Transseptal Puncture Guided by Three-Dimensional Electroanatomical Mapping: Early Experience Using a Simplified Approach in Adults with Congenital Heart Disease

AIMS

The widespread use of three-dimensional (3D) mapping systems and echocardiography in the field of cardiac electrophysiology has made it possible to perform transseptal punctures (TSP) with low or no fluoroscopy. However, such attempts in adults with congenital heart disease (ACHD) who have previously undergone surgical or interventional treatment are limited. Therefore, we sought to explore the feasibility and safety of an approach to perform zero- or low-fluoroscopy TSP in ACHD patients undergoing left atrial cardiac ablation procedures.

METHODS AND RESULTS

This study included 45 ACHD patients who underwent TSP for ablation of left-sided tachycardias (left atrium or pulmonary venous atrium). Computed tomography (CT) of the heart was performed in all patients prior to ablation. 3D mapping of the right-sided heart chambers before TSP was used to superimpose the registered anatomy, which was subsequently used for the mapping-guided TSP technique. TSP was performed with zero-fluoroscopy in 27 patients, and the remaining 18 patients had a mean fluoroscopy exposure of 315.88 ± 598.43 μGy.m² and a mean fluoroscopy duration of 1.9 ± 5.4 min. No patient in this cohort experienced TSP-related complications.

CONCLUSION

Our study describes a fluoroscopy-free or low-dose fluoroscopy approach for TSP in ACHD patients undergoing catheter ablation of left-sided tachyarrhythmias who had been previously treated surgically or interventionally due to congenital heart defects. By superimposing 3D electroanatomic mapping with cardiac CT anatomy, this protocol proved to be highly effective, feasible and safe.

Arrhythmias and Clinical Outcomes in a Swiss Multicenter Cohort of Patients With Dextro-Transposition of the Great Arteries and Atrial Switch

Background Data on the incidence of arrhythmias, associated cardiac interventions, and outcome in patients with dextro-transposition of the great arteries and atrial switch are scarce. Methods and Results In this multicenter analysis, we included adult patients with dextro-transposition of the great arteries and atrial switch regularly followed up at 3 Swiss tertiary care hospitals. The primary outcome was a composite of left ventricular assist device, heart transplantation, and death. The secondary outcome was occurrence of ventricular tachycardia, ventricular fibrillation, or sudden cardiac death. We identified 207 patients (34% women; median age at last follow-up, 35 years) with dextro-transposition of the great arteries and atrial switch. Arrhythmias occurred in 97 patients (47%) at a median age of 22 years. A pacemaker or an implantable cardioverter-defibrillator was implanted in 39 (19%) and 13 (6%) patients, respectively, and 33 (16%) patients underwent a total of 51 ablation procedures to target 60 intra-atrial re-entry tachycardias, 4 atrioventricular nodal re-entry tachycardias, and 1 atrial fibrillation. The primary outcome occurred in 21 patients (10%), and the secondary outcome occurred in 18 patients (9%); both were more common in patients with concomitant ventricular septum defect than in those without (hazard ratio [HR], 3.06 [95% CI, 1.29-7.27], P=0.011; and HR, 3.62 [95% CI, 1.43-9.18], P=0.007, respectively). Conclusions In patients with dextro-transposition of the great arteries and atrial switch reaching adulthood, arrhythmias occur in almost half of patients, and associated rhythm interventions are frequent. One-tenth of those patients do not survive until the age of 35 years free from left ventricular assist device or heart transplantation, and the outcome is worse in patients with concomitant ventricular septum defect.

The effect of first step right atrial mapping (FRAM) on ablation duration and fluoroscopy exposure during cavotricuspid isthmus ablation of atrial flutter

Aim

To investigate the clinical significance of right atrial mapping prior to cavotricuspid isthmus (CTI) ablation in patients with typical atrial flutter (AFL).

Methods

Clinical and ablation parameters were retrospectively assessed and compared in patients undergoing CTI ablation with or without a first-step right atrial mapping (FRAM) by using the CARTO 3D mapping system.

Results

CTI block by radiofrequency ablation (RFA) was achieved in all 143 patients. In the FRAM group there was a shorter ablation duration and fluoroscopy exposure compared with the non-FRAM group. CHA₂DS₂-VASc score was associated with higher ablation durations, more ablation applications and increased fluoroscopy exposure. Body mass index (BMI) was associated with longer ablation duration and more ablation applications. Furthermore, patients with reduced left ventricular ejection fraction (LVEF) had longer ablation durations and more fluoroscopy exposure. One patient in the non-FRAM group developed cardiac effusion after ablation. None of the patients had recurrence after 6 months of follow-up.

Conclusions

Patients with high BMI, high CHA₂DS₂-VASc score and reduced LVEF may benefit from the FRAM approach by reducing ablation duration, number of ablation applications and fluoroscopy exposure.

Evolution and triggers of defibrillator shocks in patients with arrhythmogenic right ventricular cardiomyopathy

INTRODUCTION

Implantable cardioverter-defibrillators (ICDs) can prevent sudden cardiac death due to ventricular arrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). The aim of our study was to assess the cumulative burden, evolution and potential triggers of appropriate ICD shocks during long-term follow-up, which may help to reduce and further refine individual arrhythmic risk in this challenging disease.

METHODS

This retrospective cohort study included 53 patients with definite ARVC according to the 2010 Task Force Criteria from the multicentre Swiss ARVC Registry with an implanted ICD for primary or secondary prevention. Follow-up was conducted by assessing all available patient records from patient visits, hospitalisations, blood samples, genetic analysis, as well as device interrogation and tracings.

RESULTS

Fifty-three patients (male 71.7%, mean age 43±2.2 years, genotype positive 58.5%) were analysed during a median follow-up of 7.9 (IQR 10) years. In 29 (54.7%) patients, 177 appropriate ICD shocks associated with 71 shock episodes occurred. Median time to first appropriate ICD shock was 2.8 (IQR 3.6) years. Long-term risk of shocks remained high throughout long-term follow-up. Shock episodes occurred mainly during daytime (91.5%, n=65) and without seasonal preference. We identified potentially reversible triggers in 56 of 71 (78.9%) appropriate shock episodes, the main triggers representing physical activity, inflammation and hypokalaemia.

CONCLUSION

The long-term risk of appropriate ICD shocks in patients with ARVC remains high during long-term follow-up. Ventricular arrhythmias occur more often during daytime, without seasonal preference. Reversible triggers are frequent with the most common triggers for appropriate ICD shocks being physical activity, inflammation and hypokalaemia in this patient population.

Arrhythmia burden, rhythm interventions and outcome in a large Swiss multicenter population of d-TGA patients with atrial switch

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with dextro-transposition of the great arteries (d-TGA) and atrial switch face a high life-time risk of arrhythmias.

Purpose

To describe the incidence of arrhythmias, associated cardiac interventions and outcome in a large Swiss population of patients with d-TGA and atrial switch.

Methods

In this multicenter analysis we included all consecutive patients with d-TGA and atrial switch treated at three Swiss tertiary care hospitals. The primary outcome was survival free from left ventricular assist device (LVAD), heart transplantation (HTx) and death. The secondary outcome was survival free from ventricular tachycardia, ventricular fibrillation and sudden cardiac death.

Results

We identified 207 patients (34% females; median age at last follow-up 35 years) with d-TGA and atrial switch. Arrhythmias occurred in 97 patients (47%) at a median age of 22 years. A pacemaker or an implantable cardioverter/defibrillator was implanted in 39 (19%) and 13 (6%) patients, respectively, and 33 (16%) underwent a total of 51 ablation procedures to target 60 intra-atrial reentry tachycardias, 4 AV nodal reentry tachycardias and one atrial fibrillation (Figure 1). The primary outcome occurred in 21 patients (10%) and the secondary outcome in 18 (9%) (Figure 2). Primary and secondary outcomes were more common in patients with concomitant ventricular septum defect (VSD) than in those without (hazard ratio [HR] 3.06; 95% confidence interval [CI] 1.29-7.27, p=0.011; and HR 3.62; 95% CI 1.43-9.18, p=0.007, respectively).

Conclusions

At a median age of 35 years, arrhythmias occur in almost half of patients with d-TGA and atrial switch and associated rhythm interventions are frequent. One in ten patients does not survive free from LVAD and HTx and outcome is worse in patients with concomitant VSD.

Predictors of left atrial fibrosis in patients with atrial fibrillation referred for catheter ablation

Background

Left atrial (LA) fibrosis in patients with atrial fibrillation (AF) is associated with an increased risk of AF recurrence after catheter ablation. Therefore, we searched for clinical risk factors that confer an increased risk of LA fibrosis, which can influence the treatment strategy.

Methods

We included 94 patients undergoing 3-dimensional electroanatomical voltage mapping-guided catheter ablation of AF. LA low-voltage areas during sinus rhythm as a surrogate parameter of fibrosis were measured with the CARTO3 mapping system and adjusted for LA volumes obtained by computed tomography. Blood tests including N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) and echocardiographic parameters of left ventricular function were also analyzed.

Results

Patients were 62.5 ± 11.4 years old, and 29% were female. LA fibrosis was present in 65%, with 50% having a fibrotic area > 5% (≥ Utah-Stage 1). Mean left ventricular ejection fraction (LVEF) was 53.9 ± 10.5%. Patients with LA fibrosis had higher NT-proBNP levels (869 ± 1056 vs. 552 ± 859 ng/L, p = 0.001) and larger LA volumes (body surface area-corrected 63.3 ± 19.3 vs. 80 ± 27.1 mL/m², p = 0.003). In univariable analyses, LA fibrosis was significantly associated with female gender, older age, increased LA volumes, hypertension, statin therapy, higher NT-proBNP values, and echocardiographic E/e′. In bivariable analyses, higher NT-proBNP, echocardiographic parameters of diastolic dysfunction, female gender, older age, and higher DR-FLASH scores remained as independent predictors of LA fibrosis.

Conclusions

In this single-center longitudinal study, surrogate parameters of elevated left-sided cardiac filling pressures such as higher NT-proBNP levels and higher echocardiographic E/e′ values as well as female gender independently predicted the prevalence of LA fibrosis in patients referred for catheter ablation of AF.

Distinctive characteristics of his bundle potentials in patients with atrioventricular nodal reentrant tachycardia

BACKGROUND

His bundle (HB) potentials vary in amplitude and duration in patients with and without slow pathways. The aim of this study was to determine the characteristics of HB potentials and to elucidate whether they can provide clues for identification of slow pathway (SP).

METHODS

The present research prospectively studied the electrophysiological findings of 162 patients with symptomatic atrioventricular nodal reentrant tachycardia (AVNRT) due to slow-fast or fast-slow type and atrioventricular reentrant tachycardia (AVRT). Maximal HB potential (HBmax, HB with the highest amplitude) among HB cloud was recorded in both groups. For AVNRT patients, the following were measured: (1) AH interval at the "jump" during programmed atrial stimulation (A2H2, taken as a reflection of SP conduction time); (2) Distance from HBmax to the successful SP ablation site (HBmax-ABL) and from HBmax to the ostium of coronary sinus (HBmax-CSO).

RESULTS

HBmax was 0.29 ± 0.10 mV in AVNRT patients, whereas it was 0.17 ± 0.05 mV in AVRT group (p < 0.0001). Likewise, the HBmax duration was 22 ± 5 ms in AVNRT group and 16 ± 3 ms in AVRT group (p < 0.0001). The area under the ROC curve of HBmax amplitude in AVNRT patients was 0.86 and the optimal HBmax cut-off to predict AVNRT was ≥ 0.22 mV with a sensitivity of 0.78 and specificity of 0.84. HBmax-CSO was positively correlated with HBmax-ABL, and HBmax-ABL was positively correlated with A2H2.

CONCLUSIONS

HBmax amplitudes were higher and durations longer in patients with AVNRT, as compared to those with AVRT. Moreover, the distance between HBmax and successful ablation site was positively correlated with the SP conduction time and with the distance from HBmax to the CS ostium.

Feasibility of zero or near zero fluoroscopy during catheter ablation procedures

BACKGROUND

Awareness of risks associated with radiation exposure to patients and medical staff has significantly increased. It has been reported before that the use of advanced three-dimensional electroanatomical mapping (EAM) system significantly reduces fluoroscopy time, however this study aimed for zero or near zero fluoroscopy ablation to assess its feasibility and safety in ablation of atrial fibrillation (AF) and other tachyarrhythmias in a "real world" experience of a single tertiary care center.

METHODS

This was a single-center study where ablation procedures were attempted without fluoroscopy in 34 consecutive patients with different tachyarrhythmias under the support of EAM system. When transseptal puncture (TSP) was needed, it was attempted under the guidance of intracardiac echocardiography (ICE).

RESULTS

Among 34 patients consecutively enrolled in this study, 28 (82.4%) patients were referred for radiofrequency ablation (RFA) of AF, 3 (8.8%) patients for ablation of right ventricular outflow tract (RVOT) ventricular extrasystole (VES), 1 (2.9%) patient for ablation of atrioventricular nodal reentry tachycardia (AVNRT), 2 (5.9%) patients for typical atrial flutter ablation. In 21 (62%) patients the en- tire procedure was carried out without the use of fluoroscopy. Among 28 AF patients, 15 (54%) patients underwent ablation without the use of fluoroscopy and among these 15 patients, 10 (67%) patients required TSP under ICE guidance while 5 (33%) patients the catheters were introduced to left atrium through a patent foramen ovale. In 13 AF patients, fluoroscopy was only required for double TSP. The total procedure time of AF ablation was 130 ± 50 min. All patients referred for atrial flutter, AVNRT, and VES of the RVOT ablation did not require any fluoroscopy.

CONCLUSIONS

This study demonstrates the feasibility of zero or near zero fluoroscopy procedure including TSP with the support of EAM and ICE guidance in a "real world" experience of a single tertiary care center. When fluoroscopy was required, it was limited to TSP hence keeping the radiation dose very low.

Low QRS Voltage and Atrial Fibrillation Precluding Implantation of a Subcutaneous Implantable Cardioverterdefibrillator in a Patient with Arrhythmogenic Cardiomyopathy

Arrhythmogenic cardiomyopathy (AC) is a rare mostly hereditary disease, in which fibro-fatty tissue replaces cardiomyocytes. Typically, the first alterations of the disease can be encountered in the epicardium of the right ventricle in adolescent patients. From there, the disease usually progresses over time. Besides the development of heart failure, the clinical significance of the disease is determined by the predisposition to potentially lethal ventricular arrhythmias. Hence, a majority of patients with AC require an implantable cardioverter-defibrillator (ICD) to be protected from sudden cardiac death. A recently developed alternative to transvenous systems are subcutaneous ICDs (S-ICD), associated with a lower risk of device-related complications such as endocarditis since no foreign material is implanted within the heart and vascular system. In this report, we describe and discuss our experience with the implantation of a S-ICD in a patient with AC, who had low QRS voltage and persistent atrial fibrillation precluding successful S-ICD implantation, as well as the challenges encountered during subsequent transvenous lead implantation.

Impact of growing cohorts of adults with con-genital heart disease on clinical workload: a 20-year experience at a tertiary care centre

BACKGROUND

Population based studies show a steady increase in adult patients with congenital heart defects. The aim of this study was to assess the evolution of such a patient cohort and its burden on clinical care at a dedicated tertiary care centre.

METHODS

All patients with congenital heart disease followed up by a dedicated multidisciplinary team at our institution were identified (n = 1725). Disease characteristics, the increase in patient numbers and interventions and the increase in selected complications were analysed and compared between the first (1996-2005) and second (2006-2015) decades of the study period.

RESULTS

Between the two decades of the study period, the number of patients in follow-up increased by 109%, the number of patients who died or underwent transplantation more than doubled and the number of outpatient visits increased by 195%. One fourth of all patients underwent at least one surgical procedure and 14% had at least one percutaneous intervention. The increase in surgical procedures between the two decades was 27% and the increase in percutaneous interventions 159%. Between the two decades the number of patients requiring direct current cardioversion increased from 32 to 95 (+197%), the number of patients requiring admission for infective endocarditis increased from 7 to 29 (+314%) and the number of women followed up during pregnancy increased from 18 to 115 (+539%).

CONCLUSION

As a result of the increasing number and complexity of adult survivors with congenital heart disease more resources will be needed to cope with the demands of this novel cohort of complex patients in adult cardiology.

Play the Map: Ablation of a Macro Reentrant Atrial Tachycardia in a Patient After Senning Repair for Transposition of the Great Arteries

A 50-year-old male patient who had undergone Senning repair for transposition of the great arteries at the age of 7 years was referred to our electrophysiology lab with recurrent supraventricular tachycardias. Fast anatomical mapping of the systemic venous atrium was performed with the CARTO electroanatomical mapping system. Propagation mapping with animated dynamic maps facilitates the understanding of the underlying mechanism and provides visualization of reentrant circuits of tachycardias in cardiac chambers with native barriers and surgical scars.

Robotic ablation of atrial fibrillation

Background: Pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). During PVI an electrical conduction block between pulmonary vein (PV) and left atrium (LA) is created. This conduction block prevents AF, which is triggered by irregular electric activity originating from the PV. However, transmural atrial lesions are required which can be challenging. Re-conduction and AF recurrence occur in 20 - 40% of the cases. Robotic catheter systems aim to improve catheter steerability. Here, a procedure with a new remote catheter system (RCS), is presented. Objective of this article is to show feasibility of robotic AF ablation with a novel system. Materials and Methods: After interatrial trans-septal puncture is performed using a long sheath and needle under fluoroscopic guidance. The needle is removed and a guide wire is placed in the left superior PV. Then an ablation catheter is positioned in the LA, using the sheath and wire as guide to the LA. LA angiography is performed over the sheath. A circular mapping catheter is positioned via the long sheath into the LA and a three-dimensional (3-D) anatomical reconstruction of the LA is performed. The handle of the ablation catheter is positioned in the robotic arm of the Amigo system and the ablation procedure begins. During the ablation procedure, the operator manipulates the ablation catheter via the robotic arm with the use of a remote control. The ablation is performed by creating point-by-point lesions around the left and right PV ostia. Contact force is measured at the catheter tip to provide feedback of catheter-tissue contact. Conduction block is confirmed by recording the PV potentials on the circular mapping catheter and by pacing maneuvers. The operator stays out of the radiationfield during ablation. Conclusion: The novel catheter system allows ablation with high stability on low operator fluoroscopy exposure.

Electrocardiographic features of disease progression in arrhythmogenic right ventricular cardiomyopathy/dysplasia

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is considered a progressive cardiomyopathy. However, data on the clinical features of disease progression are limited. The aim of this study was to assess 12-lead surface electrocardiographic (ECG) changes during long-term follow-up, and to compare these findings with echocardiographic data in our large cohort of patients with ARVC/D.

METHODS

Baseline and follow-up ECGs of 111 patients from three tertiary care centers in Switzerland were systematically analyzed with digital calipers by two blinded observers, and correlated with findings from transthoracic echocardiography.

RESULTS

The median follow-up was 4 years (IQR 1.9-9.2 years). ECG progression was significant for epsilon waves (baseline 14% vs. follow-up 31%, p = 0.01) and QRS duration (111 ms vs. 114 ms, p = 0.04). Six patients with repolarization abnormalities according to the 2010 Task Force Criteria at baseline did not display these criteria at follow-up, whereas in all patients with epsilon waves at baseline these depolarization abnormalities also remained at follow-up. T wave inversions in inferior leads were common (36% of patients at baseline), and were significantly associated with major repolarization abnormalities (p = 0.02), extensive echocardiographic right ventricular involvement (p = 0.04), T wave inversions in lateral precordial leads (p = 0.05), and definite ARVC/D (p = 0.05).

CONCLUSIONS

Our data supports the concept that ARVC/D is generally progressive, which can be detected by 12-lead surface ECG. Repolarization abnormalities may disappear during the course of the disease. Furthermore, the presence of T wave inversions in inferior leads is common in ARVC/D.

"On-site" prevention and education to improve cardiac pre-competition screening in competitive amateur athletes

STUDY/PRINCIPLES

To assess the effects of an "on-site" prevention and education programme to improve the cardiac screening in competitive amateur athletes.

METHODS

We integrated an "on-site prevention and education programme" at the 2012 edition of the Swiss Alpine Marathon in Davos, Switzerland. After a specific lecture, the athletes could visit a "Sports-Cardiology-Section" at the official "medical-park". On an anonymised questionnaire, they could state their intention for a screening programme in general and after our "on-site" intervention.

RESULTS

Among the 150 athletes who attended the medical day (3.3% of 4,500 finishers) the response rate was 82%. While 39 (31.7%) athletes were aware of "exercise related SCD", more than twice as many (64.2%) were not. 72.4% of the participants (n = 89) reported that they never had taken part in cardiac screening examinations. 70.7% (n = 87) runners were convinced that they would benefit from such a screening. 65.9% (n = 81) of the runners stated that our "on-site" prevention concept influenced their decision to consider a cardiac screening in the future.

CONCLUSION

An "on-site prevention and education" concept for the prevention of SCD in competitive amateur athletes is feasible and successfully increased the athletes' awareness of the issue. The vast majority of athletes felt to have benefited from such a programme. The current study confirms that there is an alarming lack of preventive measures in the very large group of ambitious, competitive, amateur athletes that are frequently underprepared for challenging sports events.

Usefulness of inducible ventricular tachycardia to predict long-term adverse outcomes in arrhythmogenic right ventricular cardiomyopathy

The role of the electrophysiologic (EP) study for risk stratification in patients with arrhythmogenic right ventricular cardiomyopathy is controversial. We investigated the role of inducible sustained monomorphic ventricular tachycardia (SMVT) for the prediction of an adverse outcome (AO), defined as the occurrence of cardiac death, heart transplantation, sudden cardiac death, ventricular fibrillation, ventricular tachycardia with hemodynamic compromise or syncope. Of 62 patients who fulfilled the 2010 Arrhythmogenic Right Ventricular Cardiomyopathy Task Force criteria and underwent an EP study, 30 (48%) experienced an adverse outcome during a median follow-up of 9.8 years. SMVT was inducible in 34 patients (55%), 22 (65%) of whom had an adverse outcome. In contrast, in 28 patients without inducible SMVT, 8 (29%) had an adverse outcome. Kaplan-Meier analysis showed an event-free survival benefit for patients without inducible SMVT (log-rank p = 0.008) with a cumulative survival free of an adverse outcome of 72% (95% confidence interval [CI] 56% to 92%) in the group without inducible SMVT compared to 26% (95% CI 14% to 50%) in the other group after 10 years. The inducibility of SMVT during the EP study (hazard ratio [HR] 2.99, 95% CI 1.23 to 7.27), nonadherence (HR 2.74, 95% CI 1.3 to 5.77), and heart failure New York Heart Association functional class II and III (HR 2.25, 95% CI 1.04 to 4.87) were associated with an adverse outcome on univariate Cox regression analysis. The inducibility of SMVT (HR 2.52, 95% CI 1.03 to 6.16, p = 0.043) and nonadherence (HR 2.34, 95% CI 1.1 to 4.99, p = 0.028) remained as significant predictors on multivariate analysis. This long-term observational data suggest that SMVT inducibility during EP study might predict an adverse outcome in patients with arrhythmogenic right ventricular cardiomyopathy, advocating a role for EP study in risk stratification.

Predictors of appropriate ICD therapy in patients with arrhythmogenic right ventricular cardiomyopathy: long term experience of a tertiary care center

Introduction

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare genetically transmitted disease prone to ventricular arrhythmias. We therefore investigated the clinical, echocardiographical and electrophysiological predictors of appropriate implantable cardioverter defibrillator (ICD) therapy in patients with ARVC.

Methods

A retrospective analysis was performed in 26 patients (median age of 40 years at diagnosis, 21 males and 5 females) with ARVC who underwent ICD implantation.

Results

Over a median (range) follow-up period of 10 (2.7, 37) years, appropriate ICD therapy for ventricular arrhythmias was documented in 12 (46%) out of 26 patients. In all patients with appropriate ICD therapy the ICD was originally inserted for secondary prevention. Median time from ICD implantation to ICD therapy was 9 months (range 3.6, 54 months). History of heart failure was a significant predictor of appropriate ICD therapy (p = 0.033). Left ventricular disease involvement (p = 0.059) and age at implantation (p = 0.063) were borderline significant predictors. Patients with syncope at time of diagnosis were significantly less likely to receive ICD therapy (p = 0.02). Invasive electrophysiological testing was not significantly associated with appropriate ICD therapy.

Conclusion

In our cohort of patients with ARVC, history of heart failure was a significant predictor of appropriate ICD therapy, whereas left ventricular involvement and age at time of ICD implantation were of borderline significance. These predictors should be tested in larger prospective cohorts to optimize ICD therapy in this rare cardiomyopathy.

Comparison of benefit and mortality of implantable cardioverter-defibrillator therapy in patients aged ≥75 years versus those <75 years

Implantable cardioverter-defibrillator (ICD) therapy decreases arrhythmic and all-cause mortality in patients at high risk of sudden death. However, its clinical benefit in elderly patients is uncertain. The aim of this study was to assess the long-term efficacy of ICD treatment in elderly patients and to identify markers of successful ICD therapy and risk factors of mortality. We performed multivariate analysis of a prospective long-term database from 2 tertiary care centers including 936 consecutive patients with an ICD. Predictors of ICD therapy and risk factors for mortality were assessed in patients ≥75 years old at ICD implantation compared to younger patients. Mean follow-up time was 43 ± 40 months. Rates of ICD therapy were similar in the 2 age groups. No significant predictors of ICD therapy could be identified in older patients. Median estimated survival was 132 months in patients <75 years and 81 months in those ≥75 years old (p = 0.006). Decreased ejection fraction (hazard ratio 1.62 per 10% decrease, p = 0.03) and impaired renal function (hazard ratio 1.57 per 10 ml/kg/m(2) decrease in estimated glomerular filtration rate, p = 0.02) were independent risk factors of mortality in patients ≥75 years old. However, mortality of older patients was similar to that of the age-matched general population irrespective of delivery of ICD therapy. In conclusion, ICD therapy is effective for treatment of life-threatening arrhythmias in all age groups. However, prevention of sudden cardiac death may have limited impact on overall mortality in older patients. Despite a similar rate of appropriate ICD therapies, risk of death is increased 1.6-fold in ICD recipients ≥75 years old compared to younger patients. Patients with decreased ejection fraction and impaired renal function are at highest risk.

Pre-competition cardiac screening in professional handball players - setting up at the EHF European Handball Championship 2010 in Austria

In many sports, regular cardiac screening for exercise-associated sudden cardiac death is still not provided. To set up the current situation in top-skilled handball players qualified for the 2010 European Handball Championship in Austria, a standardised questionnaire was sent to every team. The fact that only 42.7% of the players returned the questionnaire may lead to the conclusion that the awareness of the problem is quite low. However, 82% of these players have been screened according to current recommendations. Half of the teams were screened inhomogeneously: 5 players (4.1%) have not been screened within the last years, 1 athlete (0.8%) was screened without an ECG. While 69% of the athletes got their first screening only after the age of 18, 16 players (13.1%) never went through a specific screening ever. We identified 17 athletes (13.9%) with a highly suspicious history, 2 of them (1.6%) never underwent a medical screening at all.

Appropriate therapy but not inappropriate shocks predict survival in implantable cardioverter defibrillator patients

BACKGROUND

Inappropriate implantable cardioverter defibrillator (ICD) shocks have been linked to a worse clinical outcome due to direct myocardial injury.

HYPOTHESIS

The occurrence of ventricular tachyarrhythmia indicating progression of the underlying heart disease, but not the ICD shock itself, has prognostic impact in clinical routine.

METHODS

In a retrospective study, 1117 recipients of an ICD were analyzed with respect to appropriate and inappropriate therapies and survival.

RESULTS

During a mean follow-up of 2.92 years, appropriate therapy occurred in 27.7% and 54.0% of patients who had received an ICD for primary and secondary prevention of sudden cardiac death (SCD), respectively (P<0.0001). Inappropriate shock therapy occurred in 15.0% and 25.4% of patients who had received an ICD for primary and secondary prevention of SCD, respectively (P = 0.122). Appropriate ICD therapy had a strong impact on overall survival (P<0.0001), and this association was found both in primary (P<0.0001) and secondary (P = 0.002) prevention of SCD. Inappropriate ICD shocks had no impact on total mortality, neither in primary nor secondary prevention of SCD.

CONCLUSIONS

Inappropriate shocks do not affect survival, in strong contrast to appropriate ICD therapy. Our study does not support the hypothesis that shock therapy in itself worsens clinical outcome. However, it confirms that appropriate ICD therapy is a warning sign and should prompt physicians to consider additional treatment strategies.

Long-term follow-up of patients with isolated left ventricular noncompaction: role of electrocardiography in predicting poor outcome

BACKGROUND

Abnormal baseline electrocardiograms (ECGs) are common in patients with isolated left ventricular noncompaction (IVNC). Whether certain electrocardiographic parameters are associated with a poor clinical outcome, however, remains elusive. The present study was therefore designed to comprehensively assess the predictive value of baseline ECG findings in patients newly diagnosed with IVNC.

METHODS AND RESULTS

74 patients diagnosed with IVNC were included in the analysis. During follow-up, 8 patients (11%) died of a cardiovascular cause or underwent heart transplantation (primary outcome measure). On univariate analysis, several variables, including repolarization abnormalities (ST segment elevation/depression, T-wave inversion) in the inferior leads (5-year estimator: 67.1 ± 10.7% vs. 98 ± 2.2%; P = 0.001), an increase in PQ- (hazard ratio (HR) 1.032, P=0.004) and QTc-duration (HR 1.037, P=0.001), were predictive of cardiovascular death or heart transplantation. On multivariate analysis, only PQ- and QTc-duration and the presence of repolarization abnormalities in the inferior leads remained significantly predictive of a poor outcome.

CONCLUSIONS

PQ duration, QTc duration, and repolarization abnormalities in the inferior leads are independently predictive of a poor prognosis in IVNC. Further prospective studies are required to conclusively investigate the usefulness of baseline ECG parameters for risk stratification in patients with IVNC.

Double transseptal puncture for catheter ablation of atrial fibrillation: safety of the technique and its use in the outpatient setting

Introduction. For pulmonary vein isolation in patients with atrial fibrillation (AF), some centers use the double transseptal puncture technique for catheter access in order to facilitate catheter manipulation within the left atrium. However, no safety data has so far been published using this approach. Method. 269 ablation procedures were performed in 243 patients (mean age 56.6 ± 9.3 years, 75% men) using the double transseptal puncture for catheter access in all cases. Patients were considered for ablation of paroxysmal (80%), persistent (19%), and permanent (1%) AF. 230 procedures were performed on an outpatient basis (85.5%), and 26 were repeat procedures (9.7%). Results. The double transseptal puncture catheter access was successfully achieved in all patients. The procedural success with the endpoint of pulmonary vein isolation was reached in 255 procedures (95%). A total of 1048 out of 1062 pulmonary veins (99%) were successfully isolated. Major complications occurred in eight patients (3.0%). Of these, seven patients (2.6%) had pericardial effusion requiring percutaneous drainage, and one patient (0.4%) suffered a minor reversible stroke. One patient (0.4%) had a minor air embolism with transient symptoms. Conclusion. The double transseptal puncture catheterization technique allows easy catheter manipulation within the left atrium to reach the goal of acute procedural success in AF ablation. Procedure-related complications are rare, and the technique can be used safely for AF ablation in the outpatient setting.

Heart obeys the brain: seizure ceases cardiac rhythm

Ictal asystole is a rare phenomenon which may contribute to sudden death during epilepsy. Here we describe a case of a 20-year-old woman with ictal asystole and normal findings during electrophysiologic study. This case illustrates that ictal asystole may occur in patients with electrically normal hearts. We provide pathophysiologic considerations and discuss therapeutic options.

Patient satisfaction and clinical outcome following outpatient radiofrequency catheter ablation of supraventricular tachycardia

BACKGROUND

Catheter ablation is an effective and safe treatment for various arrhythmic disorders. Patients are frequently admitted for an overnight stay after the ablation procedure to monitor for possible postprocedural complications or recurrence of the arrhythmia. The aim of this study was to assess patient satisfaction in patients with supraventricular tachycardia following catheter ablation on an outpatient basis.

METHODS

243 consecutive patients (129 male, 53%; mean age 49 +/- 17 years) underwent electrophysiological study and radiofrequency catheter ablation either on an outpatient basis or a hospitalisation that included at least an overnight hospital stay (inpatient) at a university hospital. All patients were asked to complete a specially designed questionnaire that addressed patient satisfaction as well as the clinical outcome after ablation at six months.

RESULTS

The ablation procedure was performed on an outpatient basis in 119 patients (49%). The long-term procedural success rate was 99%. The overall patient satisfaction with the ablation procedure and with the clinical outcome at six months was 90%. There were no significant differences between outpatient and inpatient groups with respect to ablation results and patient satisfaction. Patients in the outpatient group returned to work after 2.8 +/- 1.9 days as compared to 3.9 +/- 2.2 days in the in hospital group (p = 0.001).

CONCLUSION

Overall patient satisfaction and self-reported clinical outcome are comparable for outpatient and inpatient catheter ablations. Patients undergoing outpatient procedures may return to work earlier. Therefore, outpatient ablation procedures may be considered for selected patients without significant comorbidities.

Interference of neodymium magnets with cardiac pacemakers and implantable cardioverter-defibrillators: an in vitro study

Permanent magnets may interfere with the function of cardiac pacemakers and implantable cardioverter-defibrillators (ICDs). Neodymium-iron-boron (NdFeB) magnets have become widely available in recent years and are incorporated in various articles of daily life. We conducted an in-vitro study to evaluate the ability of NdFeB magnets for home and office use to cause interference with cardiac pacemakers and ICDs. The magnetic fields of ten NdFeB magnets of different size and shape were measured at increasing distances beginning from the surface until a field-strength (B-field) value of 0.5 mT was reached. Furthermore, for each magnet the distance was determined at which a sample pacemaker switched from magnet mode to normal mode. Depending on the size and remanence of individual magnets, a B-field value of 0.5 mT was found at distances ranging from 1.5 cm to 30 cm and a value of 1 mT at distances from 1 cm to 22 cm. The pacemaker behavior was influenced at distances from 1 cm to 24 cm. NdFeB magnets for home and office use may cause interference with cardiac pacemakers and ICDs at distances up to 24 centimeters. Patient education and product declarations should include information about the risk associated with these magnets.

B-type natriuretic peptide kinetics and cardiopulmonary exercise testing in heart failure

BACKGROUND

In patients with chronic heart failure (CHF), B-type natriuretic peptide (BNP) is related to peak oxygen consumption (peak VO2) and the relationship between minute ventilation and carbon dioxide production (VE/VCO2 slope). However, the exercise response depends on the mode of exercise. This study sought to compare peak treadmill and bicycle exercise responses with respect to their relationship with BNP and to assess whether BNP measured at rest or during exercise could identify patients with greater functional impairment and ventilatory inefficiency.

METHODS

Twenty-three patients with mild-to-moderate stable systolic CHF (age 72+/-8 years, left ventricular ejection fraction 32+/-7%) underwent treadmill and bicycle cardiopulmonary exercise testing within 5 (interquartile range 3-7) days. BNP was measured at rest and at peak exercise.

RESULTS

BNP at rest was an independent multivariate predictor of both peak VO2 and the VE/VCO2 slope for both exercise modes. However, the proportion of variance explained univariately and multivariately was < or = 0.55, indicating that BNP did not strongly explain the variation of peak VO2 and the VE/VCO2 slope. The exercise-induced rise in circulating BNP did not differ between the test modes [treadmill: 50 (24-89) pg/ml vs. bicycle: 46 (15-100) pg/ml; p=0.73]. BNP levels at peak exercise were strongly related to resting values, but did not provide additional information on peak VO2 or the VE/VCO2 slope.

CONCLUSIONS

In typical CHF patients, BNP measured at rest or at peak exercise does not strongly predict peak VO2 or the VE/VCO2 slope regardless of the exercise mode, and is therefore not a sufficiently accurate surrogate for cardiopulmonary exercise testing.

N-terminal pro-brain natriuretic peptide used for the prediction of coronary artery stenosis

BACKGROUND

The level of the inactive N-terminal fragment of pro-brain (B-type) natriuretic peptide (NT-proBNP) is a prognostic marker in patients with acute and chronic coronary artery disease (CAD). It might also be valuable for non-invasive diagnosis of coronary artery disease.

MATERIALS AND METHODS

The NT-proBNP was measured in 781 consecutive patients with normal left ventricular function referred for coronary angiography owing to symptoms or signs of CAD. The diagnostic value of NT-proBNP was assessed for predicting CAD at angiography.

RESULTS

Elevated NT-proBNP levels were associated with the extent of CAD and with the female sex (P < 0.001). The ability of NT-proBNP to predict significant coronary disease at angiography was assessed separately for men using a cut-off point of 85 pg mL(-1), positive likelihood ratio 2.2 (95% CI, 1.7-3.0), negative likelihood ratio 0.53 (95% CI 0.45-0.63) and area under the receiver-operating-characteristic (ROC) curve 0.72: for women, it was assessed using a cut-off point of 165 pg mL(-1), positive likelihood ratio 2.4 (95% CI, 1.7-3.4), negative likelihood ratio 0.55 (95% CI, 0.44-0.70) and area under ROC curve 0.71. In multiple logistic-regression analysis, NT-proBNP added significant independent predictive power to other clinical variables in models predicting CAD (odds ratio 2.76, 95% CI, 1.76-4.32, P < 0.001).

CONCLUSIONS

The NT-proBNP is a marker of non-obstructive CAD and of significant coronary stenosis. In conjunction with other clinical information, measurement of NT-proBNP with the use of sex-specific reference ranges may improve the non-invasive prediction of CAD.

Transient left ventricular "hypertrophy" in a woman with meningoencephalitis

We report the echocardiographic findings in a 27-year-old woman with viral meningoencephalitis and a positive test for cardiac troponin. Initially, the basal parts of the left ventricle were severely hypokinetic, whereas contraction in the mid-ventricle and apex was normal. A second echocardiogram obtained 19 days after the development of pulmonary edema showed a generalized, severe myocardial thickening, the left ventricular ejection fraction being normal. Three months after the initial examination the "hypertrophy" had disappeared. The serial echocardiograms along with a positive cardiac troponin led to the diagnosis of myocarditis, which can very rarely present with the echocardiographic picture of severe left ventricular thickening.

Wavelet-Based Tachycardia Discrimination in ICDs: Impact of Posture and Electrogram Configuration

BACKGROUND

Inappropriate therapy delivery is an important concern in the management of patients with implantable cardioverter defibrillators (ICDs). Recently, a morphology-based algorithm (wavelet feature) has been introduced for differentiation of ventricular and supraventricular tachycardia. In this study, we evaluated the performance of the wavelet algorithm using various electrogram (EGM) configurations during different body positions.

METHODS

Patients with a single-chamber Medtronic model 7230 ICD (Minneapolis, MN, USA) and a double-coil lead were included. EGM templates were collected during baseline rhythm in supine position for different EGM sources (right ventricular [RV] coil-can, RV coil-superior vena cava [SVC] coil, tip-ring, SVC coil-can). For each EGM configuration, morphologic similarity (match percentage) of EGMs obtained during different body positions (supine, left and right lateral, sitting, standing, walking) were compared with the templates.

RESULTS

Twenty-eight patients (24 males; age 58 +/- 17 years) were studied. A total of 9,775 intracardiac EGMs were analyzed. Median match percentage (interquartile range) was 88% (85-94), 88% (82-94), 82% (76-88), and 73 (58-85) for the RV coil-can, RV coil-SVC coil, tip-ring, and SVC coil-can configurations, respectively. Correct classification rates, as defined by match percentage of 70% or higher, were significantly higher with the RV coil-can, RV coil-SVC coil, and tip-ring EGM configurations, as compared to the SVC coil-can configuration (95, 91, and 91 vs 58% > or =70% match percent, P < 0.001).

CONCLUSION

Wavelet-based morphology scores in ICDs may change with various body positions. These variations are relatively minor using the nominal configuration (RV coil-can), as well as by using RV coil-SVC coil and tip-ring. However, morphology scores can vary considerably when SVC coil-can is used; therefore, this configuration should be avoided while using the wavelet algorithm.

Potential interference of small neodymium magnets with cardiac pacemakers and implantable cardioverter-defibrillators

BACKGROUND

Magnetic fields may interfere with the function of cardiac pacemakers and implantable cardioverter-defibrillators (ICDs). Neodymium-iron-boron (NdFeB) magnets, which are small in size but produce strong magnetic fields, have become widely available in recent years. Therefore, NdFeB magnets may be associated with an emerging risk of device interference.

OBJECTIVE

We conducted a clinical study to evaluate the potential of small NdFeB magnets to interfere with cardiac pacemakers and ICDs.

METHODS

The effect of four NdFeB magnets (two spherical magnets 8 and 10 mm in diameter, a necklace made of 45 spherical magnets, and a magnetic name tag) was tested in forty-one ambulatory patients with a pacemaker and 29 patients with an ICD. The maximum distance at which the magnetic switch of a device was influenced was observed.

RESULTS

Magnetic interference was observed in all patients. The maximum distance resulting in device interference was 3 cm. No significant differences were found with respect to device manufacturer and device types.

CONCLUSION

Small NdFeB magnets may cause interference with cardiac pacemakers and ICDs. Patients should be cautioned about the interference risk associated with NdFeB magnets during daily life.

Integration of B-type natriuretic peptide levels with clinical data and exercise testing for predicting coronary artery disease

Natriuretic peptides have been shown to be high in patients with myocardial ischemia. We sought to create a diagnostic score using clinical data, stress testing, and B-type natriuretic peptide (BNP) levels to improve noninvasive prediction of coronary artery disease (CAD). Patients with stable angina pectoris and normal systolic left ventricular function were eligible for this prospective cohort study. Patients with arrhythmias, valvular heart disease, impaired left ventricular function, or renal dysfunction were excluded. All patients underwent clinical evaluation, bicycle stress testing, BNP testing, and coronary angiography. Then a diagnostic risk score was derived that combined cardiovascular risk factors, results of exercise testing, and BNP measurements and added 1 point for the presence of each of these variables. Seventy-one patients (52 years of age, range 31 to 61; 46 men) were included in the study. Prevalence of CAD, defined by 50% narrowing of > or =1 coronary artery on coronary angiography, was 45%. For 0 point in the risk score system, the negative predictive value was 93% with a negative likelihood ratio of 0.1 (95% confidence interval [CI] 0.02 to 0.38); for a score of 3 points, the positive predictive value was 93% with a positive likelihood ratio of 15.9 (95% CI 2.19 to 114.7). Serum BNP level >50 ng/L at rest was the best single diagnostic parameter, with 66% sensitivity and 97% specificity, and a positive likelihood ratio of 25.6 (95% CI 3.64 to 180) and a negative likelihood ratio of 0.35 (95% CI 0.22 to 0.57). In conclusion, a diagnostic score combining exercise testing, clinical data, and serum BNP values at rest can distinguish patients with CAD from those without CAD with high accuracy.

Impact of a lead glass screen on scatter radiation to eyes and hands in interventional cardiologists

The objective of this study was to assess the impact of a transparent lead glass screen (TLGS) on scatter radiation to the eyes and the hands in interventional cardiologists and to compare the results to the recommended annual threshold values of 150 and 500 mSv, respectively. Local radiation doses to the left eye and the ring finger of the left hand of three operators (A, B, C) were assessed by thermoluminiscence dosimeters during 813 coronary angiographies (CAs), including 190 ad hoc percutaneous coronary interventions (PCIs) either with a TLGS placed between patient and operator [615 CAs including 138 ad hoc PCIs; dose-area product (DAP) = 84.9 +/- 71.3 Gy x cm(2)], or without (198 CAs including 52 PCIs; DAP = 85.7 +/- 61.5 Gy x cm(2)). To determine the efficacy of the TLGS, average DAP-normalized local doses were calculated. Using a TLGS, operator A, B, and C performed 259 (in 9 months), 211 (in 8 months), and 145 CAs (in 8 months) with TLGS and acquired cumulative eye lens doses of 5.5, 1.5, and 1.0 mSv corresponding to extrapolated annual doses of 7.3, 2.3, and 1.5 mSv. The cumulative finger doses were 9.6, 10.3, and 6.4 mSv, resulting in extrapolated annual doses of 12.8, 15.5, and 9.6 mSv. Compared to 139 (in 5 months), 36 (in 2 months), and 23 CAs (in 2 months) without TLGS, the use of a TLGS reduced the DAP-normalized eye dose by a factor of 19 (with TLGS 0.153 vs. without TLGS 2.924 microSv/Gy x cm(2)), whereas only a weak effect on the dose to the hands was observed (with TLGS 0.504 vs. without TLGS 0.578 microSv/Gy x cm(2)). The consequent use of a TLGS efficiently reduces scatter radiation to the operator's eyes in daily practice, but has only minimal effects on the dose to the hands.

Aortopulmonary Fistula Occurring 4 Years After Replacement of the Ascending Aorta

A 62-year-old man presenting with congestive heart failure due to a fistula between an aortic pseudoaneurysm and the right pulmonary artery is described. The shunt occurred 4 years after aortic valve and supracoronary graft replacement and was diagnosed by transesophageal contrast echocardiography. After redo surgery the patient made an uneventful recovery.