Ripple-AT Study: A Multicenter and Randomized Study Comparing 3D Mapping Techniques During Atrial Tachycardia Ablations.

BACKGROUND: Ripple mapping (RM) is an alternative approach to activation mapping of atrial tachycardia (AT) that avoids electrogram annotation. We tested whether RM is superior to conventional annotation based local activation time (LAT) mapping for AT diagnosis in a randomized and multicenter study. METHODS: Patients with AT were randomized to either RM or LAT mapping using the CARTO3v4 CONFIDENSE system. Operators determined the diagnosis using the assigned 3D mapping arm alone, before being permitted a single confirmatory entrainment manuever if needed. A planned ablation lesion set was defined. The primary end point was AT termination with delivery of the planned ablation lesion set. The inability to terminate AT with this first lesion set, the use of more than one entrainment manuever, or the need to crossover to the other mapping arm was defined as failure to achieve the primary end point. RESULTS: One hundred five patients from 7 centers were recruited with 22 patients excluded due to premature AT termination, noninducibility or left atrial appendage thrombus. Eighty-three patients (pts; RM=42, LAT=41) completed mapping and ablation within the 2 groups of similar characteristics (RM versus LAT: prior ablation or cardiac surgery n=35 [83%] versus n=35 [85%], P=0.80). The primary end point occurred in 38/42 pts (90%) in the RM group and 29/41pts (71%) in the LAT group (P=0.045). This was achieved without any entrainment in 31/42 pts (74%) with RM and 18/41 pts (44%) with LAT (P=0.01). Of those patients who failed to achieve the primary end point, AT termination was achieved in 9/12 pts (75%) in the LAT group following crossover to RM with entrainment, but 0/4 pts (0%) in the RM group crossing over to LAT mapping with entrainment (P=0.04). CONCLUSIONS: RM is superior to LAT mapping on the CARTO3v4 CONFIDENSE system in guiding ablation to terminate AT with the first lesion set and with reduced entrainment to assist diagnosis. CLINICAL TRIALS REGISTRATION: https://www.clinicaltrials.gov. Unique identifier: NCT02451995.

Safety and Long-Term Success of Persistent Atrial Fibrillation Ablation Using THERMOCOOL SMARTTOUCH® Catheter: Real-World Experience.

BACKGROUND: To investigate the real-world clinical experience of persistent atrial fibrillation (persAF) ablation using the THERMOCOOL SMARTTOUCH® catheter with contact force (CF)-sensing ability in a prospective, multicenter registry. METHODS: Patients with persAF (excluding long-standing persAF) undergoing ablation were enrolled. Primary adverse events (AEs), 12-month success, quality of life (QoL), and correlation of success with CF were assessed. RESULTS: Overall, 150 patients with persAF (age 61.6 ± 9.4 years; 76.0% male; 90.7% Caucasian; left ventricular ejection fraction 56.9% ± 10.3%; left atrial diameter 41.5 ± 7.9 mm) underwent catheter insertion (safety cohort); 142 met eligibility criteria and were ablated (evaluable cohort). Confirmation of entrance block for all targeted pulmonary veins was achieved in 99.3% of patients. The primary AE rate was 4.0% (6/150), and 12-month success was 63.1% (95% confidence interval: 54.2%-71.4%). A non-significant trend towards higher success was observed in patients with isoproterenol/adenosine challenge vs. those without (73.1% vs. 60.2%, respectively; P=0.065). Investigators stayed within their pre-selected CF working range (catheter-tissue contact stability) 79.7% ± 12.7% of the time. When investigators stayed within the CF range ≥80% vs. <80% of the time, ablation success was 69.2% vs. 58.5%, respectively (P=0.285). QoL improved significantly at 6 months and was sustained through the 12-month follow-up (P<0.0001). CONCLUSIONS: Symptom control in a real-world setting of persAF ablation using the THERMOCOOL SMARTTOUCH® catheter was 63.1%, with significant improvements in QoL, and trended non-significantly towards increased success in patients receiving isoproterenol/adenosine challenge and when investigators stayed within their pre-selected CF range ≥80% of the time.

Improved outcome and cost effectiveness in ablation of persistent atrial fibrillation under general anaesthetic.

Aims: Outcome of persistent atrial fibrillation (AF) ablation remains suboptimal. Techniques employed to reduce arrhythmia recurrence rate are more likely to be embraced if cost-effectiveness can be demonstrated. A single-centre observational study assessed whether use of general anaesthesia (GA) in persistent AF ablation improved outcome and was cost-effective. Methods and results: Two hundred and ninety two patients undergoing first ablation procedures for persistent AF under conscious sedation or GA were followed. End points were freedom from listing for repeat ablation at 18 months and freedom from recurrence of atrial arrhythmia at 1 year. Freedom from atrial arrhythmia was higher in patients who underwent ablation under GA rather than sedation (63.9% vs. 42.3%, hazard ratio (HR) 1.87, 95% confidence interval (CI): 1.23-2.86, P = 0.002). Significantly fewer GA patients were listed for repeat procedures (29.2% vs. 42.7%, HR 1.62, 95% CI: 1.01-2.60, P = 0.044). Despite GA procedures costing slightly more, a saving of £177 can be made per patient in our centre for a maximum of two procedures if all persistent AF ablations are performed under GA. Conclusions: In patients with persistent AF, it is both clinical and economically more effective to perform ablation under GA rather than sedation.

Palpitations in a 72-year-old woman.

CLINICAL INTRODUCTION: A 72-year-old woman presented with an 8-year history of palpitations occurring every few weeks. They were sudden in onset, were associated with dizziness and could last for up to 2 hours. She was prescribed bisoprolol which reduced the frequency of events but did not abolish them. Baseline ECG and echocardiography were normal. She was referred for electrophysiological study. Despite initial difficulties, diagnostic catheters were placed in the right ventricular (RV) apex and in the coronary sinus (CS) via the right internal jugular vein and superior vena cava (SVC) (figure 1A). A narrow complex tachycardia was easily induced, and ablation was then delivered during tachycardia with the ablation catheter positioned as shown in (figure 1A). This terminated tachycardia 4 s after onset of energy delivery and on follow-up she has remained asymptomatic. She later underwent a CT scan (figure 1B,C; online supplementary video).DC1SP110.1136/heartjnl-2017-311734.supp1Supplementary file 1 heartjnl;103/19/1554/F1F1F1Figure 1(A) Fluoroscopy of catheter placement. (B) Sagittal contrast-enhanced CT image. (C) Axial contrast-enhanced CT. QUESTION: What anatomical abnormality caused difficulty in catheter placement during the procedure?Azygous continuation of the inferior vena cava (IVC)Giant Eustachian valveDextrocardiaRenal tumour compressing IVC.

Cardioverter-defibrillator implantation and generator replacement in the octogenarian.

AIMS: Increase in life expectancy has led to increased rate of implantable cardioverter-defibrillator (ICD) implantation in patients in their 80s, but there are no current formal recommendations to guide physicians when elderly patients with ICDs require elective unit replacement (EUR). This study aims at assessing survival and rates of ICD therapies in patients who have had ICD implantation or EUR above the age of 80, focusing on the latter. METHODS AND RESULTS: Retrospective analysis of a prospectively kept database of all ICD-related procedures carried out in a single tertiary centre. Patients 80 years of age or older submitted to ICD implantation (n = 42) or EUR (n = 34) between November 1991 and May 2012 were included. Using collected baseline and outcome data from this cohort, we assessed survival of these patients and the rates of ICD therapies. Median additional years of life after ICD implantation and ICD EUR in patients who died before data retrieval was 2.5 and 1.2, respectively, and while 65% of deceased patients after ICD implantation died in the first 3 years after the procedure, 50% of deceased post-ICD EUR patients died within the first year. Mortality rates at 1 and 2 years post-EUR were 23.1 and 38.1%, respectively. Furthermore, ventricular tachycardia occurred in a small minority of patients after EUR (16.7%) and no ventricular fibrillation-triggered ICD therapies were reported in both groups. CONCLUSION: In octogenarians who are due for an ICD EUR, careful thought should be given to the current clinical status, comorbidities, and general frailty prior to considering them for the procedure. A survival benefit from ICD EUR in this age stratum is not likely.

Coronary artery spasm and ventricular arrhythmias.

Coronary artery spasm (CAS) is characterised by chest pain at rest and transient ST segment elevation on the ECG. The natural history of variant angina is not fully understood. Patients with CAS are younger, mostly female subjects and usually do not have traditional cardiovascular risk factors other than cigarette smoking. Cardiac arrhythmias are known to be associated with CAS. Ventricular arrhythmia is a well-recognised complication and sudden cardiac death has also been documented. The most important diagnostic tool in CAS is coronary angiography. 24 h ECG Holter monitoring can be very useful in the diagnosis of ventricular arrhythmias caused by CAS. The mainstay therapy for CAS is calcium channel blockers and nitrates. The use of ß-blockers, especially the non-selective group, can promote attacks or prolong vasospastic state. The indication for implantable cardioverter defibrillator (ICD) implantation in a patient with CAS is still not clearly established. The role of primary prevention with the use of ICD is controversial; however, ICD implantation should be considered in high risk patients despite optimal medical treatment.

Comparative reproducibility of dermal microvascular blood flow changes in response to acetylcholine iontophoresis, hyperthermia and reactive hyperaemia.

Laser Doppler fluxmetry (LDF) can non-invasively measure skin microvascular changes in response to acetylcholine (ACh), local heating of the skin and reactive hyperaemia following arterial occlusion. Various studies have used microvascular changes in response to these stimuli, especially ACh iontophoresis and local heating, as a surrogate marker of endothelial function. There are few data in the literature regarding the comparative reproducibility of microvascular perfusion changes induced by the three stimuli. The aim of this study was to systematically assess and compare the reproducibility of skin microcirculatory function in response to each of these challenges. Ten healthy non-smoking subjects (seven males) median age 36 years (range 23-46), with no history of hypertension, diabetes, coronary artery disease or any connective tissue disorder, were studied. Changes in skin microcirculation in response to ACh iontophoresis, local heating of the skin and post-occlusive reactive hyperaemia, on two separate days (median 31, range 11-42 days), were assessed in all subjects. We measured three parameters: the change in perfusion from baseline perfusion (peak minus baseline perfusion), the relative percentage change in perfusion from baseline (peak--baseline)/baseline x 100 (%) and also the time-to-peak perfusion. The reproducibility of the change in perfusion had coefficients of variation (CV) of 9.3% for local skin heating, 19.4% for reactive hyperaemia and 25.5% for ACh iontophoresis. The relative percentage change in perfusion from baseline was more variable with CVs ranging from 23% to 39%. The coefficient of variation of time-to-peak perfusion was 7.0% for heating, 15.1% for reactive hyperaemia and 10.4% for ACh iontophoresis. We have shown that microcirculatory changes measured by the change in perfusion from baseline and time-to-peak perfusion in response to ACh, post-occlusive reactive hyperaemia and local skin heating had good reproducibility when carried out in a controlled environment with a standardized protocol. Relative change in perfusion had relatively poor reproducibility. The change in perfusion and time-to-peak perfusion for local skin heating were the most reproducible overall.