Perioperative Health Interventions in Children With Chronic Neuromuscular Conditions Undergoing Major Musculoskeletal Surgery: A Scoping Review.

BACKGROUND AND OBJECTIVES: Children with chronic neuromuscular conditions (CCNMC) have many coexisting conditions and often require musculoskeletal surgery for progressive neuromuscular scoliosis or hip dysplasia. Adequate perioperative optimization may decrease adverse perioperative outcomes. The purpose of this scoping review was to allow us to assess associations of perioperative health interventions (POHI) with perioperative outcomes in CCNMC. METHODS: Eligible articles included those published from January 1, 2000 through March 1, 2022 in which the authors evaluated the impact of POHI on perioperative outcomes in CCNMC undergoing major musculoskeletal surgery. Multiple databases, including PubMed, Embase, Cumulative Index of Nursing and Allied Health Literature, Web of Science, the Cochrane Library, Google Scholar, and ClinicalTrials.gov, were searched by using controlled vocabulary terms and relevant natural language keywords. Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines were used to perform the review. A risk of bias assessment for included studies was performed by using the Risk of Bias in Non-randomized Studies of Interventions tool. RESULTS: A total of 7013 unique articles were initially identified, of which 6286 (89.6%) were excluded after abstract review. The remaining 727 articles' full texts were then reviewed for eligibility, resulting in the exclusion of 709 (97.5%) articles. Ultimately, 18 articles were retained for final analysis. The authors of these studies reported various impacts of POHI on perioperative outcomes, including postoperative complications, hospital length of stay, and hospitalization costs. Because of the heterogeneity of interventions and outcome measures, meta-analyses with pooled data were not feasible. CONCLUSIONS: The findings reveal various impacts of POHI in CCNMC undergoing major musculoskeletal surgery. Multicenter prospective studies are needed to better address the overall impact of specific interventions on perioperative outcomes in CCNMC.

Hospital Access Patterns of Children With Technology Dependence.

OBJECTIVES: We studied hospital utilization patterns among children with technology dependence (CTD). We hypothesized that increasing pediatric healthcare concentration requires those caring for CTD to selectively navigate healthcare systems and travel greater distances for care. METHODS: Using 2017 all-encounter datasets from 6 US states, we identified CTD visits defined by presence of a tracheostomy, gastrostomy, or intraventricular shunt. We calculated pediatric Hospital Capability Indices for hospitals and mapped distances between patient residence, nearest hospital, and encounter facility. RESULTS: Thirty-five percent of hospitals never saw CTD. Of 37 108 CTD encounters within the remaining 543 hospitals, most emergency visits (70.0%) and inpatient admissions (85.3%) occurred within 34 (6.3%) high capability centers. Only 11.7% of visits were to the closest facility, as CTD traveled almost 4 times further to receive care. When CTD bypassed nearer facilities, they were 10 times more likely to travel to high-capability centers (95% confidence interval: 9.43-10.8), but even those accessing low-capability facilities bypassed less capable, geographically closer hospitals. Transfer was more likely in nearest and low-capability facility encounters. CTD with Medicaid insurance, Black race, or from lower socioeconomic communities had lower odds of encounters at high-capability centers and of bypassing a closer institution than those with white race, private insurance, or from advantaged communities. CONCLUSIONS: Children with technology dependence routinely bypass closer hospitals to access care in facilities with higher pediatric capability. This access behavior leaves many hospitals unfamiliar with CTD, which results in greater travel but less transfers and may be influenced by sociodemographic factors.

The Story of Managed Ventricular Pacing.

A significant milestone in cardiac pacing occurred approximately two decades ago, when the primary operating mode was reimagined to more closely mimic normal top-down cardiac activation. When introduced, Managed Ventricular Pacing (MVP™; Medtronic, Minneapolis, MN, USA) was an unprecedented dual-chamber mode as it preferentially paced the right atrium in the AAI/R mode and simultaneously protected against transient heart block, albeit only in the instance of dropped ventricular beats. At the time, dual-chamber DDD/R with atrial-based timing and programmable atrioventricular delay was state of the art. MVP™ "unlocked" conventional dual-chamber pacing by not consistently requiring a 1:1 atrioventricular relationship during its primary operating mode (ie, AAI/R+). Ultimately, MVP™ emerged as a primitive means to promote His-Purkinje activation, and it is not a coincidence that its roots can be traced back to first-in-man permanent His-bundle pacing.

His bundle pacing insights from electroanatomical mapping: Topography and pacing targets.

OBJECTIVES: To characterize 3D electroanatomical mapping (EAM) of the His bundle (HB) region. BACKGROUND: Visualization of selective (S) and nonselective (NS) HB capture areas by EAM has not been described and may help guide HB pacing (HBP). METHODS: EAM was performed via NavX system in 17 patients (pts) undergoing HBP. HB cloud, S-HB, NS-HB, and right bundle (RB) capture areas were mapped. RESULTS: S-HBP areas were identified in 11, NS-HBP in 14, and RB in 11 pts. Two NS-HBP areas (upper and lower) either separated by S-HBP (8 pts) or almost contiguous (5 pts) were observed. S-HBP area measured: 1.1 ± 0.9 cm2 , NS upper: -1.2 ± 0.9 cm2 , NS lower: -1.2 ± 0.9 cm2 , RB: -1.7 ± 1.3 cm2 , total His cloud: -4.1 ± 2.7 cm2 . Electrocardiogram (ECG) pacemaps were different between upper and lower NS-HBP areas in 13/14 pts (p = .006). ECG differences between NS clouds were present in inferior leads in 9 pts (more negative QRS complex from lower NS area) and in precordial leads in 5 pts. There was no correlation between HBP lead location and capture threshold. R-wave amplitude was higher at more distal locations on HB cloud (p = .02). CONCLUSION: (1) Pacemapping identifies distinct regions that may correspond to HB anatomy. (2) A linear S-HBP area is typically surrounded by two separate NS areas. (3) Pace-map ECGs from upper and lower NS-HBP areas have different morphologies. (4) These EAM features and pace-mapping may be helpful to the implanter.

Permanent His-bundle pacing using stylet-directed, active-fixation leads placed via coronary sinus sheaths compared to conventional lumen-less system.

BACKGROUND: The use of coronary sinus (CS) sheaths to deliver stylet-driven leads (SDLs) for His-bundle pacing (HBP) has not been described. Conventionally, HBP is achieved using a stylet-less lead delivered through a customized catheter. OBJECTIVE: The purpose of this study was to characterize the acute and early-term HBP experience with stylet-driven, active-fixation leads delivered through CS sheaths compared to the conventional approach. METHODS: Delivery of Medtronic 4471 and 7742 SDLs was attempted in 27 patients. Delivery was facilitated using CS guide catheters and custom-shaped stylets. Procedural characteristics and lead performance were compared to those of a group of 17 patients in whom delivery of 3830 lumen-less leads (LLLs) was attempted. Patients had heterogeneous pacing indications. RESULTS: HBP with SDL was successful in 24 of 27 patients(89%) compared to 15 of 17 patients (88%) in the LLL group. Mean procedural and fluoroscopy times in the SDL and LLL groups were 129 ± 43 minutes vs 104 ± 43 minutes and 9.6 ± 5.2 minutes vs 8.3 ± 5.0 minutes, respectively (both P = NS). There was a significant difference in procedure and fluoroscopy times within the SDL group between the first and second halves of the series, probably secondary to a learning curve. Acute HBP thresholds were higher with SDL than with LLL (2.6 ± 1.5 V vs 1.5 ± 1.2 V; P = .02) and remained stable at 8.4 ± 5.3 months. Both SDLs exhibited similar pacing thresholds. Two crossovers between groups occurred (1 in each group). Four patients with SDL and 1 patient with LLL exhibited high thresholds during follow-up. CONCLUSION: Permanent HBP using stylet-driven, active-fixation leads delivered through conventional CS sheaths is feasible. Procedural characteristics and lead performance were clinically acceptable.

Direct Visualization of the His Bundle Pacing Lead Placement by 3-Dimensional Electroanatomic Mapping: Technique, Anatomy, and Practical Considerations.

BACKGROUND: His bundle pacing (HBP) remains technically challenging and is currently guided by electrograms and 2-dimensional fluoroscopy. Our objective was to describe a new technique for HBP directly guided by electroanatomic mapping (EAM). METHODS: Twenty-eight patients were included. The atrioventricular septum was mapped via EAM, and His bundle (HB) electrograms, selective, and nonselective HB capture sites were tagged. Pacing leads were connected to EAM, navigated to tagged HB target sites and deployed. Intracardiac electrograms and pacing parameters were recorded. Lead location was tagged on the cloud of HB sites, which was divided into 3 arbitrary segments. In 5 patients, atrioventricular nodal ablation was performed with direct visualization of the HBP lead by EAM. RESULTS: Reproducible navigation of the pacing lead to predetermined HBP locations guided by EAM was achieved in all patients. The lead was successfully deployed in 25 patients. HB cloud area was 360 (212) mm2. There was no correlation between HBP threshold and lead location on the His cloud. The intracardiac electrograms atrial/ventricular ratio at the lead deployment site correlated with its EAM position on the His cloud ( P=0.045). Procedure, fluoroscopy, and mapping times were 116.0 (38.8), 8.6 (6.3), and 9.0 (11.4) minutes, respectively. HBP threshold at implant was 1.5 (2.3) V at 1.5 (1.0) ms. Distance between HB lead and ablation sites was 10.0 (1.3) mm in patients undergoing atrioventricular nodal ablation. CONCLUSIONS: Direct guidance of HBP by EAM allows for direct visualization of the pacing lead on the HB cloud and reproducible navigation to predetermined HB capture sites. Intracardiac electrograms atrial/ventricular ratio at the lead deployment site correlates with His cloud location. EAM can be applied during standard HBP procedures or combined with atrioventricular nodal ablation.

Trial of telemedicine for patients on home ventilator support: feasibility, confidence in clinical management and use in medical decision-making.

We investigated whether telemedicine (videoconferencing) was feasible in patients with special care needs on home ventilation, whether it affected the confidence of families about the clinical management of their child, and whether it supported clinical decision-making. Videoconferencing software was provided free for 14 families who had a computer and webcam. Families completed questionnaires about clinical management before the addition of telemedicine and 2-3 months after they had used telemedicine. They also completed a questionnaire about their experience with videoconferencing. There were 27 telemedicine encounters during the 9-month study. Families reported higher confidence in clinical care with telemedicine compared to telephone. They also reported that the videoconferencing was high-quality, easy to use, and did not increase their telecommunication costs. The telemedicine encounters supported clinical decision-making, especially in patients with active clinical problems or when the patient was acutely ill. The telemedicine encounters prevented the need for 23 clinic visits, three emergency room visits, and probably one hospital admission. Although the study was small, videoconferencing appears useful in the management of medically fragile patients on home ventilator support, producing high levels of family confidence in clinical management and value to clinicians in their decision-making.

Analysis of pacing/defibrillator lead failure using device diagnostics and pacing maneuvers.

Patients with Medtronic Sprint Fidelis (Medtronic Inc., Minneapolis, MN, USA) lead failures present with oversensing, resulting in pacing inhibition and inappropriate shocks. We present a case of lead noise from the right ventricular (RV) ring conductor, resulting in multiple inappropriate shocks with subsequent pacing inhibition and syncope. RV pacing lead impedance at no point exceeded 1,000 ohms. We found that increased noise and oversensing was more likely to be induced when pacing at higher pulse widths. RV pacing outputs at lower pulse widths may decrease susceptibility to noise generation and prove an effective temporizing measure in pacing-dependent patients.

Multicenter, prospective, randomized safety and efficacy study of a new atrial-based managed ventricular pacing mode (MVP) in dual chamber ICDs.

BACKGROUND: Ventricular desynchronization caused by right ventricular pacing may impair ventricular function and increase risk of heart failure (CHF), atrial fibrillation (AF), and death. Conventional DDD/R mode often results in high cumulative percentage ventricular pacing (Cum%VP). We hypothesized that a new managed ventricular pacing mode (MVP) would safely provide AAI/R pacing with ventricular monitoring and DDD/R during AV block (AVB) and reduce Cum%VP compared to DDD/R. METHODS: MVP RAMware was downloaded in 181 patients with Marquis DR ICDs. Patients were initially randomized to either MVP or DDD/R for 1 month, then crossed over to the opposite mode for 1 month. ICD diagnostics were analyzed for cumulative percentage atrial pacing (Cum%AP), Cum%VP, and duration of DDD/R pacing for spontaneous AVB. RESULTS: Baseline characteristics included age 66 +/- 12 years, EF 36 +/- 14%, and NYHA Class II-III 36%. Baseline PR interval was 190 +/- 53 msec and programmed AV intervals (DDD/R) were 216 +/- 50 (paced)/189 +/- 53 (sensed) msec. Mean Cum%VP was significantly lower in MVP versus DDD/R (4.1 +/- 16.3 vs 73.8 +/- 32.5, P < 0.0001). The median absolute and relative reductions in Cum%VP during MVP were 85.0 and 99.9, respectively. Mean Cum%AP was not different between MVP versus DDD/R (48.7 +/- 38.5 vs 47.3 +/- 38.4, P = 0.83). During MVP overall time spent in AAI/R was 89.6% (intrinsic conduction), DDD/R 6.7% (intermittent AVB), and DDI/R 3.7% (AF). No adverse events were attributed to MVP. CONCLUSIONS: MVP safely achieves functional atrial pacing by limiting ventricular pacing to periods of intermittent AVB and AF in ICD patients, significantly reducing Cum%VP compared to DDD/R. MVP is a universal pacing mode that adapts to AVB and AF, providing both atrial pacing and ventricular pacing support when needed.

Randomized pilot study of a new atrial-based minimal ventricular pacing mode in dual-chamber implantable cardioverter-defibrillators.

OBJECTIVE: We hypothesized that a new minimal ventricular pacing mode (MVP) that provides AAI/R pacing with ventricular monitoring and back-up DDD/R pacing as needed during AV block (AVB) would significantly reduce cumulative percent ventricular pacing compared to DDD/R. BACKGROUND: Conventional DDD/R mode often results in high cumulative percent ventricular pacing that may adversely affect ventricular function and increase risk of heart failure and atrial fibrillation. METHODS: MVP was made operational in 30 patients with DDD/R implantable cardioverter-defibrillators (ICDs) and no history of AVB. Patients were randomized to one week each in DDD/R and MVP. Holter monitor recordings (ECG, intracardiac electrograms, and event markers) and device diagnostics were analyzed for cumulative % atrial paced (Cum%AP), cumulative percent ventricular pacing, and frequency and duration of DDD/R pacing back-up. Diaries were used to report symptoms. RESULTS: Age of the study population was 61 years +/- 12 years and 83% were male. Baseline PR interval was 204 ms +/- 32 ms and programmed AV intervals (DDD/R) were 200 ms +/- 50 ms (paced)/167 ms +/- 54 ms (sensed). Cum%AP was similar between MVP and DDD/R (47.9 +/- 37 vs 46.3 +/- 36). Cumulative percent ventricular pacing was significantly lower in MVP vs DDD/R (3.79 +/- 16.3 vs 80.6 +/- 33.8, P < .0001). Back-up DDD/R pacing during MVP operation due to transient AVB occurred in 10% of patients (9.3 +/- 7.4 [range 1-15] episodes/patient-day, duration 39.7 minutes +/- 156 minutes). Fifteen percent of AV intervals during MVP operation exceeded 300 ms. No significant symptoms were reported during MVP operation. CONCLUSIONS: MVP dramatically reduced cumulative percent ventricular pacing compared to DDD/R while maintaining AV synchrony and providing sensor-modulated atrial pacing support. Intermittent oscillations between MVP and DDD/R during transient AV block appeared safe and well tolerated.

Efficacy of atrial antitachycardia pacing using the Medtronic AT500 pacemaker in patients with congenital heart disease.

Patients with congenital heart disease are vulnerable to atrial tachyarrhythmias, especially after atrial surgeries. We evaluated the efficacy of atrial arrhythmia detection and antitachycardia pacing (ATP) using the Medtronic AT500 pacemaker in 28 patients with congenital heart disease (age 30 +/- 18 years). Of 15 patients with atrial arrhythmias, 14 had atrial tachycardia events that were appropriately detected. ATP was enabled for 167 treatable episodes, successfully converting 90 (54%). Rhythms classified as ventricular tachycardia were detected 127 times, yet most were actually atrial or sinus tachycardia with 1:1 atrioventricular conduction. Atrial tachycardias in congenital heart disease are amenable to ATP algorithms in the AT500 pacemaker.

Rate dependent far-field R wave sensing in an atrial tachyarrhythmia therapy device.

A case is reported of far-field R wave (FFRW) oversensing resulting in inappropriate atrial tachycardia (AT) detection by a dual chamber pacemaker incorporating atrial autoadjusting sensitivity (AAS). FFRW oversensing occurred during periods of functional atrial undersensing (FAU) with PR interval prolongation. Limitations of the pacemaker's ability to reject FFRWs and programming considerations for addressing this unique behavior are discussed.