ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias∗∗This document does not cover atrial fibrillation; atrial fibrillation is covered in the ACC/AHA/ESC guidelines on the management of patients with atrial fibrillation found on the ACC, AHA, and ESC Web sites.—executive summary

Thyroid dysfunction in patients with suspected or documented supraventricular tachyarrhythmia

Background and objectives

The association between thyroid dysfunction and supraventricular tachyarrhythmia (SVT) other than atrial fibrillation (AF) is not well elucidated. We hypothesized that patients with suspected or documented SVT have undetected thyroid dysfunction more frequently than general population.

Subjects and methods

Patients with symptoms suggestive of SVT other than AF who were planned to undergo an EP study at our center were eligible for this study. Patients with known thyroid disease, medications affecting thyroid function test (TFT) or atrial fibrillation were excluded. The primary outcome was prevalence of TFT abnormalities in the study population. The secondary outcome was prevalence of clinically significant arrhythmia during the EP study.

Results

A total of 533 patients were analyzed. Patients were divided into the two groups according to TFT results. Fifty-six (10.5%) patients had abnormal TFT results (thyroid dysfunction group), while 477 (89.5%) had normal thyroid function (euthyroidism group). The overall prevalence of thyroid dysfunction was 10.5%. The thyroid dysfunction group showed a tendency for higher induction of clinically significant SVT than the euthyroidism group. However, thyroid dysfunction was not an independent predictor of clinically significant SVT during EP study.

Conclusion

In this study, patients with suspected SVT who were planned for EP study had a relatively high incidence of thyroid dysfunction. Clinically significant arrhythmia tended to be induced more frequently in the thyroid dysfunction group than in the euthyroidism group. Further investigations are needed to verify the clinical implications of TFT in patients with SVT other than AF.

Evolution of the American College of Cardiology and American Heart Association Cardiology Clinical Practice Guidelines: A 10-Year Assessment

Background

The American College of Cardiology and American Heart Association periodically revise clinical practice guidelines. We evaluated changes in the evidence underlying guidelines published over a 10‐year period.

Methods and Results

Thirty‐five American College of Cardiology/American Heart Association guidelines were divided into 2 time periods: 2008 to 2012 and 2013 to 2017. Guidelines were categorized into the following topic areas: arrhythmias, prevention, acute and stable ischemia, heart failure, valvular heart disease, and vascular medicine. Changes in recommendations were assessed for each topic area. American College of Cardiology/American Heart Association designated class of recommendation as level I, II, or III (I represented “strongly recommended”) and levels of evidence (LOE) as A, C, or C (A represented “highest quality”). The median number of recommendations per each topic area was 281 (198–536, interquartile range) in 2008 to 2012 versus 247 (190–451.3, interquartile range) in 2013 to 2017. The median proportion of class of recommendation I was 49.3% and 44.4% in the 2 time periods, 38.0% and 44.5% for class of recommendation II, and 12.5% and 11.2% for class of recommendation III. Median proportions for LOE A were 15.7% and 14.1%, 41.0% and 52.8% for LOE B, and 46.9% and 32.5% for LOE C. The decrease in the proportion of LOE C was highest in heart failure (24.8%), valvular heart disease (22.3%), and arrhythmia (19.2%). An increase in the proportion of LOE B was observed for these same areas: 31.8%, 23.8%, and 19.2%, respectively.

Conclusions

There has been a decrease in American College of Cardiology/American Heart Association guidelines recommendations, driven by removal of recommendations based on lower quality of evidence, although there was no corresponding increase in the highest quality of evidence.

See Editorial Arnett and Claas

An Economic Analysis of the Systematic Use of Mapping Systems during Catheter Ablation Procedures: Single Center Experience

INTRODUCTION

In this study we estimated the cost-effectiveness of adopting 3D Nonfluoroscopic Mapping Systems (NMSs) for catheter ablation (CA).

METHODS

This study includes patients who underwent supraventricular tachycardia (SVT) CA and atrial fibrillation (AF) CA from 2007 to 2016. A comparison was conducted between a reference year (2007) and the respective years for the two types of procedure in which the maximum optimization of patients' exposure using NMSs was obtained. We compared the data of all SVT CA performed solely using fluoroscopy in 2007 (Group I) and all SVT CA procedures performed using fluoroscopy together with an NMS in 2011 (Group II). There was also an important comparison made between AF CA procedures performed in 2007 (Group III) and AF CA in 2012 (Group IV), where patients' treatment in both years included the use of an NMS but where the software and hardware versions of the NMS were different. Two cost-effectiveness analyses were carried out. The first method was based on the alpha value (AV): the AV is a monetary reference value of avoided unit of exposure and is expressed as $/mansievert. The second one was based on the value of a statistical life (VSL): the VSL does not represent the cost value of a person's life, but the amount that a community would be willing to pay to reduce the risk of a person's death. The costs estimated from these two methods were compared to the real additional cost of using an NMS during that type of procedure in our EP Lab.

RESULTS

The use of NMS reduced the effective dose of about 2.3 mSv for SVT and 23.8 mSv for AF CA procedures. The use of NMS, applying directly AV or VSL values, was not cost-effective for SVT CA for the most countries, whereas the use of an NMS during an AF CA seemed to be cost-effective for most of them.

CONCLUSIONS

In our analysis the cost-effectiveness of the systematic use of NMSs strongly depended on the AV and VSL values considered. Nonetheless, the approach seemed to be cost-effective only during AF CA procedures.

High incidence of atrial fibrillation after successful catheter ablation of atrioventricular nodal reentrant tachycardia: a 15.5-year follow-up

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common type of supraventricular tachycardia. Slow pathway (SP) ablation is the treatment of choice with a high acute success rate and a negligible periprocedural risk. However, long-term outcome data are scarce. The aim of this study was to assess long-term outcome and arrhythmia free survival after SP ablation. In this study, 534 consecutive patients with AVNRT, who underwent SP ablation between 1994 and 1999 were included. During a mean follow-up of 15.5 years, 101 (18.9%) patients died unrelated to the procedure or any arrhythmia. Data were collected by completing a questionnaire and/or contacting patients. Clinical information was obtained from 329 patients (61.6%) who constitute the final study cohort. During the electrophysiological study, sustained 1:1 slow AV nodal pathway conduction was eliminated in all patients. Recurrence of AVNRT was documented in 9 patients (2.7%), among those 7 patients underwent a successful repeat ablation procedure. New-onset atrial fibrillation (AF) was documented in 39 patients (11.9%) during follow-up. Pre-existing arterial hypertension (odds ratio 2.61, 95% CI 1.14–5.97, p = 0.023), age (odds ratio 1.05, 95% CI 1.02–1.09, p = 0.003) and the postinterventional AH interval (odds ratio 1.02, 95% CI 1.00–1.04, p = 0.038) predicted the occurrence of AF. The present long-term observational study after successful SP ablation of AVNRT confirms its clinical value reflected by low recurrence and complication rates. The unexpectedly high incidence of new-onset AF (11.9%) may impact long-term follow-up and requires further clinical attention.

Routine Detection of Atrial Fibrillation/Flutter Predicts a Worse Outcome in a Cohort of Tetralogy of Fallot Patients During 23 Years of Follow-Up

Atrial flutter/fibrillation (AFL/AF) is a late complication in adults with repaired tetralogy of Fallot (TOF). Its effects on long-term prognosis are not fully understood. We evaluate the impact of AFL/AF in adults with repaired TOF on global mortality and unplanned hospitalizations during follow-up, and the predictors for AFL/AF occurrence. The presence of AFL/FA was analysed in all exams performed during the last 10 years of outpatients follow up in a unicentric cohort of repaired TOF between 1980 and 2003. Two-hundred and six patients were included; at a mean follow-up of 21 ± 8.2 years, there were 5 deaths (19.2%) in the AFL/AF group and 2 (1.1%) in those without arrhythmia (p < 0.001). Patients with AFL/AF where older at the time of the surgical repair (p < 0.001) and had a higher rate of reinterventions (p = 0.003). No differences were observed between the groups regarding the use of a transannular patch, ventriculotomy and previous palliative shunt. QRS duration was longer in patients with AFL/AF (174 ± 33.4) when compared to those without arrhythmia (147 ± 39.6; p < 0.0001). Age at surgery, QRS duration, and tricuspid regurgitation ≥ moderate were independent risk predictors for AFL/AF. In the multivariate analysis, atrial flutter/fibrillation and QRS duration were predictors of death and hospitalization. AFL/AF is associated with an increased risk of death and hospitalization during the follow-up of patients with repaired TOF. Early detection of AFL/AF and their predictors is an essential step in the evaluation of such population.

Evaluation of myocardial injury induced by different ablation approaches (radiofrequency ablation versus cryoablation) in atrial flutter patients: a meta-analysis

Background: To evaluate myocardial injury in Atrial flutter (AFL) patients undergoing Radiofrequency ablation (RF) and cryoablation (CRYO) treatments.

Methods: We conducted a systematic search on PubMed, Embase, Cochrane Library, and CBM databases. All relevant clinical trials (up to October 2018) on myocardial injury in AFL patients were retrieved and subsequent results analyzed with a random-effects model or a fixed-effects model.

Results: A total of eight clinical trials with a sample size of 644 patients, were identified and incorporated in the present study. The results indicated no significant differences in creatine kinase (CK) levels (mean difference (MD) = 62.74, P=0.46; 4–6 h and MD = 30.73, P=0.49; 12–24 h after ablation), creatine kinase MB(CK-MB) levels (MD = 17.32, P=0.25; 12–24 h post-ablation), troponinI (TnI) levels (MD = 0.12, P=0.08; 6 h after ablation), and troponin T (TnT) levels (MD = 0.30, P=0.08; 4–6 h post-ablation) between the two treatment approaches. However, patients receiving CRYO xhibited higher levels of CK (MD = 179.54, P=0.04; tested immediately after the procedure), CK-MB (MD = 10.08, P=0.004) 4–6 h after ablation, and TnT (MD = 0.19, P=0.002) tested the next morning. Moreover, those patients had a significantly reduced pain perception (odds ratio (OR) = 0.05, P=0.04) compared with those in the RF group.

Conclusion: These results indicate that CRYO in comparison with RF significantly increases myocardial injury in AFL patients. Additionally, it decreases pain perception during the procedure. Further large-sampled studies are needed to support these findings.

Extensive Use of 3D Nonfluoroscopic Mapping Systems for Reducing Radiation Exposure during Catheter Ablation Procedures: An Analysis of 10 Years of Activity

Purpose

3D nonfluoroscopic mapping systems (NMSs) are generally used in the catheter ablation (CA) of complex ventricular and atrial arrhythmias. The aim of this study was to evaluate the efficacy, safety, and long-term effect of the extended, routine use of NMSs for CA.

Methods

Our study involved 1028 patients who underwent CA procedures from 2007 to 2016. Initially, CA procedures were performed mainly with the aid of fluoroscopy. From October 2008, NMSs were used for all procedures.

Results

The median fluoroscopy time of the overall CA procedures fell by 71%: from 29.2 min in 2007 to 8.4 min in 2016. Over the same period, total X-ray exposure decreased by 65%: from 58.18 Gy⁎cm² to 20.19 Gy⁎cm². This reduction was achieved without prolonging the total procedure time. In AF CA procedures, the median fluoroscopy time fell by 85%, with an 86% reduction in total X-ray exposure. In SVT CA procedures, the median fluoroscopy time fell by 93%, with a 92% reduction in total X-ray exposure. At the end of the follow-up period, the estimated probability of disease-free survival was 67.7% at 12 months for AF CA procedures and 97.2% at 3 months for SVT CA, without any statistically significant difference between years.

Conclusions

Our study shows the feasibility of using NMSs as the main imaging modality to guide CA. The extended, routine use of NMSs dramatically reduces radiation exposure, with only slight fluctuations due to the process of acquiring experience on the part of untrained operators, without affecting disease-free survival.

Levels of Evidence Supporting American College of Cardiology/American Heart Association and European Society of Cardiology Guidelines, 2008-2018

Importance

Clinical decisions are ideally based on evidence generated from multiple randomized controlled trials (RCTs) evaluating clinical outcomes, but historically, few clinical guideline recommendations have been based entirely on this type of evidence.

Objective

To determine the class and level of evidence (LOE) supporting current major cardiovascular society guideline recommendations, and changes in LOE over time.

Data Sources

Current American College of Cardiology/American Heart Association (ACC/AHA) and European Society of Cardiology (ESC) clinical guideline documents (2008-2018), as identified on cardiovascular society websites, and immediate predecessors to these guideline documents (1999-2014), as referenced in current guideline documents.

Study Selection

Comprehensive guideline documents including recommendations organized by class and LOE.

Data Extraction and Synthesis

The number of recommendations and the distribution of LOE (A [supported by data from multiple RCTs or a single, large RCT], B [supported by data from observational studies or a single RCT], and C [supported by expert opinion only]) were determined for each guideline document.

Main Outcomes and Measures

The proportion of guideline recommendations supported by evidence from multiple RCTs (LOE A).

Results

Across 26 current ACC/AHA guidelines (2930 recommendations; median, 121 recommendations per guideline [25th-75th percentiles, 76-155]), 248 recommendations (8.5%) were classified as LOE A, 1465 (50.0%) as LOE B, and 1217 (41.5%) as LOE C. The median proportion of LOE A recommendations was 7.9% (25th-75th percentiles, 0.9%-15.2%). Across 25 current ESC guideline documents (3399 recommendations; median, 130 recommendations per guideline [25th-75th percentiles, 111-154]), 484 recommendations (14.2%) were classified as LOE A, 1053 (31.0%) as LOE B, and 1862 (54.8%) as LOE C. When comparing current guidelines with prior versions, the proportion of recommendations that were LOE A did not increase in either ACC/AHA (median, 9.0% [current] vs 11.7% [prior]) or ESC guidelines (median, 15.1% [current] vs 17.6% [prior]).

Conclusions and Relevance

Among recommendations in major cardiovascular society guidelines, only a small percentage were supported by evidence from multiple RCTs or a single, large RCT. This pattern does not appear to have meaningfully improved from 2008 to 2018.

Differential Effectiveness of Landiolol Between Atrial Fibrillation and Atrial Flutter/Atrial Tachycardia Patients With Left Ventricular Dysfunction

BACKGROUND

Landiolol, an ultra-short acting β₁-selective blocker, is more effective for controlling the heart rate (HR) than digoxin in patients with atrial tachyarrhythmias and left ventricular (LV) dysfunction. The impact of the type of atrial tachyarrhythmias on the effectiveness of landiolol is uncertain. We evaluated the efficacy and safety of landiolol on tachycardiac atrial fibrillation (AF) and tachycardiac atrial flutter/atrial tachycardia (AFl/AT) in patients with reduced LV function. Methods and Results: Seventy-seven patients treated with landiolol were retrospectively analyzed. There were no significant differences in the baseline characteristics between the AF group (n=65) and AFl/AT group (n=12). Despite a higher dosage, the %change in HR from baseline to 12 and 24 h was only -10.2±12.7% and -16.1±19.4% in the AFl/AT group, while it was -28.3±13.2% and -31.3±11.3% in the AF group (P<0.02), respectively. The prevalence of the responders to landiolol treatment was much greater in the AF group than in the AFl/AT group (P<0.001). Alternative treatments such as i.v. amiodarone and electrical cardioversion were required in 83% of the AFl/AT patients.

CONCLUSIONS

Landiolol was ineffective in the majority of AFl/AT patients. An alternative management to prevent any worsening of heart failure might be considered in those patients.

Beta-blockers use from the general to the hemodialysis population

Beta-blockers have numerous indications in the general population and are strongly recommended in heart failure, post-myocardial infarction and arrhythmias. In hemodialysis patients, their use is based on weak evidence because of the lack of a sufficient number of randomized clinical trials. The strongest evidence is based on two trials. The first showed better survival with carvedilol in hemodialysis patients with four sessions per week and systolic heart failure. The second found reduced cardiovascular morbidity with atenolol compared to lisinopril in mostly black hypertensive hemodialysis patients. No clinical trials exist regarding myocardial infarction. Large retrospective studies have assessed the benefits of beta-blockers in hemodialysis. A large cohort of hemodialysis patients with new-onset heart failure showed better survival when treated with carvedilol, bisoprolol or metoprolol. Another recent one of 20,064 patients found out that metoprolol compared to carvedilol was associated with less all-cause mortality. There is still uncertainty also regarding the impact of dialysability of beta-blockers on patient's survival. On top of that, many observations suggested that beta-blockers were associated with a reduced rate of sudden cardiac death in hemodialysis patients but recent data show a link between bradycardia and sudden cardiac death questioning the benefit of beta-blockade in this population. Finally, what we know for sure so far is that beta-blockers should be avoided in patients with intradialytic hypotension associated with bradycardia.

Multi-centre Randomised Controlled Trial of a Smartphone-based Event Recorder Alongside Standard Care Versus Standard Care for Patients Presenting to the Emergency Department with Palpitations and Pre-syncope: The IPED (Investigation of Palpitations in the ED) study

BACKGROUND

Patients with palpitations and pre-syncope commonly present to Emergency Departments (EDs) but underlying rhythm diagnosis is often not possible during the initial presentation. This trial compares the symptomatic rhythm detection rate of a smartphone-based event recorder (AliveCor) alongside standard care versus standard care alone, for participants presenting to the ED with palpitations and pre-syncope with no obvious cause evident at initial consultation.

METHODS

Multi-centre open label, randomised controlled trial. Participants ≥ 16 years old presenting to 10 UK hospital EDs were included. Participants were randomised to either (a) intervention group; standard care plus the use of a smartphone-based event recorder or (b) control group; standard care alone. Primary endpoint was symptomatic rhythm detection rate at 90 days. Trial registration number NCT02783898 (ClinicalTrials.gov).

FINDINGS

Two hundred forty-three participants were recruited over an 18-month period. A symptomatic rhythm was detected at 90 days in 69 (n = 124; 55.6%; 95% CI 46.9-64.4%) participants in the intervention group versus 11 (n = 116; 9.5%; 95% CI 4.2-14.8) in the control group (RR 5.9, 95% CI 3.3-10.5; p < 0.0001). Mean time to symptomatic rhythm detection in the intervention group was 9.5 days (SD 16.1, range 0-83) versus 42.9 days (SD 16.0, range 12-66; p < 0.0001) in the control group. The commonest symptomatic rhythms detected were sinus rhythm, sinus tachycardia and ectopic beats. A symptomatic cardiac arrhythmia was detected at 90 days in 11 (n = 124; 8.9%; 95% CI 3.9-13.9%) participants in the intervention group versus 1 (n = 116; 0.9%; 95% CI 0.0-2.5%) in the control group (RR 10.3, 95% CI 1.3-78.5; p = 0.006).

INTERPRETATION

Use of a smartphone-based event recorder increased the number of patients in whom an ECG was captured during symptoms over five-fold to more than 55% at 90 days. This safe, non-invasive and easy to use device should be considered part of on-going care to all patients presenting acutely with unexplained palpitations or pre-syncope.

FUNDING

This study was funded by research awards from Chest, Heart and Stroke Scotland (CHSS) and British Heart Foundation (BHF) which included funding for purchasing the devices. MR was supported by an NHS Research Scotland Career Researcher Clinician award.

Multi-centre randomised controlled trial of a smart phone-based event recorder alongside standard care versus standard care for patients presenting to the Emergency Department with palpitations and pre-syncope - the IPED (Investigation of Palpitations in the ED) study: study protocol for a randomised controlled trial

BACKGROUND

Palpitations and pre-syncope are together responsible for 300,000 annual Emergency Department (ED) attendances in the United Kingdom (UK). Diagnosis of the underlying rhythm is difficult as many patients are fully recovered on ED arrival; and examination and presenting electrocardiogram (ECG) are commonly normal. The only way to establish the underlying heart rhythm is to capture an ECG during symptoms. Recent technology advances have led to several novel ECG monitoring devices appearing on the market. This trial aims to compare the symptomatic rhythm detection rate at 90 days of one such smart phone-based event recorder (AliveCor Heart Monitor and AliveECG) with standard care for participants presenting to the ED with palpitations and pre-syncope and no obvious cause in the ED.

METHODS/DESIGN

This is a multi-centre hospital ED / Acute Medical Unit (AMU) open label, randomised controlled trial. Participants will be recruited in 10 tertiary and district general hospitals in the UK. Participants aged ≥ 16 years presenting with an episode of palpitations or pre-syncope with no obvious cause and whose underlying ECG rhythm during these episodes remains undiagnosed after clinical assessment will be included. Participants will be randomised to either: (1) the intervention arm, standard care plus the use of a smart phone-based event recorder; or (2) the control arm, standard care. Primary endpoint will be symptomatic rhythm detection rate at 90 days. A number of secondary clinical, process and cost-effectiveness endpoints will be collected and analysed. Analysis will be on an intention-to-treat basis.

DISCUSSION

The Investigation of Palpitations in the ED (IPED) study aims to recruit 242 participants across 10 hospital sites. It will be the first study to investigate the ability of a smart phone-based event recorder to detect symptomatic cardiac rhythms compared to standard care for ED patients with palpitations and pre-syncope with no obvious cause in the ED. This smart phone event recorder will allow ED patients who have presented with palpitations or pre-syncope to record their ECG tracing if they have a further episode and may increase the rate of underlying rhythm diagnosis.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02783898 . Registered on 26 May 2016.

An unusual propagation pattern along the tricuspid annulus after cavo-tricuspid isthmus ablation: Insights into posterior transverse conduction revealed by an ultra-high-resolution 3-dimensional mapping system

Cavo-tricuspid isthmus (CTI) ablation is a cornerstone of atrial flutter ablation. The goal of CTI-dependent flutter ablation is achievement of bidirectional CTI block. Usually bidirectional CTI block is confirmed by atrial activation during septal and lateral atrial pacing or the use of differential pacing maneuvers. According to the pathological findings, the transmural muscle fibers connect the endo- and epicardium. An epicardial-endocardial breakthrough (EEB) sometimes interferes with the confirmation of bidirectional block. Recently, a new ultra-high-resolution 3-dimentional mapping systems (Rhythmia^®, Boston Scientific, Marlborough [Cambridge] MA, USA) that allows rapid ultra-high-resolution electroanatomical mapping was introduced. A 64-year-old man with a sustained atrial flutter (AFL) was referred to us. Catheter ablation was performed using an ultra-high-resolution 3-dimensional mapping system. Here, we report the case of a patient with an EEB visualized by ultra-high-resolution 3-dimensional mapping. <Learning objective: The crista terminalis are recognized as the anatomic structure responsible for line of conduction block at the posterior right atrial wall. This block line is mainly functional, and transverse conduction across the posterior wall can be observed. This is the first report to visualize the EEB and examine its influence on the conventional electrophysiological findings.>.

A Cost-Effective Analysis of Systematically Using Mapping Systems During Catheter Ablation Procedures in Children and Teenagers

The aim of this study is to evaluate the cost-effectiveness of an extended use of 3D non-fluoroscopic mapping systems (NMSs) during paediatric catheter ablation (CA) in an adult EP Lab. This study includes 58 consecutive patients (aged between 8 and 18) who underwent CA from March 2005 to February 2015. We compare the fluoroscopy data of two groups: group I, patients who underwent CA from 2005 to 2008 using only fluoroscopy, and group II, patients who underwent CA from 2008 to 2015 performed also using NMSs. Two cost-effectiveness analyses were carried out: the first method was based on the alpha value (AV), and the second one was based on the value of a statistical life (VSL). For both methods, a children's correction factor was also considered. The reduction cost estimated from all these methods was compared to the real additional cost of using NMSs. The use of an NMS during a CA procedure has led to an effective dose reduction (ΔE) of 2.8 milli-Sievert. All presented methods are based on parameters with a wide range of values. The use of an NMS, applying directly AV values or VSL values, is not cost-effective for most countries. Only considering the children's correction factor, the CA procedure using an NMS seems to be cost-effective. The cost-effectiveness of a systematic use of NMSs during CA procedures in children and teenagers remains a challenging task. A positive result depends on which value of AV or VSL is considered and if the children's correction factor is applied or not.

Hospitalization rate of paroxysmal supraventricular tachycardia in Sweden

INTRODUCTION

The hospitalization rate of paroxysmal supraventricular tachycardia (PSVT) in a nationwide study is not established. We determined age- and sex-specific hospitalization rates and time trends for hospitalized PSVT in the Swedish population between 1987 and 2010.

METHODS

This nationwide study is based on the Swedish Hospital Discharge Register. The patients with first PSVT diagnoses between January 1987 and December 2010 were identified.

RESULTS

A total of 42,765 individuals with PSVT were diagnosed (mean age 60 years; 44% males). The overall age- and sex-adjusted hospitalization rate was 20 per 100,000 person-years. The hospitalization rate increased with advancing age with highest hospitalization rates in individuals aged 80-84 years (67.12 per 100,000 person-years) and did not change significantly over time. A total of 20,011 (46.8%) patients had "lone" PSVT without any comorbidities. Lone PSVT patients were younger than PSVT patients with comorbidities (mean age 54 vs. 67 years, p = .0002).

CONCLUSIONS

This study showed a slight preponderance for females and stable hospitalization rate of PSVT over time; the hospitalization rate increased with age. A high proportion of PSVT patients had no comorbidities. They were affected at a younger age than patients with comorbidities, which suggests an inherent predisposition. Key messages This study represents the first extensive and nationwide hospitalization study of PSVT. Hospitalization is highest in old age but a bimodal pattern was observed with a small peak in the first years of life. Patients with lone PSVT are younger than those with comorbidities; which suggests an inherent predisposition.

Wide complex tachycardia discrimination using dynamic time warping of ECG beats

BACKGROUND AND OBJECTIVE

Automatic processing and accurate diagnosis of wide complex tachycardia (WCT) arrhythmia groups using electrocardiogram signals (ECG) remains a challenge. WCT arrhythmia consists of two main groups: ventricular tachycardia (VT) and supraventricular tachycardia with aberrancy (SVT-A). These two groups have similar morphologies in the realm of ECG signals. VT and SVT-A arrhythmias originate from the ventricle and atrium, respectively. Hence, inaccurate diagnosis of SVT-A instead of VT can be fatal.

METHODS

In this paper, we present a novel algorithm using dynamic time warping (DTW) to discriminate between VT and SVT-A arrhythmias. This method includes pre-processing, best template search (BTS), and classifier modules. The first module, pre-processing, is responsible for filtering, R-wave detection, and beat detection of ECG signals. The second module, BTS, automatically extracts the minimum possible number of signals as a template from the entire training dataset using an intelligent algorithm. These template signals have the greatest morphological difference, which leads to accurate WCT discrimination. Finally, a 1NN classifier categorizes the test data using DTW distance.

RESULTS

Our proposed method was evaluated on an ECG signal database consisting of 171 subjects. The results showed that the proposed algorithm can accurately discriminate between VT, SVT-A, and normal subjects, and appears to be suitable for future use in clinical application. The obtained accuracy, sensitivity, specificity, and positive predictive values were 93.22%, 88.68%, 96.98%, and 90.27%, respectively.

CONCLUSION

The presented diagnostic method for discriminating VT and SVT-A, using only one ECG lead, is suitable for future clinical use. It can reduce needless therapeutic interventions and minimize risk for patients.

Perioperative management of patients with pre-excitation syndromes

Patients with pre-excitation abnormalities are at a high risk for life-threatening perioperative arrhythmias. In Wolff-Parkinson-White syndrome, the anaesthetics used for invasive diagnostic testing/ablation, should not affect cardiac electrophysiology; propofol, sevoflurane, fentanyl, sufentanil, alfentanil are suitable. In non-ablative surgery, propofol, sevoflurane, isoflurane, fentanyl, alfentanil, sufentanil have been used safely. Among neuromuscular blockers, cis-atracurium, rocuronium and vecuronium are good choices. Ketamine, pancuronium and pethidine should be avoided because of their sympathomimetic actions. Anticholinergic/ anticholinesterase combinations for neuromuscular block reversal should preferably be omitted, while sugammadex seems more attractive. In regional anaesthesia, addition of epinephrine and high sympathetic blocks should be avoided. Hypotension should be treated with pure alpha-adrenergic agonists. Other pre-excitation abnormalities associated with different accessory pathways are the Mahaim Fiber and Lown-Ganong-Levine syndrome. Sympathetic activation should be avoided. Total intravenous anaesthesia with propofol probably represents the safest option. A careful anaesthetic plan and close cooperation with cardiologists are mandatory for successful management.

Recommendations for the use of electrophysiological study: Update 2018

The field of cardiac electrophysiology has greatly developed during the past decades. Consequently, the use of electrophysiological studies (EPSs) in clinical practice has also significantly augmented, with a progressively increasing number of certified electrophysiology centers and specialists. Since Zipes et al published the Guidelines for Clinical Intracardiac Electrophysiology and Catheter Ablation Procedures in 1995, no official document summarizing current EPS indications has been published. The current paper focuses on summarizing all relevant data of the role of EPS in patients with different types of cardiac pathologies and provides up-to-date recommendations on this topic. For this purpose, the PubMed database was screened for relevant articles in English up to December 2018 and ESC and ACC/AHA Clinical Practice Guidelines, and EHRA/HRS/APHRS position statements related to the current topic were analyzed. Current recommendations for the use of EPS in clinical practice are discussed and presented in 17 distinct cardiac pathologies. A short rationale, evidence, and indications are provided for each cardiac disease/group of diseases. In conclusion, because of its capability to establish a diagnosis in patients with a variety of cardiac pathologies, the EPS remains a useful tool in the evaluation of patients with cardiac arrhythmias and conduction disorders and is capable of establishing indications for cardiac device implantation and guide catheter ablation procedures.

Impairment of the antegrade fast pathway in patients with atrioventricular nodal reentrant tachycardia can be functional and treated by slow pathway ablation: a case report study

Background

Slow pathway (SP) ablation is considered to be the standard treatment for symptomatic atrioventricular nodal reentrant tachycardia (AVNRT). This may be challenging in patients with documented PR interval prolongation due to the potential increased risk of atrioventricular (AV) block in some patients.

Case Summary

We report two cases of symptomatic recurrent AVNRT refractory to medical treatment with significant baseline PR interval prolongation (304 ms and 336 ms). In both of these cases, the baseline electrophysiological study demonstrated dual AV nodal physiology with a functional antegrade fast pathway and evidence for transient normalization of the PR interval. Slow/fast AVNRT was confirmed in both cases. Slow pathway ablation was successfully performed resulting in normalization of the PR interval to 144 ms and 168 ms with no evidence of AV block. After a mean follow-up of 30 months, the patients remained asymptomatic with normal PR interval, no recurrence of AVNRT, and no documentation of high degree AV block.

Discussion

Our cases illustrate a common dilemma when dealing with patients with AVNRT and prolonged baseline interval. We show that SP ablation is feasible and safe as long as a preserved antegrade FP is present.

Hypertension and cardiac arrhythmias: a consensus document from the European Heart Rhythm Association (EHRA) and ESC Council on Hypertension, endorsed by the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS) and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE)

Hypertension is a common cardiovascular risk factor leading to heart failure (HF), coronary artery disease, stroke, peripheral artery disease and chronic renal insufficiency. Hypertensive heart disease can manifest as many cardiac arrhythmias, most commonly being atrial fibrillation (AF). Both supraventricular and ventricular arrhythmias may occur in hypertensive patients, especially in those with left ventricular hypertrophy (LVH) or HF. Also, some of the antihypertensive drugs commonly used to reduce blood pressure, such as thiazide diuretics, may result in electrolyte abnormalities (e.g. hypokalaemia, hypomagnesemia), further contributing to arrhythmias, whereas effective control of blood pressure may prevent the development of the arrhythmias such as AF. In recognizing this close relationship between hypertension and arrhythmias, the European Heart Rhythm Association (EHRA) and the European Society of Cardiology (ESC) Council on Hypertension convened a Task Force, with representation from the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE), with the remit to comprehensively review the available evidence to publish a joint consensus document on hypertension and cardiac arrhythmias, and to provide up-to-date consensus recommendations for use in clinical practice. The ultimate judgment regarding care of a particular patient must be made by the healthcare provider and the patient in light of all of the circumstances presented by that patient.

Additional data from clinical examination on site significantly but marginally improve predictive accuracy of the Revised Trauma Score for major complications during Helicopter Emergency Medical Service missions

INTRODUCTION

The Revised Trauma Score (RTS) accurately identifies trauma patients at high risk of adverse events or death. Less is known about its usefulness in the general population and non-trauma recipients of Helicopter Emergency Medical Service (HEMS). The RTS is a simple tool and omits a lot of other data obtained during clinical evaluation. The aim was to assess the role of the RTS to identify patients at risk of major complications (death, cardiopulmonary resuscitation, defibrillation, intubation) in the general population of HEMS patients. Clinical factors beyond the RTS were analyzed to identify additional prognostic factors for predicting major complications.

MATERIAL AND METHODS

A retrospective analysis of medical records of adult patients routinely collected during HEMS missions in the years 2011-2014 was performed.

RESULTS

The analysis included 19 554 HEMS missions. Patients were 55 ±20 years old and 68% were male. The most common indication for HEMS was diseases of the circulatory system - 41%. Major complications occurred in 2072 (10.6%) cases. In the general population of HEMS patients, the RTS accurately identified individuals at risk of major complications at a cut-off value of 10.5 and area under the curve (AUC) of 93.5%. In multivariate analysis, additional clinical data derived from clinical examination (ECG; skin, pupil and breathing examination) significantly but marginally improved the accuracy of RTS assessment: AUC 95.6% (p < 0.001 for the difference).

CONCLUSIONS

The Revised Trauma Score accurately identifies individuals at risk of major complications during HEMS missions regardless of the indication. Additional clinical data significantly but marginally improved the accuracy of RTS in the general population of HEMS patients.

Outcome of slow pathway modulation for atrioventricular nodal reentrant tachycardia with 50 versus 30 watts-more power, more effect?

PURPOSE

Slow pathway modulation is the treatment of choice in patients with atrioventricular nodal reentrant tachycardia (AVNRT). No comparative data on ablation strategies exist. Therefore, we sought to compare two common ablation approaches.

METHODS

We analyzed prospective ablation databases of two high-volume tertiary centers (> 1000 ablations/year) using either 30 or 50 W for slow pathway modulation from 2012 to 2013. We analyzed procedural characteristics as well as short- and long-term outcomes. Mean follow-up was 36 ± 9 months.

RESULTS

Six hundred thirty-four patients (50 W center: n = 342, 30 W center: n = 292) were ablated. Slow pathway modulation was successful in 99% in both groups (p = ns). Periprocedural AV block occurred in nine patients (2.6%) in the 50 W and five patients (1.7%) in the 30 W group (p = 0.59), respectively. We documented no permanent higher-degree AV block. The number of RF lesions and seconds of RF delivery was significantly less in the 50 W group (p = 0.04 for number of lesions; p < 0.001 for seconds). AVNRT recurrence was similar (p = 0.23). In males, significantly fewer recurrences accrued in the 50 W group (p = 0.04), while in females less transient AV blocks occurred during the procedure with 30 W (p = 0.07).

CONCLUSIONS

The 30 and 50 W target power approaches for slow pathway modulation are highly effective and safe. Significantly, fewer RF duration was necessary to modulate the slow pathway with higher power output (50 W). Our subgroup analysis suggests that males and females might benefit most from different modulation approaches.

Right atrium enlargement predicts clinically significant supraventricular arrhythmia in patients with pulmonary arterial hypertension

BACKGROUND

Right atrial (RA) enlargement is a common finding in patients with pulmonary arterial hypertension (PAH) and an important predictor of mortality, however its relation to the risk of atrial arrhythmias has not been assessed.

OBJECTIVES

To assess whether RA enlargement is associated with supraventricular arrhythmias (SVA) and whether it predicts new clinically significant SVA (csSVA).

METHODS

Patients with PAH were recruited between January 2010 and December 2014 and followed until January 2017. csSVA was diagnosed if it resulted in hospitalization. To assess predictors of new csSVA, only patients without a history of SVA at baseline were analyzed.

RESULTS

Among 97 patients, any SVA was observed in 45 (46.4%) and included permanent atrial fibrillation(AF, n = 8), paroxysmal AF (n = 10), permanent atrial flutter (AFl, n = 1), paroxysmal AFl (n = 2) or other types of supraventricular tachycardia (n = 24). Patients with SVA as compared to patients without SVA were characterized by older age, lower distance in a 6-minute test, higher NT-proBNP, higher RA area index (RAai), left atrial area index, mean right atrial pressure (mRAP) and were more commonly treated with β-blocker. Eighty five patients who were in sinus rhythm at baseline assessment and had no history of significant SVA were observed for 37 ± 19.9 months. During that time csSVA occurred in 15.3%. In univariate models, the occurrence of csSVA were predicted by age, right ventricular ejection fraction, right ventricular end diastolic index, RAai and mRAP, but in multivariate model only RAai remained significant predictor for csSVA (HR of 1.23, 95%CI: 1.11-1.36, p < 0.001). The optimal threshold for RA enlargement as discriminator of csSVA was 21.7 cm2/m2.

CONCLUSIONS

In PAH patients RA enlargement is associated with increased prevalence of SVA. RAai is an independent predictor of hospitalization due to csSVA.

Gemcitabine-Induced Supraventricular Tachycardia

The superior toxicity profile is one of the major reasons for the widespread use of gemcitabine in cancer treatment. Bone marrow suppression is the most common side effect, while non-hematological events are relatively infrequent. Cardiac toxicity is a rare complication and cardiac arrhythmia is even rarer. We report the case of a 67-year-old woman with metastatic breast cancer without a history of cardiac arrhythmia or ischemic heart disease who developed supraventricular tachycardia. The symptoms had started immediately after gemcitabine treatment. The arrhythmia responded poorly to common treatment and was eventually controlled by oral propranolol five days after admission. The present case suggests that supraventricular tachycardia may be triggered by gemcitabine even without underlying significant heart disease and may be resistant to conventional therapy.

Impact of Supraventricular Tachyarrhythmia in Patients With Inherited Cardiac Arrhythmia

Supraventricular tachyarrhythmia (SVT), especially atrial fibrillation (AF), has been observed in patients with inherited cardiac arrhythmia (ICA). Data on the time course of SVT and the occurrence of SVT other than AF is limited. In this study, we examined the prevalence, co-existence, and the time course of different types of SVT in patients with various ICAs. In this retrospective study, we selected 393 patients (median 49 years, range 17 to 87, 57% male) from a cohort of patients visiting the outpatient clinic for cardiogenetic screening of ICA. Patients' medical records were examined for the occurrence of AF and other SVT. AF/SVT was found in 49 patients (12%, 31 male, 42 ± 17 years). Patients presenting with only AF (n = 12, 3%) were older than patients presenting with only SVT (n = 28, 7%), respectively 52 ± 18 versus 37 ± 14, p = 0.007. Nineteen patients (5%) had multiple episodes of either AF (n = 7, 2%) or SVT (n = 12, 3%). Alternating episodes of AF and SVT occurred in 9 patients (2%). Intervals between second and third AF episodes were significantly shorter than between first and second episodes (p = 0.02). An implantable cardioverter defibrillator (ICD) was implanted in 158 patients (40.2%) and 26 patients (16%) had inappropriate ICD shocks (SVT 25, AF 1), particularly those with multiple SVT episodes (p = 0.003). In patients with a variety of ICAs, episodes of AF/SVT occurred in 12%. In patients with multiple AF episodes, intervals between consecutive episodes became significantly shorter over time. AF/SVT episodes are associated with inappropriate ICD shocks and aggressive therapy of AF/SVT is therefore justified.

Occurrence of primarily noninducible atrioventricular nodal reentry tachycardia after radiofrequency delivery in the slow pathway region during empirical slow pathway modulation

BACKGROUND

The first-line therapy for atrioventricular nodal reentry tachycardia (AVNRT) is catheter-based slow pathway modulation. If AVNRT is not inducible during an electrophysiological study, an empirical slow pathway modulation (ESPM) may be considered in patients with dual atrioventricular nodal physiology and/or a typical electrocardiogram (ECG).

METHODS

We screened 149 symptomatic patients who underwent ESPM in our department between 1993 and 2013. All patients fulfilled the following criteria: (1) either dual atrioventricular nodal (AVN) physiology with up to 2 AVN echo beats or characteristic ECG documentation or both, (2) noninducibility of AVNRT by programmed stimulation, and (3) completion of a telephone questionnaire for long-term follow-up. Out of this population we retrospectively investigated 13 patients who were primarily noninducible but in whom an AVNRT occurred during or after radiofrequency (RF) delivery.

RESULTS

When AVNRT occurred, the procedure lost its empirical character, and RF delivery was continued until the procedural endpoint of noninducibility of AVNRT. This endpoint was reached in all but one patient (92%). After a follow-up of 73 ± 15 months, this patient was the only one who reported no benefit from the procedure.

CONCLUSIONS

Out of 149 initially noninducible patients, a considerable number (9%) exhibited AVNRT during or after RF delivery. These patients crossed over from empirical to controlled slow pathway modulation resulting in a good clinical outcome. Our observations should encourage electrophysiologists to repeat programmed stimulation even after initial empirical RF delivery to retest for inducibility.

Prevalence of Cardiac Arrhythmias in Asian Patients With Obstructive Sleep Apnea: A Singapore Sleep Center Experience

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is associated with increased cardiovascular morbidity and mortality. Cardiac arrhythmias are common in patients with OSA. However, the prevalence and significance of cardiac arrhythmias in Asian patients with OSA are not well studied. The aim of this study is to determine the prevalence of cardiac arrhythmias in patients with OSA in Singapore and to evaluate possible factors that may predispose patients with OSA to arrhythmias.

METHODS

A retrospective study of 2,019 patients was carried out from January 2011 to December 2012 at a sleep center in a tertiary medical center. Of the population, 1,457 patients were found to have OSA and 144 patients were found to have cardiac arrhythmias. Data collected included patient demographics, comorbidities, and polysomnogram parameters.

RESULTS

The prevalence of cardiac arrhythmias in our OSA population is 8.0%, compared to that of primary snorers at 4.8% (P = .015). The univariate analysis revealed that older age, higher body mass index, comorbidities, and severity of OSA, including apnea-hypopnea index (AHI), lowest oxygen saturation (LSAT) and hypoxic time were correlated with a higher prevalence of cardiac arrhythmias (P < .05). However, the multivariate analysis showed that only age and body mass index were significantly correlated with arrhythmias. AHI, LSAT, and hypoxic time were no longer statistically significant.

CONCLUSIONS

Our study demonstrated that cardiac arrhythmias are common in patients with OSA in Singapore. It also suggests that given the different demographics of our population, ethnicity may play a significant role in the development of cardiovascular disease among patients with OSA.

COMMENTARY

A commentary on this article appears in this issue on page 1229.

Adenosine versus intravenous calcium channel antagonists for supraventricular tachycardia

BACKGROUND

People with supraventricular tachycardia (SVT) frequently are symptomatic and present to the emergency department for treatment. Although vagal manoeuvres may terminate SVT, they often fail, and subsequently adenosine or calcium channel antagonists (CCAs) are administered. Both are known to be effective, but both have a significant side effect profile. This is an update of a Cochrane review previously published in 2006.

OBJECTIVES

To review all randomised controlled trials (RCTs) that compare effects of adenosine versus CCAs in terminating SVT.

SEARCH METHODS

We identified studies by searching CENTRAL, MEDLINE, Embase, and two trial registers in July 2017. We checked bibliographies of identified studies and applied no language restrictions.

SELECTION CRITERIA

We planned to include all RCTs that compare adenosine versus a CCA for patients of any age presenting with SVT.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane. Two review authors independently checked results of searches to identify relevant studies and resolved differences by discussion with a third review author. At least two review authors independently assessed each included study and extracted study data. We entered extracted data into Review Manager 5. Primary outcomes were rate of reversion to sinus rhythm and major adverse effects of adenosine and CCAs. Secondary outcomes were rate of recurrence, time to reversion, and minor adverse outcomes. We measured outcomes by calculating odds ratios (ORs) and assessed the quality of primary outcomes using the GRADE approach through the GRADEproGDT website.

MAIN RESULTS

We identified two new studies for inclusion in the review update; the review now includes seven trials with 622 participants who presented to an emergency department with SVT. All included studies were RCTs, but only three described the randomisation process, and none had blinded participants, personnel, or outcome assessors to the intervention given. Moderate-quality evidence shows no differences in the number of people reverting to sinus rhythm who were treated with adenosine or CCA (89.7% vs 92.9%; OR 1.51, 95% confidence interval (CI) 0.85 to 2.68; participants = 622; studies = 7; I² = 36%). Low-quality evidence suggests no appreciable differences in major adverse event rates between CCAs and adenosine. Researchers reported only one case of hypotension in the CCA group and none in the adenosine group (0.66% vs 0%; OR 3.09, 95% CI 0.12 to 76.71; participants = 306; studies = 3; I² = 0%). Included trials did not report length of stay in hospital nor patient satisfaction.

AUTHORS' CONCLUSIONS

Moderate-quality evidence shows no differences in effects of adenosine and calcium channel antagonists for treatment of SVT on reverting to sinus rhythm, and low-quality evidence suggests no appreciable differences in the incidence of hypotension. A study comparing patient experiences and prospectively studied adverse events would provide evidence on which treatment is preferable for management of SVT.

Different Implications of Heart Failure, Ischemic Stroke, and Mortality Between Nonvalvular Atrial Fibrillation and Atrial Flutter-a View From a National Cohort Study

BACKGROUND

Atrial flutter (AFL) has been identified to be equivalent to atrial fibrillation (AF) in terms of preventing ischemic stroke, although differences exist in atrial rate, substrate, and electrophysiological mechanisms. This study aimed to investigate differences in clinical outcomes between nonvalvular AF and AFL.

METHODS AND RESULTS

AF and AFL patients without any prescribed anticoagulation were enrolled from a 13-year national cohort database. Under series exclusion criteria, ischemic stroke, heart failure hospitalization, and all-cause mortality were compared between the groups in real-world conditions and after propensity score matching. We identified 175 420 patients in the AF cohort and 6239 patients in the AFL cohort, and the prevalence of most comorbidities and frequency of medications were significantly higher in the AF group than the AFL group. In the real-world setting the AF patients had higher incidence rates of ischemic stroke, heart failure hospitalization, and all-cause mortality than the AFL patients (all P<0.001). After propensity score matching, the incidence rate of ischemic stroke in the AF cohort was 1.63-fold higher than in the AFL cohort (P<0.001), the incidence rate of heart failure hospitalization in the AF cohort was 1.70-fold higher than in the AFL cohort (P<0.001), and the incidence rate of all-cause mortality in the AF cohort was 1.08-fold higher than in the AFL cohort (P=0.002).

CONCLUSIONS

There were differences between AF and AFL in comorbidities and prognosis with regard to ischemic stroke, heart failure hospitalization, and all-cause mortality.

Atrial flutter presenting as broad complex tachycardia in a patient with right sided pneumonectomy

A 71-year-old man with no history of coronary artery disease presented with palpitations to the emergency department. The 12-lead ECG showed a regular tachycardia with wide QRS complexes (220 bpm) suggestive of ventricular tachycardia. Instead invasive electrophysiological investigation revealed typical atrial flutter as underlying arrhythmia. The altered QRS morphology resulted from displacement of the heart into the right hemithorax due to right-sided pneumonectomy in combination with bundle branch block.

Patients' and procedural characteristics of AV-block during slow pathway modulation for AVNRT-single center 10year experience

BACKGROUND

Permanent AV-block is a recognized and feared complication of slow pathway modulation for AVNRT. We aimed to assess incidence of transient and permanent AV-block as well as consequences of transient AV-block in a large contemporary AVNRT ablation cohort.

METHODS

We searched our single center prospective ablation database for occurrence of transient and permanent AV-block during slow pathway modulation between January 2004 and October 2015. We analyzed patients' and procedural characteristics as well as outcome of patients in whom transient or permanent AV-block occurred.

RESULTS

Of 9170 patients who underwent a catheter ablation at our institution between January 2004 and October 2015, 2101 patients (64% women, mean age 50±18years) underwent slow pathway modulation. In three patients, permanent AV-block occurred during RF application. Additional two patients had transient AV-block that recovered (after a few minutes and 25min), but recurred within two days of the procedure. All five patients underwent dual chamber pacemaker implantation (0.2%). Transient AV-block related to RF delivery occurred in 44 patients (2%). Transient mechanical AV-block occurred in additional 17 patients (0.8%). In 12 patients, ablation was continued despite transient AV-block. One of these patients developed permanent AV-block.

CONCLUSION

Permanent AV-block following slow pathway modulation is a rare event, occurring in 0.2% of patients in a large contemporary single center cohort. Transient AV-block is more frequent (2%).

Danon disease for the cardiologist: case report and review of the literature

Danon disease is a rare, X-linked dominant genetic disorder that is caused by defects in the lysosome-associated membrane protein 2 (LAMP2) gene. It manifests predominantly in young males with a classic triad of cardiomyopathy, skeletal myopathy, and intellectual disability. Death from cardiac disease is the ultimate cause of demise in many patients if left untreated. Given the rarity of the condition, the natural history is poorly understood. Here, we present a case report on a 14-year-old Hispanic boy with Danon disease, highlighting major clinical events and diagnostic study findings over a six-year period from age of symptom onset to age of death. He had significant hypertrophic cardiomyopathy (ventricular septal thickness 65 mm) and experienced various arrhythmias during his clinical course including Wolf-Parkinson-White syndrome, non-sustained ventricular tachycardia, and pre-excited atrial fibrillation with a fasciculoventricular anomalous accessory pathway. He had sudden cardiac death from ventricular fibrillation at age 14 and his heart had a weight of 1425 grams at autopsy. We also provide a review of the cardiac Danon disease literature related to diagnostic and management approaches to aid cardiologists in evaluating and treating cardiac manifestations in Danon disease patients.

High Patient Satisfaction with Deep Sedation for Catheter Ablation of Cardiac Arrhythmia

BACKGROUND

Patients' satisfaction with invasive procedures largely relies on periprocedural perception of pain and discomfort. The necessity for intraprocedural sedation during catheter ablation of cardiac arrhythmias for technical reasons is widely accepted, but data on patients' experience of pain and satisfaction with the procedural sedation are scarce. We have assessed patients' pain and discomfort during and after the procedure using a standardized questionnaire.

METHODS

One hundred seventeen patients who underwent catheter ablation answered a standardized questionnaire on periprocedural perception of pain and discomfort after different anesthetic protocols with propofol/midazolam with and without additional piritramide and ketamine/midazolam.

RESULTS

Patients report a high level of satisfaction with periprocedural sedation with 83% judging sedation as good or very good. The majority of patients was unconscious of the whole procedure and did not recollect experiencing pain. Procedural pain was reported by 7.7% of the patients and 16% reported adverse effects, e.g., postprocedural nausea and episodes of headache.

CONCLUSION

The results of our study show that deep sedation during catheter ablation of cardiac arrhythmias is generally well tolerated and patients are satisfied with the procedure. Yet, a number of patients reports pain or adverse events. Therefore, studies comparing different sedation strategies should be conducted in order to optimize sedation and analgesia.

[Emergency treatment of tachycardias]

The treatment of symptomatic tachycardia is a key challenge in intensive care medicine and emergency care. Making a quick and authoritative diagnosis on an ECG and applying adequate emergency treatment requires a structured approach to analyzing and treating arrhythmias. This CME article offers a practical categorization of the multitude of tachycardias, with medical and electrical treatment options and ECG examples. Appropriate first- and second-line treatment options are presented for most common tachyarrhythmias.

Tachycardia-induced cardiomyopathy in pregnancy

Heart failure in pregnancy is rare, but usually ascribed to peripartum cardiomyopathy in the absence of other possible diagnoses. However, heart failure can develop solely due to a tachycardia, so-called 'tachycardia-induced cardiomyopathy'. The incidence of tachycardia-induced cardiomyopathy in pregnancy is unknown, but it is a treatable and potentially reversible cause of heart failure. Clinically, tachycardia-induced cardiomyopathy during pregnancy might present in a similar manner, but its management has to be individualized according to the arrhythmic substrate and usually involve multidisciplinary input from specialists in obstetrics, cardiac electrophysiology and heart failure.

Predictors of Pharmacological Therapy of Ectopic Atrial Tachycardia in Children

Ectopic atrial tachycardia (EAT) is a relatively common type of supraventricular tachycardia in the pediatric population, and it can be resistant to antiarrhythmic drugs and lead to tachycardia-induced cardiomyopathy (TIC) if not properly managed. The purpose of this study was to determine the predictors of the response to pharmacological therapy in children with EAT. From January 2009 to April 2014, 115 children were admitted to our hospital with a diagnosis of EAT and placed on antiarrhythmic drugs. We examined the clinical history, response to therapy, and follow-up of the children. The incidence of TIC secondary to EAT was 22.6% (n = 26) in children. Incessant EAT accounted for 44.3% of all patients. Control of EAT with antiarrhythmic therapy was achieved in 73.9% (n = 85) of the children. The combination of sotalol and propafenone performed well in controlling EAT in children [complete control in 35 (49.3%) of 71]. The mean time of conversion to sinus rhythm was 24 days, and the mean duration of therapy was 11 months in children with resolution. Multivariate predictors of the control of EAT were age at presentation (OR 0.289, P = 0.038) and tachycardia type (OR 0.276, P = 0.006). TIC occurs in 22.6% of children with EAT. Incessant EAT is more frequently complicated by TIC. Independent factors associated with a good response to pharmacological therapy include a younger age at presentation and non-incessant tachycardia in children with EAT.