Catheter Ablation of Atrial Fibrillation Using Zero-Fluoroscopy Technique: A Randomized Trial.

BACKGROUND: Recent advances in 3D mapping systems, such as simultaneous visualization of multiple catheters and contact force measurement, have allowed a significant reduction in fluoroscopic times during radiofrequency (RF) ablation (RFA) procedures. The objective was to investigate whether RFA of paroxysmal atrial fibrillation (PAF) using the CARTO 3 system (Biosense Webster, Diamond Bar, CA, USA) and intracardiac echocardiography (ICE) can be performed safely without fluoroscopy. METHODS AND RESULTS: Eighty patients with PAF were randomized in a 1:1 ratio to undergo either fluoroscopically guided pulmonary vein isolation (PVI) (X+) or PVI without fluoroscopy (X-). In the X- fluoroscopy group, catheter placement, transseptal puncture, left atrial geometry reconstruction, and PVI were accomplished solely using ICE imaging and CARTO mapping. The total procedure duration and RF application time in both the X- and X+ groups were comparable (92.5 ± 22.9 minutes vs 99.9 ± 15.9 minutes, P = 0.11 and 1785 ± 548 seconds vs 1755 ± 450 seconds, P = 0.79, respectively). Zero fluoroscopic time was achieved in all patients in the X- group with the exception of one patient, where 8 seconds of fluoroscopy was needed to assess proper position of the guide-wire in the femoral vein. No serious procedure-related complications were recorded and no differences in arrhythmia-free survival at 12 months were found between the groups. CONCLUSION: RFA using ICE imaging and the CARTO 3 mapping system with contact force measurement is capable of eliminating fluoroscopy in patients undergoing PVI. Exclusion of fluoroscopic imaging does not seem to compromise patient safety and does not affect overall procedure duration, RF application time, or mid-term efficacy.

Sequential Hybrid Surgical CryoMaze and Transvenous Catheter Ablation of Atrial Fibrillation.

BACKGROUND: The aim of the study was to evaluate whether the sequential hybrid approach combining surgical CryoMaze followed by the radiofrequency (RF) catheter ablation can improve freedom from atrial arrhythmias. METHODS: Thirty-five patients with persistent atrial fibrillation underwent a CryoMaze procedure in conjunction with cardiac surgery for structural heart disease. Three months after surgery, all patients underwent a 7-day electrocardiogram Holter followed by an electrophysiological study and mapping of the left and right atria. All pulmonary veins were reisolated and all ablation lines were completed, if necessary, using RF energy. Patients were followed-up at 3 months, 6 months, and 12 months after the catheter ablation. RESULTS: Before the mapping study and RF ablation, nine patients (26%) had ongoing atrial fibrillation or atrial tachycardia, 10 patients (28%) had paroxysmal atrial tachyarrhythmia, and 16 patients (46%) had sinus rhythm on the 7-day Holter monitoring. During the electrophysiological procedure, complete cryoablation lines around the left pulmonary veins were found in 29 patients (83%), around the right pulmonary veins in 25 patients (71%), between the superior veins in 20 patients (57%), between the inferior veins in 27 patients (77%), across the mitral isthmus in 12 patients (34%), and across the cavotricuspid isthmus in one patient (3%). Arrhythmia-free survival rate of antiarrhythmic drugs after reisolation of the veins and completion of the lines was 86% at 12 months. CONCLUSION: Ablation lines created using surgical CryoMaze are often incomplete. Sequential surgical CryoMaze procedures followed by catheter ablation significantly increase freedom from arrhythmia in patients with persistent atrial fibrillation.

Factors influencing psychological status and quality of life in patients with implantable cardioverter-defibrillators.

Various mental and social problems can negatively impact the quality of life and overall health in patients with implantable cardiac defibrillators (ICD). In this report, we review and summarize the main studies and research related to this topic. Depression, anxiety, panic attacks, stress and post-traumatic stress are the most common symptoms of ICD-related disorders that can negatively impact mental status. Factors than can influence the impact of these psychological disorders include socio-demographic variables (younger age, gender, and employment), variables related to the ICD (number of ICD shocks, generator size, time from ICD implant, etc.) and psycho-social variables (negative coping strategies, lack of social support and personality type). Fortunately, these disorders, and their symptoms, can be prevented, treated or managed, if recognized.

Landfill mining in Austria: foundations for an integrated ecological and economic assessment.

For the first time, basic technical and economic studies for landfill mining are being carried out in Austria on the basis of a pilot project. An important goal of these studies is the collection of elementary data as the basis for an integrated ecological and economic assessment of landfill mining projects with regard to their feasibility. For this purpose, economic, ecological, technical, organizational, as well as political and legal influencing factors are identified and extensively studied in the article. An important aspect is the mutual influence of the factors on each other, as this can significantly affect the development of an integrated assessment system. In addition to the influencing factors, the definition of the spatial and temporal system boundaries is crucial for further investigations. Among others, the quality and quantity of recovered waste materials, temporal fluctuations or developments in prices of secondary raw material and fuels attainable in the markets, and time and duration of dumping, play a crucial role. Based on the investigations, the spatial system boundary is defined in as much as all the necessary process steps, from landfill mining, preparing and sorting to providing a marketable material/product by the landfill operator, are taken into account. No general accepted definition can be made for the temporal system boundary because the different time-related influencing factors necessitate an individual project-specific determination and adaptation to the facts of the on-site landfill mining project.

Adenosine plus dipyridamole: a novel strategy to enhance adenosine-induced conduction recovery after pulmonary vein isolation.

AIMS: Intravenous administration of adenosine after a pulmonary vein (PV) isolation procedure can unmask residual, so-called 'dormant', conduction that would otherwise remain unnoticed. Elimination of these dormant potentials is challenging because of the transient effect of adenosine, often requiring repeated injections. We tested the hypothesis that dipyridamole, a drug which inhibits adenosine deamination, can provoke longer-lasting unmasking of dormant conduction. METHODS AND RESULTS: In 191 patients with drug refractory paroxysmal atrial fibrillation, a bolus of 12-24 mg of adenosine was administered after all 764 PVs were isolated. In the case of transient dormant conduction, a short infusion of dipyridamole 50 mg was given and a bolus of adenosine was repeated. In all cases, re-isolation was attempted guided by the activation pattern in the PV on a circular mapping catheter. Duration of adenosine-induced dormant conduction before and after dipyridamole was recorded as the time between administration of adenosine and cessation of dormant conduction either spontaneously or by catheter ablation. Transient dormant conduction was re-established by a single bolus of adenosine in 24 of 191 patients (12.6%). Mean duration of adenosine-induced dormant conduction before dipyridamole was 13.1 ± 6.4 s, whereas it was significantly longer at 218.9 ± 165.6 s after dipyridamole (P < 0.0001). Eighteen of the 24 PVs were re-isolated by catheter ablation before spontaneous cessation of dormant conduction, and in 6 cases dormant conduction disappeared spontaneously before PV re-isolation was achieved. CONCLUSION: Dipyridamole significantly prolongs the effect of adenosine to unmask dormant conduction after PV isolation and may thus facilitate its elimination by catheter ablation.

A new approach to confirming or excluding ventricular pre-excitation on a 12-lead ECG.

AIMS: The purpose of this study was to determine simple features of the standard 12-lead electrocardiogram (ECG) and incorporate them in a stepwise algorithm that would help confirm or exclude the presence of ventricular pre-excitation. METHODS AND RESULTS: We retrospectively analysed multiple variables on pre- and post-ablation ECGs in 238 patients with manifest accessory pathways that had been successfully ablated. A new variable, PR dispersion, was defined as a difference between maximum and minimum PR intervals on a single 12-lead ECG. A logistic regression analysis showed the combination of the following criteria to be powerful in the confirmation of the diagnosis in patients with suspected delta wave: presence of both PR interval < or = 120 ms and PR dispersion > or = 20 ms, absence of initial positive deflection (septal R wave) in lead augmented voltage right arm (aVR), and horizontal QRS transition in lead V1 or before. A stepwise algorithm was developed based on these criteria. Of the total 476 ECGs, seven patients with pre-excitation and one patient with normal ECG were misdiagnosed using the algorithm. Even though the retrospectively determined sensitivity and specificity of the three stepwise criteria were high (97% and 99%, respectively) a prospective study evaluating the algorithm is needed. CONCLUSION: Using a stepwise approach is a very sensitive and specific technique for excluding or confirming ventricular pre-excitation on a 12-lead ECG.

Nurse-performed venous sheath removal in patients undergoing radiofrequency catheter ablation for atrial fibrillation: a randomised study.

BACKGROUND: Catheter ablation procedures have recently become a widely accepted method for treating cardiac arrhythmias, and referrals for these procedures have been steadily increasing. As a result, it is now common that sheath removal is handled as a nursing procedure. Regardless of who performs the sheath removal, it is important to extract ablation sheaths without any early or late complications. OBJECTIVE: The aim of this randomised study was to determine the safety of sheath extraction after heparin reversal with low-dose protamine sulfate in patients undergoing radiofrequency catheter ablation for atrial fibrillation and whether these sheaths can be safely removed by nurses. METHODS: Eighty-one patients were randomly assigned to either receiving protamine to reverse heparin after an ablation ( n=40) or to the standard protocol without heparin reversal ( n=41). Nurse-led sheath removal was done in the cath lab (protamine group) or on the ward (standard group) as soon as activated partial thromboplastin time dropped below 60 s. All adverse events, groin compression time, immobilisation time and procedure characteristics were recorded. RESULTS: The manual compression time for the standard group was significantly longer than for the protamine group (15.9 ± 2.5 vs. 21.9 ± 3.1 minutes, P<0.001) as well as the total immobilisation time (13.2 ± 2.4 vs. 20.3 ± 3.8 hours, P=0.01). Minor groin haematomas occurred less frequently in the protamine group (4 vs. 12, P=0.02) and the haematomas tended to be smaller (4.1 ± 2.1 vs. 5.2 ± 2.5 cm, P=0.09). No serious adverse events were observed when the femoral sheaths were extracted by specially trained staff nurses. CONCLUSION: Fewer and milder complications and shorter immobilisation times were reported with protamine reversal compared to the conventional method. Staff nurses can safely remove femoral venous sheaths after a radiofrequency ablation for atrial fibrillation.

Dynamic coupling between heart rate and ventricular repolarisation.

A novel model for the coupling between ventricular repolarisation and heart rate (QT/RR) is presented. It is based upon a transfer function (TRF) formalism that describes the static and dynamic properties of this coupling, i.e., the behaviour after a sudden change in heart rate. Different TRF models were analysed by comparing their capability to describe experimental data collected from 19 healthy volunteers using several RR stimulation protocols: (i) rest with deep breathing at 0.1 Hz; (ii) tilt with controlled breathing at 0.1 and 0.33 Hz; and (iii) cycling. A search for the best TRF led to unambiguous identification of a three-parameter model as the most suitable descriptor of QT/RR coupling. Compared with established static models (linear or power-law), our model predictions are substantially closer to the experimental results, with errors approximately 50% smaller. The shape of the frequency and step responses of the TRF presented is essentially the same for all subjects and protocols. Moreover, each TRF may be uniquely identified by three parameters obtained from the step response, which are believed to be of physiological relevance: (i) gain for slow RR variability; (ii) gain for fast RR variability; and (iii) time during which QT attains 90% of its steady-state value. The TRF successfully describes the behaviour of the RR control following an abrupt change in RR interval, and its parameters may offer a tool for detecting pharmacologically induced changes, particularly those leading to increased arrhythmogenic risk.

Correlates of Arrhythmia Recurrence After Hybrid Epi- and Endocardial Radiofrequency Ablation for Persistent Atrial Fibrillation.

BACKGROUND: Long-term efficacy of catheter-based treatment of persistent atrial fibrillation is unsatisfactory. Minimally invasive surgical ablation techniques have been developed recently, but their efficacy has never been systematically tested. METHODS AND RESULTS: Seventy patients (median age, 63.5 years) with persistent atrial fibrillation underwent epicardial thoracoscopic radiofrequency pulmonary vein isolation, linear ablation, Marshal ligament disruption, and exclusion of the left atrial appendage. The procedure was followed by electroanatomic mapping and ablation (EAM) 2 to 3 months later. Only 76% of patients were in normal sinus rhythm at the beginning of EAM. All 4 pulmonary veins and the left atrium posterior wall were found isolated in 69% and 23% of patients, respectively. Arrhythmia-free survival off antiarrhythmic drugs 12 months after EAM was 77%. Using previously ineffective antiarrhythmic drugs and reablation procedures, arrhythmia free-survival increased to 97% during follow-up (mean, 936±432 days; range, 346-1509 days). The majority of arrhythmia recurrences occurred during the first 12 months after EAM. In a multivariable-adjusted estimates, left atrium volume >165 mL, absent normal sinus rhythm at admission for EAM, and inducibility of any sustained tachyarrhythmia at the end of EAM procedure were identified as independent correlates of atrial fibrillation recurrence. CONCLUSIONS: Our report demonstrated that the majority of patients after epicardial ablation, using bipolar radiofrequency instruments, required endocardial catheter ablation to complete the linear ablation lesions and a significant proportion of patients required spot-ablations to complete electric pulmonary vein isolation. Noninducibility of any arrhythmia after a staged hybrid procedure seemed to be the strongest correlate of long-term arrhythmia-free survival. CLINICAL TRIAL REGISTRATION: URL: www.ablace.cz. Unique identifier: cz-060520121617.

Sequential Hybrid CryoMaze Ablation versus Surgical CryoMaze Alone for the Treatment of Atrial Fibrillation (SurHyb): study protocol for a randomized controlled trial.

BACKGROUND: Atrial fibrillation is common in patients with structural heart disease who are undergoing cardiac surgery. Surgical CryoMaze has been shown to be an effective treatment in several trials, but success rates have varied considerably, between 47-95 %. The sequential hybrid approach, combining surgical CryoMaze followed by radiofrequency catheter ablation, can achieve high freedom from atrial arrhythmias, even when rigorous methods to detect arrhythmias after the procedure are used. However, data from randomized trials comparing hybrid ablations to surgical ablations alone are lacking. METHODS/DESIGN: The SurHyb study is a prospective, multicenter, randomized study. Patients with persistent or long-standing persistent atrial fibrillation will be randomized to either surgical CryoMaze alone or surgical CryoMaze followed by catheter ablation 3 months post-surgery. The primary outcome measure is arrhythmia-free survival without class I or III antiarrhythmic drugs, which will be evaluated using 7-day ECG Holter monitoring at 24 months. A total of 260 patients will be investigated from three medical centers in the Czech Republic to obtain the relevant information. DISCUSSION: This is the first randomized study that compares surgical CryoMaze alone with the staged hybrid surgical CryoMaze followed by catheter ablation in patients with persistent or long-standing persistent atrial fibrillation. These results will contribute to the optimization of the treatment for these patients. TRIAL REGISTRATION: Czech Clinical Trials Registry, cz-301020151253 . Registered on 30 October 2015.

Sequential hybrid procedure for persistent atrial fibrillation.

BACKGROUND: Catheter ablation of persistent atrial fibrillation yields an unsatisfactorily high number of failures. The hybrid approach has recently emerged as a technique that overcomes the limitations of both surgical and catheter procedures alone. METHODS AND RESULTS: We investigated the sequential (staged) hybrid method, which consists of a surgical thoracoscopic radiofrequency ablation procedure followed by radiofrequency catheter ablation 6 to 8 weeks later using the CARTO 3 mapping system. Fifty consecutive patients (mean age 62±7 years, 32 males) with long-standing persistent atrial fibrillation (41±34 months) and a dilated left atrium (>45 mm) were included and prospectively followed in an unblinded registry. During the electrophysiological part of the study, all 4 pulmonary veins were found to be isolated in 36 (72%) patients and a complete box-lesion was confirmed in 14 (28%) patients. All gaps were successfully re-ablated. Twelve months after the completed hybrid ablation, 47 patients (94%) were in normal sinus rhythm (4 patients with paroxysmal atrial fibrillation required propafenone and 1 patient underwent a redo catheter procedure). The majority of arrhythmias recurred during the first 3 months. Beyond 12 months, there were no arrhythmia recurrences detected. The surgical part of the procedure was complicated by 7 (13.7%) major complications, while no serious adverse events were recorded during the radiofrequency catheter part of the procedure. CONCLUSIONS: The staged hybrid epicardial-endocardial treatment of long-standing persistent atrial fibrillation seems to be extremely effective in maintenance of normal sinus rhythm compared to radiofrequency catheter or surgical ablation alone. Epicardial ablation alone cannot guarantee durable transmural lesions. CLINICAL TRIAL REGISTRATION: URL: www.ablace.cz Unique identifier: cz-060520121617.

A fast and simple echocardiographic method of determination of the optimal atrioventricular delay in patients after biventricular stimulation.

The optimization of atrioventricular (AV) delay is known to significantly contribute to maximum cardiac performance. The aim of this study was to validate a new, fast, and simple echocardiographic method of identifying the AV delay that provides the maximum cardiac output (CO). Right heart catheterization and Doppler echocardiography of transmitral filling were performed simultaneously in 18 patients with heart failure and at least minimum functional mitral regurgitation treated with atrial synchronized biventricular pacing. CO derived from catheterization and Doppler filling parameters were measured at the predicted optimal AV delay (oAVD), the short AV delay (oAVD - 50 ms), and the long AV delay (oAVD + 28 ms on average/range, +10 ms to +50 ms) during a constant heart rate. The AV delay was regarded as optimal if the end of atrial contraction (represented by the end of A wave of transmitral filling) coincided with the beginning of ventricular contraction (heralded by the onset of the systolic component of mitral regurgitation). Prediction of the optimal AV delay included the following steps: (1) The maximum AV delay at which full ventricular capture is still preserved was found under electrocardiographic control. (2) This value, decreased by 5 to 10 ms, was designated as "the testing long AV delay," and the time interval from the end of the A wave to the onset of the systolic component of mitral regurgitation (time t1) was measured at this setting. (3) oAVD was simply calculated as "the testing long AV delay"- time t1. The CO measured at the oAVD (4.5 +/- 0.7 1. min-1) significantly exceeded those at the short AV delay (4.3 +/- 0.7 1. min-1, P < 0.01) and the long AV delay (4.4 +/- 0.8 1. min-1, P < 0.01), respectively. The method correctly determined the maximum CO in 78% of the patients. In conclusion, Doppler echocardiography enables very rapid and accurate optimization of AV synchrony in patients after the implantation of a biventricular pacemaker.