[In Germany too many ICD implantations are performed: pro]. / In Deutschland werden zu viele ICD implantiert: Pro.

Implantable cardioverter defibrillators (ICD) have undoubtedly developed into one of the most successful therapies in the field of cardiology over the last decades; however, a significant number of ICD operations are carried out in patients who do not benefit from ICD therapy despite significant left ventricular dysfunction. These patients can easily be identified. An ICD therapy does not prolong life in the setting of significant chronic kidney disease. In elderly patients the benefit of prophylactic ICD therapy is very small. Simple risk scores can identify other patients who do not benefit from this treatment. The number of ICD operations can also be significantly reduced by the use of devices with an extended longevity.

Variations of heart rate variability parameters prior to the onset of ventricular tachyarrhythmia and sinus tachycardia in ICD patients. Results from the heart rate variability analysis with automated ICDs (HAWAI) registry.

The HAWAI registry evaluated the role of heart rate variability in predicting the occurrence of ventricular tachycardia and fibrillation (VT/VF) and sinus tachycardia in patients with an implantable cardioverter-defibrillator (45 patients with 155 RR recordings). A significant decrease of the mean value of all RR intervals (MeanNN) was observed in the period starting 20 and 40 min prior to VT/VF and sinus tachycardia, respectively. The standard deviation of RR intervals (SDNN) and the power at low frequency (LF) were the only parameters with significant changes prior to VT/VF. For sinus tachycardia, the root mean square of successive differences of all successive RR intervals (r-MSSD) and the power at low and high frequency (HF) decreased, whereas SDNN and the power at very low frequency increased. Comparison of RR recordings preceding VT/VF and sinus tachycardia revealed significant differences of the MeanNN, SDNN, r-MSSD, LF and HF. Based on a classification and regression tree analysis, MeanNN, SDNN and r-MSSD showed a sensitivity of 94.4% and a specificity of 50.6% as predictors of VT/VF. Our results suggest that the temporal changes in heart rate before an arrhythmic event can be used to predict the occurrence of VT/VF. These parameters may be used to optimize pacing therapies designed to prevent VT/VF recurrences as well as for improving device-based discriminators for VT/VF and sinus tachycardia.

[Implantable cardioverter defibrillator]. / Implantierbarer Kardioverter/Defibrillator.

This article aims to give an overview over important articles in the field of implantable cardioverter defibrillator (ICD) therapy in 2012. Important publications concern analyses on therapy efficacy and safety of the subcutaneous ICD, gender-specific differences in the complication rate and prognosis after ICD implantation, the necessity of intraoperative testing of the defibrillation threshold and the impact of preventive measures to reduce ICD therapies on prognosis after device implantation. The relevance of the study findings for daily clinical practice is briefly discussed.

[Recommendations of the Working Group of Arrhythmias of the German Society of Cardiology on the approach to patients with Riata® and Riata ST® leads (St. Jude Medical). Nucleus of the Working Group of Arrhythmias of the German Society of Cardiology]. / Empfehlungen der Deutschen Gesellschaft für Kardiologie (Arbeitsgruppe Rhythmologie) zum Umgang mit Patienten mit ICD-Elektroden Riata® und Riata ST® der Firma St. Jude Medical. Nucleus der AG Rhythmologie der Deutschen Gesellschaft für Kardiologie.

Riata® and Riata ST® implantable cardioverter defibrillator (ICD) leads (St. Jude Medical, Sylmar, CA) show an increased incidence of insulation defects, particularly "inside-out" lead fracture where inner, separately insulated cables penetrate through the surrounding silicone of the lead body. The exact incidence of Riata® lead problems is not clear and seems to range between 2-4% per year in the first 5 years after implantation according to new registry data. We recommend beyond a detailed information the following care of patients with Riata® and Riata ST® leads: 1) Activation of automatic ICD alerts, 2) remote monitoring with automatic daily alerts whenever possible, 3) monthly ICD controls in patients at high risk (pacemaker dependency, history of ventricular tachyarrhythmias) and high or moderate lead-related risk (8F, 7F single coil), 3-monthly controls in moderate patient and lead-related risk, 3 to 6-monthly controls in low patient and lead-related risk (no bradycardia, no history of ventricular tachyarrhythmia). Every ICD control should include meticulous analysis of oversensing artifacts in stored electrograms (EGMs) of sustained and non-sustained ventricular tachyarrhythmias and registration of EGMs during provocation testing (pectoral muscle activity, arm movements). If electrical abnormalities are observed, reoperation with addition of a new ICD lead is recommended; lead extraction only if indicated according to current guidelines. Fluoroscopy should only be performed if electrical abnormalities are found by an experienced electrophysiologist and a high frame rate and resolution. Management of fluoroscopic abnormalities in the absence of electrical abnormalities is not clear. Therefore, routine fluoroscopy of patients with Riata® leads without electrical abnormalities is not recommended.

Implantation of cardiac resynchronization therapy systems in the CARE-HF trial: procedural success rate and safety.

AIMS: To assess procedural characteristics and adjudicated procedure-related (300 cm(3); and, influence of the participating study-centres. Implantation was attempted in 404/409 patients assigned to CRT, and in 65/404 patients assigned to medical therapy. Among these 469 patients, 450 (95.9%) received a successfully implanted and activated device. Complications occurred within 24 h in 47 patients (10.0%), mainly lead dislodgments (n = 10, 2.1%) and coronary sinus dissection/perforation (n = 10, 2.1%), and between 24 h and 30 days in 26 patients (5.5%), mainly lead dislodgment (n = 13, 2.8%). Mean LV lead stimulation threshold was significantly higher than at the right atrium or right ventricle, though remained stable, delivering effective, and reliable CRT. Implanting experience was the only predictor of procedural outcome. CONCLUSION: Transvenous CRT system implantation, using a CS lead designed for long-term LV pacing, was safe and reliable. As implanting centres become more experienced, this success rate is expected to increase further.

The RIONI study rationale and design: validation of the first stored electrograms transmitted via home monitoring in patients with implantable defibrillators.

Appropriate and inappropriate therapies of implantable cardioverter defibrillators (ICDs) have a major impact on morbidity and quality of life in ICD recipients. The recently introduced home monitoring of ICD devices is a promising new technique which remotely offers information about the status of the system. Stored intracardiac electrograms (IEGMs), which are essential for correct classification of appropriate and inappropriate ICD discharges, have until now not been available with ICD home monitoring on a day-by-day basis because of limitations of transferable data. We demonstrate the first compressed IEGMs daily transferable via home monitoring (IEGM-online). Validation of these electrograms will be performed in the Reliability of IEGM-Online Interpretation (RIONI) study. A total of 210 episodes of stored IEGMs will be collected by at least 12 European centres. The primary endpoint of this study is to investigate whether the IEGM-online based evaluation of the appropriateness of the ICDs therapeutic decision following episode detection is equivalent to the evaluation based on the complete ICD episode Holter extracted from the IEGM stored. The evaluation is independently done by an expert board of three experienced ICD investigators. The equivalence of the two methods is accepted if the evaluations yield a different conclusion for <10% of all evaluated IEGMs. The conclusion of the study is expected at the beginning of 2007. If RIONI successfully validates IEGMs transmitted via home monitoring, a strong basis for the use of this promising technique will be established.

Transvenous ICD implantation after artificial tricuspid valve replacement. A new approach placing a transvenous ICD lead in the mid cardiac vein of the coronary sinus.

Implantation of a transvenous device in patients with a tricuspid valve replacement or a complex congenital heart disease with no access to the right ventricle represents problems. The lack of access to the right ventricle might preclude transvenous placement of a defibrillation lead at ICD implantation. A young patient (21 years) with a history of severe chest trauma with rupture of the tricuspid valve as well as the right coronary artery and consecutive inferior myocardial infarction was initially treated with tricuspid valve replacement (St Jude Medical artificial prosthesis, 33 mm) and a bypass graft to the right coronary artery. Four years later, the patient was admitted with a hemodynamically not tolerated ventricular tachycardia (VT: CL 250 ms, LBBB, left axis). The VT could be reproduced during electrophysiological testing. An ICD was implanted subpectorally in combination with a transvenous active fixation ICD lead. The transvenous ICD lead was placed via a guiding catheter into a coronary sinus branch (middle cardiac vein). Acceptable pacing and sensing values could be obtained. The defibrillation threshold was 25 J. In conclusion transvenous ICD lead implantation into a side branch of the coronary sinus in combination with a pectorally implanted "active can" ICD device seems to be an alternative approach. This approach may avoid implantation of additional subcutaneous defibrillation leads or even thoracotomy for ICD implantation.

[Cardiac resynchronization therapy and arrhythmias]. / Kardiale Resynchronisationstherapie und Arrhythmien.

Cardiac resynchronization therapy (CRT) is now considered an established therapy for patients with chronic heart failure in the presence of a wide QRS complex. Though proarrhythmic effects have been described in a few cases, CRT did not increase the frequency of ventricular tachyarrhythmias in prospective studies. In patients on CRT therapy, persistent atrial fibrillation sometimes converts back to sinus rhythm, possibly dependent on the duration of atrial fibrillation.

QRS duration: a simple marker for predicting cardiac mortality in ICD patients with heart failure.

BACKGROUND: Patients resuscitated from ventricular tachyarrhythmias benefit from implantable cardioverter-defibrillators (ICDs) as opposed to medical treatment. Patients with increased QRS duration receiving an ICD in the presence of heart failure are at greatest risk of cardiac death and benefit most from ICD therapy. OBJECTIVE: To determine whether an increased QRS duration predicts cardiac mortality in ICD recipients. DESIGN: Consecutive patients with heart failure in New York Heart Association functional class III were grouped according to QRS duration (< 150 ms, n = 139, group 1; v > or = 150 ms, n = 26, group 2) and followed up for (mean (SD)) 23 (20) months. PATIENTS: 165 patients were studied (80% men, 20% women); 73% had coronary artery disease and 18% had dilated cardiomyopathy. Their mean age was 62 (10) years and mean ejection fraction (EF) was 33 (14)%. They presented either with ventricular tachycardia (VT) or ventricular fibrillation (VF). MAIN OUTCOME MEASURES: Overall and cardiac mortality; recurrence rates of VT, fast VT, or VF. RESULTS: Mean left ventricular EF did not differ between group 1 (33 (13)%) and group 2 (31 (15)%). Forty patients died (34 cardiac deaths). There was no difference in survival between patients with EF > 35% and < or = 35%. Cardiac mortality was significantly higher in group 2 than in group 1 (31.3% at 12 months and 46.6% at 24 months, v 9.5% at 12 months and 18.2% at 24 months, respectively; p = 0.04). The recurrence rate of VT was similar in both groups. CONCLUSIONS: Within subgroups at highest risk of cardiac death, QRS duration-a simple non-invasive index-predicts outcome in ICD recipients in the presence of heart failure.

Rationale and design of a randomised controlled clinical trial on supplemental intake of n-3 fatty acids and incidence of cardiac arrhythmia: SOFA.

BACKGROUND: Evidence from earlier studies indicates that intake of very long-chain n-3 polyunsaturated fatty acids (n-3 PUFA, also named omega-3 fatty acids) as present in fish oil reduces the risk of sudden death. Sudden death forms a major part of mortality from cardiovascular disease and is in most cases a direct consequence of cardiac arrhythmia. n-3 PUFA may exert their protective effect through reducing the susceptibility for cardiac arrhythmia. OBJECTIVE: To investigate the effect of n-3 PUFA on the incidence of recurrent ventricular arrhythmia. This paper presents the rationale, design and methods of the Study on Omega-3 Fatty acids and ventricular Arrhythmia (SOFA) and discusses problems encountered in conducting a multicentre clinical trial on food. DESIGN: A randomised, parallel, placebo-controlled, double blind intervention study, which obeys the guidelines for Good Clinical Practice. SETTING: Multiple cardiology centres in Europe. SUBJECTS: A total of 500 patients with an implantable cardioverter defibrillator (ICD). An ICD detects, treats and stores cardiac arrhythmic events in its memory chip. INTERVENTIONS: Patients receive either 2 g/day of fish oil, containing approximately 450 mg eicosapentaenoic acid and 350 mg docosahexaenoic acid, or placebo for 12 months. PRIMARY OUTCOME: Spontaneous ventricular tachyarrhythmias as recorded by the ICD or all-cause mortality. CONCLUSION: SOFA is designed to answer the question whether intake of n-3 PUFA from fish-a regular food ingredient-can reduce the incidence of life-threatening cardiac arrhythmia. If this proves to be true, increasing the intake of n-3 PUFA could be an easy, effective and safe measure to prevent fatal arrhythmia in the general population.

[Evaluating the first German diagnosis-related groups (G-DRG) in cardiological patients: problems in the correct medical and economic grouping]. / Probleme bei der Abbildung kardiologischer Erkrankungen im deutschen Fallpauschalen-System (G-DRG).

About three years ago, the German Government initiated a complete change in the reimbursement system for costs of the in-hospital treatment of patients. A commission of representatives from every component of the German health system decided to adapt the Australian refined Diagnosis Related Groups (AR-DRG system). The AR-DRG system was selected as it would fit best to the German system and because of its high flexibility and preciseness reflecting severity of diseases and treatments. In October 2002, the first German Diagnosis Related Groups (G-DRGs) were calculated from the data of about 116 hospitals. These data now allow first analyses in how far a correct and precise grouping of patients in specific hospital settings is indeed performed and corresponds to the actual costs. Thus, we thoroughly calculated all costs for material and personnel during the in-hospital stay for each patient discharged during the first 4 months of 2002 from our cardiological department. After performing the grouping procedure for each patient, we analyzed in how far inhomogeneous patient distribution in the DRGs occurred and which impact this had on costs and potential reimbursements. Several different problems were identified which should be outlined in this work regarding three G-DRGs: costs of patients who received an implantable cardioverter defibrillator (F01Z) were markedly influenced by multimorbidity and additional expensive interventions which were not reflected by this G-DRG. Use of numerous catheters and expensive drugs represented a major factor for costs in patients with coronary angioplasty in acute myocardial infarction (F10Z) but seemed to be not sufficiently included in the cost weight. A specific area of patient management in our department is high frequency ablation of tachyarrhythmias which is included in other percutaneous interventions (F19Z). Complex procedures such as ablation of ventricular tachycardia or new innovative procedures as ablation of atrial fibrillation were associated with high costs leading to inadequate reimbursement. Furthermore, problems in the associated codes for diseases and procedures became apparent. Opportunities for future optimization such as specific new DRGs, splitting of DRGs, or the impact of changes in reimbursement for high-outliers were discussed.

Morphology discrimination: a beat-to-beat algorithm for the discrimination of ventricular from supraventricular tachycardia by implantable cardioverter defibrillators.

Inappropriate therapy of SVTs by ICDs remains a major clinical problem despite enhanced detection criteria like "sudden onset" and "rate stability" in third-generation devices. Electrogram morphology discrimination offers an additional approach to improve discrimination of supraventricular tachycardia (SVT) from ventricular tachycardia (VT). In a prospective, multicenter study, patients received an ICD with a beat-to-beat algorithm for morphological analysis of the intracardiac electrogram (Morphology Discrimination, MD). A nominal programmingfor standard enhancement criteria and morphology discrimination was required at implant. Electrogram storage of tachycardia episodes irrespective of delivery of therapy was used to assess sensitivity and specificity of the morphology algorithm alone and in combination with established detection criteria. During a 126 6-month follow-up, 886 episodes of device stored electrograms from 82 of 256patients were evaluated. Atnominal settings, the MD algorithm correctly identified 423 of 551 episodes as VT resulting in sensitivity of 77%. The classification of SVT was met in 239 of 335 episodes resulting in specificity of 71%. In combination with sudden onset, sensitivityincreased to 99.5% at the expense of specificity (48%). In conclusion, SVT-VT discrimination based on morphological analysis alone results in limited sensitivity and specificity. Programming the monitor mode allows individual assessment of the performance of this detection enhancement feature during clinical follow-up without compromising device safety. Only in patients with documented efficacy of morphology discrimination should this feature be subsequently activated.

Defibrillation efficacy comparing a subcutaneous array electrode versus an "active can" implantable cardioverter defibrillator and a subcutaneous array electrode in addition to an "active can" implantable cardioverter defibrillator: results from active can versus array trials I and II.

INTRODUCTION: Placement of implantable cardioverter defibrillators (ICDs) has been simplified by using the shell of a pectorally implanted ICD as a defibrillation electrode in combination with an endocardial right ventricular defibrillation lead. However, a sufficiently low defibrillation threshold (DFT) cannot be obtained in a few patients. Therefore, alternative approaches were systematically tested in the Active Can versus Array Trial (ACAT). METHODS AND RESULTS: In the first of two prospective randomized studies, the DFT of a subcutaneous left dorsolateral array anode introduced from a pectoral incision was compared to that of a standard active can anode in 68 patients. Intraoperatively, the DFT was determined twice in each patient using either the active can or, in patients with a subcutaneous array lead, once with all three fingers and once omitting the middle finger of the array. The second prospective randomized study included 40 patients. DFT also was determined twice in each patient using an active can in a left pectoral position as anode alone and combined with a left dorsolateral array electrode with two fingers. In ACAT I, stored energy at DFT decreased from 13.1+/-7.7 J (active can) to 9.6+/-6.1 J (three-finger array lead) (P = 0.04), impedance decreased from 53+/-8 ohms to 40+/-6 ohms (P < 0.0001). Omitting the middle finger of the array lead, stored energy at DFT increased by 0.9 J (P = 0.47) and impedance by 2 ohm (P < 0.0001). In ACAT II, DFT and impedance using an active can device were significantly lower when a two-finger array lead was added that decreased stored energy at DFT from 10.1+/-5.2 J to 6.9+/-3.9 J (P = 0.001) and impedance from 56+/-5 1 to 42+/-5 l (P < 0.0001). CONCLUSION: In combination with a right ventricular defibrillation electrode, a left pectoral subcutaneous array lead improves defibrillation efficacy if used instead of, or in addition to, a left pectoral active can ICD device. Implantation of the array lead can be simplified by using two instead of three fingers, without a significant loss of defibrillation efficacy.

The impact of anti-endotoxin core antibodies on endotoxin and cytokine release and ventilation time after cardiac surgery.

OBJECTIVES: We hypothesized that a temporary cardiopulmonary bypass (CPB)-induced reduction of endotoxin antibody levels contributes to elevated endotoxin levels and the associated inflammatory consequences, with a significant influence on the postoperative ventilation time period. BACKGROUND: Cardiac surgery using CPB induces a systemic inflammatory response syndrome with an associated risk of increased postoperative morbidity and mortality. METHODS: A total of 100 consecutive patients undergoing elective coronary artery bypass graft surgery using CPB were prospectively investigated. Endotoxin core antibodies (immunoglobulin [Ig] M/IgG against lipid A and lipopolysaccharide), endotoxin, interleukin (IL)-1-beta, IL-6, IL-8 and tumor necrosis factor-alpha were measured serially from 24 h preoperatively until 72 h postoperatively. RESULTS: Eighty-five patients had no complications (group 1), whereas 15 patients required prolonged ventilation (group 2). In both groups, there was a decrease of all antibodies 5 min after CPB onset, compared with baseline values (p < 0.001), an increase of endotoxin and IL-8 peaking at 30 min postoperatively (p < 0.001) and an increase of IL-6 peaking 3 h postoperatively (p < 0.001). In group 2, preoperative antibody levels were lower (p < 0.01)--specifically, the decrease in IgM was significantly stronger and of longer duration (p < 0.002)--and levels of endotoxin (p < 0.001) and IL-8 (p < 0.001) were higher at 30 min postoperatively. CONCLUSIONS: We conclude that an CPB-associated temporary reduction of anti-endotoxin core antibody levels contributes to elevated endotoxin and IL-8 release. Furthermore, lower levels of IgM anti-endotoxin core antibodies were associated with a greater rise in endotoxin and IL-8, as well as prolonged respirator dependence.

[Syncope of unknown origin in heart failure: which diagnostic possibilities should be considered today?]. / Unklare Synkopen bei Herzinsuffizienz: Welche diagnostischen Uberlegungen sind heute anzustellen?

In patients with congestive heart failure, unexplained syncope is often due to ventricular arrhythmias and associated with a poor prognosis. Electrophysiological studies should be considered early in the work-up of syncope. Implantation of a defibrillator might become necessary in many patients with syncope and heart failure.

Implantation of a dual chamber pacing and sensing single pass defibrillation lead.

Dual-chamber ICDs are increasingly used to avoid inappropriate shocks due to supraventricular tachycardias. Additionally, many ICD patients will probably benefit from dual chamber pacing. The purpose of this pilot study was to evaluate the intraoperative performance and short-term follow-up of an innovative single pass right ventricular defibrillation lead capable of bipolar sensing and pacing in the right atrium and ventricle. Implantation of this single pass right ventricular defibrillation lead was successful in all 13 patients (age 63 +/- 8 years; LVEF 0.44 +/- 0.16; New York Heart Association [NYHA] 2.4 +/- 0.4, previous open heart surgery in all patients). The operation time was 79 +/- 29 minutes, the fluoroscopy time 4.7 +/- 3.1 minutes. No perioperative complications occurred. The intraoperative atrial sensing was 1.7 +/- 0.5 mV, the atrial pacing threshold product was 0.20 +/- 0.14 V/ms (range 0.03-0.50 V/ms). The defibrillation threshold was 8.8 +/- 2.7 J. At prehospital discharge and at 1-month and 3-month follow-up, atrial sensing was 1.9 +/- 0.9, 2.1 +/- 0.5, and 2.7 +/- 0.6 mV, respectively, (P = NS, P < 0.05, P < 0.05 to implant, respectively), the mean atrial threshold product 0.79, 1.65, and 1.29 V/ms, respectively. In two patients, an intermittent exit block occurred in different body postures. All spontaneous and induced ventricular arrhythmias were detected and terminated appropriately. Thus, in a highly selected patient group, atrial and ventricular sensing and pacing with a single lead is possible under consideration of an atrial pacing dysfunction in 17% of patients.

Antitachycardia pacing for rapid VT during ICD charging: a method to prevent ICD shocks.

In patients with ICDs, rapid VTs are usually treated with shocks. It is unknown, if antitachycardia pacing (ATP) delivered once for rapid VT during capacitor charging can avoid painful shocks without increasing the risk of syncope. In patients in whom rapid monomorphic VT (cycle length 300-220 ms) could be reproducibly induced during predischarge ICD testing, the success of cardioversion (defibrillation threshold plus 10 J) and a single ATP attempt (burst with 8 or 16 stimuli) was compared using a randomized crossover study design. Consciousness of the patients was checked by the signal from a button constantly pushed by the patient. In 20 patients (ejection fraction 0.50 +/- 0.19) rapid VTs (253 +/- 26 ms) were reproducibly induced. A single burst successfully terminated 11 (55%) of 20 rapid VTs, 6 episodes could not be terminated with a single burst pacing and 3 VTs accelerated. Rapid VTs not terminated by ATP were significantly faster than those that could be terminated (246 vs 258 ms, P = 0.026). Cardioversion (19 +/- 3 J) terminated the VTs in all cases. No patient suffered syncope during rapid VTs. A single ATP may terminate rapid VT with cycle lengths < 300 ms in 55% of patients without increasing the risk of syncope. Therefore, in rapid VTs one attempt of ATP may be suitable as an additional therapy option during ICD capacitor charging to avoid painful shocks without compromise of safety. Thus, future ICDs should implement the option of ATP during charging of capacitors.