Pulmonary vein isolation implemented by second-generation cryoballoon for treating hypertrophic cardiomyopathy patients with symptomatic atrial fibrillation:a case-control study

Background Atrial fibrillation(AF)is a generally acknowledged turning-point of the natural history of hypertrophic cardiomyopathy(HCM);however,data from the cryoballoon ablation(CBA)for AF in HCM patients are relatively scarce.The study aimed to evaluate the efficacy and safety of CBA in HCM patients with AF.Methods We retrospectively analyzed HCM patients among 1253 patients with symptomatic AF who underwent CBA for pulmonary vein isolation in a single center.The study analyzed the AF recurrence and assessed the CBA indexes,including nadir temperature,time-to-isolation,CBA failure,pulmonary vein potentials(PVPs),and redo procedure.Results A total of 108 patients were included(mean age:59.0±6.9 years),27 patients(25%)had HCM,with the median follow-up duration of 25.5 months.The one-year AF-free rates were 79.0%vs.63.0%(non-HCM vs.HCM),while the two-year AF-free rates were 77.8%vs.55.1%[hazard ratio(HR)=2.758,log-rank P=0.024].Patients with persistent AF had poor AF-free rates compared to those with paroxysmal AF(P<0.001).The CBA failure was the most common in the right inferior pulmonary veins,which had the lowest PVPs.Multivariate Cox regression analysis indicated that HCM and persistent AF were risk factors for AF recurrence(HR=2.74,95%CI:1.29–5.79,P=0.008;and HR=3.97,95%CI:1.85–8.54,P<0.001,respectively).Conclusions The CBA can be effectively and safely used to treat HCM patients with symptomatic AF.The freedom from AF for HCM patients after CBA is relatively low compared to that for non-HCM patients.

Cryoballoon pulmonary vein isolation and left atrial appendage occlusion prior to atrial septal defect closure: A case report

BACKGROUND In patients who suffer from both atrial fibrillation(AF)and atrial septal defect(ASD),cryoballoon pulmonary vein isolation(PVI),sequential left atrial appendage(LAA)occlusion and ASD closure could be a strategy for effective prevention of stroke and right heart failure.CASE SUMMARY A 65-year-old man was admitted to our institution due to recurrent episodes of palpitations and shortness of breath for 2 years,which had been worsening over the last 48 h.He had a history of AF,ASD,coronary heart disease with stent implantation and diabetes.Physical and laboratory examinations showed no abnormalities.The score of CHA2DS2VASc was 3,and HAS-BLED was 1.Echocardiography revealed a 25-mm secundum ASD.Pulmonary vein(PV)and LAA anatomy were assessed by cardiac computed tomography.PV mapping with 10-pole Lasso catheter was performed following ablation of all four PVs with complete PVI.Following the cryoballoon PVI,the patient underwent LAA occlusion under transesophageal echocardiographic monitoring.Lastly,a 34-mm JIYI ASD occlude device was implanted.A follow-up transesophageal echocardiography at 3 mo showed proper position of both devices and neither thrombi nor leakage was found.CONCLUSION Sequential cryoballoon PVI and LAA occlusion prior to ASD closure can be performed safely in AF patients with ASD.

Paroxysmal atrial fibrillation ablation:Achieving permanent pulmonary vein isolation by point-by-point radiofrequency lesions

Pulmonary vein isolation by point-by-point radiofrequency catheter ablation constitutes the cornerstone of catheter ablation strategies for the treatment of atrial fibrillation. However, despite advances in pulmonary vein isolation ablation strategies, long-term success rates after ablation remain suboptimal, which highlights the need to develop techniques to achieve more durable lesions. Strategies proposed to improve the durability of pulmonary vein isolation can be divided into two groups: Those addressed to improving the quality of the lesion and those that optimize the detection of acute PV reconnection during the ablation procedure. This manuscript reviews the role and potential benefits of these techniques according to current clinical evidence.

Reversal of pulmonary vein remodeling after catheter ablation of atrial fibrillation

Background Pulmonary veins （PV） and the atria undergo electrical and structural remodeling in atrial fibrillation （AF）. This study aimed to determine PV and left atrial （LA） reverse remodeling after catheter ablation for AF assessed by chest computed tomography （CT）. Methods PV electrophysiologic studies and catheter ablation were performed in 63 patients （68% male; mean ± SD age： 56 ± 10 years） with symptomatic AF （49% paroxysmal, 51% persistent）. Chest CT was performed before and 3 months after catheter ablation. Results At baseline, patients with persistent AF had a greater LA volume （91 ±29 cm3 vs. 66 ± 27 cm3; P = 0.003） and mean PV ostial area （241 ＋ 43 mm2 vs. 212 ± 47 mm2; P = 0.03） than patients with paroxysmal AF. There was no significant correlation between the effective refractory period and the area of the left superior PV ostium. At 3 months of follow-up after ablation, 48 patients （76%） were AF free on or off antiarrhythmic drugs. There was a significant reduction in LA volume （77 ±31 cm3 to 70 ± 28 cm3; P 〈 0.001） and mean PV ostial area （224 ± 48 mm2 to 182 ± 43 mm2; P 〈 0.001）. Patients with persistent AF had more reduction in LA volume （11.8 ± 12.8 cm3 vs. 4.0 ± 11.2 cm3; P = 0.04） and PV ostial area （62 mm2 vs. 34 mm2; P = 0.04） than those who have paroxysmal AF. The reduction of the averaged PV ostial area was significantly correlated with the reduction of LA volume （r = 0.38, P = 0.03）. Conclusions Catheter ablation of AF improves structural remodeling ofPV ostia and left atrium. This finding is more apparent in patients with persistent AF treated by catheter ablation.

Epicardial isolation of pulmonary veins with ethanol in open chest dogs

Background Radiofrequency （RF） ablation has become a widely accepted treatment for atrial fibrillation （AF）. This study aimed to identify the efficacy and safety of pulmonary vein （PV） ablation with ethanol and to explore an alternative energy source for catheter ablation of AF. Methods Twelve open-chest mongrel dogs were randomized into ethanol ablation group and control group. Both the injections and electrophysiological mapping procedures were performed epicardialy. In ethanol ablation group （n=-6）, injections were performed to circumferentially ablate the root of each PV （0.2 ml each site, 3 mm apart） with 95% ethanol using an 1 ml injector. In control group （n=6）, saline was injected other than ethanol.

A randomized prospective comparison of CartoMerge and CartoXP to guide circumferential pulmonary vein isolation for the treatment of paroxysmal atrial fibrillation

Background CartoXP and CartoMerge have been used to treat atrial fibrillation （AF） for several years. Our randomized prospective study compared clinical outcomes of these two versions of three dimensional electroanatomic mapping system in guiding catheter ablation for paroxysmal atrial fibrillation （PAF）. Methods Eighty-one patients with symptomatic, drug refractory PAF were randomly assigned to CartoMerge group （n=-42, mean age （54.5 ＋ 13.1） years, history of AF = 3.2 years） or CartoXP group （n=39, mean age （59.8 ± 15.6） years, history of AF = 2.9 years）. All patients underwent 64-slice computed tomography （MSCT） 1 to 3 days prior to ablation procedure. Using CartoMergeTM Image Integration Module, 3D anatomical images of the left atrium （LA） and pulmonary veins （PVS） derived from MSCT of CartoMerge group were established and merged with the electroanatomical map. The integrated images were used to guide the procedure of circumferential pulmonary vein isolation （CPVl）. In the other group, CPVl was guided just by CartoXP. The endpoint of CPVl in both groups was abolition or dissociation of pulmonary vein potentials （PVPs）. Results Mapping points to establish the electroanatomical model of the LA/PVs were 48.7＋13.4 in CartoMerge group and 62.5±15.7 in CartoXP group （P〈0.001）. Mean distance between mapping points and the MSCT surfaces in CartoMerge group was （1.59±0.33） mm. Accomplishment of abolition or dissociation of PVPs was achieved 95.2% in CartoMerge group and 92.3% in CartoXP group. Durations of procedure and exposure to X-ray were （156±25） minutes, （179±21） minutes （P〈0.001） and （19.6±7.5） minutes, （28.5±12.8） minutes （P 〈0.001）, respectively. After a follow-up with duration of （11.9＋3.1） months vs （12.4±3.6） months post the first ablation procedure, patients free of AF were 33 （78.6%） in CartoMerge group and 29 （74.4%） in CartoXP group （P〉0.50）. No patient suffered pulmonary vein stenosis, atenoesophageal fistula, stroke or death. Conclusion Compared to CartoXP, CartoMerge shortened the catheter ablation procedure and exposure to X-ray, without affecting the clinical outcomes of circumferential pulmonary vein isolation for the treatment of paroxysmal atrial fibrillation in experienced centres.

Mechanisms and clinical significance of early recurrences of atrial arrhythmias after catheter ablation for atrial fibrillation

Early recurrence of atrial arrhythmias(ERAA) after ablation is common and strongly predicts late recurrences and ablation failure. However, since arrhythmia may eventually resolve in up to half of patients with ERAA, guidelines do not recommend immediate reintervention for ERAA episodes occurring during a 3-mo postablation blanking period. Certain clinical demographic, electrophysiologic, procedural, and ERAA-related characteristics may predict a higher likelihood of longterm ablation failure. In this review, we aim to discuss potential mechanisms of ERAA, and to summarize the clinical significance, prognostic implications, and treatment options for ERAA.

Initial experience with circumferential pulmonary vein isolation guided~ by Overlay Ref and CartoMerge in the treatment of paroxysmal atrial fibrillation

Background CartoMerge has been widely used in guiding circumferential pulmonary vein isolation （CPVI） for the treatment of paroxysmal atrial fibrillation （PAF）. However, the procedure of landmarks selection varies among operators according to their experience. Techniques have to be established to standardize this procedure. We propose that Overlay Ref could facilitate this procedure. This paper aimed to report our initial experience with CPVI guided by Overlay Ref and CartoMerge for the treatment of PAF. Methods Fifty-nine patients with PAF were enrolled in this study. Using Overlay Ref technique, a reference image （inverted） was faded into the live fluoroscopic image. Landmarks of CartoMerge were selected from anatomic points of the top of superior pulmonary veins （PVs） and the bottom of inferior PVs guided by Overlay Ref image. Overlay Ref images were also used to guide the ablation procedure combining with CartoMerge. Results All patients were successfully mapped by CartoMerge guided by Overlay Ref. The distance between the mapping points and the CT surfaces was （1.42±0.67） mm for the patients as a whole. This led to a successful rate of 96% for isolation of pulmonary veins. Duration of ablation procedure was （92±17） minutes. And the total duration of procedure was （139±32） minutes. CartoMerge could also be performed just with 3 paries to 4 paries selected landmarks guided by Overlay Ref without a full anatomic model constructed by Carto. Then, the total duration of procedure could be shortened to （115±38） minutes. Conclusions Overlay Ref technique can facilitate the catheter ablation of PAF and can help to standardize the procedure of landmarks selection.

Pulmonary vein antrum isolation of pre-excited atrial fibrillation

Background Pulmonary vein antrum isolation （PVAI） of pre-excited atrial fibrillation （AF） is controversial. This study aimed to observe the therapeutic effects of PVAI on pre-excited AF. Methods Twenty-nine patients with pre-excited AF were prospectively divided into a PVAI group （group I, 19 cases） and a control group （group II, 10 cases）. To each case in group I, PVAI was performed, and then electroanatomical mapping of accessory pathways （AP） and ablation were constructed on a three-dimensional （3D） map of the valve annulus. Only AP ablation was performed in each case of group II. Results Of the 29 cases, three were found to have dual APs, two had intermittent APs, and the remaining 24 had single APs. All APs were successfully ablated after the procedure. There were no significant statistical differences in the AP procedure duration （（77.4±21.3） minutes vs. （85.3±13.1） minutes）, the AP ablation time （（204±34） seconds vs. （223±62） seconds） and the AP X-ray exposure time （（18.6±4.4） minutes vs. （19.1±4.5） minutes） respectively between groups I and II. As compared with the control group （5 of 10 cases, 50%）, the PVAI group had a significantly lower AF recurrence rate （2 of 19 cases, 11%; P 〈0.05） during follow-up of （20.5±10.0） months. All seven patients who recurred were successfully abolished by a second ablation. Conclusions In patients with pre-excited AF, PVAI is an effective therapeutic approach with a low AF recurrence rate. 3D electroanatomical maps of AP contributed to the high success rate of ablation without significantly prolonging of operational duration and X-ray exposure time.

Plasma N-terminal pro-Brain natriuretic peptide levels after hybrid therapy with pulmonary vein isolation and amiodarone for atrial fibrillation

Background The purpose of this study was to investigate the effect of hybrid therapy and the relationship between the plasma N-terminal pro-Brain natriuretic peptide （NT-pro BNP） levels and the recurrence rate of the atrial fibrillation （AF） patients underwent pulmonary vein isolation （PVI） with or without amiodarone. Methods There were two groups in this study： control group and hybrid group. In the control group, 54 patients （36 males, 54±13 years） including paroxysmal （PAF） 22, persistent （Pers-AF） 15, and permanent AF （perm-AF） 17, respectively, underwent the PVI procedure only; In the hybrid, 63 AF patients （41 males, 53±12 years） including PAF 24, Pers-AF 18, and perm-AF 21, respectively,underwent the PVI procedure and used amiodarone to enhance the effect of PVI. Blood samples were collected before and 3 months after PVI. NT-pro BNP concentrations were determined by immunoassays. Results In the control group, AF recurred in 29 patients （PAF 5 in 22, Pers-AF 11 in 15, and perm-AF 13 in 17） after the initial PVI procedure; And in the hybrid group, AF recurrred in 20 patiens （PAF 3 in 24, Pers-AF 7 in 18, and perm-Af 11 in 21 ）. The average recurrent rate decreased significantly in the hybrid group （53.7% vs 31.7%, P0.01）. While the NT pro- BNP level （pg/mL） was significantly different between the 2 groups （PAF 294.34±54.4 versus 241.69±17.6 pg/mL, P=0.047; Pers-AF 487.51±47.9 versus 248.76±19.4, P=0.001; Perm-AF 490.91±38.3 versus 300.86±31.8, P=0.032）, While the NT pro- BNP level was also much lower in hybird group than control group in total （263.43±26.1 versus 409.88±49.7, P=0.02）. Conclusions Sinus rhythm（SR）following AF ablation is associated with a dramatic decrease in NT-pro BNP. The hybrid group which had the administration of amiodarone after PVI would significantly decrease the plama NT pro-BNP levels and the recurrent rate of AF.

Study of the Impact of the Patient Rhythm during Cryoballoon Ablation on the Acute Biophysical Parameters

Background: Pulmonary vein isolation by means of cryoballoon is a well-established way of treatment of atrial fibrillation. The aim of the study was to compare the acute cryoballoon biophysical parameters attained during energy applications to the individual pulmonary vein during sinus rhythm versus atrial fibrillation. Methods: 100 Patients who underwent their first-time PVI using second-generation cryoballoon for symptomatic and drug-refractory AF, between the beginning of March to end of August 2016, were initially screened. 61 patients with paroxysmal AF were included in the present study. 39 patients with persistent AF were excluded. No pre-procedural anatomical imaging was reported. Results: A total of 61 patients (male 80%, age 59.3 ± 13.4 years) were included in the present analysis. A total of 243 pulmonary veins were isolated with an average of 1.87 ± 1.14 cryo energy applications per individual vein. During cryo application, there were no significant differences between applications delivered during sinus rhythm or ongoing AF in the rate of temperature drop at 5 and 30 s, rate of warming at 5 s after freezing stop or achieved balloon nadir temperature. The same also was observed for both the balloon cooling rate and warming times. Conclusions: The present analysis shows no impact of the patient baseline rhythm at the time of energy application upon the acute balloon biophysical parameters in patients with normal sinus rhythm and those with ongoing atrial fibrillation using the second-generation cryoballoon.

Comparison of the efficacy and safety of pulmonary vein isolation using cryoballoon versus radiofrequency ablation for paroxysmal atrial fibrillation： An updated metaanalysis

Background Radiofrequency catheter ablation （RFCA） and cryoballoon ablation （CBA） are the two common ablation technologies used for the treatment of paroxysmal atrial fibrillation （PAF）. However, there is no consensus on which ablation method is the optimal choice. Methods We searched PubMed, EMBASE, Cochrane Library, Web of Knowledge and clinical trials.gov for clinically controlled trials （published up to January 11, 2017）. All included studies included fulfilled our previously defined criteria. The primary clinical outcome was the proportion of participants free from atrial fibrillation at 12-months follow-up. ; The secondary clinical outcomes were as the procedure time, fluoroscopy time, and total complications. Results We identified 573 studies, seven randomized controlled trials （RCTs） and 11 non-RCTs were included in this analysis （n=4982 participants）. Compared with RFCA, CBA had similar proportion of participants free from PAF at 12-months follow-up （70.8% vs. 69%; relative risk [RR] ： 1.01; 95% CI： 0.97 to 1.05）. Additionally, procedure time （149.61 vs. 174.73min; weighted mean difference WMD： 25.55; 95% CI： 44.69 to 6.41） was shorter in the CBA group, but the fluoroscopy time （34.52 vs. 38.59 min; WMD： 2.08; 95% CI： 5.86 to 1.71） did not have any significant difference. Total complication was not significantly different in both groups （RR： 1.22; 95% CI： 0.74 to 2.02 ）. Conclusions CBA is similar to RFCA with respect to clinical efficacy for PAF during the follow-up period of 12 months, and with no increased overall safety risk in the cryoballoon group CBA.

Strategies of catheter ablation of persistent atrial fibrillation

Atrial fibrillation （AF） is the commonest type of arrhythmia which is seen as a growing public healthburden affecting patients＇ morbidity and mortality.1 Since the end of last century, catheter ablation has been evolving as the treatment of choice in a particular subset of patients with AF,2＇3 and currently being the most common catheter ablation procedure performed worldwide. Most centers have progressively moved from performing paroxysmal AF to more complex long-standing persistent AF.

Long-term Outcomes after Second-Generation Cryoballoon Ablation of Atrial Fibrillation and Analysis of Risk Factors Related to Recurrence

Objective:This study is aimed to analyze the long-term safety and effectiveness of second-generation cryoballoon(CB2)ablation in the treatment of atrial fibrillation(AF).Methods:Data from 760 consecutive patients in the Department of Cardiology,General Hospital of Northern Theater Command from August 2016 to December 2018 with drug-refractory symptomatic AF undergoing pulmonary vein isolation(PVI)using CB2 were assessed.Procedure-related safety and freedom from AF and atrial flutter/atria tachycardia through 3 years were determined.The risk factors related to atrial tachyarrhythmia recurrence were analyzed.Results:Acute PVI was achieved in 100%of the 760 patients.Radiofrequency application for additional focal ablation was needed in 11(1.4%)patients and for 14 pulmonary veins(0.5%,14/(760×4))to achieve PVI.A total of 748 patients,including 539 with paroxysmal AF(PAF)and 209 with persistent AF(SAF)completed the follow-up,and only 12(1.6%)patients were lost.The mean follow-up duration was(19±8)months.The rate of major complications was 0.9%,including 0.8%of right phrenic nerve injury,which resolved before discharge.Freedom from all tachyarrhythmias was achieved in 75.0%,69.4%,and 63.2%of patients with PAF,respectively,at 12-,24-,and 36-month follow-up,and in 75.1%,67.4%,and 60.9%for SAF,with no significant differences between the PAF and SAF groups.AF course and the rate of body weight gain were independent risk factors for recurrence at 12 months after ablation(P=0.001 and P=0.009,respectively).Conclusion:PVI using CB2 has a high acute success rate and good safety in the treatment of PAF and SAF.Long course of AF and weight gain after ablation were independent risk factors for recurrence.