Single operator experience, learning curve, outcomes, and insights gained with conduction system pacing.

BACKGROUND: Conduction system pacing (CSP) is increasingly utilized to prevent and correct dyssynchrony. Barriers to CSP adoption include limited training, methodologic variability, laboratory slot allocation, and few data on learning curves. We report learning curves/clinical outcomes from a single experienced electrophysiologist who was new to CSP, and share gained insights. METHODS: Retrospective analysis of all patients who underwent attempted CSP implantation (2016-2023). Patient characteristics, ECGs, echocardiograms, fluoroscopy/procedure times, lead data were recorded at implant and follow-up. RESULTS: CSP leads were implanted successfully in 167/191(87.4%) patients with a follow-up of 278 ± 378 days. His-bundle pacing (HBP = 59) and left-bundle-area pacing (LBAP = 108) had similar procedure/fluoroscopy times, QRS duration decreases, and ejection fraction improvements (all p > NS). Eight HBP lead revisions were required for high capture thresholds LBAP demonstrated lower pacing thresholds, higher lead impedances, and greater R-wave amplitudes at implant and follow-up. After 25 HBP cases, implant pacing thresholds, fluoroscopy, procedural times did not decrease. After 25 LBAP cases, there were significant decreases in all these parameters (p < 0.05). A separate analysis in LBAP patients with recorded Purkinje signals showed no differences in paced ECG characteristics between patients with pre- QRS Purkinje signals versus patients with Purkinje signals post-QRS onset. CONCLUSIONS: Experienced implanters who are new to CSP can achieve steady-state procedural/fluoroscopy times after a learning curve of 25 implants. LBAP showed lower capture thresholds and higher success rates. Adequate depth of lead deployment (as determined by published parameters) does not require Purkinje potential to be pre-QRS. Operators new to CSP.can forego HBP and directly implement LBAP.

Beyond biventricular pacing: Exploring the advantages of his-bundle pacing and left bundle branch pacing in heart failure-A systematic review and meta-analysis.

BACKGROUND: This meta-analysis compares His-Purkinje system pacing (HPSP), a novel cardiac resynchronization therapy (CRT) technique that targets the intrinsic conduction system of the heart, with conventional biventricular pacing (BiVP) in heart failure (HF) patients with left ventricular (LV) dysfunction and dyssynchrony. METHODS: We searched multiple databases up to May 2023 and identified 18 studies (five randomized controlled trials and 13 observational studies) involving 1291 patients. The outcome measures were QRS duration, left ventricular ejection fraction (LVEF) improvement, left ventricular end-diastolic diameter (LVEDD) change, HF hospitalization, and New York Heart Association (NYHA) functional class improvement. We used a random-effects model to calculate odds ratios (OR), and mean differences (MD) with 95% confidence intervals (CI). We also assessed the methodological quality of the studies. RESULTS: The mean LVEF was 30.7% and the mean follow-up duration was 8.1 months. Among LBBP, HBP, and BiVP, HBP provided the shortest QRS duration [MD: -18.84 ms, 95% CI: -28.74 to -8.94; p = 0.0002], while LBBP showed the greatest improvement in LVEF [MD: 5.74, 95% CI: 2.74 to 7.46; p < 0.0001], LVEDD [MD: -5.55 mm, 95% CI: -7.51 to -3.59; p < 0.00001], and NYHA functional class [MD: -0.58, 95% CI: -0.80 to --0.35; p < 0.00001]. However, there was no significant difference in HF hospitalization between HPSP and BiVP. CONCLUSION: LBBP as modality of HPSP demonstrated superior outcomes in achieving electrical ventricular synchrony and systolic function, as well as alleviating HF symptoms, compared to other pacing techniques.

Ablation Versus Antiarrhythmic Drugs as First-Line Therapy for Treatment-Naive Atrial Fibrillation: A Systematic Review and Meta-Analysis.

Evidence on the relative safety and efficacy of atrial fibrillation catheter ablation and antiarrhythmic drugs (AADs) as the first-line therapy for patients with treatment-naive atrial fibrillation (AF) remains disputed. Digital databases were queried to identify relevant randomized controlled trials. The incidence of recurrent AF, major adverse cardiovascular events, and its components (all-cause death, nonfatal stroke, and bleeding) were compared using the DerSimonian and Laird method under the random-effects model to calculate pooled unadjusted risk ratio (RR) with 95% confidence intervals (CIs). A total of 6 randomized controlled trials consisting of 1,120 patients (574 ablation and 549 AADs) were included in the final analysis. Over a median follow-up of 1 year, the risk of any AF recurrence (RR 0.54, 95% CI 0.39 to 0.75) was significantly lower in patients receiving ablation than in patients receiving AADs. However, there was similar risk of major adverse cardiovascular events (RR 2.65, 95% CI 0.61 to 11.46), trial-defined composite end point of adverse events (RR 0.71, 95% CI 0.28 to 1.80), stroke (RR 2.42, 95% CI 0.22 to 26.51), all-cause mortality (RR 1.98, 95% CI 0.28 to 13.90), and procedure/medication failure (RR 2.65, 95% CI 0.61 to 11.46) with both therapies. In conclusion, in patients presenting with treatment-naive AF, ablation as a first-line therapy lowers the risk of AF recurrence with no associated increase in major adverse events, stroke, and mortality compared with AADs.

Evaluating Goldberger's triad as a marker of congestive heart failure: A systematic review and retrospective study.

BACKGROUND: In 1982, Drs. Barold and Goldberger described an ECG triad associated with left ventricular dysfunction (LVD) consisting of high precordial QRS voltage, low limb lead voltage, and poor precordial R wave progression. Studies have since attempted to replicate the originally reported sensitivity (70%), specificity (>99%), and positive predictive value (PPV, 100%) of Goldberger's triad (GT) with variable results. PURPOSE: To assess sensitivity, specificity and PPV of GT as a screening tool for LVD in the current era. METHODS: We performed: (1) A systematic review of the published studies; (2) Searched our hospital ECG database (GE MUSE) for diagnoses of "low limb-voltage" and "left ventricular hypertrophy" from 2017 to 2022; identified ECGs were analyzed for GT criteria and their medical records were screened for LVD. (3) ECG analysis of patients with known idiopathic LVD for the GT. RESULTS: A total of 11,115 patients from 8 studies were included in the systematic review of published studies and showed widely varying sensitivity, specificity and PPV. A total of 4576 ECGs (in GE MUSE) from 372 patients met initial screening criteria of low limb lead voltage and LVH; only 12 patients had ECGs that satisfied GT. Of these 12, only 1 patient had evidence of LVD, yielding a PPV of 8%. Finally, of the 40 patients with known LVD, only 1 met the ECG criteria for GT, resulting in a sensitivity of 2.5%. CONCLUSION: Our literature review does not support the original results of GT. ECGs from our database that met GT (searched by low limb-voltage and left ventricular hypertrophy) over a span of 5 years were rare. When present, the PPV of GT was 8%. In patients with established LVD, the sensitivity was 2.5%. These data do not validate GT as tool to identify LVD in the current era.

Adverse outcomes of atrial fibrillation ablation in heart failure patients with and without cardiac amyloidosis: a Nationwide Readmissions Database analysis (2015-2019).

Aims: Atrial fibrillation (AF) in patients with cardiac amyloidosis (CA) has been linked with a worse prognosis. The current study aimed to determine the outcomes of AF catheter ablation in patients with CA. Methods and results: The Nationwide Readmissions Database (2015-2019) was used to identify patients with AF and concomitant heart failure. Among these, patients who underwent catheter ablation were classified into two groups, patients with and without CA. The adjusted odds ratio (aOR) of index admission and 30-day readmission outcomes was calculated using a propensity score matching (PSM) analysis. A total of 148 134 patients with AF undergoing catheter ablation were identified on crude analysis. Using PSM analysis, 616 patients (293 CA-AF, 323 non-CA-AF) were selected based on a balanced distribution of baseline comorbidities. At index admission, AF ablation in patients with CA was associated with significantly higher adjusted odds of net adverse clinical events (NACE) [adjusted odds ratio (aOR) 4.21, 95% CI 1.7-5.20], in-hospital mortality (aOR 9.03, 95% CI 1.12-72.70), and pericardial effusion (aOR 3.30, 95% CI 1.57-6.93) compared with non-CA-AF. There was no significant difference in the odds of stroke, cardiac tamponade, and major bleeding between the two groups. At 30-day readmission, the incidence of NACE and mortality remained high in patients undergoing AF ablation in CA. Conclusion: Compared with non-CA, AF ablation in CA patients is associated with relatively higher in-hospital all-cause mortality and net adverse events both at index admission and up to 30-day follow-up.

Safety of Adenosine for the Treatment of Supraventricular Tachycardia in Hospitalized Patients with COVID-19 Pneumonia.

Coronavirus disease 2019 (COVID-19) is associated with pulmonary involvement and cardiac arrhythmias, including supraventricular tachycardia (SVT). Adenosine is commonly used to treat SVT and is generally safe, but is rarely associated with bronchospasm. There are no data regarding the safety of adenosine use in patients with COVID-19 pneumonia and physicians may hesitate to use it in such patients. We surveyed resident physicians and cardiology attendings regarding their level of comfort in administering adenosine to hospitalized COVID-19 patients. We compared a study group of 42 COVID-19 hospitalized patients who received adenosine for SVT to a matched (for age, sex, and co-morbidities) control group of 42 non-COVID-19 hospitalized patients during the same period, all of whom received IV adenosine for SVT. Escalation of care following intravenous adenosine administration was defined as increased/new pressor requirement, need for higher O2 flow rates, need for endotracheal intubation, new nebulizer therapy, or transfer to intensive care unit within 2 h of adenosine administration. Survey results showed that 82% (59/72) of residents and 62% (16/26) of cardiologists expressed hesitation/significant concerns regarding administering adenosine in hospitalized COVID-19 patients. Adenosine use was associated with escalation of care in 47.6% (20/42) COVID-19 as compared to 50% (21/42) non-COVID-19 patients (odds ratio 0.95, 95% CI 0.45-2.01, p = NS). Escalation of care was more likely in patients who were on higher FiO2, on prior nebulizer therapy, required supplemental oxygen, or were already on a ventilator. In conclusion, we identified significant hesitation among physicians regarding the use of adenosine for SVT in hospitalized COVID-19 patients. In this study, there was no evidence of increased harm from administering adenosine to patients with SVT and COVID-19. This finding needs to be confirmed in larger studies. Based on the current evidence, adenosine for treatment of SVT in this setting should not be avoided. Key Points: Question: Given the known bronchospastic effects of adenosine, is the use of adenosine safe for treatment of supraventricular tachycardia in hospitalized patients with COVID-19? Findings: A survey of residents and cardiology attending identified that a majority expressed some level of apprehension in using adenosine for SVT in COVID-19 patients. In our matched cohort study, we found adenosine use to be comparably safe in COVID-19 and non-COVID-19 hospitalized patients. Meaning: Based on current evidence, adenosine for treatment of SVT in this setting should not be avoided.

Dyssynchronous Heart Failure: A Clinical Review.

PURPOSE OF THE REVIEW: Dyssynchrony occurs when portions of the cardiac chambers contract in an uncoordinated fashion. Ventricular dyssynchrony primarily impacts the left ventricle and may result in heart failure. This entity is recognized as a major contributor to the development and progression of heart failure. A hallmark of dyssynchronous heart failure (HFd) is left ventricular recovery after dyssynchrony is corrected. This review discusses the current understanding of pathophysiology of HFd and provides clinical examples and current techniques for treatment. RECENT FINDINGS: Data show that HFd responds poorly to medical therapy. Cardiac resynchronization therapy (CRT) in the form of conventional biventricular pacing (BVP) is of proven benefit in HFd, but is limited by a significant non-responder rate. Recently, conduction system pacing (His bundle or left bundle branch area pacing) has also shown promise in correcting HFd. HFd should be recognized as a distinct etiology of heart failure; HFd responds best to CRT.

An unusual case of non-reentrant atrioventricular nodal tachycardia.

INTRODUCTION: Although uncommonly encountered, dual atrioventricular nodal non-reentrant tachycardia (DAVNNRT) is a well-described arrhythmia that can manifest in patients with dual atrioventricular nodal pathways physiology. This arrhythmia is characterized on electrocardiogram (ECG) by a single P wave followed by two conducted QRS complexes (so-called "double fire"), and on intracardiac electrograms by a single atrial electrogram followed by two separate His deflections and ventricular electrograms. METHODS/RESULTS: We report a rare case of "triple-fire" atrioventricular non-reentrant tachycardia in which a patient was found to have three distinct atrioventricular nodal pathways and multiple triple fire responses, both on surface ECG and intracardiac electrograms. CONCLUSION: Multiple pathways physiology and it's clinical ramifications are discussed.

Conduction system pacing versus biventricular pacing: Reduced repolarization heterogeneity in addition to improved depolarization.

INTRODUCTION: His-bundle pacing (HBP) and left-bundle-area pacing (LBAP) are conduction system pacing (CSP) modalities increasingly used as alternatives to conventional biventricular pacing (BiVP). While effects of CSP on ventricular depolarization have been reported, effects on ventricular repolarization have not. METHODS: QRS duration (QRSd) and validated ECG parameters of ventricular repolarization associated with arrhythmic risk (T-peak-to-T-endTransmural , T-peak-to-T-endTotal , T-peak dispersion, QTc, QTc dispersion) were analyzed post-implant in 107 patients: 60 with CSP (HBP: n = 35, LBAP: n = 25) and 47 with BiVP. T-wave memory resolution and QTc shortening were analyzed on ECGs obtained ≥25 days post-implant. Twenty blinded measurements were obtained by both authors to assess Interobserver variability. RESULTS: Although QRSd was shorter with HBP versus LBAP (119 ± 7 ms vs. 132 ± 9 ms, p = .02), there were no significant differences in any repolarization parameters between these methods of CSP. However, when comparing CSP (HBP + LBAP) to BiVP, both QRSd (125 ± 5 ms vs. 147 ± 7 ms, p < .0001) and repolarization parameters (T-peak-to-T-endTransmural : 83 ± 5 ms vs. 107 ± 8 ms; T-peak-to-T-endTotal : 110 ± 7 ms vs. 137 ± 10 ms; QTc: 470 ± 12 ms vs. 506 ± 12 ms; all p ≤ .0001) were significantly shorter with CSP. Improved T-peak-to-T-end values were unrelated to pre-implant QRSd or LV function. Interobserver variability was 4.6 ± 1.9 ms. Frontal QRS-T angle narrowing (132° to 104°, p = .001) and QTc shortening (483 ± 13 ms to 464 ± 12 ms, p = .008) were seen only with CSP. CONCLUSIONS: In addition to improved depolarization, CSP reduced repolarization heterogeneity and provided greater T-wave memory resolution as compared to BiVP. Both modalities of CSP (HBP + LBAP) resulted in comparably reduced repolarization heterogeneity regardless of baseline QRSd and LV function. These observations may confer lower arrhythmogenic risk and warrant further study.

A Novel Module Based Method of Teaching Electrocardiogram Interpretation for Emergency Medicine Residents.

Audience: This online learning module is designed for PGY 1-3 emergency medicine (EM) residents. Introduction: Interpretation of the 12-lead electrocardiogram (ECG) is an essential skill for EM residents. The traditional approach to ECG interpretation in medical school is primarily didactic, teaching: "rate, rhythm, axis," etc. Throughout residency, EM residents continue to receive lectures and practical ECG teaching to independently interpret ECGs with accuracy and efficiency. In addition to basic rhythm interpretation, physicians must be able to identify cardiac ischemia, abnormal rhythms, and subtle ECG findings that could herald sudden death.1 Life-threatening diagnoses such as digitalis toxicity or hyperkalemia can be made promptly through ECG evaluation and catastrophic if missed. If correctly diagnosed through ECG, many channelopathies can be treated and cardiac events can be prevented.2,3 Lecture-based learning is a necessary part of medical education, but there is a need to supplement the traditional teaching approach with online learning modules. Online learning modules provide learners with an accessible and efficient tool that allows them to improve their ECG skills on their own time. Educational Objectives: After completion of the module learners should be able to: 1) correctly recognize and identify ECG abnormalities including but not limited to abnormal or absent P waves, widened QRS intervals, ST elevations, abnormal QT intervals, and dysrhythmias that can lead to sudden cardiac death; and 2) synthesize findings into a succinct but accurate interpretation of the ECG findings. Educational Methods: An online module was developed using Articulate 360 and was implemented with EM residents. The module covers common ECG findings seen in the emergency department including ischemia, atrioventricular blocks, and bundle branch blocks. The module uniquely emphasizes ECG findings of arrythmias that could lead to sudden cardiac death and highlights that diagnosing sudden cardiac death syndromes relies on both clinical presentation and specific ECG findings. Online modules have proven to be as effective as lecture-based learning at improving ECG interpretation among healthcare professionals and are convenient and easily accessible to the busy EM resident.4,5 Additionally, the module is self-paced, can be completed at any time, and includes elements of active learning by incorporating knowledge checks throughout. This allows learners in real time to see where individualized improvement is needed. The ease of embedment of self-paced questions into the module is one of the salient reasons why module-based learning can be superior to lecture-based learning. This allows for real time retrieval practice, feedback, and repetition, all of which can be powerful and effective tools for learning.6. Research Methods: This module was offered at a single academic institution with a 3-year residency program. The investigation was reviewed and approved for exemption by the Institutional Review Board of Sydney Kimmel Medical College. The module was evaluated using survey data; before the module was disseminated, residents were given a pre-module survey. The survey was used to evaluate the methods residents used to interpret ECGs prior to completion of the module and to evaluate their baseline confidence in ECG interpretation. The residents were then given access to the module and had two weeks to complete it. After the two-week period, the post-module survey was used to evaluate resident satisfaction with the delivery of the module, the methods residents used to interpret ECGs after the module, and resident confidence in ECG interpretation. The objective efficacy of the educational content in the module was assessed using a pre- and post-module assessment. The assessments consisted of 15 ECGs.Residents were asked to provide a one-sentence interpretation for each of the 15 ECGs and the final answers were based on interpretation by an electrophysiologist. Results: A group of 37 EM residents had two weeks to complete the module between pre- and post-tests. There was an 18.2% absolute increase in the mean percent correct after the module, a 42.5% relative increase from pre-test (t= -8.0, p < 0.001). Subjective data demonstrated that after completing the module, residents utilized the novel approach, were more confident in interpreting ECGs, and would use the module as a resource in the future. Discussion: Most participants were not confident in their ability to interpret an ECG prior to completing the module, despite most of the participants having ECG training in the six months prior to the study. Almost all the participants reported using "rate, rhythm, axis" as their method of ECG interpretation. Even with recent training, and an understanding of "rate, rhythm, axis," there was a very low accuracy on the pre-test and lack of perceived baseline confidence in this skill. These findings highlight the need for a concise, effective supplemental ECG tool that can be incorporated into residency program curricula.The online learning module was effective at increasing confidence of ECG interpretation skills in residents as well as increasing accuracy of interpretation. Overall, participants were satisfied with the module as a resource for practicing their ECG interpretation, and most participants reported that they would use the module in the future as a reference. Implementation of the module as an additional resource in resident education is very simple. It can be accessed through any device that has internet and can be completed in a short period of time. Additionally, most experienced ECG readers will speak about "pattern recognition" as an important tool in ECG interpretation. This ability goes above and beyond the "rate, rhythm, axis" approach, but is acquired over time, often after many years of ECG interpretation. It is possible that the modular method may accelerate such pattern recognition abilities. Topics: Electrocardiogram, online module, sudden cardiac death, ischemia.

Advancing global equity in cardiac care as cardiac implantable electronic device reuse comes of age.

A nation's health and economic development are inextricably and synergistically connected. Stark differences exist between wealthy and developing nations in the use of cardiac implantable electronic devices (CIEDs). Cardiovascular disease is now the leading cause of death in low- and middle-income countries (LMIC), with a significant burden from rhythm-related diseases. As science, technology, education, and regulatory frameworks have improved, CIED recycling for exportation and reuse in LMIC has become possible and primed for widespread adoption. In our manuscript, we outline the science and regulatory pathways regarding CIED reuse. We propose a pathway to advance this technology that includes creating a task force to establish standards for CIED reuse, leveraging professional organizations in areas of need to foster the professional skills for CIED reuse, collaborating with regulatory agencies to create more efficient regulatory expectations and bring the concept to scale, and establishing a global CIED reuse registry for quality assurance and future science.

Implantation of cardiac electronic devices in active COVID-19 patients: Results from an international survey.

BACKGROUND: Cardiac implantable electronic device (CIED) implantation rates as well as the clinical and procedural characteristics and outcomes in patients with known active coronavirus disease 2019 (COVID-19) are unknown. OBJECTIVE: The purpose of this study was to gather information regarding CIED procedures during active COVID-19, performed with personal protective equipment, based on an international survey. METHODS: Fifty-three centers from 13 countries across 4 continents provided information on 166 patients with known active COVID-19 who underwent a CIED procedure. RESULTS: The CIED procedure rate in 133,655 hospitalized COVID-19 patients ranged from 0 to 16.2 per 1000 patients (P <.001). Most devices were implanted due to high-degree/complete atrioventricular block (112 [67.5%]) or sick sinus syndrome (31 [18.7%]). Of the 166 patients in the study survey, the 30-day complication rate was 13.9% and the 180-day mortality rate was 9.6%. One patient had a fatal outcome as a direct result of the procedure. Differences in patient and procedural characteristics and outcomes were found between Europe and North America. An older population (76.6 vs 66 years; P <.001) with a nonsignificant higher complication rate (16.5% vs 7.7%; P = .2) was observed in Europe vs North America, whereas higher rates of critically ill patients (33.3% vs 3.3%; P <.001) and mortality (26.9% vs 5%; P = .002) were observed in North America vs Europe. CONCLUSION: CIED procedure rates during known active COVID-19 disease varied greatly, from 0 to 16.2 per 1000 hospitalized COVID-19 patients worldwide. Patients with active COVID-19 infection who underwent CIED implantation had high complication and mortality rates. Operators should take these risks into consideration before proceeding with CIED implantation in active COVID-19 patients.

Describing heart rate variability in patients with chronic atrial fibrillation during hospitalization for COVID-19.

INTRODUCTION: Myriad cardiovascular manifestations have been reported with COVID-19. We previously reported that failure of PR interval shortening with increasing heart rate (HR) in patients with COVID-19 is associated with adverse outcomes. Here, we report on heart rate variability (HRV) and clinical outcomes in patients with chronic atrial fibrillation (cAF) hospitalized for COVID-19. METHODS: A retrospective review of admitted COVID-19 patients with cAF between 1 March 2020 to 30 June 2020 was performed. HRV in cAF was compared during pre-COVID-19 and COVID-19 admissions; we selected pre-COVID-19 ECGs with HRs that were within 10 beats per minute of the COVID-19 ECGs. Mean HR and each RR interval were recorded. Time-domain measurements of HR variability were then calculated (SDSD, RMSSD, pNN50). Clinical outcomes during COVID-19 were correlated to indices of HRV. RESULTS: A total of 184 ECGs (95 pre-COVID-19, 89 COVID-19) from 38 cAF in-patients were included. Mean age 78.6 ± 11.4 years, male 44.7%. The mean number of ECGs analyzed per patient pre-COVID-19 was 2.50 and during COVID-19 was 2.34. Comparing pre-COVID-19 versus COVID-19 ECGs showed: mean HR (95.9 ± 24.3 vs. 101.6 ± 22.8 BPM; P = .10), SDSD (109.0 ± 50.6 vs. 90.3 ± 37.2 ms; P < .01), RMSSD (184.1 ± 80.4 vs. 147.3 ± 59.8 ms; P < .01), pNN50 (73.8 ± 16.3 vs. 65.6 ± 16.6%; P < .01). Patients who had a smaller pNN50 during a COVID-19 admission had increased mortality (50.0% vs. 14.3%; log-rank test P = .02). CONCLUSION: In patients with cAF, the HRV was reduced during COVID-19 compared with prior illnesses at similar average heart rates. Patients with the most depressed HRV as measured by pNN50 had an associated increase in mortality compared with patients whose HRV was preserved.

A Shocking Case of Far-Field Atrial Oversensing in Giant-Cell Myocarditis.

We report a unique case of delivery of inappropriate implantable cardioverter-defibrillator therapies related to a "perfect storm": presence of an integrated lead, insufficient lead slack related to right heart dilation resulting in shock coil misplacement, myocarditis with loss of R waves, and the concomitant occurrence of an incessant atrial tachycardia. (Level of Difficulty: Advanced.).

Tricuspid regurgitation associated with implantable electrical device insertion: A systematic review and meta-analysis.

BACKGROUND: Implantable cardioverter defibrillator (ICD) and permanent pacemaker (PPM) lead placement may worsen or result in tricuspid regurgitation (TR). While the association between lead placement and the incidence of TR has been established, current understanding of this problem remains incomplete. This systematic review and meta-analysis sought to pool the existing evidence to better understand the occurrence and severity of TR associated with cardiac implantable electrical device (CIED) insertion. METHODS: An electronic search was performed to identify all relevant studies published from 2000 to 2018. Overall, 15 studies were selected for the analysis comprising 4019 patients with data reported on TR development following ICD or PPM lead placement. Demographic information, perioperative clinical variables, and clinical outcome measures, including pre and postoperative echocardiographic TR grade changes, were extracted and pooled for systematic review. RESULTS: Mean patient age was 69 years [95% CI: 64.62-73.59], and 63% [95% CI: 57-68] were male. Devices implanted included ICD in 57% [95%CI: 43-70] and PPM in 41% [95%CI: 31-52]. The most common indications for pacemaker implantation were sick sinus syndrome in 22% [95% CI: 22-37] and AV block in 21% [95%CI:12-34. The commonest indications for ICD implantation were primary and secondary prevention of sudden cardiac death. Atrial fibrillation was present in 37% [95%CI: 28-46] and congestive heart failure in 15% [95%CI: 2-57]. Baseline distribution of TR grades were as follows: grade 0/1 TR in 89% [95%CI: 82-93], grade 2 TR in 8% [95%CI: 5-13], grade 3 TR in 2% [95%CI: 0-7] and grade 4 TR in 2% [95%CI: 1-4]. Post-procedure, grade 0/ 1 TR decreased to 68% [95% CI: 51-81] (p < 0.01), grade 2 TR increased to 21% [15-28] (p < 0.01), grade 3 TR increased to 13% [95%CI: 5-32] (p = 0.02), and grade 4 TR increased to 7% [95%CI: 5-9] (p < 0.01). CONCLUSION: ICD and PPM lead placement is associated with increased TR post-procedure. Further studies are warranted to evaluate changes in TR grade in the long term.

Ventricular tachycardia induced by a backup pacing stimulus in a patient with a dual chamber pacemaker with AutoCapture.

Manufacturers of cardiac implantable electronic devices have incorporated automatic features to allow for remote monitoring, improve device longevity, and additional safety. Algorithms to automatically measure capture threshold and adjust output to preserve battery life are one such feature. Automatic features may occasionally result in unexpected or undesirable clinical outcomes. We report on a patient who developed ventricular tachycardia inadvertently induced by the AutoCapture. feature of an Abbott/St. Jude Medical (SJM) pacemaker.

Electromagnetic interference between implantable cardiac devices and continuous-flow left ventricular assist devices: a review.

Many patients with continuous-flow left ventricular assist devices (CF-LVAD) have other, co-existing implantable cardiac devices. While such devices often function appropriately, there is potential for electromagnetic interference (EMI). A literature review was performed to identify cases of EMI between CF-LVAD and other implanted cardiac devices to better understand their etiology, outcomes, and the strategies used to overcome such interference. The cases identified included interference between CF-LVAD and pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy. The EMI reported in the current literature can be broken down into two general categories: interference leading to difficulty establishing telemetry and interference leading to impaired electrical signal sensing. Such interference led to inappropriate shock delivery in some cases. The type of interference, and thus treatments, differed and were device dependent. The strategies employed to reduce interference included metal shielding, physical manipulation to increase the distance between devices, and even exchange of the implanted device with another brand of the same class. To avoid such EMI in the future, physicians must be aware of the reported interference between certain devices, and manufacturers must work more closely to increase the compatibility of implanted cardiac devices.

The diagnostic yield of implantable loop recorders stratified by indication: "real-world" use in a large academic hospital.

PURPOSE: To report on the clinical utility of implantable loop recorders (ILRs) in a large academic hospital setting over a 4-year period. METHODS: Retrospective study (2013-2016) of patients receiving ILRs for any indication including syncope, cryptogenic stroke (CrS), atrial fibrillation (AF) burden, palpitations, ventricular arrhythmias (VA), and other. Remote checks, symptomatic transmissions, and in-person checks were reviewed. Time to diagnosis was documented. RESULTS: A total of 263 patients (54% male, mean age 63 ± 15 years, mean follow-up 601 (range 9-1714) days) received ILRs for 324 indications; multiple indications were noted in 53/263 (20.2%) patients. ILR indications were 126 (39%) syncope, 81 (25%) CrS, 46 (14%) AF, 37 (11%) palpitations, 10 (3%) VA, and 24 (7%) other. Diagnostic yield for each indication was compared to the overall yield for all other indications. Three indications showed a significantly higher yield: AF (65% vs. 22%, p < 0.002), palpitations (60% vs. 24%, p < 0.001), and VA (70% vs. 28%, p < 0.004). For all other indications, there were no significant differences. Syncope had nearly half the diagnostic yield of previously published trials (28% vs. 43-56%). We observed a fourfold increase in ILR implant rate over the study duration. CONCLUSIONS: In a "real-world" academic hospital setting, the diagnostic rate of ILRs was highest for AF, palpitations, and VA; however, these high yield indications comprised only 29% of all indications. The diagnostic yield for the commonest indication (syncope) was approximately half that reported in the previously published trials. With increasing implantation rates, additional studies are required to refine guideline-based indications for ILR implantation to improve diagnostic yield.