Different leadless pacemakers working in harmony (Aveir in the atrium/Micra AV2 in the ventricle) in a patient with dextrocardia and double outlet right ventricle after high-risk infected device extraction.

INTRODUCTION: Patients with congenital heart disease are at increased risk for requiring cardiac pacing during their lifetime. METHODS: We present the first described case of using two leadless pacing systems manufactured by separate companies implanted within the same patient to provide atrial and ventricular pacing due to complex congenital anatomy. RESULTS: A 27-year-old male with dextrocardia with double outlet right ventricle, subaortic ventricular septal defect, and pulmonary stenosis status-post pulmonary valve replacement complicated by ventricular pacing dependence and subsequent atrial pacing dependence after atriotomy-based atypical flutter ablation developed recurrent mediastinitis and pocket infection with erosion despite prolonged antibiotic treatment. Due to atrial and ventricular pacing dependence, a comprehensive congenital care team concluded the need for lead extraction and replacement of pacemaker via leadless peacemaking device. Laser-lead extraction and temporary atrial pacemaker placement was performed. Afterward, a transesophageal echocardiogram guided implantation of both a Micra AV 2 (Medtronic) leadless pacemaker in the interventricular septum within the right ventricle and an Aveir (Abbott) leadless pacemaker in the superior base of the right atrial appendage was performed with successful pacing. Although there is no communication between these devices, atrial-mechanical ventricular pacing was reliable with good implant thresholds, impedances and sensing from both devices. CONCLUSION: Our case demonstrates the feasibility of using dual leadless pacing modalities to simultaneously pace someone at complex, prohibitive risk for temporary permanent or permanent pacemaker devices.

Aveir retrievable, 38-mm length, leadless pacemaker implantation in a 23-kg pediatric patient with congenital heart disease.

INTRODUCTION: Complications are more prevalent in pediatric patients receiving pacemaker implants. METHODS: We performed a retrospective review of a retrievable, 38 mm leadless pacemaker implantation in a 23-kg pediatric patient. CASE/DISCUSSION: An active 9-year-old, 23 kg male patient with tetralogy of Fallot with intermittent pacing need presented with a fractured lead and pacing need. He underwent implant of a retrievable leadless pacemaker (Abbott Aveir) via internal jugular vein access, without complication, and with echocardiographic guidance. His threshold was stable at 1.25 V @0.4 ms, with stable impedance and sensing at 5-month follow-up. CONCLUSION: Aveir retrievable leadless pacemakers can be implanted safely in a child with tetralogy of Fallot, as small as 23 kilograms.

Aveir VR, retrievable leadless pacing in the young.

INTRODUCTION: Successful implantations of the Aveir VR, have been effectively demonstrated in adults; however, there remain limited reports supporting safe and feasible implantation of the Aveir VR in the young population. METHODS: Retrospective, observational study of Aveir VR implantation of young patients (≦21 years old) at UC Davis Medical Center from November 2022 to January 2024 via the internal jugular or femoral vein implantation approaches. Indications for pacing, patient demographics, pacing thresholds and longevity were reported at the time of implantation and last follow-up. RESULTS: A total of 10 patients received the Aveir VR with a median age of years (IQR 12.5-17) and median weight of 50.8 kg (IQR 44.6-60.9) kg. The majority were male (80%). Aveir VR leadless pacemaker occurred via internal jugular venous (90%) or femoral venous (10%) approaches. Indications for placement were intermittent complete heart block (60%) and sinus pauses (40%). Adequate impedance, sensing and thresholds were maintained from implantation to a median follow-up of 9 months. Predicted pacemaker longevity at follow-up median was 23.8 years. There were no complications in any of the 10 patients. CONCLUSION: Aveir VR implantation via the internal jugular and femoral veins is feasible in the young patient population with stable pacing parameters at follow-up.

Vectorcardiography signs of a failing Fontan: Heart rate, PR interval, RtQRSvm, QRSvm and SPQRS-T angle as noninvasive markers of late Fontan complications and mortality.

BACKGROUND: Limited data exists on interpreting vectorcardiography (VCG) parameters in the Fontan population. OBJECTIVE: The purpose of this study was to demonstrate the associations between ECG/VCG parameters and Fontan failure (FF). METHODS/RESULTS: 107 patients with a Fontan operation after 1990 and without significant ventricular pacing were included. FF and Fontan survival (FS) groups were compared. The average follow-up after Fontan operation was 11.8 years ±7.1 years. 14 patients had FF (13.1%) which was defined as having protein-losing-enteropathy (1.9%), plastic bronchitis (2.8%), Fontan takedown (1.9%), heart transplant (5.6%), NYHA class III-IV (2.8%) or death (0.9%). A 12­lead ECG at last follow up or prior to FF was assessed for heart rate, PR interval, QRS duration, Qtc and left/right sided precordial measures (P-wave, QRS and T-wave vector magnitudes, spatial P-R and QRS-T angles). Transthoracic echocardiogram evaluated atrioventricular valve regurgitation and ventricular dysfunction at FF or last follow up. A cox multivariate regression analysis adjusted for LV dominance, ventricular dysfunction, HR, PR, QTc, Pvm, QRSvm, SPQRST-angle, RtPvm, RtQRSvm and RtTvm. Ventricular dysfunction, increased heart rate and prolonged PR interval were significantly associated to FF at the multivariate analysis. ROC analysis and Kaplan-meier analysis revealed an increased total mortality associated with a heart rate > 93 bpm, PR interval > 155 mv, QRSvm >1.91 mV, RtQRSvm >1.8 mV and SPQRST angle >92.3 mV with p values <0.001 to 0.018. CONCLUSION: We demonstrate the importance of ECG/VCG monitoring in the Fontan population and suggest specific indicators of late complications and mortality.

Incidence and Risk Factors for Medical Device-Related Pressure Injury in Hemodynamically Unstable Intensive Care Unit Patients: A Prospective Cohort Study.

PURPOSE: The purpose of this study was to determine the incidence and identify potential risk factors for medical device-related pressure injury (MDRPI) in critically ill and hemodynamically unstable adults (patients classified class III or IV on the Therapeutic Intervention Scoring System-28; TISS-28). DESIGN: Prospective cohort study. SUBJECTS AND SETTING: The target population was critically ill adults who were using one or more medical devices and categorized as class III or IV on the TISS-28. The study sample comprised 77 participants followed daily until discharge, death, transfer, or lesion development. Data were collected from January to March 2020. The study setting was an intensive care unit with 40 beds in a large hospital in a municipality in the state of Minas Gerais, Brazil. METHODS: Sociodemographic and pertinent clinical data, pressure injury (PI) risk assessed using the Braden Scale for Pressure Sore Risk, and head-to-toe skin inspections were completed. The incidence rate of MDRPIs was calculated, and survival analyses were completed via the Kaplan-Meier method and Cox regression model. RESULTS: Forty-nine of 77 participants developed an MDRPI, reflecting an incidence rate of 63.6%. Collectively, 71 MDRPIs occurred in these 49 participants. Univariate analysis indicated significant associations between MDRPI occurrences and level of consciousness (P = < .001), use of tube holder for ventilation devices (P = .013), nasal cannula (P = .034), nasogastric cannula (P = .034), presence of edema (P = .001), infection (P = .007), higher TISS score (P = .047), and greater number of medical devices (P = .022). Survival analysis indicated that a high or very high-risk score on the Braden Scale for Pressure Sore Risk (P = .043) and edema (P = .030) are risk factors for MDRPI occurrences in this vulnerable population. CONCLUSIONS: The incidence rate of MDRPIs was 63.6%. The categories with the highest high or very high risk scores on the Braden Scale for Risk of Pressure Pain and Edema emerged as risk factors for MDRPI in this critically ill and vulnerable population.

Atrial placement of Aveir-VR leadless pacemaker in a patient with complex cardiac anatomy.

Leadless pacemakers have provided new treatment modalities that can be especially useful in patients with complex cardiac anatomy and contraindications toward other pacemaker approaches. The Aveir™ single-chamber (VR) leadless pacemaker (LP) (Abbott Laboratories, Chicago, IL) is a recently approved device that can be placed in the right ventricle for patients with bradycardia. In this case, we present a novel use for the device through placement in the atrium to control atrial flutter in a patient with a hypoplastic right ventricle.

Retrievable leadless pacemakers (Aveir VR) may be beneficial in adult patients with congenital heart disease.

INTRODUCTION: Congenital heart disease may present in up to 1.6 % of newborns. Given high burden of pacing need in adult patients with repaired congenital heart disease and availability of different pacing options, more information on outcomes of newer pacemaker types are needed. Retrievable leadless pacemaker implants in adult congenital patients have not been described. METHODS: Retrospective review of three Aveir (Abbott) retrievable leadless pacemaker implants were reviewed at the UC Davis Medical Center. All patients underwent implant via femoral access. RESULTS: All patients had one deployment only, after mapping prior. No complications occurred. Implant thresholds were 0.5 V (V) @0.2msilliseconds (ms) for patients 1 and 2 and 1 V @0.4 ms for patient 3. With impedances between 500 and 1290 Ω. Sensing was 5.5-8 mV (mV). Follow-up occurred up to one year (for two patients) with similar values overall. The predicted longevities of each device were between 22.6 and >25 years. CONCLUSION: Safety and short-mid-term parameters of retrievable leadless pacemaker implantation is reported in three patients with adult congenital heart disease.

Loop recorder implantation in patients as young as 3-months of age; the benefit of the sub-scapular approach.

BACKGROUND: Loop recorder implants may have value in pediatric patients; however, size limitations exist due to the risk of erosion. METHODS: Retrospective review of five patients who underwent subscapular loop recorder implantation were reviewed. RESULTS: No complications occurred. Stable R-waves were noted but could be positional but with adequate diagnostics provided. CONCLUSION: Subscapular loop recorder implantation is feasible in patients as young as 3 months of age.

First report of an Aveir retrievable leadless pacemaker in a pediatric patient, via internal jugular vein access.

BACKGROUND: The Aveir device allows retrievability and mapping prior to fixation over alternative leadless pacemakers. CASE SUMMARY: We describe the first case of Aveir leadless pacemaker implantation into a 44.5 kg, pediatric patient with symptomatic sinus dysfunction. Access by the right internal jugular vein (RIJ) with 1st attempt implantation into the septal location. DISCUSSION: Placement of the Aveir leadless pacemaker is feasible in a 44.5 kg pediatric patient via a RIJ approach.

Catheter ablation of atrioventricular nodal reentrant tachycardia, when AVNRT presented as a fetus or infant.

BACKGROUND: Atrioventricular nodal reentrant tachycardia (AVNRT) does not commonly present during infancy. Although relative safety of catheter ablation of AVNRT has been demonstrated in pediatrics, this procedure is rarely indicated in children <15 kg. METHODS: Retrospective review of seven cases of AVNRT that presented in children younger than 1 year of age and required catheter ablation for definitive management. Electrophysiology (EP) study was planned with two or three catheters. Area of ablation determined by voltage mapping, propagation sinus wave collision and slow pathway potential location. Ablation performed with cryothermal energy. No fluoroscopy was used. RESULTS: Presentation ranged from 36 weeks of gestation to 11 months of age. Two presented in fetal life and two in the neonatal period. The median age of ablation was 20 months (range 17-31 months). The median weight at ablation was 11.4 kg (range 8.9-14.9 kg). Median follow-up time was 16 months. All had typical AVNRT. The median tachycardia cycle length was 216 ms. 100% successful rate using cryoablation. No complications. No recurrence of tachycardia during the follow-up period. CONCLUSION: Slow AV nodal pathway cryoablation may be safely performed, with good short and medium-term outcomes in patients under 15 kg.

Decreased vector magnitudes may help identify events in patients with Long QT syndrome.

INTRODUCTION: All Long QT syndrome (LQTS) patients are at elevated risk for channelopathy-induced delayed myocardial repolarization and consequently potentially life-threatening cardiac events with 90% of initial cardiac events occurring between preteen and 40 years old. Utilizing ECG and derived vectorcardiographic parameters, including T wave Vector Magnitude (TwVM) measurement data, this study attempts to determine whether TwVM from baseline ECGs is effectively predictive of future cardiac events for genotype-positive LQTS patients. METHODS: Verified carriers of established LQTS disease-causing genotypes were selected from University of Minnesota patient encounters between 2010 and 2020 for inclusion in this retrospective study. Baseline and predictive ECG and derived vectorcardiographic parameter evaluation, clinical data, and statistical analysis were compared between patients with and patients without cardiac events. First recorded ECG was at presentation to our hospital and final ECG is defined as ECG just prior to cardiac event (event defined below in Methods) or the most final documented ECG before cut-off year of 2020 for the event-free group. RESULTS: Of 41 participants, 15 experienced cardiac events and 26 did not. While many baseline electrocardiographic parameter measurements did not show significant differences between patient groups, vectorcardiographic parameters at baseline, specifically the QRS vector magnitude (QRSVM) and azimuth of the spatial ventricular gradient, showed significance. Additionally, final vectorcardiographic parameters, particularly the QRSVM, TwVM, and azimuth of the spatial ventricular gradient showed significant differences between patient groups. Final T-wave frontal axis was significantly larger in those without cardiac events. Significant Kaplan-Meier curve separation between patient groups was noted based on a QRSVM of 1.43 mV or lower, with additional consideration to patient age, genotype, and beta blocker use. CONCLUSION: This study shows evidence of ECG and derived vectorcardiographic parameters, including TwVM, being effective in early prediction of cardiac events in genotype-positive LQTS patients.

Leadless pacemaker implantation for pediatric patients through internal jugular vein approach: A case series of under 30 kg.

BACKGROUND: We demonstrate a case series of 8 pediatric patients, all under 30 kg, who had leadless pacemaker implants via the internal jugular vein. METHODS: A retrospective review of pediatric leadless pacing placement via the internal jugular vein at the University of Minnesota Masonic Children's Hospital and UC Davis Medical Center from 2018 through 2021 was performed. Rationales for pacing, demographics of patients, pacing thresholds, and longevity of devices were recorded. RESULTS: Eight internal jugular pacemaker insertions were performed successfully in patients weighing between 10.9 kg and 29 kg. Five patients had Micra implantation via the right internal jugular vein, whereas 3 patients had insertion via the left internal jugular vein. No surgical cut-downs were performed. No venous complications occurred. Up to 3 years of follow-up were noted. CONCLUSION: Leadless pacemaker implantation, via left or right internal jugular veins, is feasible without surgical cutdown in patients <30 kg.

Inappropriate sinus tachycardia: an examination of existing definitions.

AIMS: Inappropriate sinus tachycardia (IST) is a syndrome characterized by an elevated sinus rate unassociated with known physiological, pathological, or pharmacological causes. Despite published consensus documents, IST definitions appear to vary in the literature. In this study, we reviewed IST publications to evaluate IST definition variability and ascertain the degree to which consensus definitions are being adopted. METHODS AND RESULTS: English-language articles in PubMed, Ovid MEDLINE, Ovid Embase, and Google Scholar published from 1 January 1970 to 1 June 2021 with the title terms 'inappropriate sinus tachycardia,' 'non-paroxysmal sinus tachycardia,' or 'permanent sinus tachycardia' were searched. In each, the IST definition used, qualifying characteristics, and publications cited to support each definition were recorded. We identified 138 publications meeting the search criteria. Inappropriate sinus tachycardia definitions were provided in 114 of 138 articles (83%). A majority of definitions (92/114, 81%) used distinct heart rate (HR) thresholds. Among these, the most common threshold was ≥100 beats per minute (BPM) (75/92, 82%), mainly measured at rest (54/92, 59%). Most definitions (47/92, 51%) included a second criterion to qualify for IST; these were most often an HR threshold of 90 BPM measured over 24 h by ambulatory electrocardiogram (37/47, 79%). Diagnosis of exclusion was a common criterion (75/92, 82%) but symptom status was not (41/92, 45%). The 2015 Heart Rhythm Society IST consensus was commonly cited but adopted in only 37% of definitions published after 2015. CONCLUSIONS: Inappropriate sinus tachycardia definitions in current literature are inconsistent, and professional society consensus IST definitions have, to date, had limited impact.

Is derived vectorcardiography a potential screening tool for pulmonary hypertension?

BACKGROUND: Patients with atrial septal defects and pulmonary hypertension would benefit from early identification and treatment of pulmonary hypertension prior to closure. Noninvasive screening tools for pulmonary hypertension are inadequate. Electrocardiography, though readily available, has so far been of limited screening utility in patients with pulmonary hypertension. We hypothesize that derived vectorcardiographic parameters will aid in identifying increased right ventricular afterload and thus provide an additional screening tool for pulmonary hypertension in patients with secundum atrial septal defects. OBJECTIVE: Establish whether vectorcardiography can be used to screen for pulmonary hypertension. METHODS: A retrospective review of patients with secundum atrial septal defects (ASD) who underwent cardiac catheterization at the University of Minnesota from 2012 to 2020 was performed. We excluded patients with other congenital heart diagnoses, insufficient hemodynamic data, or lacking sinus rhythm electrocardiogram at time of cardiac catheterization. Parameters analyzed included: Sokolow-Lion right ventricular hypertrophy criteria, PR duration, QRS duration, corrected QT intervals, QRS and T wave frontal plane axes, rSR', R' amplitude, as well as vectorcardiographic parameters (Kors regression-related method), the QRS vector magnitude, T wave vector magnitude, and the spatial QRS-T angle. These were compared to measures of pulmonary hypertension obtained at cardiac catheterization. RESULTS: The spatial QRS-T angle significantly differentiated ASD patients with pulmonary hypertension (median 104 degrees, interquartile range 55-137 degrees) from ASD patients without pulmonary hypertension (median 37 degrees, interquartile range 21-63 degrees, p-value of 0.002). At a cut-off of 124 degrees, the positive and negative predictive values for identification of pulmonary hypertension were 36.4% and 96.4%, respectively, with an odds ratio of 13.4 (95% confidence interval of 2.9 to 63.7). The positive predictive value was significantly improved when combined with echocardiographic data to screen for pulmonary hypertension. CONCLUSION: The spatial QRS-T angle is associated with pulmonary hypertension in patients with secundum atrial septal defects.

Conduction System Pacing in Pediatrics and Congenital Heart Disease, a Single Center Series of 24 Patients.

His-bundle pacing has demonstrated feasibility in numerous adult studies to reverse and prevent pacing-induced cardiomyopathy, however, is met with higher capture thresholds with deployment sheaths designed for adults with his-bundles in the typical location. To describe 24 pediatric and adult congenital patients post-physiologic pacing. Patients at the University of Minnesota Masonic Children's Hospital with congenital complete heart block or congenital heart disease and atrioventricular block presented for pacemaker placement between November 2019 and January 2021. Twenty-four patients had attempted his-bundle placement using either Medtronic's C315 or C308 sheaths and 3830 leads except for 3 patients who had Boston Scientific's His system with the Shape 3 sheath and 7842 leads. Twenty-four total patients underwent physiologic pacing (23 his-bundle, 13 female, 11 male) with median age of 14 years (range 8-39 years) with median weight of 51 kg (range 21.2-81 kg) with five right-sided implants performed. Twelve patients had congenital heart disease including atrioventricular canal defects, tetralogy of Fallot, and ventricular septal defect repairs (nine patients with ventricular septal defect repairs). Twelve patients had selective His-bundle pacing (six with congenital heart disease). Median threshold to capture was 0.5 V at 0.4 ms (range 0.4 to 1.1 V at 0.4 ms), impedance 570 ohms (range 456-1140 ohms), and sensing median of 9.7 mV (range 1.5-13.8 mV if present). The median follow-up time was 610 days (range 240-760 days). No complications occurred peri-procedurally or during follow-up. His-bundle pacing is feasible in pediatric and congenital heart disease patients.

Successful cryoablation of junctional ectopic tachycardia is feasible in a 13.4kg, 18-month-old toddler.

JET (junctional ectopic tachycardia) is a complicated and rare form of supraventricular tachycardia that is associated with a high rate of morbidity and mortality. Pharmaceutical management can be insufficient, and cryoablation has been described for congenital JET management. We describe cryoablation for congenital JET in an prior 32-week gestational aged, 18-month-old (corrected 16-month-old) with no JET post-ablation with normal Holter and follow-up within 6 months following cryoablation. This report demonstrates the safety and feasibility of cryoablation in patients as young as 18 months old.

Peripartum management of a patient with catecholaminergic polymorphic ventricular tachycardia.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal cardiac channelopathy characterized by episodes of ventricular tachycardia (VT) during exercise or in stressful situations. As the peripartum period creates a stressful environment, we describe our approach of this rare condition in a very common situation, child birth.

Three-dimensional mapping for His-bundle pacing in pediatric patients, a case series.

INTRODUCTION: Pediatric patients who receive pacemakers may have a lifetime of repeat exposure to fluoroscopy. His bundle pacing may provide better long-term pacing for these patients. To minimize fluoroscopy and for improved localization of the His bundle, we utilized three-dimensional mapping to guide His bundle pacing and we follow-up short-term results. METHODS: An Octapolar Livewire catheter (Abbott, Minneapolis, USA) was used for mapping and location of the His bundle while 3-dimensional mapping via the EnSite Precision system (Abbott Medical, Abbott Park, IL) was utilized to create a 3-dimensional geometry. The EnSite Precision system also mapped and recorded His bundle signal strengths and earliest ventricular activation or retrograde His bundle activation. RESULTS: Three patients are presented and followed for 4-5 months. The ages ranged from 10 to 15 years with 1 male patient. Diagnoses including progressive atrioventricular block, alternating bundle branch block and atrioventricular canal defect with complete heart block. All patients received selective His-bundle pacing systems. The range in fluoroscopy time was 6.4 to 9.9 min with 5.64 mGy to 10.18 mGy. Stable lead thresholds, impedances and sensing were present at last follow-up. CONCLUSIONS: His bundle pacing in our 3 pediatric patients including one with altered His-bundle physiology (case 3 with atrioventricular canal defect) was successful with good short-term follow-up results.

Vectorcardiography as a prognostic tool in hypertrophic cardiomyopathy.

BACKGROUND: Vectorcardiography (VCG) has demonstrated diagnostic value in the assessment of hypertrophic cardiomyopathy (HCM), however, determining its prognostic value over time has not yet been investigated. This study sought to assess the correlation of VCG parameters with the progression of HCM. METHODS: A retrospective chart review of 119 pediatric patients with diagnosis of HCM at the University of Minnesota. Eighty-three cases were excluded because of age, presence of congenital heart disease, not meeting criteria for HCM or negative phenotype. Sample was divided into 2 groups based on the presence or not of cardiac events (ventricular tachycardia, cardiac arrest, ventricular assist device, heart transplant). Derived vectorcardiography from standard 12­lead ECG was obtained for the first ECG and last available or prior to sentinel event. RESULTS: Of the 36 cases that met inclusion criteria, 9 (25%) developed a sentinel event. The median age for the event group was 10.1 ± 7.5 years and for the non-event group was 8.7 ± 6.35 years. There was no significant difference in age or sex between the groups. The T wave vector magnitude value was significantly smaller in the event group than in the non-event group (0.302 ± 0.146 mV Vs. 0.561 ± 0.305 mV, p 0.002), with a hazard ratio of 0.651 (95% CI 0.463 to 0.915). No other parameter showed significant difference between the two groups. CONCLUSIONS: The T wave vector magnitude may predict sentinel events in HCM. Prospective studies are necessary to evaluate the utility of the evolution of VCG parameters.

Selective His-bundle pacing in an adult with atrioventricular canal defect via retrograde His localization.

Adult congenital heart disease patients may undergo numerous fluoroscopically guided procedures including pacemaker implantation during their lifetime. One alternative to traditional pacemaker setup which may improve long-term pacing outcomes is His bundle pacing. Given the altered His-bundle location, and given increased radiation exposure over a lifetime, we used 3-dimensional mapping to locate the His and to minimize fluoroscopy for placement of a His-bundle pacemaker system in a 31-year old patient with atrioventricular canal defect and complete heart block with 100% RV pacing and epicardial lead fracture. METHODS: An Octapolar Livewire catheter (Abbott, Minneapolis, USA) was used for mapping and location of the His bundle from a right femoral venous access on the EnSite Precision system 3-dimensional mapping system (Abbott Medical, Abbott Park, IL). The same map was used to guide 3830 lead placement into the posterior-inferior His-bundle position. RESULTS: Successful placement of a His-bundle pacing system with thresholds of 1Volt@0.4ms for both the atrial and ventricular leads with selective His-bundle pacing noted. Ten-month follow-up demonstrated His-bundle capture at 0.75V@0.4ms with stable impedance, sensing and with 100% right ventricular pacing a projected longevity of 12 years total. CONCLUSIONS: Successful placement of selective His-bundle pacing can be achieved in an adult patient with atrioventricular canal defect using 3-dimensional mapping.