Intraoperative Epicardial Triventricular Pacing in a Pediatric Patient

Cardiac resynchronization therapy (CRT) is used as an adjunctive therapy in adults with advanced heart failure but remains less commonly applied in pediatric patients. Further, CRT is traditionally conducted via biventricular transvenous pacing from the right ventricle and coronary sinus to activate the left ventricle and improve electromechanical synchrony; however, triventricular pacing, in which a third ventricular lead is utilized to activate an additional ventricular location, has been shown to be a feasible therapeutic alternative to typical CRT in patients with advanced heart failure or nonresponders. Limited adult studies involving triventricular pacing have been performed to date but no pediatric data are available. Thus, we present the case of a 12-month-old patient with congenital complete heart block and subsequent pacemaker-induced cardiomyopathy in whom triventricular epicardial pacing was applied in an effort to increase the available knowledge.

Pacemaker Implantation in Neonates and Infants: Favorable Outcomes with Epicardial Pacing Systems

The implantation of pacemakers (PM) in neonates and infants requires particular consideration of small body size, marked body growth potential, and the decades of future pacing therapy to be expected. The aim of this study is to quantify the complications of implantation and outcome occurring at our center and to compare these with other centers. Retrospective analysis of 52 consecutive patients undergoing PM implantation at a single tertiary care center within the first year of life. PMs were implanted at a median age of 3 months (range 0-10 months). Structural heart defects were present in 44 of 52 patients. During a median follow-up time of 40.4 months (range 0.1-114 months), measurements for sensing, pacing thresholds, and lead impedance remained stable. No adverse pacing effect was observed in left ventricular function or dimensions over time. There were 20 reoperations in 13 patients at a median time of 4.7 years (range 0.05-8.2 years) after implantation, for end of battery life (n = 10), lead dysfunction (n = 3), device dislocation (n = 3), infection (n = 3), and diaphragmatic paresis (n = 1). No PM-related mortality occurred. Epicardial pacemaker implantation in neonates and infants is an invasive but safe and effective procedure with a relatively low risk of complications. Our current implantation technique and the use of bipolar steroid-eluting electrodes, which we prefer to implant on the left ventricular apex, lead to favorable long-term results.

Temporal patterns of premature atrial complexes predict atrial fibrillation occurrence in bradycardia patients continuously monitored through pacemaker diagnostics

The frequency of premature atrial complexes (PACs) has been related with atrial fibrillation (AF) occurrence and adverse prognosis. Research objective was to evaluate whether temporal patterns of PACs are directly associated with AF onset in pacemaker patients with continuous monitoring of the atrial rhythm. Overall, 193 pacemaker patients (49% female, 72 ± 9 years old), enrolled in a national registry, were analyzed. Frequency of daily PACs was measured in a 14-day initial observation period, during which patients were in sinus rhythm. In the following period, temporal occurrence and frequency of daily PACs and eventual onset of AF were derived by pacemaker diagnostics. In the run-in period, median PACs frequency was 614 PACs/day (interquartile range 70-3056). Subsequently, in a median follow-up of 6 months, AF occurred in 109 patients, in particular in 37/96 (38.5%) patients with a PAC rate < 614 PACs/day and in 72/97 (74.2%) patients with PAC rate ≥ 614 PACs/day (p < 0.001). In patients with AF occurrence, the number of daily PACs, normalized by dividing for the average of PACs in ten preceding days, progressively increased in the 5 days preceding AF. Cox model predictive analysis showed that the risk of AF was significantly higher in patients with a relative increase of the daily PACs higher than 30% compared with PACs average number in ten preceding days [hazard ratio (95% confidence interval) 3.67 (2.40-5.59), p < 0.001]. PACs frequency increases in the 5 days preceding AF onset. A relative increase of the daily PACs is significantly associated with the risk of AF occurrence.

Benefit of Rate Response with Closed-Loop Stimulation in Patients with Difficult Hemodialysis

Rate-responsive pacing is known to improve quality of life (QOL) in patients with sick sinus syndrome and chronotropic incompetence. However, the sensors for rate response include accelerometers, closed-loop stimulation (CLS), and minute ventilation sensors (MV sensors), each of which has a different mode of action. For this reason, it is important to select appropriate sensors that match the daily habits and behavioral patterns of the patient. For example, young and active patients are expected to have a rate increase when an accelerometer is used, while elderly patients and patients with a physical disability who are only able to move slowly often have a poor response to the accelerometer. MV sensors are therefore better suited to these patients. Furthermore, CLS is considered effective for patients who require an increase in heart rate when at rest, for example, patients undergoing maintenance dialysis.We describe a representative case, demonstrating the effectiveness of closed-loop stimulation in a patient with hypotension during dialysis.

Patients with bicuspid aortic valves may be associated with infra-hisian conduction disease requiring pacemakers

BACKGROUND

Bicuspid aortic valves (BAVs) are associated with accelerated valvular dysfunction. Increasing rates of conduction system disease are seen in patients with calcific tricuspid aortic valves (TAVs). However, little is known regarding the extent of conduction disorders in BAV patients. We sought to determine the extent of infra-hisian conduction pathology among patients with BAVs undergoing EP studies.

METHODS

We prospectively analyzed patients presenting to the EP laboratory from 2006 to 2017 at our institution. Thirty-three BAV patients had measured HV intervals. Each individual was matched by age and gender to two control patients. Clinical characteristics were collected and compared, and patients followed for outcomes.

RESULTS

The BAV cohort had a mean age of 47.8 ± 17.2 years (range 19-76 years). Indications for referral to the EP lab in the BAV cohort included SVT ablation (n = 16), VT ablation (n = 10), and EP study for syncope, pre-syncope, or palpitations (n = 29). Patients with BAVs had a mean HV interval of 58.7 ms ± 18.6 ms, compared to a mean of 47.2 ms ± 9.6 ms for controls (p value = 0.0001). Over a 10-year follow-up period, 9 BAV patients (27%) went on to require permanent pacing compared to 6 patients (9%) in the control group (p value = 0.03).

CONCLUSION

Compared to patients with TAVs presenting for EP evaluation, individuals with BAVs have longer HV intervals and a significantly increased requirement for pacemaker therapy over long-term follow-up. Closer monitoring of progressive conduction system disease in BAV patients may be warranted.

Utility of Head up Tilt Table Testing to Demonstrate Selective Denervation of the Sinus Node after Cardioneuroablation

A 65-year-old female who underwent cardioneuroablation for recurrent vasovagal syncope presented for 6 month follow-up visit. She had no further syncope after the procedure. A follow up tilt table testing (TT) demonstrated sinus tachycardia and variable degrees of atrioventricular block (AVB) after sublingual glyceryl trinitrate. She had no syncope during the test. As per existing knowledge, the occurrence of AVB during vasovagal reaction induced by TT should be preceded by sinus rhythm slowing.  In this patient, sinus tachycardia during TT demonstrates highly specific denervation of ganglion cells which send postganglionic fibers directly to the sinus node without obvious influence on the atrioventricular node.

Radiotherapy is safe in patients with implantable cardiac devices. Analysis of a systematic interrogation follow-up

INTRODUCTION

The number of patients who have a cardiac implantable electronic device (CIEDs) that undergo a course of radiotherapy is increasing due to the ageing population. The majority of clinical studies only evaluate any CIED malfunction at the end of a course of irradiation or in a case of there being symptoms of possible malfunction. As a result, little data has been collected on CIED status acquired during an active course of irradiation.

MATERIAL AND METHODS

We aimed to evaluate the correct functioning of a CIED during a course of radiotherapy. So, a retrospective analysis was made of all patients having CIEDS in a single institution during their course of radiotherapy. All CIEDs were systematically checked before and during the course of radiotherapy according to the risk of device failure and patient dependence.

RESULTS

Data was analysed from 56 patients (43 men, 13 women) with a mean age of 78.2 years, of whom 87.5% of the patients carried a pacemaker (PM), the 39% of the patients were PM dependent, and the remaining patients carried an implantable cardioverter-defibrillator (ICD). An observable dose of irradiation was evident in only 10 cases. 69.1% of the CIEDs were checked daily and the remainder were checked weekly. During the radiotherapy course, 82% of the patients did not complain of any cardiological event. The CIED of five patients experienced an increase in the threshold and, in another case, a sudden reduction in the duration of the battery was reported. Another patient with a CIED experienced a cardiac insufficiency episode triggered by a ventricular tachycardia.

CONCLUSION

In conclusions, although adverse clinical events from exposure of a CIED to irradiation are rare, they can appear in any group of risk. No dose-dependency was observed on the malfunction of the CIED.

Managing cardiac implantable electronic device patients during a health care crisis: Practical guidance

Our world is faced with a global pandemic that threatens to overwhelm many national health care systems for a prolonged period. Consequently, the elective long-term cardiac implantable electronic device (CIED) management of millions of patients is potentially compromised, raising the likelihood of patients experiencing major adverse events owing to loss of CIED therapy. This review gives practical guidance to health care providers to help promptly recognize the requirement for expert consultation for urgent interrogation and/or surgery in CIED patients.

Evaluation of the incidence, timing, and potential recovery rates of complete atrioventricular block after transcatheter aortic valve implantation: a Japanese multicenter registry study

Data on the accurate onset date and serial changes of the complete atrioventricular block (CAVB) after transcatheter aortic valve implantation (TAVI) are limited. This study aimed to assess the incidence, timing, and potential recovery of CAVB following TAVI. Total 696 patients who underwent TAVI were enrolled. Acute CAVB was evaluated within 24 h; delayed CAVB was evaluated 24 h after TAVI. Recovered CAVB was defined as ventricular pacing < 1% during the follow-up or transit block without the need for permanent pacemaker implantation (PMI). The other patients with CAVB were categorized as continued CAVB. Clinical differences between the recovered and continued CAVB groups were evaluated, and the predictive factors of continued CAVB were assessed. The incidence rates of CAVB, acute CAVB, and delayed CAVB were 6.9% (48/696), 4.6% (32/696), and 2.3% (16/696), respectively. Overall, 47.9% (23/48) of patients had recovered CAVB, which was more prevalent in the acute CAVB group than in the delayed CAVB group [59.4% (19/32) vs. 25.0% (4/16), p = 0.025]. CAVB recovery occurred within 24 h (61.0%, 14/23) and after 24 h (39.0%, 9/23). Before CAVB recovery, 21.7% (5/23) of patients had already undergone PMI. A pre-existing complete right bundle branch block (CRBBB) was the only independent predictive factor of continued CAVB (odds ratio 4.51, 95% confidence interval 1.03-19.6, p = 0.045). In conclusion, a pre-existing CRBBB and the timing and prolonged duration of CAVB may be used in risk stratification to determine the appropriateness of early discharge, optimal PMI date, and PMI indication.

Focused Ultrasound Thalamotomy with Dentato-Rubro-Thalamic Tractography in Patients with Spinal Cord Stimulators and Cardiac Pacemakers

Magnetic resonance image-guided high-intensity focused ultrasound (MRgFUS)-based thermal ablation of the ventral intermediate nucleus of the thalamus (VIM) is a minimally invasive treatment modality for essential tremor (ET). Dentato-rubro-thalamic tractography (DRTT) is becoming increasingly popular for direct targeting of the presumed VIM ablation focus. It is currently unclear if patients with implanted pulse generators (IPGs) can safely undergo MRgFUS ablation and reliably acquire DRTT suitable for direct targeting. We present an 80-year-old male with a spinal cord stimulator (SCS) and an 88-year-old male with a cardiac pacemaker who both underwent MRgFUS for medically refractory ET. Clinical outcomes were measured using the Clinical Rating Scale for Tremor (CRST). DRTT was successfully created and imaging parameter adjustments did not result in any delay in procedural time in either case. In the first case, 7 therapeutic sonications were delivered. The patient improved immediately and durably with a 90% CRST-disability improvement at 6-week follow-up. In our second case, 6 therapeutic sonications were delivered with durable, 75% CRST-disability improvement at 6 weeks. These are the first cases of MRgFUS thalamotomy in patients with IPGs. DRTT targeting and MRgFUS-based thermal ablation can be safely performed in these patients using a 1.5-T MRI.

Involving patients as key stakeholders in the design of cardiovascular implantable electronic device data dashboards: Implications for patient care

Background

Data from remote monitoring (RM) of cardiovascular implantable electronic devices (CIEDs) currently are not accessible to patients despite demand. The typical RM report contains multiple pages of data for trained technicians to read and interpret and requires a patient-centered approach to be curated to meet individual user needs.

Objective

The purpose of this study was to understand which RM data elements are important to patients and to gain design insights for displaying meaningful data in a digital dashboard.

Methods

Adults with implantable cardioverter–defibrillators (ICDs) and pacemakers (PMs) participated in this 2-phase, user-centered design study. Phase 1 included a card-sorting activity to prioritize device data elements. Phase 2 included one-on-one design sessions to gather insights and feedback about a visual display (labels and icons).

Results

Twenty-nine adults (mean age 71.8 ± 11.6 years; 51.7% female; 89.7% white) participated. Priority data elements for both ICD and PM groups in phase 1 (n = 19) were related to cardiac episodes, device activity, and impedance values. Recommended replacement time for battery was high priority for the PM group but not the ICD group. Phase 2 (n = 10) revealed that patients would like descriptive, nontechnical terms to depict the data and icons that are intuitive and informative.

Conclusion

This user-centered design study demonstrated that patients with ICDs and PMs were able to prioritize specific data from a comprehensive list of data elements that they had never seen before. This work contributes to the goal of sharing RM data with patients in a way that optimizes the RM feature of CIEDs for improving patient outcomes and clinical care.

Pacemaker detected active minutes are superior to pedometer-based step counts in measuring the response to physical activity counseling in sedentary older adults

BACKGROUND

In patients with permanent pacemakers (PPM), physical activity (PA) can be monitored using embedded accelerometers to measure pacemaker detected active hours (PDAH), a strong predictor of mortality. We examined the impact of a PA Counseling (PAC) intervention on increasing activity as measured by PDAH and daily step counts.

METHODS

Thirteen patients (average age 80 ± 6 years, 84.6% women) with implanted Medtronic PPMs with a ≤ 2 PDAH daily average were included in this study. Patients were randomized to Usual Care (UC, N = 6) or a Physical Activity Counseling Intervention (PACI, N = 7) groups. Step count and PDAH data were obtained at baseline, following a 12-week intervention, then 12 weeks after intervention completion. Data were analyzed using independent t-tests, Pearson's r, chi-square, and general linear models for repeated measures.

RESULTS

PDAH significantly differed by time point for all subject combined (P = 0.01) but not by study group. Subjects with baseline gait speeds of > 0.8 m/sec were responsible for the increases in PDAH observed. Step counts did not differ over time in the entire cohort or by study group. Step count and PDAH significantly correlated at baseline (r = 0.60, P = 0.03). This correlation disappeared by week 12.

CONCLUSION(S)

PDAH can be used to monitor PA and PA interventions and may be superior to hip-worn pedometers in detecting activity. A significant increase in PA, regardless of treatment group, suggests that patient awareness of the ability to monitor PA through a PPM increases PA in these patients, particularly in patients with gait speeds of < 0.8 m/sec.

TRIAL REGISTRATION

ClincalTrials.gov NCT03052829. Date of Registration: 2/14/2017.

An operational approach to the execution of MR examinations in patients with CIED

In the context of the increasing spread of cardiac active implantable heart devices (CIEDs) in the population and of the wide diagnostic/therapeutic utility of magnetic resonance (MRI) examinations, the goal of this paper is to provide the experience of the Santa Maria Nuova Hospital of the USL Tuscany Center in Florence and to report an organizational proposal to perform, in the hospital settings, MRI examinations on patients carrying CIED. This report is intended to show the operational choices of a Radiology Department which organizes this activity in accordance with the new Italian regulatory framework in the field of safety of MR sites (Ministero della Salute in Decreto Ministeriale 10 agosto 2018 Determinazione degli standard di sicurezza e impiego per le apparecchiature a risonanza magnetica, 2018).

A case report: upgrade to cardiac resynchronization therapy with a blocked persistent left-sided superior vena cava

Background 

Pacemaker-induced cardiomyopathy (PICM) can occur in up to 9% of patients having a pacemaker. Pacemaker-induced cardiomyopathy can be treated by upgrade to a biventricular pacemaker with a left ventricular (LV) lead implantation. The procedure can be technically challenging in patients with persistent left-sided superior vena cava (PLSVC).

Case summary 

We report the case of a 72-year-old gentleman with a PLSVC, who had a dual-chamber pacemaker implanted 15 years ago for complete heart block. After 12 years of good health, the gentleman developed breathlessness due to PICM. At upgrade to biventricular pacemaker, his coronary sinus was found to be occluded and a collateral branch was used to successfully position an LV lead. Marked clinical improvement was seen before representation with syncope after 2 years due to simultaneous failure of both LV and right ventricular leads. Subsequently, a right-sided de novo biventricular pacemaker was implanted. In this instance, the PLSVC was beneficial because it isolated the existing leads from the new implant, thereby reducing the risk of SVC obstruction.

Discussion 

Although implantation of pacemaker leads through a PLSVC constitutes a challenging procedure due to manoeuvring difficulties of the pacing leads into the cardiac chambers, in this particular case, the presence of PLSVC was beneficial because it meant that no leads were present in the true SVC, reducing the risk of occlusion and avoiding the need for lead extraction.

Targeted Intraoperative Radiotherapy Is a Safe Approach for Patients with Pacemakers: A Case Study and Literature Review

Case reports detailing the effects of targeted intraoperative radiation therapy (IORT) on patients with cardiac pacemakers (PMs) are rare. This growing population sub-group requiring IORT and lack of standardized guidelines necessitate more practical published research. An 81-year-old patient with clinical stage II, T1 N0 grade III, triple-negative invasive ductal carcinoma and an implanted single-lead chamber PM (VVIR mode, model: Biotronik, type Effecta SR) received targeted intraoperative radiotherapy at the time of wide local excision and sentinel lymph node biopsy. It presents the shortest distance between the outer diameter of the PM and IORT applicator in literature. Target IORT was performed utilizing an Intrabeam device (50 kV, Carl Zeiss Surgical, Oberkochen, Germany). This case elucidates the successful use of targeted IORT for breast-conserving surgery in a patient with a single ipsilateral chamber VVIR mode PM. No device failure or malfunction was reported for the PM before, during, or after the procedure. These findings support the use of targeted IORT for patients diagnosed with early-stage breast carcinomas who have a PM implanted. However, further research is needed to understand the safety of other methods and devices for IORT patients with cardiac implantable electronic devices.

Programming and follow-up of patients with His bundle pacing

His bundle pacing (HBP) is being increasingly adopted worldwide, with the aim of providing more physiological stimulation of the heart as opposed to right ventricular pacing or as an alternative to cardiac resynchronization therapy (CRT). Current devices are not specifically designed for HBP, which gives rise to programming challenges. This article aims to provide practical recommendations for HBP programming and follow-up.

Cardiac Magnetic Resonance Imaging (MRI) in Children is Safe with Most Pacemaker Systems, Including Those with Epicardial Leads

Magnetic resonance imaging (MRI) of patients with pacemakers remains concerning because of possible magnetic field effects on the device. Many pacemaker models are labeled as non-conditional, or contraindicated for MRI, or do not have any specific safety guidelines listed. This study describes our experience with pacemaker function and adverse events in pediatric and young adult patients after clinically indicated MRI scanning at 1.5 Tesla (T). We hypothesized that generator battery voltage, pacemaker lead threshold, and lead impedance would not be altered by MRI. This was a retrospective review of Children's Wisconsin clinical MRI data for all patients with pacemakers scanned between January 1, 2010 and March 31, 2018. Pacemakers were interrogated by the Electrophysiology Team before and immediately after MRI and at outpatient follow up. Twenty-one patients underwent forty-four MRI scans. No significant immediate changes were seen in any pacemaker parameter for any manufacturer/model/lead at the time of MRI. At first clinical follow up post MRI, (median 4.4 months, range 0.2-12.3), battery voltage was reduced (2.78 V pre-MRI versus 2.77 V at follow up, p = 0.02), but there were no other significant changes. No adverse events were noted. Pediatric patients with pacemakers, including those with epicardial leads, can be scanned at 1.5 T safely without alteration in pacemaker function. Using appropriate precautions, pediatric patients with pacemakers can be imaged with MRI.

Epicardial Pacemaker in Neonates and Infants: Is There a Relationship Between Patient Size, Device Size, and Wound Complicatıon?

We aimed to investigate the complications after epicardial pacemaker (PM) implantation in neonates and infants and their relationship with factors such as device size and patient size. Between May 2010 and July 2018, 55 patients under 1 year of age who underwent epicardial PM placement were retrospectively evaluated. PM-related complications requiring rehospitalization were determined as wound site problems requiring surgical intervention, battery pocket infection, battery pocket dehiscence without infection, PM removal, relocation of the PM system, and replacement of the PM system with another system. The patients were divided into three groups: < 3 kg, 3-5 kg and > 5 kg. Fifty-five patients underwent PM implantation, 43 (78.2%) because of postoperative atrioventricular block (AVB), 10 (18.2%) because of congenital AVB, and two (3.6%) with diagnoses of c-TGA and AVB. Five (9%) patients incurred 18 complications. No statistically significant difference was observed in complication development between the groups (p > 0.05). Single- or dual-chamber device implantation did not affect complication development (p > 0.05). Despite the role of factors such as low weight, low age, and device volume in the development of wound complications, the relationship between these factors and complications is not statistically significant. Therefore, our results are encouraging in terms of the use of dual-chamber PMs instead of single-chamber ones in heart diseases in which AV synchronization is important.

A 60-year-old with heart failure symptoms due to 1st degree AV-Block caused by granulomatosis with polyangiitis (Wegener's granulomatosis)

Granulomatosis with polyangiitis is a rare systemic inflammatory disorder mainly affecting the small vessels. Cardiac involvement is rare, conduction delay being the most rare one. This case reports on a middle-aged male patient with heart failure symptoms due to a 1st degree atrioventricular block with a marked PR prolongation of 480 ms on electrocardiography (ECG). Because of heart failure symptoms as well as elevated N-terminal pro-B-type natriuretic peptide and no other relevant findings in the blood test it was initially planned to treat the conduction disorder with a pacemaker. During further investigations a certain diagnosis of granulomatosis with polyangiitis was determined. After administration of high-dose steroids a complete clinical remission of heart failure symptoms and normal conduction on ECG were demonstrated, so that no pacemaker therapy was needed. <Learning objective: Although atrioventricular (AV) conduction disorders have been described previously in patients with granulomatosis with polyangiitis, this is the first case reporting of vasculitis causing heart failure symptoms due to non-severe conduction disorder such as 1st degree AV-block. Even in the case of non-severe AV conduction delay, which causes symptoms, it is essential to investigate possible rare causes of the conduction disorder before considering pacemaker treatment.

Stent interventional treatment of superior vena cava syndrome with a pacemaker placement complication in an infant

Background

Epicardial pacemaker is the preferred method for newborns and children under 10 kg of weight. However, its placement presents a high rate of premature failure.

Case report

The case of an infant requiring placement of pacemaker by congenital atrioventricular block with prenatal diagnosis is described. The patient showed critical stenosis of the superior vena cava as a complication. Interventional resolution using a stent at the site of stenosis corrected the superior vena cava syndrome effectively.

Conclusions

This case represents a clinically viable alternative for the treatment of superior vena cava syndrome, which can be used after other conventional therapies have failed.

Iatrogenic Decompensated Heart Failure

Purpose of Review

To provide an overview of the potential iatrogenic causes of acute decompensated heart failure (AHF) and an evidence-based management strategy to address this.

Recent Findings

As the heart failure (HF) population continues to age and become burdened with greater comorbidities and polypharmacy, patients become more susceptible to the iatrogenic precipitants of HF. The following clinical scenarios are familiar to clinicians, but the sequelae to AHF are often unanticipated: HF medications withdrawn during an intercurrent illness and not restarted, cardiotoxic therapy prescribed for cancer without timely and regular monitoring of left ventricular function, excessive intravenous fluids administered for sepsis or postoperatively, a blood transfusion volume not adjusted for body weight, iatrogenic anaemia that goes unnoticed or an inappropriate type of pacemaker implanted in a patient with underlying left ventricular systolic dysfunction.

Summary

Iatrogenic decompensated HF is a phenomenon that is infrequently documented in the literature but increasingly confronted by clinicians of all specialties. It is associated with a high mortality and morbidity rate. By having greater awareness of these triggers, iatrogenic AHF should be one that is prevented rather than managed when it occurs.

Are implantable cardiac monitors reliable tools for cardiac arrhythmias detection? An intra-patient comparison with permanent pacemakers

INTRODUCTION

Implantable cardiac monitor (ICM) is an established tool for the management of unexplained syncope and atrial fibrillation (AF) even if its accuracy of arrhythmia detection may be suboptimal. The aim of this study was to perform an intra-patient comparison of the diagnostic capability of ICM with a dual-chamber PM as a gold standard.

METHODS

We included 19 patients with a previously implanted ICM (BioMonitor 2 Biotronik, Berlin, Germany), who received a dual-chamber PM for standard indications. ICM-detected arrhythmic events in a 6-month follow-up were compared with those detected by the PM and classified by visual inspection of intracardiac electrograms.

RESULTS

During follow up, ICMs generated 15 false asystole and 39 false bradycardia detections in 5 patients (26.3%) due to recurrent premature ventricular contractions. A total of 34 true high ventricular rate (HVR) episodes were detected by the PM. Of them, 30 (88%) events were also recorded by the ICM, which further detected 14 false HVR snapshots, leading to a sensitivity and positive predictive value of 88% and 68%, respectively. In addition, PM identified 234 true AF episodes. Of them, 225 (96%) events were also detected by the ICM, while 8 (42%) ICMs stored 50 AF episodes classified as false positives. The ICM sensitivity for AF was 96% with a positive predictive value of 82%.

CONCLUSION

Our intra-patient comparison with permanent PM confirmed that ICM is an effective tool for cardiac arrhythmias detection. ICM algorithms for AF and HVR detection were highly sensitive with an acceptable rate of false positive episodes.

The presence of ectopic atrial rhythm predicts adverse cardiovascular outcomes in a large hospital-based population

BACKGROUND

Whether ectopic atrial rhythm (EAR) is a high-risk cardiovascular phenotype (eg, the manifestation of a diseased sinoatrial node) or just a benign accelerated ectopic pacemaker remains unclear.

OBJECTIVE

We aimed to analyze the cardiovascular outcomes and underlying mechanisms in patients with EAR.

METHODS

From a 12-lead electrocardiogram hospital-based electrocardiogram database, a total of 2896 adults with EAR were propensity score matched at 1:5 with 14,480 patients with sinus rhythm (SR). Patients were retrospectively followed up for cardiovascular mortality (the primary outcome) and permanent pacemaker implantation (the secondary outcome). Heart rate variability was analyzed to compare autonomic function between patients with EAR and those with SR.

RESULTS

The prevalence of EAR was 1.13%, which increased with age. Compared with the matched patients, those with EAR had a higher risk of cardiovascular mortality (adjusted hazard ratio 1.93; 95% confidence interval 1.52-2.44; P < .0001) and permanent pacemaker implantation (adjusted hazard ratio 5.94; 95% confidence interval 3.89-9.09; P < .0001) according to the Cox proportional hazards regression model. The risk of cardiovascular mortality was similar across the subgroups on the basis of age, sex, hypertension, type 2 diabetes mellitus, congestive heart failure, myocardial infarction, stroke, and chronic kidney diseases. In patients with EAR, the low frequency/high frequency and standard deviation of the mean normal-to-normal intervals/root mean square of successive RR interval differences ratios for heart rate variability were both lower than those in patients with SR. This implied autonomic imbalance in patients with EAR.

CONCLUSION

Patients with EAR have a higher risk of cardiovascular mortality and permanent pacemaker implantation, which was associated with autonomic imbalance.