Validation of novel 3-dimensional electrocardiographic mapping of atrial tachycardias by invasive mapping and ablation: a multicenter study

OBJECTIVES This study prospectively evaluated the role of a novel 3-dimensional, noninvasive, beat-by-beat mapping system, Electrocardiographic Mapping (ECM), in facilitating the diagnosis of atrial tachycardias (AT). BACKGROUND Conventional 12-lead electrocardiogram, a widely used noninvasive tool in clinical arrhythmia practice, has diagnostic limitations. METHODS Various AT (de novo and post-atrial fibrillation ablation) were mapped using ECM followed by standard-of-care electrophysiological mapping and ablation in 52 patients. The ECM consisted of recording body surface electrograms from a 252-electrode-vest placed on the torso combined with computed tomography-scan-based biatrial anatomy (CardioInsight Inc., Cleveland, Ohio). We evaluated the feasibility of this system in defining the mechanism of AT-macro-re-entrant (perimitral, cavotricuspid isthmus-dependent, and roof-dependent circuits) versus centrifugal (focal-source) activation-and the location of arrhythmia in centrifugal AT. The accuracy of the noninvasive diagnosis and detection of ablation targets was evaluated vis-à-vis subsequent invasive mapping and successful ablation. RESULTS Comparison between ECM and electrophysiological diagnosis could be accomplished in 48 patients (48 AT) but was not possible in 4 patients where the AT mechanism changed to another AT (n = 1), atrial fibrillation (n = 1), or sinus rhythm (n = 2) during the electrophysiological procedure. ECM correctly diagnosed AT mechanisms in 44 of 48 (92%) AT: macro-re-entry in 23 of 27; and focal-onset with centrifugal activation in 21 of 21. The region of interest for focal AT perfectly matched in 21 of 21 (100%) AT. The 2:1 ventricular conduction and low-amplitude P waves challenged the diagnosis of 4 of 27 macro-re-entrant (perimitral) AT that can be overcome by injecting atrioventricular node blockers and signal averaging, respectively. CONCLUSIONS This prospective multicenter series shows a high success rate of ECM in accurately diagnosing the mechanism of AT and the location of focal arrhythmia. Intraprocedural use of the system and its application to atrial fibrillation mapping is under way.

Percutaneous management of left atrial appendage perforation during device closure.

A 76-year-old male patient was admitted for percutaneous left atrial appendage (LAA) closure because of chronic atrial fibrillation and a history of gastrointestinal bleeding under oral anticoagulation. The procedure was complicated by perforation of the LAA with the lobe of the closure device being placed in the pericardial space. Keeping access to the pericardial space with the delivery sheath, the LAA closure device was replaced by an atrial septal defect closure device to seal the perforation. Then the initial LAA closure device was reimplanted in a correct position. Needle pericardiocentesis was required but the subsequent course was uneventful.

Clinical role of atrial arrhythmias in patients with arrhythmogenic right ventricular dysplasia

BACKGROUND: The clinical role of atrial fibrillation/atrial flutter (AF-AFl) and variables predicting these arrhythmias are not well defined in patients with arrhythmogenic right ventricular dysplasia (ARVD). We hypothesized that transthoracic echocardiography (TTE) and 12-lead electrocardiography (ECG) would be helpful in predicting AF-AFl in these patients. METHODS AND RESULTS: ECGs and TTEs of 90 patients diagnosed with definite or borderline ARVD (2010 Task Force Criteria) were analyzed. Data were compared in (1) patients with AF-AFl and (2) all other patients. A total of 18 (20%) patients experienced AF-AFl during a median follow-up of 5.8 years (interquartile range 2.0-10.4). Kaplan-Meier analysis revealed reduced times to AF-AFl among patients with echocardiographic RV fractional area change <27% (P<0.001), left atrial diameter ≥24.4 mm/m(2)(parasternal long-axis, P=0.001), and right atrial short-axis diameter ≥22.1 mm/m(2)(apical 4-chamber view, P=0.05). From all ECG variables, P mitrale conferred the highest hazard ratio (3.37, 95% confidence interval 0.92-12.36, P=0.067). Five patients with AF-AFl experienced inappropriate implantable cardioverter-defibrillator (ICD) shocks compared with 4 without AF-AFl (36% vs. 9%, P=0.03). AF-AFl was more prevalent in heart-transplant patients and those who died of cardiac causes (56% vs. 16%, P=0.014). CONCLUSIONS: AF-AFl is associated with inappropriate ICD shocks, heart transplantation, and cardiac death in patients with ARVD. Evidence of reduced RV function and atrial dilation helps to identify the ARVD patients at increased risk for AF-AFl.

Left atrial remodeling, early repolarization pattern, and inflammatory cytokines in professional soccer players

OBJECTIVES: Although regular physical exercise clearly reduces cardiovascular morbidity risk, long-term endurance sports practice has been recognized as a risk factor for atrial fibrillation (AF). However, the mechanisms how endurance sports can lead to AF are not yet clear. The aim of our present study was to investigate the influence of long-term endurance training on vagal tone, atrial size, and inflammatory profile in professional elite soccer players. METHODS: A total of 25 professional major league soccer players (mean age 24+/-4 years) and 20 sedentary controls (mean age 26+/-3 years) were included in the study and consecutively examined. All subjects underwent a sports cardiology check-up with physical examination, electrocardiography, echocardiography, exercise testing on a bicycle ergometer, and laboratory analysis [standard laboratory and cytokine profile: interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, IL-8, IL-10]. RESULTS: Athletes were divided into two groups according to presence or absence of an early repolarization (ER) pattern, defined as a ST-segment elevation at the J-point (STE) >/=0.1mm in 2 leads. Athletes with an ER pattern showed significantly lower heart rate and an increased E/e' ratio compared to athletes without an ER pattern. STE significantly correlated with E/e' ratio as well as with left atrial (LA) volume. The pro-inflammatory cytokines IL-6, IL-8, TNF-alpha as well as the anti-inflammatory cytokine IL-10 were significantly elevated in all soccer players. However, athletes with an ER pattern had significantly higher IL-6 plasma levels than athletes without ER pattern. Furthermore, athletes with "high" level IL-6 had significantly larger LA volumes than players with "low" level IL-6. CONCLUSIONS: Athletes with an ER pattern had significantly higher E/e' ratios, reflecting higher atrial filling pressures, higher LA volume, and higher IL-6 plasma levels. All these factors may contribute to atrial remodeling over time and thus increase the risk of AF in long-term endurance sports.

Epicardial phrenic nerve displacement during catheter ablation of atrial and ventricular arrhythmias: procedural experience and outcomes.

BACKGROUND Arrhythmia origin in close proximity to the phrenic nerve (PN) can hinder successful catheter ablation. We describe our approach with epicardial PN displacement in such instances. METHODS AND RESULTS PN displacement via percutaneous pericardial access was attempted in 13 patients (age 49±16 years, 9 females) with either atrial tachycardia (6 patients) or atrial fibrillation triggered from a superior vena cava focus (1 patient) adjacent to the right PN or epicardial ventricular tachycardia origin adjacent to the left PN (6 patients). An epicardially placed steerable sheath/4 mm-catheter combination (5 patients) or a vascular or an esophageal balloon (8 patients) was ultimately successful. Balloon placement was often difficult requiring manipulation via a steerable sheath. In 2 ventricular tachycardia cases, absence of PN capture was achieved only once the balloon was directly over the ablation catheter. In 3 atrial tachycardia patients, PN displacement was not possible with a balloon; however, a steerable sheath/catheter combination was ultimately successful. PN displacement allowed acute abolishment of all targeted arrhythmias. No PN injury occurred acutely or in follow up. Two patients developed acute complications (pleuro-pericardial fistula 1 and pericardial bleeding 1). Survival free of target arrhythmia was achieved in all atrial tachycardia patients; however, a nontargeted ventricular tachycardia recurred in 1 patient at a median of 13 months' follow up. CONCLUSIONS Arrhythmias originating in close proximity to the PN can be targeted successfully with PN displacement with an epicardially placed steerable sheath/catheter combination, or balloon, but this strategy can be difficult to implement. Better tools for phrenic nerve protection are desirable.

Electrophysiologic assessment of conduction abnormalities and atrial arrhythmias associated with amyloid cardiomyopathy.

BACKGROUND Arrhythmias in cardiac amyloidosis (CA) result in significant comorbidity and mortality but have not been well characterized. OBJECTIVE The purpose of this study was to define intracardiac conduction, atrial arrhythmia substrate, and ablation outcomes in a group of advanced CA patients referred for electrophysiologic study. METHODS Electrophysiologic study with or without catheter ablation was performed in 18 CA patients. Findings and catheter ablation outcomes were compared to age- and gender-matched non-CA patients undergoing catheter ablation of persistent atrial fibrillation (AF). RESULTS Supraventricular tachycardias were seen in all 18 CA patients (1 AV nodal reentrant tachycardia, 17 persistent atrial tachycardia [AT]/AF). The HV interval was prolonged (>55 ms) in all CA patients, including 6 with normal QRS duration (≤100 ms). Thirteen supraventricular tachycardia ablations were performed in 11 patients. Of these, 7 underwent left atrial (LA) mapping and ablation for persistent AT/AF. Compared to non-CA age-matched comparator AF patients, CA patients had more extensive areas of low-voltage areas LA (63% ± 22% vs 34% ± 22%, P = .009) and a greater number of inducible ATs (3.3 ± 1.9 ATs vs 0.2 ± 0.4 ATs, P <.001). The recurrence rate for AT/AF 1 year after ablation was greater in CA patients (83% vs 25%), and the hazard ratio for postablation AT/AF recurrence in CA patients was 5.4 (95% confidence interval 1.9-35.5, P = .007). CONCLUSION In this group of patients with advanced CA and atrial arrhythmias, there was extensive conduction system disease and LA endocardial voltage abnormality. Catheter ablation persistent AT/AF in advanced CA was associated with a high recurrence rate and appears to have a limited role in control of these arrhythmias.

miRNAS circulantes como biomarcadores para fibrilação atrial aguda

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Some non-coding RNAs (miRNAs) have been involved in regulatory activity in arrhythmogenesis, targeting genes that contribute to the development of AF. The present study aimed to evaluate the expression of candidate miRNAs in plasma from patients with AF and new-onset AF and its application as future markers for diagnosis and monitoring of disease. miR-21, miR-133a, miR-133b, miR-150, miR-328 and miR-499 were selected as targets in this study through a prior literature review. They were isolated from plas-ma of individuals aged from 20 to 85 years old with AF (n = 17), new-onset AF (n = 5) and without AF (n = 15), where the latter was the control group. The results were ana-lyzed by Real-Time PCR (RT-PCR) with miScript SYBR Green PCR. We observed that miR-21, miR-133b, miR-328 and miR-499 had different levels of expression be-tween the three groups (p <0.05). Increased expression of miR-21 (0.6-fold), miR-133b (1.4-fold), miR-328 (2.0-fold) and miR-499 (2.3-fold) in patients with new-onset AF when compared to AF and control subjects. The miR-133a and miR-150 expression did not differ among the groups. miR-21, miR-133b, miR-328 and miR-499 may be potential biomarkers for AF as well as for new-onset AF, for monitoring and for the di-agnosis. These findings may contribute to the understanding of the process that trig-gers AF and suggest application these molecules as future biomarkers for AF.

miRNAS circulantes como biomarcadores para fibrilação atrial aguda

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Some non-coding RNAs (miRNAs) have been involved in regulatory activity in arrhythmogenesis, targeting genes that contribute to the development of AF. The present study aimed to evaluate the expression of candidate miRNAs in plasma from patients with AF and new-onset AF and its application as future markers for diagnosis and monitoring of disease. miR-21, miR-133a, miR-133b, miR-150, miR-328 and miR-499 were selected as targets in this study through a prior literature review. They were isolated from plas-ma of individuals aged from 20 to 85 years old with AF (n = 17), new-onset AF (n = 5) and without AF (n = 15), where the latter was the control group. The results were ana-lyzed by Real-Time PCR (RT-PCR) with miScript SYBR Green PCR. We observed that miR-21, miR-133b, miR-328 and miR-499 had different levels of expression be-tween the three groups (p <0.05). Increased expression of miR-21 (0.6-fold), miR-133b (1.4-fold), miR-328 (2.0-fold) and miR-499 (2.3-fold) in patients with new-onset AF when compared to AF and control subjects. The miR-133a and miR-150 expression did not differ among the groups. miR-21, miR-133b, miR-328 and miR-499 may be potential biomarkers for AF as well as for new-onset AF, for monitoring and for the di-agnosis. These findings may contribute to the understanding of the process that trig-gers AF and suggest application these molecules as future biomarkers for AF.

Two-year clinical outcome from the Iberian registry patients after left atrial appendage closure

AIMS: The aim of this study was to observe the percentage of thromboembolic and haemorrhagic events over a 2-year follow-up in patients with non-valvular atrial fibrillation (NVAF) undergoing closure of the left atrial appendage (LAA) with an occlusion device. Observed events and CHADS2 (congestive heart failure, hypertension, age, diabetes, stroke history), CHA2DS2-VASc (also adding: vascular disease and sex) and HAS-BLED (hypertension, abnormal liver/renal function, stroke history, bleeding predisposition, labile international normalised ratios, elderly, drugs/alcohol use)-predicted events were compared. METHODS: LAA closure with an occlusion device was performed in 167 NVAF patients contraindicated for oral anticoagulants and recruited from 12 hospitals between 2009 and 2013. At least two transoesophageal echocardiograms were performed in the first 6 months postimplantation. Antithrombotics included clopidogrel and aspirin. Patients were monitored for death, stroke, major and relevant bleeding and hospitalisation for concomitant conditions. Mean age was 74.68±8.58, median follow-up was 24 months, 5.38% had intraoperative complications and implantation was successful in 94.6% of subjects. Mortality during follow-up was 10.8%, mostly (9.5%) non-cardiac related. Bleeding occurred in 10.1% of subjects, 5.7% major and 4.4% minor though relevant, and 4.4% suffered stroke. Major bleeding and stroke/transient ischaemic attack events within 2 years (annual event rates, 290 patients/year) were less frequent than expected from CHADS2 (2.4% vs 9.6%), CHA2DS2-VASc (2.4% vs 8.3%) and HAS-BLED (3.1% vs 6.6%) risk scores (p<0.001, p=0.003, p=0.047, respectively). CONCLUSIONS: LAA closure with an occlusion device in patients contraindicated for oral anticoagulants is a therapeutic option associated with fewer thromboembolic and haemorrhagic events than expected from risk scores, particularly in the second year postimplantation.

Interatrial block and atrial arrhythmias in centenarians: Prevalence, associations, and clinical implications

Data are lacking on the characteristics of atrial activity in centenarians, including interatrial block (IAB). The aim of this study was to describe the prevalence of IAB and auricular arrhythmias in subjects older than 100 years and to elucidate their clinical implications. We studied 80 centenarians (mean age 101.4 ± 1.5 years; 21 men) with follow-ups of 6–34 months. Of these 80 centenarians, 71 subjects (88.8%) underwent echocardiography. The control group comprised 269 septuagenarians. A total of 23 subjects (28.8%) had normal P wave, 16 (20%) had partial IAB, 21 (26%) had advanced IAB, and 20 (25.0%) had atrial fibrillation/flutter. The IAB groups exhibited premature atrial beats more frequently than did the normal P wave group (35.1% vs 17.4%; P < .001); also, other measurements in the IAB groups frequently fell between values observed in the normal P wave and the atrial fibrillation/flutter groups. These measurements included sex preponderance, mental status and dementia, perceived health status, significant mitral regurgitation, and mortality. The IAB group had a higher previous stroke rate (24.3%) than did other groups. Compared with septuagenarians, centenarians less frequently presented a normal P wave (28.8% vs 53.5%) and more frequently presented advanced IAB (26.3% vs 8.2%), atrial fibrillation/flutter (25.0% vs 10.0%), and premature atrial beats (28.3 vs 7.0%) (P < .01). Relatively few centenarians (<30%) had a normal P wave, and nearly half had IAB. Our data suggested that IAB, particularly advanced IAB, is a pre–atrial fibrillation condition associated with premature atrial beats. Atrial arrhythmias and IAB occurred more frequently in centenarians than in septuagenarians.

Left atrial anatomy relevant to catheter ablation

The rapid development of interventional procedures for the treatment of arrhythmias in humans, especially the use of catheter ablation techniques, has renewed interest in cardiac anatomy. Although the substrates of atrial fibrillation (AF), its initiation and maintenance, remain to be fully elucidated, catheter ablation in the left atrium (LA) has become a common therapeutic option for patients with this arrhythmia. Using ablation catheters, various isolation lines and focal targets are created, the majority of which are based on gross anatomical, electroanatomical, and myoarchitectual patterns of the left atrial wall. Our aim was therefore to review the gross morphological and architectural features of the LA and their relations to extracardiac structures. The latter have also become relevant because extracardiac complications of AF ablation can occur, due to injuries to the phrenic and vagal plexus nerves, adjacent coronary arteries, or the esophageal wall causing devastating consequences.

Caveat Anicula! Beware of the Quiet Little Old Ladies : Demographics, Pharmacotherapy, Survival and Readmissions in a 10 Year Cohort of Heart Failure Patients with Preserved Systolic Function

Objective--To determine whether heart failure with preserved systolic function (HFPSF) has different natural history from left ventricular systolic dysfunction (LVSD). Design and setting--A retrospective analysis of 10 years of data (for patients admitted between 1 July 1994 and 30 June 2004, and with a study census date of 30 June 2005) routinely collected as part of clinical practice in a large tertiary referral hospital.Main outcome measures-- Sociodemographic characteristics, diagnostic features, comorbid conditions, pharmacotherapies, readmission rates and survival.Results--Of the 2961 patients admitted with chronic heart failure, 753 had echocardiograms available for this analysis. Of these, 189 (25%) had normal left ventricular size and systolic function. In comparison to patients with LVSD, those with HFPSF were more often female (62.4% v 38.5%; P = 0.001), had less social support, and were more likely to live in nursing homes (17.9% v 7.6%; P < 0.001), and had a greater prevalence of renal impairment (86.7% v 6.2%; P = 0.004), anaemia (34.3% v 6.3%; P = 0.013) and atrial fibrillation (51.3% v 47.1%; P = 0.008), but significantly less ischaemic heart disease (53.4% v 81.2%; P = 0.001). Patients with HFPSF were less likely to be prescribed an angiotensin-converting enzyme inhibitor (61.9% v 72.5%; P = 0.008); carvedilol was used more frequently in LVSD (1.5% v 8.8%; P < 0.001). Readmission rates were higher in the HFPSF group (median, 2 v 1.5 admissions; P = 0.032), particularly for malignancy (4.2% v 1.8%; P < 0.001) and anaemia (3.9% v 2.3%; P < 0.001). Both groups had the same poor survival rate (P = 0.912). Conclusions--Patients with HFPSF were predominantly older women with less social support and higher readmission rates for associated comorbid illnesses. We therefore propose that reduced survival in HFPSF may relate more to comorbid conditions than suboptimal cardiac management.

Do anti-inflammatory agents promote linear ablation lesion discontinuities? : an electrophysiological examination

Background: Catheter ablation for atrial fibrillation (AF) is more efficacious than antiarrhythmic therapy. Post ablation recurrences reduce ablation effectiveness and are contributed by lesion discontinuity in the fibrotic linear ablation lesions. The anti-fibrotic role of statins in reducing AF is being assessed in current trials. By reducing the chronic pathological fibrosis that occurs in AF they may reduce AF. However if statins also have an effect on the acute therapeutic fibrosis of an ablation, this could exacerbate lesion discontinuity and AF recurrence. We tested the hypothesis that statins attenuate ablation lesion continuity in a recognised pig atrial linear ablation model. Aims: To assess whether Atorvastatin diminishes the bi-directional conduction block produced by a linear atrial ablation lesion. Methods: Sixteen pigs were randomised to statin (n=8) or placebo (n=8) with drug pre-treatment for 3 days and a further 4 weeks. At initial electrophysiological study (EPS1) 3D right atrium (RA) mapping and a vertical ablation linear lesion in the posterior RA with bidirectional conduction block were completed (Gepstein Circ 1999). Follow-up electrophysiological assessment (EPS2) at 28 days assessed bidirectional conduction block maintenance. Results: Data of 15/16 (statin=7) pigs were analysed. Mean lesion length was 3.7 ± 0.8cm with a mean of 17.9 ± 5.7 lesion applications. Bi-directional conduction block was confirmed in 15/15 pigs (100%) at EPS1 and EPS2. Conclusions: Atorvastatin did not affect ablation lesion continuity in this pig atrial linear ablation model. If patients are on long-term statins for AF reduction, periablation cessation is probably not necessary.

Rates of attendance at a smoking cessation clinic within a cardiac rehabilitation service

Objectives: Smoking cessation has been shown to be an important intervention for preventing cardiovascular events and improving the health of patients with heart disease. However, unaided quit attempts in these patients often leads to high rates of failure and a return to smoking. Outpatient smoking cessation clinics using face-to-face counseling, ongoing behavioral support, advice on smoking pharmacotherapy and objective monitoring, have been found to be one of the most effective interventions for improving quit smoking rates. An outpatient smoking cessation clinic was trialed within a cardiac rehabilitation service in order to explore its effects on smoking rates for patients with or at risk of heart disease. Attendance rates to the clinic were also monitored. Methods: A descriptive exploratory design was used for this newly developed clinic. Patients who currently smoked tobacco and who had a history of either coronary artery disease, heart failure, atrial fibrillation or those seen under a chest pain assessment service were invited to an outpatient ‘Cardiac Patients Smokers Clinic’. Initially patients were offered up to 10 clinic visits over a 3 month period. Follow-up clinic visits were conducted at 3, 6 and 12 months. A portable carbon monoxide meter was used to objectively measure levels of smoking and validate smoking abstinence. Primary outcomes included rates of attendance. Results: Preliminary findings showed 24 per cent of participants (N = 6) completed all their clinic visits and remained smoke free as measured by their ongoing expired carbon monoxide readings. Clinic attendance rates appeared lowest for those with significant mental health issues such as schizophrenia or substance abuse. However, rates of attendance were improved by having an administration officer make reminder telephone calls prior to clinic visits. Conclusions: Early findings indicate the feasibility of providing a specialist smoking cessation clinic within a cardiac rehabilitation service. Further, that reminder telephone calls prior to appointments improved attendance rates in patients with heart disease to this type of clinic. However, future investigations are warranted.