Pacing Using Cardiac Implantable Electric Device During TAVR: 10-Year Experience of a High-Volume Center

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is an effective and safe therapy for severe aortic stenosis. Rapid or fast pacing is required for implantation, which can be performed via a pre-existing cardiac implantable electric device (CIED). However, safety data on CIEDs for pacing in TAVR are missing.

OBJECTIVES

The aim of this study was to elucidate procedural safety and feasibility of internal pacing with a CIED in TAVR.

METHODS

Patients undergoing TAVR with a CIED were included in this analysis. Baseline characteristics, procedural details, and complications according to Valve Academic Research Consortium 3 (VARC-3) criteria after TAVR were compared between both groups.

RESULTS

A total of 486 patients were included. Pacing was performed using a CIED in 150 patients and a transient pacemaker in 336 patients. No differences in technical success according to VARC-3 criteria or procedure duration occurred between the groups. The usage of transient pacers for pacing was associated with a significantly higher bleeding rate (bleeding type ≥2 according to VARC-3-criteria; 2.0% vs 13.1%; P < 0.01). Furthermore, impairment of the CIED appeared in 2.3% of patients after TAVR only in the group in which pacing was performed by a transient pacer, leading to surgical revision of the CIED in 1.3% of all patients when transient pacemakers were used.

CONCLUSIONS

Internal pacing using a CIED is safe and feasible without differences of procedural time and technical success and might reduce bleeding rates. Furthermore, pacing using a CIED circumvents the risk of lead dislocation. Our data provide an urgent call for the use of a CIED for pacing during a TAVR procedure in general.

Clinical practice of continuous rhythm monitoring after embolic stroke of undetermined source

AIMS

Embolic stroke of undetermined source (ESUS) accounts for up to 20% of ischemic strokes annually. Undetected atrial fibrillation (AF) is one important potential underlying cause. For AF, oral anticoagulation has evolved as the most preferable means of secondary stroke prevention. To detect unrecognized paroxysmal AF, long-term ECG monitoring is required, and implantable cardiac monitors (ICM) appear most suitable. Yet, ICMs are particularly costly, implantation is invasive, and remote monitoring places a personnel burden on health care providers. Here, we use data from a large cohort of ESUS patients to systematically analyze the effort of ICM remote monitoring for AF diagnosis and the strain on health care providers.

METHODS AND RESULTS

From a prospective, single-center, observational ESUS registry, we analyzed all ICM-equipped patients post-ESUS (n = 172) between January 1st, 2018, and December 31st, 2019. Through January 2nd, 2023, 48 patients (27.9%) were diagnosed with AF by ICM remote monitoring. During follow-up, a total of 29,180 remote monitoring episodes were transmitted, of which 17,742 were alarms for AF. A systematic estimation of workload revealed that on average, 20.3 trained physician workhours are required to diagnose one patient with AF.

CONCLUSION

ICM remote monitoring is useful to diagnose AF in cohort of post-ESUS patients. However, the number of ICM alarms is high, even in a cohort at known high risk of AF and in whom AF detection is therapeutically consequential. Improved automated event classification, clear recommendations for ICM interrogation after AF diagnosis, and a careful patient selection for ICM monitoring are warranted.

Effect of Acute Altitude Exposure on Anaerobic Threshold Assessed by a Novel Electrocardiogram-Based Method

Background: Acute altitude has a relevant impact on exercise physiology and performance. Therefore, the positive impact on the performance level is utilized as a training strategy in professional as well as recreational athletes. However, ventilatory thresholds (VTs) and lactate thresholds (LTs), as established performance measures, cannot be easily assessed at high altitudes. Therefore, a noninvasive, reliable, and cost-effective method is needed to facilitate and monitor training management at high altitudes. High Alt Med Biol. 25:94-99, 2024. Methods: In a cross-sectional setting, a total of 14 healthy recreational athletes performed a graded cycling exercise test at sea level (Munich, Germany: 512 m/949 mbar) and high altitude (Zugspitze: 2,650 m/715 mbar). Anaerobic thresholds (ATs) were assessed using a novel method based on beat-to-beat repolarization instability (dT) detected by Frank-lead electrocardiogram (ECG) monitoring. The ECG-based ATs (ATdT°) were compared to routine LTs assessed according to Dickhuth and Mader. Results: After acute altitude exposure, a decrease in AT was detected using a novel ECG-based method (ATdT°: 159.80 ± 52.21 W vs. 134.66 ± 34.91 W). AtdT° levels correlated significantly with LTDickhuth and LTMader, at baseline (rDickhuth/AtdT° = 0.979; p < 0.001) (rMader/AtdT° = 0.943; p < 0.001), and at high altitude (rDickhuth/AtdT° = 0.969; p < 0.001) (rMader/AtdT° = 0.942; p < 0.001). Conclusion: Assessment of ATdT is a reliable method to detect performance alterations at altitude. This novel method may facilitate the training management of athletes at high altitudes.

Effects of contemporary hard- and software mapping and ablation features on acute and long-term success in premature ventricular complex ablation

BACKGROUND

Current standards of ablation of premature ventricular complexes (PVC) combine modern hard- and software mapping and ablation features like multielectrode mapping catheters (MEC), contact force (CF) guided ablation catheters and pattern matching filters (PMF). Benefits of these individual tools were described for selected patients with PVC, but data on combination of these features in the real world setting is sparse.

METHODS

Between 2015 and 2021 we retrospectively enrolled 172 consecutive patients undergoing PVC ablation in our center. The utilization of MEC, CF guided ablation catheters and PMF software was analyzed in terms of procedural data, acute and long-term success after 12 months.

RESULTS

Acute ablation success was reached in 71% of patients (n = 118) with an overall recurrence rate of 34% after 12 months. PMF software was used in 130 patients (78%), MEC in 131 patients (79%) and ablation was guided using CF in 99 patients (60%). PMF significantly reduced procedural duration and time of radiofrequency application (RF, 150 vs. 185 min, p 0.04 and 325 vs. 556 min, p 0.01). CF enabled significantly shorter radiation time (7.9 vs. 12.3 min, p 0.01), whereas MEC did not influence procedural data. Acute and long-term outcomes were not affected by these modern mapping and ablation features, yet, multivariable regression analysis revealed an underlying cardiomyopathy and the respective focus as independent predictors for recurrence.

CONCLUSION

Contemporary hard- and software mapping and ablation features could reduce procedural, radiation and RF time in PVC ablation. Furthermore, patient characteristics rather than technical factors alter outcome of this all-comer collective.

Impact of Preparticipation Hypohydration on Cognitive Performance and Concussion-like Symptoms in Recreational Athletes

BACKGROUND

Sports-related concussion is a relevant risk of contact sports, with several million cases per year worldwide. Prompt identification is crucial to prevent complications and late effects but may be impeded by an overlap with dehydration-associated impairment of cognitive function. Researchers have extensively studied the effects of pronounced dehydration in endurance sports, especially in the heat. However, little is known about the effects of isolated and mild dehydration.

METHODS

Healthy recreational athletes underwent a standardized fluid deprivation test. Hypohydration was assessed by bioelectrical impedance analysis (BIA) and laboratory testing of electrolytes and retention parameters. Participants underwent cardiopulmonary exercise testing (CPET) with a cycle ramp protocol. Each participant served as their own control undergoing CPET in a hypohydrated [HYH] and a euhydrated [EUH] state. Effects were assessed using a shortened version of Sport Concussion Assessment Tool 3 (SCAT3).

RESULTS

Fluid deprivation caused a mild (2%) reduction in body water, resulting in a calculated body mass loss of 0.8% without alterations of electrolytes, serum-osmolality, or hematocrit. Athletes reported significantly more (1.8 ± 2.2 vs. 0.4 ± 0.7; p < 0.01) and more severe (4.4 ± 6.2 vs. 1.0 ± 1.9; p < 0.01) concussion-like symptoms in a hypohydrated state. Balance was worse in HYH by trend with a significant difference for tandem stance (1.1 ± 1.3 vs. 0.6 ± 1.1; p = 0.02). No relevant differences were presented for items of memory and concentration.

CONCLUSIONS

Mild dehydration caused relevant alterations of concussion-like symptoms and balance in healthy recreational athletes in the absence of endurance exercise or heat. Further research is needed to clarify the real-life relevance of these findings and to strengthen the differential diagnosis of concussion.

[Cardiac implantable electric devices in forensic medicine : Overview from the forensic and cardiology perspective]

In 2021, about 75,000 persons in Germany died unnaturally or due to unexplained reasons. As a consequence, there are difficulties in more precisely identifying the time, cause and circumstances of death. Nevertheless, clarification is crucial not only from the clinical perspective, but these data are of considerable importance in the context of investigative procedures as they can be used to answer numerous legally relevant questions. Cardiac implantable devices (CIED) are of vital importance in the treatment of cardiac arrhythmias. In 2020 about 100,000 patients underwent CIED implantation in Germany. Therefore, CIED are present in a relevant proportion of the deceased mentioned above. The valuable source of information represented by postmortal CIED interrogation has been shown in numerous studies. Nevertheless, postmortal CIED interrogation is not routinely performed in the context of forensic medical examinations for reasons of practicability. This article summarizes benefits and limitations of postmortal CIED interrogation from the perspective of forensic medicine and cardiology and gives a recommendation for realization.

Impact of Preparticipating Hypohydration on Cardiopulmonary Exercise Capacity in Ambitious Recreational Athletes

BACKGROUND

Heat induces a thermoregulatory strain that impairs cardiopulmonary exercise capacity. The aim of the current study is to elucidate the effect of isolated dehydration on cardiopulmonary exercise capacity in a model of preparticipating hypohydration.

METHODS

Healthy recreational athletes underwent a standardised fluid deprivation test. Hypohydration was assessed by bioelectrical impedance analysis (BIA) and laboratory testing of electrolytes and retention parameters in the blood and urine. The participants underwent cardiopulmonary exercise testing (CPET) with a cycle ramp protocol. Each participant served as their own control undergoing CPET in a hypohydrated [HYH] and euhydrated [EUH] state.

RESULTS

Fluid deprivation caused a mild (2%) but significant reduction of body water (38.6 [36.6; 40.7] vs. 39.4 [37.4; 41.5] %; p < 0.01) and an increase of urine osmolality (767 [694; 839] vs. 537 [445; 629] mosm/kg; p < 0.01). Hypohydration was without alterations of electrolytes, serum osmolality or hematocrit. The oxygen uptake was significantly lower after hypohydration (-4.8%; p = 0.02 at ventilatory threshold1; -2.0%; p < 0.01 at maximum power), with a corresponding decrease of minute ventilation (-4% at ventilatory threshold1; p = 0.01, -3.3% at maximum power; p < 0.01). The power output was lower in hypohydration (-6.8%; p < 0.01 at ventilatory threshold1; -2.2%; p = 0.01 at maximum power).

CONCLUSION

Isolated hypohydration causes impairment of workload as well as peak oxygen uptake in recreational athletes. Our findings might indicate an important role of hypohydration in the heat-induced reduction of exercise capacity.

A patient with Takayasu arteritis presenting with malignant hypertension: a case report

Background

Takayasu arteritis (TA) is a rare large-vessel vasculitis primarily affecting the aorta and its proximal branches. The manifestation of TA is variable, ranging from asymptomatic cases to severe organ dysfunction secondary to vascular damage, which often delays diagnosis.

Case summary

Here, we present a 37-year-old male patient suffering from visual impairment and malignant hypertension. Emergency fundoscopy showed large left subretinal bleeding and bilateral signs of hypertensive retinopathy. Echocardiographic and magnetic resonance imaging showed mildly reduced left ventricular ejection fraction and signs of hypertensive cardiomyopathy. Evaluation for secondary causes of arterial hypertension did not reveal an underlying disease, and the patient was discharged with optimal medical therapy. He was re-admitted after 11 days with fever of unknown origin, fatigue, and elevated inflammatory markers. The diagnosis of TA was finally established using ¹⁸F-fluorodeoxyglucose positron emission computed tomography scan and sonography of carotid and subclavian arteries. Anti-inflammatory combination therapy for active, severe TA with ophthalmologic involvement was initiated using high-dose glucocorticoids and the tumour necrosis factor alpha inhibitor adalimumab to minimize drug-related risks. The patient was scheduled for multidisciplinary follow-up appointments, including specialist consultation in rheumatology, angiology, cardiology, diabetology, and ophthalmology.

Discussion

This case highlights the diversity of initial symptoms, the challenges of TA diagnosis, and the importance of comprehensive evaluation for rare secondary causes of arterial hypertension. Individualized acute and long-term care necessitates multidisciplinary management of immunosuppressive therapy, secondary organ involvement, and concomitant diseases.

Prevalence, management, and prediction of venous access site occlusion in patients undergoing lead revision surgery

BACKGROUND

Implantable electronic cardiac devices (CIED) have emerged as an essential component in the treatment of cardiac arrhythmias and heart failure. Due to increased life expectancy, expanding indications and limited technical survival, an increasing number of revision procedures can be anticipated. Venous access site occlusion (VASO) is the main obstacle during revision surgery. In this retrospective study we evaluated the prevalence, predictive parameters and operative management of venous access site occlusion.

METHODS AND RESULTS

Between 01/2016 and 12/2020 304 patients underwent lead revision surgery of transvenous CIED in our department. Prevalence of VASO was 25.7% (n = 78), one patient was symptomatic. Independent predicting clinical parameters were male sex (2.86 (1.39-5.87), p < 0.01) and lead age (1.11 (1.05-1.18), p < 0.01)). Revision surgery despite VASO was successful in 97.4% (n = 76) without prolongation of the total surgery time or higher complication rates. Yet, lead extraction was possible in 92% of patients with VASO vs. 98.2% of patients without VASO (p 0.01).

CONCLUSION

VASO is a frequent condition in patients undergoing lead revision surgery, but successful revision is feasible in most cases without preceding lead extraction. However, the lower success rates of lead extractions may be prognostically relevant, especially for younger patients.

Review: Sex-related differences in the treatment of cardiac arrhythmia

Cardiac arrhythmias are a common and potentially serious cardiovascular disorders that affect both men and women. However, there is evidence to suggest that there may be sex-related differences in the prevalence, clinical presentation, and management of cardiac arrhythmias. Hormonal and cellular factors may play a role in these sex-specific differences. In addition, there are differences in the types of arrhythmias that men and women experience, with men more likely to experience ventricular arrhythmias and women more likely to experience supraventricular arrhythmias. The management of cardiac arrhythmias also differs between men and women. For example, some studies have found that women are less likely to receive appropriate treatment for arrhythmias and are more likely to have adverse outcomes following treatment. Despite these sex-related differences, the majority of research on cardiac arrhythmias has been conducted in men, and there is a need for more research to specifically examine the differences between men and women. This is especially important given that the prevalence of cardiac arrhythmia is increasing, and it is essential to understand how to effectively diagnose and treat these conditions in both men and women. In this review, we examine the current understanding of sex-related differences in cardiac arrhythmias. We also review the available data on sex-specific management strategies for cardiac arrhythmias and highlight areas of future research.

Evaluation of a Standardized Training and Adherence Surveillance Programme to Overcome Quality-of-Life Impairments and Enhance Compliance in Patients Treated with Wearable Cardioverter Defibrillator

BACKGROUND

Treatment with wearable cardioverter defibrillators (WCD) is a non-invasive, transient therapy option for prevention of sudden cardiac death (SCD) in patients with temporary contraindications for implantation of a permanent cardioverter defibrillator. Due to the constant risk of fatal arrhythmias, compliance is the fundamental requirement for effectiveness of a WCD, but this might be hindered by the poor quality-of-life (QoL) during WCD therapy. In this retrospective single-center study, we examined if a standardized WCD training and adherence surveillance programme could enhance compliance and QoL.

METHODS

All patients with a prescription for WCD treatment from January 2017 to August 2019 were included and received a standardized WCD training programme. QoL was validated using the modified EQ-5D-3L questionnaire. The findings were compared to a historical, previously published, retrospective cohort from our center (WCD prescription period 03/2012-02/2016), not receiving the additional training programme. Endpoints comprised therapy adherence, arrhythmic episodes, and dimensions of QoL.

RESULTS

Ninety-two patients underwent WCD treatment in the study cohort for a median of 49 days. Median daily wear time was enhanced in the study cohort (historical cohort vs study cohort 21.9 vs 23.3 hours/per day, p<0.01) and artefact alarms occurred less frequently (67.9% vs 48.9%, p 0.01). Major restrictions in QoL in the study cohort were found in mobility (48%), daily routine (44%), and sleep (49%), but the dimensions pain (36% vs 4%, p<0.01), mental health (43% vs 29%, p 0.03), and restrictions in daily routine (48% vs 30%, p 0.04) improved.

CONCLUSION

A standardized training and adherence surveillance programme might have beneficial effects on compliance and QoL. As these findings are essential for therapy success, they might potentially lead to a reduction in arrhythmic deaths in upcoming WCD trials.

Determination of time of death by blinded post-mortem interrogation of cardiac implantable electrical devices

Postmortal interrogation of cardiac implantable electrical devices (CIED) may contribute to the determination of time of death in forensic medicine. Recent studies aimed to improve estimation of time of death by combining findings from autopsy, CIED interrogation and patients´ medical history. CIED from deceased undergoing forensic autopsy were included, if time of death remained unclear after forensic assessment. CIED explanted from deceased with known time of death were analysed as a control cohort. CIED were sent to our device interrogation lab and underwent analysis blinded for autopsy findings, medical history and police reports. The accuracy of time of death determination and the accuracy of time of death in the control cohort served as primary outcome. A total of 87 CIED were analysed. The determination of time of death was possible in 54 CIED (62%, CI 52–72%). The accuracy of the estimated time of death was 92.3% in the control cohort. Certain CIED type and manufacturers were associated with more successful determination. Blinded postmortal analysis enables a valid determination of the time of death in the majority of CIED. Analysis of explanted CIED in a cardiological core lab is feasible and should be implemented in forensic medicine.

Combined effect of acute altitude exposure and vigorous exercise on platelet activation

Exposure to high altitudes and exercise alters body's physiology and may cause acute cardiovascular events. Platelet activation is one of the key players in these events. Therefore, we investigated the effect of vigorous exercise at higher altitude (2650 m) on platelet aggregation and serum markers of platelet activation. 14 healthy subjects performed a step incremental ergometer test until exhaustion at the Environmental Research Station (UFS, 2650 m) at Zugspitze. Platelet aggregation and serum levels of endothelin-1, soluble p-selectin, platelet factor 4 and Chromogranin A were measured. Platelet activation was significantly enhanced after exercise at high altitude compared to measures immediately prior exercise. We detected significantly enhanced serum levels of endothelin-1 and soluble p-selectin whereas chromogranin A and platelet factor 4 remained unchanged. This effect might be due to increased endothelin-1 levels causing pulmonary vasoconstriction, rheological changes and direct platelet activation. This might be of clinical relevance, especially in patients with pre-existing diseases.

Single-center experience of ultra-high-density mapping guided catheter ablation of focal atrial tachycardia

Introduction

Catheter ablation is the treatment of choice for recurrent focal atrial tachycardia (FAT) as medical therapy is limited. Routinely, a three‐dimensional mapping system is used. Whether or not optimized signal detection does improve ablation success rates has not yet been investigated. This retrospective cohort study compared ablation procedures using an ultra‐high‐density mapping system (UHDM, Rhythmia, Boston Scientific) with improved signal detection and automatic annotation with procedures using a conventional electroanatomic mapping system (CEAM, Biosense Webster, CARTO).

Methods

All patients undergoing ablation for FAT using UHDM or CEAM from April 2015 to August 2018 were included. Endpoints comprised procedural parameters, acute success as well as freedom from arrhythmia 12 months after ablation.

Results

A total of 70 patients underwent ablation (48 with UHDM, 22 with CEAM). No significant differences were noted for parameters like procedural and radiation duration, area dose, and RF applications. Acute success was significantly higher in the UHDM cohort (89.6% vs. 68.2%, p = .03). Nevertheless, arrhythmia freedom 12 months after ablation was almost identical (56.8% vs. 60%, p = .87), as more patients with acute success of ablation presented with a relapse during follow‐up (35.0 vs. 7.7%, p = .05).

Conclusion

Acute success rate of FAT ablation might be improved by UHDM, without an adverse effect on procedural parameters. Nevertheless, further research is needed to understand the underlying mechanism for increased recurrence rates after acute successful ablation.

Impairment of Quality of Life in Patients with Implanted Subcutaneous Cardioverter Defibrillator (S-ICD) Compared to Implanted Transvenous Cardioverter Defibrillator Therapy

BACKGROUND

The subcutaneous cardioverter defibrillator (S-ICD) has been shown to be a viable alternative to transvenous ICDs (TV-ICD) in all patients at risk of sudden cardiac death (SCD) but without pacing indication.

AIM

The aim of this study was to examine the impact of therapy with current S-ICD devices on quality of life (QoL) in comparison to patients with TV-ICD devices.

METHODS

In our single-centre study, 52 consecutive patients with S-ICD and 52 matched patients with TV-ICD were analysed. QoL has been assessed by a standardized questionnaire (EQ-5D-3L, modified). Additionally, clinical baseline and follow-up data were evaluated.

RESULTS

Two-thirds of the total study population reported restrictions in daily routine compared to their life before ICD implantation. A total of 27.7% of S-ICD patients stated to expect an improvement of QoL by deactivation or explantation of their defibrillator compared to only 6.4% of patients with TV-ICD (p=0.006), which was mainly caused by discomfort and pain from the S-ICD pocket (relevant discomfort and pain in 32.6% vs 11.5%; p<0.01).

LIMITATIONS

Main limitation of the study is that quality of life was assessed for one single time point only and time since implantation differed significantly between S-ICD and TV-ICD. Furthermore our collective is younger, and, due to the high proportion of patients without cardiomyopathy, the mean EF is better than usual ICD collective. The absence of heart failure in about the half of our patients might have relevant impact on our QoL analysis.

CONCLUSION

A relevant proportion of S-ICD patients expects an improvement of QoL by explantation of the device. Of note, this impression was not driven by the fear of receiving shocks but mainly by discomfort and pain caused by the pulse generator.

Effect of acute altitude exposure on ventilatory thresholds in recreational athletes

PURPOSE

High altitude (HA) training is frequently used in endurance sports and recreational athletes increasingly participate in cross mountain competitions. At high altitude aerobic physiology changes profoundly. Ventilatory thresholds (VTs) are measures for endurance performance but the impact of exposure to acute altitude (AA) on VTs in recreational athletes has been insufficiently explored to date and most studies investigated effects under normobaric hypoxia.

METHODS

In this cross-sectional study we investigated the effects of AA exposure at 2650 m/715 mbar on anerobic threshold (VT1) and respiratory compensation point (VT2) in a graded cycling test in 14 recreational athletes (4 female, 10 male) compared to baseline levels (521 m, 949 mbar).

RESULTS

At VT1, a decline in power output (PO) from median 115.5 W to 105.0 W (median -12.3 %, p = 0.032; Wilcoxon test) during exposure to HA was observed. VO₂/body weight and VO₂/heart rate decreased markedly (- 9.5 %, p = 0.016; -10.5 %, p = 0.012). At VT2 we found a significant decline of PO from 184.5-170.5 W (-13.1 %, p = 0.0014), of VO₂/body weight and of VO₂/heart rate (-10.1 %, p = 0.0015; -8.7 %, p = 0.002) compared to baseline values. Absolute VO₂ decreased (-9.5 %, p = 0.0014 and -10.1 %, p = 0.0002) while minute ventilation and heart rates remained unchanged at both thresholds.

CONCLUSION

Our data allows a quantification of performance loss at HA in recreational athletes and demonstrates that VT-guided training intensities and workloads need to be adapted for training at HA.

Survival after left ventricular assist device implantation correlates with a novel device-based measure of heart rate variability: the heart rate score

OBJECTIVES

The heart rate score (HRS) serves as a device-based measure of impaired heart rate variability and is an independent predictor of death in patients with heart failure and a cardiac implantable electrical device. However, no data are available for predicting death from the HRS in patients with end stage heart failure and a left ventricular assist device.

METHODS

From November 2011 to July 2018, a total of 56 patients with a pre-existing cardiac implantable electrical device underwent left ventricular assist device implantation at our 2 study sites. The ventricular HRS was calculated retrospectively during the first cardiac implantable electrical device follow-up examination following the index hospitalization. Survival during follow-up was correlated with initial HRS.

RESULTS

During the follow-up period, 46.4% of the patients (n = 26) died. The median follow-up period was 33.2 months. The median HRS after the index hospitalization was 41.1 ± 21.8%. More patients with an HRS >65% died compared to patients with an HRS <30% (76.9% vs 14.4%; P = 0.007).

CONCLUSIONS

In our multicentre experience, survival of patients after an left ventricular assist device implant correlates with the HRS. After confirmation of our findings in a larger cohort, the effect of rate-responsive pacing will be within the scope of further investigation.

Infection with SARS-CoV-2 in primary care health care workers assessed by antibody testing

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a pandemic threat of public health during the last month causing more than 10 million infections and 500 000 deceased patients worldwide. Nevertheless, data about risk of infection for health care workers are sparse.

METHODS

In a large primary care facility, 151 workers underwent SARS-CoV-2 immunoglobulin G (IgG) testing. In addition, participants had to complete a survey regarding symptoms and their individual risk of infection.

RESULTS

Symptoms suspicious for COVID-19 occurred in 72%, fever in 25% of all subjects. Four workers (2.6%, 95% confidence interval 0.8-7.1%) had a positive SARS-CoV-2 antibody testing. None of these was free from COVID-19 suspicious symptoms. Source of infection was presumably professional in three of four individuals.

CONCLUSION

Our systematic analysis of SARS-CoV-2 infection in a cohort of health care workers in a large outpatient centre revealed an apparently low rate of 2.6% past SARS-CoV-2 infections. Relative risk for infection following health care profession cannot be derived as data about infection rates in the corresponding general population are lacking.

Effect of Acute Altitude Exposure on Serum Markers of Platelet Activation

Background: Platelets are the key factor in primary hemostasis. It has been shown that chronic altitude exposure increases platelets' aggregability. Nevertheless, data about acute effects and the underlying mechanisms are sparse. Methods: Sixteen healthy volunteers were examined in our hospital (519 m alt.) and 30 minutes after arrival in the environmental research station on the Zugspitze Mountain (2656 m alt.). Serum levels of soluble p-selectin were examined to elucidate platelet activation. In addition, serum levels of chromogranin A (CGA) as a measure of adrenergic activation, endothelin 1 (ET-1) representing pulmonary vascular tone and monocyte chemoattractant protein-1 (MCP-1) as a measure of inflammatory response were examined. Results: Acute altitude exposure induced a significant increase of p-selectin (116 ± 4.8 pg/mL vs. 132 ± 6.2 pg/mL; p < 0.01). Whereas MCP-1 was significantly lowered (538 ± 50.6 pg/mL to 470 ± 41.1 pg/mL; p = 0.02) and CGA was not altered significantly (88 ± 47.4 ng/mL vs. 79 ± 44 ng/mL; p = 0.22), ET1 was increased significantly from 0.8 ± 0.07 pg/mL to 1.15 ± 0.09 pg/mL (p < 0.01). Conclusion: Our study could demonstrate relevant platelet activation that was accompanied by a 44% increase of ET-1. This activation might obtain clinical relevance in patients with pre-existing cardiovascular disease as a trigger for acute events.

Initial single centre experience with the novel Rhythmia© high density mapping system in an all comer collective of 400 electrophysiological patients

BACKGROUND

A novel, automatically annotating ultra-high density mapping system (Rhythmia©, Boston Scientific) collects a high number and quality of electrograms (EGMs). So far, data on general use in the electrophysiological laboratory are sparse.

METHODS

We retrospectively analyzed all our ablations using Rhythmia and recorded patient clinical data, procedural parameters, and mapping parameters including the count of EGMs, mapping time, and mapping volume. Where appropriate, procedural parameters were compared over time to assess a learning curve.

RESULTS

400 patients underwent ablation of atrial fibrillation (n = 202), typical (n = 16) or atypical atrial flutter (n = 49), VT (n = 48), PVC (n = 35), accessory pathways (n = 14), AVNRT (n = 4), and focal atrial tachycardia (n = 32). System use was feasible, as no procedure had to be stopped for technical reasons and no ablation had to be withheld because of mapping failure, and safe, with an overall complication rate of 2.25%. Initial restrictions in manoeuvrability of the mapping catheter were overcome rapidly, as indicated by a significant decrease of fluoroscopy time (20 vs. 14 min, p = 0.02), use of contrast agent (50 vs. 40 ml; p < 0.01), and (not significant) lower procedure times (194 vs. 170 min; p = 0.12; comparing the first with the last third of patients undergoing pulmonary vein isolation only procedure). Ablation of complex left atrial, focal and ventricular tachycardias benefited from the reliable automatic annotation of a high number of EGMs.

CONCLUSION

The use of the Rhythmia is feasible and safe. Initial restrictions in manoeuvrability of the Orion mapping catheter were overcome rapidly. The procedures that benefit the most from ultra-high density mapping are complex left atrial tachycardias, focal tachycardias, and ventricular tachycardias.

Effect of Physical Exercise on Platelet Reactivity in Patients with Dual Antiplatelet Therapy

It is known that physical exercise may increase platelet activity. However, the effect of exercise on platelet reactivity in patients on dual antiplatelet therapy has not been investigated yet. In our study, 21 patients with coronary artery disease on dual antiplatelet therapy and 10 controls were enrolled. We performed an exercise test using a cycle ergometer and determined the adenosine diphosphate-induced platelet reactivity before and immediately after exercise testing. Additionally, we analysed maximal exercise capacity and an electrocardiogram. Further, we assessed chromogranin A and P-selectin levels and platelet counts.

Alteration of Endothelin 1, MCP-1 and Chromogranin A in patients with atrial fibrillation undergoing pulmonary vein isolation

BACKGROUND

The relation between arrhythmias and stress is known. The aim of our current study was to elucidate whether plasma levels of previously described stress parameters are altered in highly symptomatic patients with atrial fibrillation (AF) per se and in patients undergoing ablation therapy by pulmonary vein isolation (PVI).

METHODS

96 patients with AF undergoing PVI were recruited. Plasma levels of Endothelin-1 (ET-1), MCP-1 and Chromogranin-A (CGA) were measured before and three months after ablation completed with clinical follow-up with respect to AF recurrence. Additionally, we examined 40 healthy age- and sex-matched volunteers as a reference.

RESULTS

Symptomatic AF patients showed increased levels of ET-1 compared to healthy controls (2.62pg/ml vs. 1.57pg/ml; p<0.01). Baseline levels of ET-1 were higher in patients presenting with AF after PVI (2.96pg/ml vs. 2.57pg/ml;p = 0.02). The temporal comparison revealed decreased ET-1 levels in patients without (2.57pg/ml vs. 2.33pg/ml; p<0.01) and unchanged ET-1 levels in patients with AF after PVI. Baseline MCP-1 was increased in AF patients vs. controls (268pg/ml vs. 227 pg/ml; p = 0.03). Both groups, with and without AF after PVI, showed an increase of MCP-1 compared to baseline (268pg/ml vs. 349pg/ml;p<0.01; 281pg/ml vs. 355pg/ml;p = 0.03). CGA was lower in AF patients compared to healthy controls (13.8ng/ml vs. 25.6ng/ml;p<0.01). Over time patients without AF after PVI showed an increase of CGA (14.2ng/ml vs. 20.7ng/ml;p<0.01). No change was observed in patients with AF after PVI.

CONCLUSION

Our study demonstrated dysregulated levels of ET-1, MCP-1 and CGA in symptomatic AF patients. We could demonstrate an association between ET-1 to presence or absence of AF. Furthermore, we could show that a decrease of ET-1 as well as an increase of CGA after PVI, representing a trend towards control cohort levels, were both associated with restoration of sinus rhythm. These results provide new insights into the role of stress-related biomarkers in AF and AF treatment by ablation therapy.

Influence of polyphenol-rich diet on exercise-induced immunomodulation in male endurance athletes

Stress is associated with increased susceptibility to infection. We investigated if the mechanism involves immunomodulation of dendritic cells and whether this can be inhibited by a polyphenol-rich diet. Blood samples were taken from a total of 100 male endurance athletes at 5 time points around a marathon run: 4 weeks before; 1 week before; and immediately, 24 h, and 72 h after. Participants were randomized into 2 double-blinded groups. One group received a polyphenol-rich beverage during a 3-week training phase before marathon while the other group received a placebo beverage. Flow cytometric analysis of dendritic cell (DC) counts and subpopulation counts (myeloid, plasmocytoid DCs) was performed. Levels of viral antigen presenting toll-like receptor (TLR) 7 messenger RNA was measured by real-time polymerase chain reaction. Marathon running induced a significant increase of circulating myeloid DCs (0.2% vs. 0.33% of whole-blood leukocytes (wbl); p < 0.01) and a significant decrease of plasmozytoid DCs (0.12% vs. 0.03% of wbl; p < 0.01) and TLR7 expression (decline of 60%; p < 0.01). Polyphenol supplementation did not significantly affect mobilization of dendritic cells but showed beneficial effects on regeneration of TLR7 expression in wbl at 3 days postmarathon (decline of 40% vs. increase of 1000%; p < 0.05). In conclusion, physical stress affects circulating DCs, with an increase of myeloid and a decrease of plasmozytoid DCs. This may partially explain the susceptibility to viral infections after strenuous exercise. These detrimental effects are not attenuated by polyphenol supplementation. However, polyphenols support regeneration of viral antigen presenting TLR7 after strenuous exercise.

Impact of polyphenols on physiological stress and cardiac burden in marathon runners – results from a substudy of the BeMaGIC study

Both physiologic stress and chronic heart disease are associated with increased systemic levels of chromogranin A (CGA) and NT-proBNP. Marathon running causes physiological stress and imposes a significant cardiac burden. Polyphenol-rich Mediterranean and Asian diets have been demonstrated to exert beneficial effects on the cardiovascular system. In this study we investigated whether pretreatment with a polyphenol beverage could attenuate the physiological and cardiac stress associated with a marathon. In the BeMaGIC trial, 277 athletes were randomized into 2 groups in a double-blinded fashion, receiving 1–1.5 L/day of the same beverages either with (study beverage) or without (placebo) polyphenol enrichment (approximately 400 mg of gallic acid equivalents per day of a complex mixture of polyphenols). Blood samples were taken 3 weeks and 1 day before, and immediately, 24 h, and 72 h after running a marathon. In our current substudy, CGA and NT-proBNP levels were analyzed by ELISA in the fastest 18 and the slowest 22 runners. CGA and NT-proBNP levels increased significantly immediately after the marathon and returned to baseline at 72 h after the marathon. Neither CGA nor NT-proBNP differed significantly between athletes receiving study beverage versus placebo. Separating our cohort into fast and slow runners did not reveal any significant difference regarding CGA or NT-proBNP levels between groups. Our study provides no evidence that polyphenol supplementation attenuates marathon running-induced physiological stress and cardiac burden in fast or slow runners.

Soluble Vascular Cell Adhesion Molecule-1 (VCAM-1) as a Biomarker in the Mouse Model of Experimental Autoimmune Myocarditis (EAM)

Vascular cell adhesion molecule-1 (VCAM-1) is strongly upregulated in hearts of mice with coxsackie virus-induced as well as in patients with viral infection-triggered dilated cardiomyopathy. Nevertheless, the role of its soluble form as a biomarker in inflammatory heart diseases remains unclear. Therefore, we investigated whether plasma levels of soluble VCAM-1 (sVCAM-1) directly correlated with disease activity and progression of cardiac dysfunction in the mouse model of experimental autoimmune myocarditis (EAM). EAM was induced by immunization of BALB/c mice with heart-specific myosin-alpha heavy chain peptide together with complete Freund`s adjuvant. ELISA revealed strong expression of cardiac VCAM-1 (cVCAM-1) throughout the course of EAM in immunized mice compared to control animals. Furthermore, sVCAM-1 was elevated in the plasma of immunized compared to control mice at acute and chronic stages of the disease. sVCAM-1 did not correlate with the degree of acute cardiac inflammation analyzed by histology or cardiac cytokine expression investigated by ELISA. Nevertheless, heart to body weight ratio correlated significantly with sVCAM-1 at chronic stages of EAM. Cardiac systolic dysfunction studied with positron emission tomography indicated a weak relationship with sVCAM-1 at the chronic stage of the disease. Our data provide evidence that plasma levels of sVCAM-1 are elevated throughout all stages of the disease but showed no strong correlation with the severity of EAM.

Influence of High Polyphenol Beverage on Stress-Induced Platelet Activation

OBJECTIVES

Platelets are playing a crucial role in acute cardiovascular events. We investigated if physical stress activates platelets and whether this activation can be inhibited by a polyphenol-enriched diet.

METHODS

Blood samples were taken from a total of 103 athletes three weeks before, one day before, immediately as well as 24 hours and 72 hours after a marathon run. Participants were randomized, double-blinded and divided into two groups. One group received a polyphenol-rich beverage the other the same beverage without polyphenols. Besides analysis of platelet counts and impedance-aggregometric-measurement of platelet activity, soluble P-selectin and Endothelin-A measurements were performed.

RESULTS

In the control group, runners showed a 2.2-fold increased platelet aggregation directly after completing a marathon and within the following three days when compared with baseline values (p<0.01). In accordance, significant increases in sP-selectin (57.52ng/ml vs. 94.86ng/ml;p<0.01) were detectable. In contrast, for the group consuming a beverage with increased polyphenol content (upper quartile of study beverage intake) we did not find any increase of platelet aggregation.

DISCUSSION

Physical stress causes a significant increase in platelet activity. Our results demonstrate that a diet enriched in polyphenols is capable of preventing platelet activation. These findings might indicate a diminished cardiovascular stress-reaction following pre-exposition to polyphenol-enriched diet.