION: SRA was found to be highly sensitive to detect possible or definitive AF in clinical routine within a short monitoring time. However, low specificity and poor accuracy do not allow diagnosing AF by SRA alone, but with the high NPV compared to current diagnostic standard, it is a valid diagnostic tool to rule out AF. Thereby, SRA is a contribution to clarify stroke etiology.

Postoperative ergometry-guided programming does not prevent T-wave oversensing and inappropriate shocks in S-ICD patients.

BACKGROUND: T-wave oversensing (TWOS) is a feared complication after subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation, potentially leading to inappropriate shocks (IS) with tremendous impact on quality of life. HYPOTHESIS: Postoperative ergometry facilitates primary and secondary prevention of TWOS or other potential causes of IS and optimizes S-ICD programming. METHODS: We analyze the impact of ergometry guided-programming (EMGP) on primary and secondary prevention of TWOS/IS in S-ICD patients, we screened 146 patients implanted in our center (2010-2016) for the incidence of TWOS/IS during postoperative ergometry. Furthermore, to evaluate the outcome in 123 eligible patients complete follow-up (FU) of at least 6 months up to 2 years was retrospectively analyzed. RESULTS: (1) Primary prevention: TWOS could only be provoked postoperatively in 3.7% of patients (n = 3/82). FU analyses did not reveal significant differences compared to our control group (Ctrl: n = 6/61, 9.8% vs EMGP: n = 5/62, 8.1%; P = 0.731). Further subgroup analyses of patients with postoperative ergometry in the close postoperative period (< 7 days; n = 3/45, 6.7%; P = 0.563) did not yield any significant difference. (2) Secondary prevention: We found various causes of TWOS/IS. In patients who underwent reprogramming due to previous TWOS/IS events we observed a 66.7% (n = 6/9) reduction of TWOS/IS using EMGP. CONCLUSION: TWOS/IS has various causes while not all cases are exercise-associated. Postoperative ergometry does not seem to be useful for primary prevention. Further trials need to investigate the potential benefit of EMGP for secondary prevention of TWOS/IS.

Thoracic aortic aneurysm expansion due to late distal stent graft-induced new entry.

OBJECTIVES: This study analyzed the mechanism and risk factors of thoracic aortic aneurysm expansion due to late distal stent graft-induced new entry (dSINE). BACKGROUND: This late complication of thoracic endovascular aneurysm repair (TEVAR) for aortic dissection is under-recognized but potentially life-threatening. METHODS: In 142 patients who underwent TEVAR with endovascular entry sealing for acute and chronic aortic type B dissection, using commercially available straight (nontapered) stent-grafts, we examined the oversizing rate, the aortic taper ratio, and the need for reintervention. RESULTS: Nine of 142 patients developed thoracic aortic aneurysm expansion due to dSINE after TEVAR. The median follow-up was 47.5 ± 37.4 months. There was a significant difference in the distal stent-aorta angle between the patients with and without dSINE (149.08 ± 15.09° vs. 166.72 ± 12.47°, P < 0.005). Patients with dSINE showed a significantly higher taper ratio of the true lumen of the aorta (40.9 ± 14.13% vs. 25.36 ± 20.2%, P < 0.05). There was also a significant difference in the oversizing of the stent-graft in the distal landing zone (95.88 ± 49.3% vs. 55.94 ± 36.23%, P < 0.01). All patients with dSINE underwent a secondary endograft procedure without any complications or deaths. In 7 cases we used a custom-made, highly tapered stent-graft. CONCLUSIONS: Lifelong follow-up of patients is mandatory after TEVAR. A stent-graft with a tapered design should be used in aortic dissection to avoid oversizing and devastating late complications.

Delayed occurrence of an accelerated idioventricular rhythm with alternating bundle branch block after myocardial infarction as predictor of sudden cardiac arrest: a case report.

BACKGROUND: Accelerated idioventricular rhythm (AIVR) is known as reperfusion arrhythmia in the setting of acute myocardial infarction (AMI). In healthy individuals, it is usually considered to be benign. Alternating bundle branch block (ABBB) often progresses to complete atrioventricular block requiring permanent pacemaker implantation. We report a case of delayed appearance of AIVR following myocardial infarction (MI) in combination with ABBB as precursor of sudden cardiac arrest due to ventricular fibrillation (VF). CASE SUMMARY: A 62-year-old male with pre-existing left bundle branch block (LBBB) was admitted with an acute non-ST segment elevation MI. He underwent successful percutaneous coronary intervention (PCI) of a subtotal proximal left anterior descending artery (LAD) stenosis. Before and after PCI the electrocardiogram (ECG) demonstrated sinus rhythm with LBBB. The patient was discharged 5 days after PCI, left ventricular function at this time was moderately reduced (ejection fraction of 40%). After another 5 days, the patient was admitted for elective cardiac rehabilitation. At this time, the ECG demonstrated an AIVR with right bundle branch block morphology. Due to ABBB, the patient was scheduled for permanent pacemaker implantation. Before pacemaker implantation could take place, the patient developed a sudden cardiac arrest due to VF and was successfully resuscitated. A follow-up coronary angiography revealed no novel lesions. A cardiac resynchronization therapy defibrillator was implanted for secondary prevention of sudden cardiac death. DISCUSSION: Delayed occurrence of AIVR in combination with ABBB following AMI could be a predictor of sudden cardiac death. These patients are probably at high risk for malignant ventricular arrhythmias.

Extended ECG monitoring with an implantable loop recorder in patients with cryptogenic stroke: time schedule, reasons for explantation and incidental findings (results from the TRACK-AF trial).

BACKGROUND: Implantable loop recorders (ILR) may be used to detect occult atrial fibrillation (AF) in patients with cryptogenic stroke. At present, there has been no description on the incidental findings of stored episodes in these patients. Furthermore, no standard practice has been established with respect to the duration of continued ECG monitoring in these patients. MATERIALS AND METHODS: In the prospective monocentric study (TRACK-AF), a total of 173 patients with cryptogenic stroke received an ILR for detection of AF between November 2010 and December 2014. Before implantation all patients had undergone recommended protocols for detection of stroke causes. RESULTS: During a mean follow-up of 24.8 ± 11.5 months, atrial tachyarrhythmias were detected in n = 33 pts (19.1%). Diagnosis of AF was made after a mean of 10.7 ± 11.4 months, time to first AF detection ranged between 0.2 and 39.8 months. In 15 patients (8.7%), other incidental findings were stored in the ILR memory. Short episodes of sinus arrest at night not requiring a permanent pacemaker were present in 8 pts (4.6%). DDD-pacemaker implantation due to sinus arrest or symptomatic bradyarrhythmias occurred in 5 patients (2.9%) after a median monitoring period of 23.1 ± 7.4 months. Further incidental findings were atrial flutter and an AV-nodal-reentry tachycardia in one patient, respectively. Both patients underwent successful catheter ablation. So far, ILR were explanted in 111 pts, and 71 ILR were explanted before end of service status of the battery. Main reason for ILR explantation was patients' preference (51%), followed by battery depletion (24%) and diagnosis of AF (15%). CONCLUSION: The present study revealed a significant number of ECG findings during continued ECG monitoring for AF in patients with cryptogenic stroke. Apart from AF (17.5% during the first 1.5 years), other clinical relevant arrhythmias requiring, e.g., pacemaker implantations, were observed. With respect to these findings, we recommend to extend ILR monitoring to the end of battery life. However, acceptance of continued ECG monitoring until battery depletion was poor; in 71 patients (64%), the ILR were explanted before the end of battery life. TRIAL REGISTRATION: Registered at ClinicalTrials.gov: NCT02641678.

Feasibility of entirely subcutaneous ICD™ systems in patients with coronary artery disease.

BACKGROUND: The subcutaneous ICD (S-ICD™) is an important advance in device therapy for the prevention of sudden cardiac death (SCD). Although current guidelines recommend S-ICD™ use, long-term data are still limited, especially in subgroups. Among several cardiac diseases that prone to SCD, coronary artery disease (CAD) carries several peculiarities that may hamper S-ICD™ therapy in this cohort. CAD can lead to an ischemic cardiomyopathy (ICM) with a reduced left-ventricular ejection fraction (LVEF) and bundle branch blocks, which can be difficult for ICD sensing and discrimination of arrhythmia. CAD is mainly driven by risk factors such as diabetes mellitus, which put these patients at an elevated risk for infectious complications of cardiac devices. Furthermore, in ICM myocardial scars are frequent and are a potential substrate for ventricular tachycardia, which may be accessible for antitachycardia pacing. At the moment, it remains unclear if there is a value of S-ICD™ therapy in this subgroup. Therefore, this study analysed patients with CAD. MATERIALS AND METHODS: All S-ICD™ patients with CAD as the main indication for ICD implantation (n = 45 patients) in our large-scaled single-center S-ICD™ registry (n = 249 patients) were included in this study. Baseline characteristics, appropriate and inappropriate shocks, and complications were documented in a mean follow-up of 22.5 ± 8.3 months. RESULTS: Primary prevention of SCD was the indication for implantation of an S-ICD™ in 28 patients (62%). Of all 45 patients with an overall mean age of 58.1 ± 11.4 years, 40 were male (88%). The mean LVEF was 37.7 ± 12.6%. Three episodes of ventricular arrhythmia (one monomorphic, one polymorphic, one ventricular fibrillation) were adequately terminated in three patients (7%). In only one patient, oversensing resulting in an inappropriate shock was observed, which could be managed by changing the sensing vector. 15 of the examined 45 patients previously had a transvenous ICD, which was explanted due to system-related infections. In only two patients, S-ICD™ was changed to transvenous ICD because of the need of antibradycardia stimulation. There were no S-ICD™ system-related infections. CONCLUSION: The S-ICD™ seems to be a valuable option for the prevention of SCD in CAD patients. Patients with systemic infections of a transvenous ICD and, therefore, a need for an alternative might benefit from the absence of intracardiac leads as the S-ICD™ is safe and works flawlessly in these patients. Inadequate shock delivery was very rare, while every episode of ventricular arrhythmia was terminated by the first shock.

Follow-up of the first patients with a totally subcutaneous ICD in Germany from implantation till battery depletion.

BACKGROUND: The subcutaneous ICD is a promising treatment option in patients at risk for sudden cardiac death. Approved in 2009, the first S-ICD® in Germany was implanted in June 2010. Although large prospective registry studies have shown safety and efficacy of the system, there is a lack of long-term data with regard to battery longevity of the S-ICD®. Therefore, we report follow-up of our first initial S-ICD® cases from implantation till battery depletion. MATERIALS AND METHODS: All S-ICD® patients with device replacement for battery depletion in our large single-center S-ICD® registry were included in this study. Baseline characteristics, appropriate and inappropriate shocks, and complications were documented in a median follow-up of 75.9 ± 6.8 months. RESULTS: Twenty-eight patients with S-ICD® systems were included in this study. Of these patients, 21 were male and 7 were female, with an overall mean age of 41.9 ± 12.6 years. Primary prevention of sudden cardiac death was the indication in 19 patients (67.9%). Ventricular tachycardia was adequately terminated in two patients (7.1%). In 7 patients, non-sustained ventricular arrhythmias were not treated. A total of three inappropriate shocks occurred in three patients (10.7%). Mean time from implantation till battery depletion was 65.8 ± 8.1 months. Only one patient presented premature elective replacement criteria because of rapid battery depletion. No lead-related complication occurred during follow-up and no complications were seen regarding device replacement. In one patient (3.6%), the system was explanted without replacement due to patient's preference. CONCLUSION: The estimated battery longevity of S-ICD® of about 5 years was reached in all but one patient. Compared to larger S-ICD® registry studies, frequency of inappropriate shocks was relatively high in the initial S-ICD® cases. Both technological improvement as well as programming and operators' experience have led to a reduction of complications. Replacement of the S-ICD® seems to be a safe and effective procedure.

Right versus left parasternal electrode position in the entirely subcutaneous ICD.

OBJECTIVES: The subcutaneous implantable cardioverter defibrillator (S-ICD®) has been established as an alternative to conventional transvenous ICD for the prevention of sudden cardiac death. Initial studies have shown safety and efficacy of the system with a left parasternal (LP) electrode. However, several case studies reported a right parasternal (RP) position. The purpose of this study was to analyze shock efficacy and safety of an RP electrode position. METHODS: Between June 2010 and May 2016, 120 S-ICD® were implanted at our institution. On the basis of the heart location on preoperative chest radiography (CXR), the investigators decided on an RP (n = 52) or LP electrode position (n = 68). All perioperative induced VF episodes, and spontaneous appropriate and inappropriate episodes during follow-up were analyzed. RESULTS: Patients with an RP electrode did not differ in terms of age, sex, or ejection fraction. A statistically significant difference in underlying cardiac disease was observed between the RP and LP electrode group, with more patients with channelopathies in the RP electrode group and more patients with non-ischemic cardiomyopathy in the LP electrode group. During a mean follow-up of 24.3 ± 19.5 months, 27 appropriate (19 in the LP group and 8 in the RP group) and 28 inappropriate (18 LP and 10 RP) ICD shocks occurred (p value = NS). CONCLUSIONS: In the present study, an RP electrode position was chosen on the basis of chest radiographic characteristics and was efficient in terms of sensing and shock efficacy. Thus, a right-sided electrode implant might be an alternative if a left-sided electrode implant is inadequate. It might also be favorable for young patients with narrow heart silhouettes in the midsagittal position.

Long-term single-center experience of defibrillator therapy in children and adolescents.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) systems are established therapy for prevention of sudden cardiac death. Long-term data on ICD systems in children and adolescents is rare. The present study displays a long-term single-center follow-up of children and adolescents with ICD systems. METHODS AND RESULTS: The present study represents a single-center experience of patients younger than 18 years who received an ICD (n = 58). Follow-up data included in-house follow-up as well as examinations of collaborating specialists. Mean age at implantation was 14.0 ±â€¯3.3 years and 33 patients (56.9%) were male. A transvenous ICD system was implanted in 54 patients (93.1%). In 33 patients (56.9%) electrical heart disease or idiopathic ventricular fibrillation represented the underlying condition of ICD implantation. Median follow-up duration was 70 months (45; 94). 3 patients (5.2%) died during the observation period. None of these deaths was associated with ICD failure. Appropriate shocks occurred in 32 patients (55.2%). Inappropriate shock delivery was recorded in 17 patients (29.3%). Supraventricular tachycardia represented the most frequent cause of inappropriate shock delivery (9 patients, 52.9%). T-wave oversensing led to inappropriate shock delivery in 3 patients (17.6%). In 5 patients (29.4%), lead failure caused inappropriate shock delivery. Of note, during follow-up lead failure was reported in 15 patients (25.9%) leading to surgical revision. CONCLUSION: ICD therapy in children and adolescents is effective for prevention of sudden cardiac death. The rate of appropriate shock deliveries was significantly higher as compared with large ICD trials. Inappropriate therapies occurred frequently. In particular supraventricular tachycardia, T-wave oversensing and lead failures were responsible for these episodes.

[Management of inappropriate shocks/T-wave-oversensing in S-ICD®-patients]. / Management von inadäquaten Schocks/T-Wellen-Oversensing bei S-ICD®-Patienten.

Inappropriate shocks are a feared complication after implantable cardioverter-defibrillator (ICD) implantation and have a tremendous impact on quality of life. Inappropriate shocks in patients with subcutaneous ICD (S-ICD®, Boston Scientific, Marlborough, MA, USA) have various underlying causes. This review summarizes the current literature on this topic and lists possible treatment options.

Long-Term Experience With the Subcutaneous Implantable Cardioverter-Defibrillator in Teenagers and Young Adults.

OBJECTIVES: This study sought to examine the use of the subcutaneous implantable cardioverter-defibrillator (S-ICD) in teenagers and young adults. BACKGROUND: The S-ICD is an important advance in device therapy for the prevention of sudden cardiac death. Although guidelines recommend S-ICD use, long-term data are still limited, especially in subgroups. Therefore, this study analyzed teenagers and young adults <26 years of age with S-ICD in our large single-center S-ICD registry. METHODS: Between July 2010 and December 2016, 147 S-ICD systems were inserted at our institution. Thirty-one patients were included in the study; 13 were teenagers (<20 years of age), and 18 were young adults (20 to 26 years of age). The patients were compared with an age-matched control group with transvenous ICDs. RESULTS: Primary prevention of sudden cardiac death was the indication in 13 patients (41.9%). Ventricular arrhythmias were adequately terminated in 8 patients (25.8%). In 5 patients (16.1%), oversensing resulting in at least 1 inappropriate shock was observed. All inappropriate shocks occurred in teenagers. Younger age was an independent predictor of inappropriate shocks in S-ICD (hazard ratio: 0.56; 95% confidence interval: 0.34 to 0.92; p < 0.05). No ineffective shocks were observed in a median follow-up of 25.7 ± 20.2 months. CONCLUSIONS: Young patients may be suitable candidates for S-ICD because of the high number of lead failures with transvenous systems expected in these patients during their lifetime. In the present study, S-ICD therapy was safe and feasible in teenagers and young adults. However, episodes of inappropriate shocks may occur, but rates of inappropriate shocks were comparable to those in patients with transvenous ICDs.

Posttraumatic stress and quality of life with the totally subcutaneous compared to conventional cardioverter-defibrillator systems.

BACKGROUND: For prevention of sudden cardiac death, the transvenously implantable cardioverter-defibrillator therapy (tv-ICD) is well accepted. The subcutaneous system (S-ICD®) is promising in terms of reducing ICD complications. Nevertheless, the impact of the novel generator position on patients' quality of life (QoL) is yet unknown. OBJECTIVE: This study aimed at comparing QoL and posttraumatic stress with both systems. METHODS: 60 S-ICD® and 60 case-controlled tv single-chamber ICD patients were asked to respond to three standardized questionnaires. PDS [screening for posttraumatic stress disorders (PTSD)] and PHQ-D (detection of the most predominant psychological disorders) were used to screen for potential mental comorbidities. The SF-12 questionnaire was used to evaluate physical and mental well-being. Groups were compared in terms of QoL and PTSD. RESULTS: n = 42 (70%) pairs were analyzed (n = 30 male, mean age 44.6 ± 12.2 years). Prior appropriate (p = 0.06) or inappropriate episodes (p = 0.24), ejection fraction (p = 0.28), or underlying cardiac disease did not differ significantly between groups. PDS revealed a PTSD in n = 6 tv-ICD and n = 6 S-ICD® patients (14.3%) equally. In the PHQ-D questionnaire, n = 4 tv-ICD and n = 2 S-ICD® patients fulfilled criteria for a major depression (p = 0.68). Panic disorders (n = 2 tv, n = 0 S-ICD®, p = 0.5), and anxiety disorders (n = 3 S-ICD®, n = 0 tv-ICD, p = 0.24) did not differ between groups. The physical well-being score was 39.9 ± 12.5 in patients with a tv-ICD compared to 46.6 ± 9.9 in S-ICD® patients (p = 0.01). The mental well-being score was comparable in both groups (tv-ICD 51.8 ± 10.8 vs. S-ICD® 51.9 ± 10.4, p = 0.95). CONCLUSIONS: Our case-control study revealed equal or even better physical well-being of patients with the S-ICD®. PTSD occurred in almost 15% of ICD patients irrespective of the type of system.

Long-time "real-life" performance of the subcutaneous ICD in patients with electrical heart disease or idiopathic ventricular fibrillation.

BACKGROUNDS: The totally subcutaneous implantable defibrillator (S-ICD) has been designed as a new alternative to conventional implantable defibrillators. This system is especially attractive for young patients. However, long-term experience is not yet available. To address the question whether the S-ICD system is safe and feasible for young patients with electrical heart disease or idiopathic ventricular fibrillation (VF), the data of a standard of care prospective single center S-ICD registry were evaluated. METHODS: In the present study, 24 patients (age 34.2 ± 11.5 years) with electrical heart disease or idiopathic VF received an S-ICD for primary (n = 8) or secondary prevention (n = 16). The mean follow-up duration was 29.6 ± 15.1 months. RESULTS: Ventricular arrhythmias were adequately detected in four patients (17 %). In three patients (13 %) oversensing was noticed and led to at least one inappropriate shock in two patients (8 %). Further adverse events included surgical revision due to a mobile pulse generator as well as explantation of one system and switch to a transvenous ICD system due to several ineffective shocks. CONCLUSIONS: The results of the present study suggest that S-ICD therapy may be an attractive alternative in young patients with electrical heart disease or idiopathic VF. However, episodes of oversensing as well as ineffective shocks may occur.

Intraoperative Defibrillation Testing of Subcutaneous Implantable Cardioverter-Defibrillator Systems-A Simple Issue?

BACKGROUND: The results of the recently published randomized SIMPLE trial question the role of routine intraoperative defibrillation testing. However, testing is still recommended during implantation of the entirely subcutaneous implantable cardioverter-defibrillator (S-ICD) system. To address the question of whether defibrillation testing in S-ICD systems is still necessary, we analyzed the data of a large, standard-of-care prospective single-center S-ICD registry. METHODS AND RESULTS: In the present study, 102 consecutive patients received an S-ICD for primary (n=50) or secondary prevention (n=52). Defibrillation testing was performed in all except 4 patients. In 74 (75%; 95% CI 0.66-0.83) of 98 patients, ventricular fibrillation was effectively terminated by the first programmed internal shock. In 24 (25%; 95% CI 0.22-0.44) of 98 patients, the first internal shock was ineffective and further internal or external shock deliveries were required. In these patients, programming to reversed shock polarity (n=14) or repositioning of the sensing lead (n=1) or the pulse generator (n=5) led to successful defibrillation. In 4 patients, a safety margin of <10 J was not attained. Nevertheless, in these 4 patients, ventricular arrhythmias were effectively terminated with an internal 80-J shock. CONCLUSIONS: Although it has been shown that defibrillation testing is not necessary in transvenous ICD systems, it seems particular important for S-ICD systems, because in nearly 25% of the cases the primary intraoperative test was not successful. In most cases, a successful defibrillation could be achieved by changing shock polarity or by optimizing the shock vector caused by the pulse generator or lead repositioning.

Recent advances in the entirely subcutaneous ICD System.

The entirely subcutaneous implantable cardioverter defibrillator (S-ICD(®)) is emerging as a widely accepted therapeutic alternative to a conventional implantable cardioverter defibrillator (ICD) for prevention of sudden cardiac death. Essentially, the S-ICD(®) is promising in terms of reduction of electrode-related complications such as lead failure and infections. The conventional transvenous ICD has proven efficacy in various randomized clinical trials. The first results of S-ICD(®) studies confirm efficacy and safety in primary and secondary prevention as well. Owing to basic differences between S-ICD(®) and transvenous ICD-such as limited programming options and lack of pacing-not all patients are eligible for the S-ICD(®). Concerns exist regarding inappropriate shocks due to T-wave oversensing, dimensions of the device, and shorter battery longevity. However, the S-ICD(®) should be considered a useful supplementation of ICD therapy in those patients at risk for sudden cardiac death who are not expected to require pacing due to bradycardia or antitachycardic pacing.

[Screening for diabetic retinopathy in type 2 diabetes: a critical review of an annual routine]. / Screening für diabetische Retinopathie bei Typ-2-Diabetes: Eine kritische Evaluation der jährlichen Routine.

BACKGROUND: The German diabetes guideline published in 2010 recommends an annual retinopathy screening for all type 2 diabetics. Patients' and physicians' questions about the need for this routine procedure prompted our critical review. METHODS: Based on guidelines from six industrial nations, recent scientific studies, and from the type 2 disease management programme of North Rhine-Westphalia we reviewed alternative retinopathy screening strategies and their implications for over- and underuse. RESULTS: A comparison of the English, Australian, US, Swedish, Canadian and German guidelines shows that a fixed screening interval is recommended in four countries, while an individualised, risk profile-adjusted screening interval of up to two to three years is favoured in two countries (Sweden, Canada). Current studies indicate that diabetes patients without retinopathy may safely be screened every two to three years without adverse health outcomes if performed consequently. CONCLUSIONS: An individualised retinopathy screening based on the patient's risk factor profile may be a reasonable alternative to achieve the best possible health outcome and to avoid overuse.