Visualization of the SyncAV® Algorithm for CRT Optimization by Non-invasive Imaging of Cardiac Electrophysiology: NICE-CRT Trial.

(1) Background: Periodic repetitive AV interval optimization using a device-based algorithm in cardiac resynchronization therapy (CRT) devices may improve clinical outcomes. There is an unmet need to successfully transform its application into clinical routine. (2) Methods: Non-invasive imaging of cardiac electrophysiology was performed in different device programming settings of the SyncAV® algorithm in 14 heart failure patients with left bundle branch block and a PR interval ≤ 250 milliseconds to determine the shortest ventricular activation time. (3) Results: the best offset time (to be manually programmed) permitting automatic dynamic adjustment of the paced atrioventricular interval after every 256 heart beats was found to be 30 and 50 milliseconds, decreasing mean native QRS duration from 181.6 ± 23.9 milliseconds to 130.7 ± 10.0 and 130.1 ± 10.5 milliseconds, respectively (p = 0.01); this was followed by an offset of 40 milliseconds (decreasing QRS duration to 130.1 ± 12.2 milliseconds; p = 0.08). (4) Conclusions: The herein presented NICE-CRT study supports the current recommendation to program an offset of 50 milliseconds as default in patients with left bundle branch block and preserved atrioventricular conduction after implantation of a CRT device capable of SyncAV® optimization. Alternatively, offset programming of 30 milliseconds may also be applied as default programming. In patients with no or poor CRT response, additional efforts should be spent to individualize best offset programming with electrocardiographic optimization techniques.

Ventricular arrhythmia detection for contemporary Biotronik and Abbott implantable cardioverter defibrillators with markedly prolonged detection in Biotronik devices.

BACKGROUND: Implantable cardioverter defibrillators (ICDs) are typically programed with both ventricular tachycardia (VT) and ventricular fibrillation (VF) treatment zones. Biotronik and Abbott ICDs do not increment the VT counter when the tachycardia accelerates to the VF zone, which could result in a prolonged delay in tachycardia detection. METHODS: Patients with Biotronik and Abbott ICDs receiving care at Veterans Affairs facilities in Northern California were identified. Patient information and device tracings for patients with any ICD therapies were examined to assess for possible delayed tachycardia detection. RESULTS: Among 52 patients with Biotronik ICDs, 8 (15%) experienced appropriate ICD therapy over a median follow-up of 29 months. Among 68 patients with Abbott ICDs, 26 (38%) experienced appropriate ICD therapy over a median follow-up of 83 months. Three of the patients with Biotronik ICDs who received appropriate therapy experienced a delay in VT/VF detection due to the tachycardia rate oscillating between the VT and VF treatment zones (longest 31.2 s on detection), compared with four of the patients with Abbott ICDs (longest 4.1 s on the detection and 8 s on redetect). One of the patients with a Biotronik ICD experienced recurrent syncope associated with delayed detection and another died on the day of delayed detection. One of the patients with an Abbott ICD experienced syncope. CONCLUSIONS: Because contemporary Biotronik and Abbott ICDs freeze the VT counters when tachycardia is in the VF zone, ICD therapies can be markedly delayed when the tachycardia oscillates between the VT and VF zone.

Antitachycardia pacing success in implantable cardioverter-defibrillators by patient, device, and programming characteristics.

BACKGROUND: Antitachycardia pacing (ATP) is an established implantable cardioverter-defibrillator (ICD) therapy that terminates ventricular tachycardias (VTs) without painful ICD shocks. However, factors influencing ATP success are not well understood. OBJECTIVE: The purpose of this study was to examine ATP success rates by patient, device, and programming characteristics. METHODS: This retrospective analysis of the PainFree SmartShock Technology study included spontaneous ATP-treated monomorphic VT episodes. ATP success rates were calculated for various factors. Also, the relationship of ATP programming on shock burden and syncope were investigated. RESULTS: Of the 2770 enrolled patients (2200 [79%] male; mean age 65 years), 1699 (61%) received an ICD and 1071 (39%) a cardiac resynchronization therapy - defibrillator. ATP had >80% rate of success for terminating VTs overall, with similar rates observed between ICD and cardiac resynchronization therapy - defibrillator devices (82.2% vs 80.3%, respectively; P = .81) as well as between primary and secondary prevention patients with ICDs (77.2% vs 83.9% respectively; P = .25). Arrhythmias with a median cycle length of ≥320 ms had a significantly higher ATP success rate (88.0%; 95% confidence interval 84.8%-90.6%). The cumulative percentage of ATP success increased from 71% at 1 ATP sequence delivered to 87% at ≥8 sequences delivered. Programming more ATP sequences was associated with lower shock burden (P = .0005). There was no evidence that more sequences were associated with higher rates of syncope (P = .16). CONCLUSION: Delivering more ATP sequences resulted in a higher overall success of terminating VTs, while programming more ATP was associated with decreased shock burden and no evidence of increased syncope or acceleration. This suggests that more ATP sequences should be programmed when possible, but confirmation in prospective studies will be necessary.

Preliminary results from the LUX-Dx insertable cardiac monitor remote programming and performance (LUX-Dx PERFORM) study.

Despite the wide adoption of insertable cardiac monitors (ICMs), high false-positive rates, suboptimal signal quality, limited ability to detect atrial flutter, and lack of remote programming remain challenging. The LUX-Dx PERFORM study was designed to evaluate novel technologies engineered to address these issues. Here, we present preliminary results from the trial focusing on the safety of ICM insertion, remote monitoring rates, and the feasibility of remote programming. LUX-Dx PERFORM is a multicenter, prospective, single-arm, post-market, observational study with planned enrollment of up to 827 patients from 35 sites in North America. A preliminary cohort consisting of the first 369 patients who were enrolled between March and October 2021 was selected for analysis. Three hundred sixty-three (363) patients had ICM insertions across inpatient and outpatient settings. The mean time followed was 103.4 ± 61.8 days per patient. The total infection rate was 0.8% (3/363). Interim results show high levels of remote monitoring with a median 94% of days with data transmission (interquartile range: 82-99). Thirteen (13) in-clinic and 24 remote programming sessions were reported in 34 subjects. Reprogramming examples are presented to highlight signal quality, the ability to detect atrial flutter, and the positive impact of remote programming on patient management. Interim results from LUX-Dx PERFORM study demonstrate the safety of insertion, high data transmission rates, the ability to detect atrial flutter, and the feasibility of remote programming to optimize arrhythmia detection and improve clinical workflow. Future results from LUX-Dx PERFORM will further characterize improvements in signal quality and arrhythmia detection.

Combined therapy with subcutaneous implantable cardiac defibrillator and leadless pacemaker in a patient with persistent left superior vena cava and mega coronary sinus: A challenging case for the best treatment.

In a patient requiring pacing and defibrillation therapy, but without superior venous access, combined therapy with S-ICD and leadless pacemaker could be the best solution. An appropriate programming of both devices represents the technical challenge in order to avoid inappropriate shocks due to leadless pacing oversensing.

Utilization and programming of an automatic MRI recognition feature for cardiac rhythm management devices.

BACKGROUND: Cardiac implantable electronic devices (CIED)-ie, pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy devices-have recently been designed to allow for patients to safely undergo magnetic resonance imaging (MRI) when specific programming is implemented. MRI AutoDetect is a feature that automatically switches CIED's programming into and out of an MR safe mode when exposed to an MRI environment. OBJECTIVE: The purpose was to analyze de-identified daily remote transmission data to characterize the utilization of the MRI AutoDetect feature. METHODS: Home Monitoring transmission data collected from MRI AutoDetect-capable devices were retrospectively analyzed to determine the workflow and usage in patients experiencing an MRI using the MRI AutoDetect feature. RESULTS: Among 48,756 capable systems, 2197 devices underwent an MRI using the MRI AutoDetect feature. In these 2197 devices, the MRI AutoDetect feature was used a total of 2806 times with an average MRI exposure of 40.83 minutes. The majority (88.9%) of MRI exposures occurred on the same day as the MRI AutoDetect programming. A same day post-MRI exposure follow-up device interrogation was performed 8.6% of the time. A device-related complaint occurred within 30 days of the MRI exposure in 0.25% of MRI exposures using MRI AutoDetect but with no adverse clinical outcome. CONCLUSION: As a result of automation in device programming, the MRI AutoDetect feature eliminated post-MRI device reprogramming in 91.4% of MRI exposures and, while less frequent, allowed for pre-MRI interrogations prior to the day of the MRI exposure-reducing resource utilization and creating workflow flexibility.

Perioperative Interrogation of Medtronic Cardiovascular Implantable Electronic Devices: A Guide for Anesthesiologists.

This is the final review article in a 4-part series focusing on the perioperative management of the 4 major companies' cardiovascular implantable electronic devices (CIEDs) in the United States. This article presents information pertinent to the perioperative management of Medtronic (Minneapolis, MN) transvenous CIEDs, including responses to magnet application, interpretation of interrogation reports, and basic programming (eg, mode, rate, rate modulation, and tachyarrhythmia therapies). Information regarding the Medtronic Micra (Medtronic, Minneapolis, MN) has been published previously. In addition, it contains an introduction to the concept of magnetic resonance (MR) conditional devices and magnetic resonance imaging (MRI) practices.

Right ventricular lead induced ventricular arrhythmia-A rare complication of cardiac resynchronization therapy.

BACKGROUND: A 53-year-old male with heart failure secondary to anterior wall myocardial infarction treated with cardiac resynchronization-defibrillator (CRT-D) device presented with ventricular arrhythmia: repetitive incessant slow ventricular tachycardias (VT) below the CRT-D detection zone, accelerated ventricular rhythm, and numerous premature ventricular ectopic beats (ExV), resulting in loss of biventricular pacing. METHODS AND RESULTS: Nonsustained monomorphic VT (nsVT) and ExV were observed in an electrocardiogram under biventricular stimulation. During noninvasive CRT-D programming, ventricular bigeminy reproducibly recurred only at right ventricular (RV) pacing and its morphology was almost identical to the stimulated beats. The left ventricular (LV) pacing failed to induce ventricular ectopy or tachycardia. CONCLUSIONS: This unusual case shows a rare phenomenon of late proarrhythmic effect due to the RV lead pacing-a new finding reported only in a few publications. Here we present our approach to CRT programming that suppressed the clinical arrhythmia without the need of catheter ablation and achieving the high biventricular pacing capture rate along with optimal hemodynamic CRT-D performance.

Pacemaker and Defibrillator Implantation and Programming in Patients with Deep Brain Stimulation.

The need for cardiac device implantation in patients receiving deep brain stimulation (DBS) is increasing. Despite the theoretical risk of the two systems interacting, there are no clear guidelines for cardiologists carrying out cardiac device implantation in this population. We performed a review of the literature and describe 13 case reports in which patients have both DBS and a cardiac pacemaker or ICD implanted. Except for one early study, in which an ICD shock reset the deep brain stimulator, no significant interactions have been reported. We discuss the potential interactions between DBS and cardiac devices, and provide practical advice for implanting cardiologists. We conclude that, provided that specific precautions are taken, cardiac device implantation is likely to be safe in patients with DBS.

Perioperative Interrogation of Biotronik Cardiovascular Implantable Electronic Devices: A Guide for Anesthesiologists.

Biotronik cardiovascular implantable electronic devices, specifically Biotronik pacemakers, contain unique features that are relevant to perioperative management. For example, Biotronik pacemakers have a programmable response to magnet application, a default magnet response that does not result in sustained asynchronous pacing, and a unique method of rate adaptation (eg, closed loop stimulation). This review article focuses on these unique features; the interpretation of Biotronik interrogation reports; and the basic programming (eg, mode, rate, rate adaptation, tachyarrhythmia therapies) relevant to the perioperative management of Biotronik cardiovascular implantable electronic devices.

Optimizing Cardiac Resynchronization Therapy Devices in Follow-up to Improve Response Rates and Outcomes.

Although cardiac resynchronization therapy (CRT) will improve symptoms and survival in selected heart failure patients, there still remains a high percentage of CRT recipients who do not obtain benefit from the therapy. During CRT follow-up, an effort should be made to identify and to treat reversible causes of nonresponse to CRT. This effort includes optimization of medical therapy, checking for appropriate and effective biventricular pacing, and treatment of arrhythmias and other reversible causes of CRT malfunction.

Failure to detect life-threatening arrhythmias in ICDs using single-chamber detection criteria.

BACKGROUND: There are anecdotal reports of sudden death despite a functional implantable cardioverter defibrillator (ICD). We sought to describe scenarios leading to fatal or near-fatal outcome due to inappropriately inhibited ICD therapy in devices programmed with single-chamber detection criteria. METHODS: Programmed settings, episode lists, and intracardiac electrograms from 24 patients with a life-threatening event (n = 12) or fatal outcome (n = 12) related to failed ventricular arrhythmia detection were used to clarify the underlying scenario. RESULTS: Fifty episodes of failed ventricular arrhythmia detection were identified and categorized into six scenarios: (1) spontaneous ventricular tachycardia (VT) or ventricular fibrillation (VF) with a rate below the detection limits, (2) misclassification of polymorphic VT (PVT) or VF as supraventricular tachycardia (SVT), (3) misclassification of VT/VF as cluster of nonsustained VT episodes, (4) misclassification of monomorphic VT (MVT) as SVT, (5) inappropriate shock abortion, and (6) false termination detection. These scenarios occurred respectively 6, 9, 3, 9, 8, and 15 times. In 9/9 (100%) patients with PVT/VF classified as SVT, rate stability was active for rates ranging from 222 to 250 beats/min. MVT detected as SVT was due to the sudden onset criterion in 7/9 (78%) patients and twice a consequence of the rate stability criterion active for rates ranging from 200 to 250 beats/min. CONCLUSION: We describe six scenarios leading to failure of ventricular arrhythmia detection in a single-chamber detection setting withholding life-saving therapy. These scenarios are more likely to occur with high-rate programming and long detection times, especially if combined with rate stability and sudden onset.

How to Perform His Bundle Pacing: Tools and Techniques.

Recently, permanent His bundle pacing (HBP) has emerged as a viable pacing strategy for chronic ventricular pacing. It allows for recruitment of the native His Purkinje system thereby preventing pacing-induced ventricular dyssynchrony seen in traditional right ventricular pacing. Current tools allow for relatively good success rates for implantation. Understanding the various responses to HBP is crucial for long-term success. With better tools and unique pacing and sensing algorithms designed specifically for this form of pacing, HBP is likely to increase as a tool for long-term pacing therapy.

Perioperative Interrogation of St. Jude Cardiovascular Implantable Electronic Devices: A Guide for Anesthesiologists.

Feelings of trepidation or uncertainty regarding cardiovascular implantable electronic devices (CIEDs) in the perioperative period can often be mitigated by a thorough knowledge of societal recommendations, recommended management options, and familiarity with CIEDs. Given that effective interpretation of an interrogation report is vital to determining perioperative management options and applying societal recommendations, the creation and interpretation of St. Jude CIED interrogation reports are discussed. In an effort to increase the familiarity with St. Jude transvenous CIEDs amongst anesthesiologists, basic programming of a St. Jude pacemaker and implantable cardioverter defibrillator (ICD) also are described.

Approach to cardio-oncologic patients with special focus on patients with cardiac implantable electronic devices planned for radiotherapy: results of the European Heart Rhythm Association survey.

The aim of this European Heart Rhythm Association (EHRA) survey was to evaluate clinical practice regarding cardio-oncologic patients, with special focus on patients with cardiac implantable electronic devices (CIEDs) planned for anticancer radiotherapy (RT), among members of the EHRA electrophysiology research network. Of the 36 responding centres, 89% managed patients who were diagnosed or treated oncologically, and this diagnosis affected 1-5% of cardiovascular patients in majority of centres (57%). The main side effects of anticancer therapy in patients treated by cardiologists were thromboembolic complications and left ventricular dysfunction (both reported as 'frequent' by 43% of the centres). The main agents associated with complications were anthracyclines, RT, and monoclonal antibodies. Echocardiography was the most common method of screening for cardiovascular complications (93%), and 10% of the centres did not routinely screen for treatment-induced cardiotoxicity. Opinions on the safe radiation dose, methods of device shielding, and risk calculation prior to RT in CIED patients differed among centres. Precaution measures in high-risk CIED patients were very heterogeneous among centres. Our survey has shown that the awareness of cardiac consequences of anticancer therapy is high, despite relatively low proportion of patients treated oncologically among all cardiovascular patients. There is a consensus of which screening methods should be used for cardiotoxicity of anticancer treatment, but the apprehension of screening necessity is low. Methods of risk assessment and safety measures in CIED patients undergoing RT are very heterogeneous among the European centres, underscoring the need for standardization of the approach to cardio-oncologic patients.

Additional electrodes on the Quartet™ LV lead provide more programmable pacing options than bipolar and tripolar equivalents.

AIMS: The aim of this study was to evaluate any benefits to the number of viable pacing vectors and maximal spatial coverage with quadripolar left ventricular (LV) leads when compared with tripolar and bipolar equivalents in patients receiving cardiac resynchronization therapy (CRT). METHODS AND RESULTS: A meta-analysis of five previously published clinical trials involving the Quartet™ LV lead (St Jude Medical, St Paul, MN, USA) was performed to evaluate the number of viable pacing vectors defined as capture thresholds ≤2.5 V and no phrenic nerve stimulation and maximal spatial coverage of viable vectors in CRT patients at pre-discharge (n = 370) and first follow-up (n = 355). Bipolar and tripolar lead configurations were modelled by systematic elimination of two and one electrode(s), respectively, from the Quartet lead. The Quartet lead with its four pacing electrodes exhibited the greatest number of pacing vectors per patient when compared with the best bipolar and the best tripolar modelled equivalents. Similarly, the Quartet lead provided the highest spatial coverage in terms of the distance between two furthest viable pacing cathodes when compared with the best bipolar and the best tripolar configurations (P < 0.05). Among the three modelled bipolar configurations, the lead configuration with the two most distal electrodes resulted in the highest number of viable pacing vectors. Among the four modelled tripolar configurations, elimination of the second proximal electrode (M3) resulted in the highest number of viable pacing options per patient. There were no significant differences observed between pre-discharge and first follow-up analyses. CONCLUSION: The Quartet lead with its four electrodes and the capability to pace from four anatomical locations provided the highest number of viable pacing vectors at pre-discharge and first follow-up visits, providing more flexibility in device programming and enabling continuation of CRT in more patients when compared with bipolar and tripolar equivalents.