Feasibility of radiofrequency ablation for cancer patients with atrial fibrillation / 中华心血管病杂志

Objective: To analyze the impact of cancer on the recurrence rate of atrial fibrillation (AF) after AF radiofrequency ablation and further evaluate the feasibility of radiofrequency ablation therapy in cancer patients with AF. Methods: This study was a single-center, retrospective study. Cancer patients with AF undergoing radiofrequency ablation for the first time in the First Affiliated Hospital of Dalian Medical University from May 30, 2008 to September 30, 2018 were included (cancer group). AF patients without cancer undergoing radiofrequency ablation for the first time during the same period served as non-cancer group. Clinical data including age, gender, past history, cancer and AF-related parameters, etc. were analyzed. Patients were followed up after radiofrequency ablation. The primary endpoints were AF recurrence or all-cause death. Kaplan-Meier survival analysis was used to analyze the effect of cancers on the recurrence after AF ablation. The multivariate cox regression analysis was further applied to correct for other confounding factors to analyze whether the impact of cancers on the recurrence of atrial fibrillation was statistically significant. Results: A total of 90 patients were enrolled, there were 30 patients in the cancer group (mean age (64.8±6.6) years, 16 (53.3%) males) and 60 patients in the non-cancer group (mean age (63.6±6.2) years, 32 (53.3%) males). Clinical data, such as age, gender, and cancer treatment, were similar between the two groups. During an average follow-up period of (328.7±110.2) days, there were 6 AF recurrences (recurrence rate 20.0%) in the cancer group, and 17 AF recurrences (recurrence rate 28.3%) in the control group. AF recurrence rate was similar between the two groups (P>0.05). During the follow-up period, there was no all-cause death in the two groups. Kaplan-Meier survival analysis showed that cancer was not related to AF recurrence after radiofrequency ablation (P = 0.383). After adjusting for other confounding factors, the multivariate Cox regression analysis showed that cancer was not an independent predictor of AF recurrence after radiofrequency ablation (HR=0.508, 95%CI: 0.192-1.342, P = 0.172). Conclusions: The combination of cancer has no impact on the recurrence of AF after radiofrequency ablation. For cancer patients with AF, radiofrequency ablation therapy can be considered as a feasible heart rhythm control treatment strategy.

Alterations in the transmural gradient of ventricular repolarization with different pacing sites in normal and heart failure canines / 生理学报

Alterations of the transmural gradient of repolarization may contribute to the increase of transmural dispersion of repolarization and ventricular arrhythmias. The transmural gradient of repolarization may play an important role in sudden death associated with left ventricular epicardial pacing. To investigate the changes of transmural gradient dispersion of ventricular repolarization with different pacing sites in heart failure (HF) canines, 8 mongrel dogs were randomized into healthy group and HF group (n = 4). We mapped the monophasic action potential duration (MAPD) in the subendocardial, subepicardial and mid-myocardial layers of the left ventricle (LV) in canines of healthy and HF groups during right atrium (RA) pacing, right ventricular apical endocardial (RV) pacing, left ventricular lateral epicardial (LV) pacing and biventricular (Biv) pacing respectively. The results showed that in the healthy group, the MAPDs were significantly different among the three layers during RA pacing (all P 0.05). In the HF group, the MAPDs in all three layers were prolonged compared with those in the same locations in the healthy group (all P 0.05). By MAP recording with our new mapping electrode, we found a transmural MAPD gradient among the three layers of the LV during RA pacing and the gradient between the subendocardial and subepicardial layers vanished during RV, LV or Biv pacing in healthy dogs. In contrast, there was no transmural MAPD gradient during RA, RV, LV or Biv pacing in HF dogs. These results are helpful to understand the mechanism of ventricular arrhythmias in patients with HF.

Efficacy and safety of early initiation of sacubitril-valsartan therapy in patients with acute decompensated heart failure / 中华心血管病杂志

Objective: To assess the efficacy and safety of the initiation of sacubitril-valsartan （ARNI） therapy, as compared with ACEI therapy, after hemodynamic stabilization among patients hospitalized for acute decompensated heart failure （ADHF）. Methods: A total of 199 hospitalized patients for ADHF in our department from January 2017 to June 2019 were included in this retrospective analysis. According to the medication early after hemodynamic stabilization, patients were divided into ARNI group (n=92) and ACEI group (n=107). Among the included patients, 61 patients with newly diagnosed heart failure at the time of admission were also divided into ARNI group (n=30) and ACEI group (n=31) according to the applied medication. Clinical baseline data and follow-up results of enrolled patients were collected through the electronic medical records at admission, outpatient and telephone follow-up. The primary effectiveness observation index was left ventricular ejection fraction (LVEF) and left ventricular end diastolic dimension (LVEDD) measured by echocardiography; the secondary observation index was death from any causes and hospitalization for heart failure. Safety outcomes were the incidences of symptomatic hypotension, worsening renal function, hyperkalemia, and angioedema. Results: The clinical baseline characteristics were similar between ARNI group and ACEI group（all P>0.05）. The duration of follow up was (15.2±6.5) months in all patients enrolled, (12.3±5.0) months in ARNI group, and (18.2±6.5) months in ACEI group. At the end of follow-up, prevalence of an absolute LVEF increase of more than 5% was 48.9% (45/92) in ANRI group and 25.2% (27/107) in ACEI group (P=0.001). Percent of LVEF increase to more than 50% was 17.4% (16/92) in ANRI group and 3.7% (4/107) in ACEI group (P=0.001). Percent of patients with more than 10 mm LVEDD reduction was 14.1% (13/92) in ANRI group and 3.7% (4/107) in ACEI group (P=0.009). All-cause mortality rate was 5.7% (5/88) in ARNI group and 15.3% (13/85) in ACEI group (P=0.038). Rate of re-hospitalization due to heart failure was 50% (46/92) in ARNI group and 71% (76/107) in ACEI group（P=0.002）.The rates of symptomatic hypotension, worsening renal function, hyperkalemia, and angioedema were similar between ARNI group and ACEI group (all P>0.05). In patients with first diagnosed heart failure，percent of LVEF increase to more than 50% was 30% (9/30) in ANRI group and 6.5% (2/31) in ACEI group (P=0.017). Percent of more than 10 mm LVEDD reduction was 26.7%(8/30) in ANRI group and 3.2%(1/31) in ACEI group (P=0.012). Percent of an absolute LVEF increase of more than 5% was 53.3% (16/30) in ANRI group and 51.6% (16/31) in ACEI group (P=0.893). Re-hospitalization due to heart failure was 23.3% (7/30） in ARNI group and 73.3% (11/31) in ACEI group（P<0.01）. Rate of all-cause death tended to be lower in patients receiving ARNI (3.4% (1/29)) as compared to patients receiving ACEI (13.0% (3/23), P=0.197）. Conclusions: Among patients with heart failure with reduced ejection fraction hospitalized for ADHF, the initiation of ARNI therapy after hemodynamic stabilization is associated with a more significant improvement of cardiac remodeling and pump function than ACEI therapy and satisfactory safety. In ADHF patients with first diagnosed heart failure, initiation of ARNI therapy after hemodynamic stabilization can more effectively improve cardiac remodeling and pump function than treatment with ACEI.

Comparison of cryoballoon ablation for atrial fibrillation guided by real-time three-dimensional transesophageal echocardiography vs. contrast agent injection / 中华医学杂志(英文版)

BACKGROUND@#Pulmonary vein (PV) occlusion generally depends on repetitive contrast agent injection when cryoballoon ablation for atrial fibrillation (AF). The present study was to compare the effect of cryoballoon ablation for AF guided by transesophageal echocardiography (TEE) vs. contrast agent injection.@*METHODS@#Eighty patients with paroxysmal AF (PAF) were enrolled in the study. About 40 patients underwent cryoballoon ablation without TEE (non-TEE group) and the other 40 underwent cryoballoon ablation with TEE for PV occlusion (TEE group). In the TEE group during the procedure, PVs were displayed in 3-dimensional images to guide the balloon to achieve PV occlusion. The patients were followed up at regularly scheduled visits every 2 months.@*RESULTS@#No differences were identified between the groups in regard to the procedure time and cryoablation time for each PV. The fluoroscopy time (6.7 ± 4.2 min vs. 17.9 ± 5.9 min, P < 0.05) and the amount of contrast agent (3.0 ± 5.1 mL vs.18.1 ± 3.4 mL, P < 0.05) in the TEE group were both less than the non-TEE group. At a mean of 13.0 ± 3.3 mon follow-up, success rates were similar between the TEE group and non-TEE group (77.5% vs. 80.0%, P = 0.88).@*CONCLUSIONS@#Cryoballoon ablation with TEE for occlusion of the PV is both safe and effective. Less fluoroscopy time and a lower contrast agent load can be achieved with the help of TEE for PV occlusion during procedure.

Long term outcome of atrial fibrillation patients with KCNA5 and NPPA mutations post circumferential pulmonary vein ablation / 中华心血管病杂志

<p><b>OBJECTIVE</b>The outcome of atrial fibrillation patients with genetic mutations post ablation was not well evaluated.</p><p><b>METHODS AND RESULTS</b>Three atrial fibrillation patients with evidence of mutations in KCNA5 and NPPA post successful circumferential pulmonary vein ablation were included. Mutation in KCNA5 was found in one male patient with paroxysmal atrial fibrillation. He was free of atrial fibrillation post ablation after 46 months follow-up. Mutations in NPPA were found in two male patients with persistent atrial fibrillation and they were free from atrial fibrillation after 64 months and 38 months follow-up post circumferential pulmonary vein ablation, roof line and mitral isthmus line ablation.</p><p><b>CONCLUSION</b>Satisfactory long term results are observed in atrial fibrillation patients with KCNA5 and NPPA mutations post circumferential pulmonary vein ablation.</p>

Predictive value of HATCH score on atrial fibrillation recurrence post radiofrequency catheter ablation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To determine the predictive value of HATCH score on recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA).</p><p><b>METHODS</b>The data of 123 consecutive AF patients (74 paroxysmal and 49 persistent AF) who underwent RFCA between April 2009 and December 2010 in our department were retrospectively analyzed. Of theses patients, 65 (52.9%) patients had HATCH score = 0, 41 (33.3%) patients had HATCH score = 1, and 17 (13.8%) patients had HATCH score ≥ 2 (HATCH = 2 in 11 patients, HATCH = 3 in 5 patients, HATCH = 4 in 1 patient). The recurrence was defined as atrial tachyarrhythmia lasting more than 30 seconds after 3 months post RFCA. The patients were divided into recurrence group and no recurrence group. Relationship between HATCH score and recurrence was observed.</p><p><b>RESULTS</b>There were 43 cases in recurrence group and 80 cases in no recurrence group. After 12 months follow-up, HATCH score was significant higher in recurrence group than in non-recurrence group [(0.91 ± 0.94) score vs. (0.53 ± 0.80) score, P < 0.05]. The ratio of patients with HATCH ≥ 2 in recurrence group was higher than in non-recurrence group [23.3% (10/43) vs. 8.8% (7/80), P < 0.01]. The sensitivity and specificity of HATCH ≥ 2 to define the risk of recurrence was 25.0%, 92.4% respectively. Cumulative non-recurrence rate of patients with HATCH score ≥ 2 was lower than patients with HATCH score = 0 and 1 (P < 0.05).</p><p><b>CONCLUSION</b>Higher HATCH score is associated with increased risk of AF recurrence post RFCA.</p>

Substrate of complex fractionated atrial electrograms: evidence by pathologic analysis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Ablation of complex fractionated atrial electrograms (CFAE) is an important adjunctive therapy in atrial fibrillation (AF). The present study was to elucidate the substrate underlying CFAE.</p><p><b>METHODS</b>Nine adult mongrel dogs were involved in the present study. AF was induced through rapid atrial pacing with vagosympathetic nerve stimulation. CFAE was recorded during AF. Ablation was performed at CFAE sites. Based on the location of the ablation scar, the atrial specimens were divided into CFAE and non-CFAE sites. Serial sections of the atrium were stained respectively with hematoxylin-eosin (HE) and the general neural marker protein gene product 9.5 (PGP9.5). We compared the characteristics of the myocardium and the ganglionated plexus (GPs) distribution between the CFAE and non-CFAE sites.</p><p><b>RESULTS</b>The myocardium of non-CFAE sites was well-organized with little intercellular substance. However, the myocardium in the CFAE site was disorganized with more interstitial tissue ((61.7 ± 24.3)% vs. (34.1 ± 9.2)%, P < 0.01). GPs in the CFAE site were more abundant than in non-CFAE sites ((34.45 ± 37.46) bundles/cm(2) vs. (6.73 ± 8.22) bundles/cm(2), P < 0.01).</p><p><b>CONCLUSION</b>The heterogeneity of the myocardium and GPs distribution may account for the substrate of CFAE and serve as a potential target of ablation.</p>

Efficacy of ibutilide for cardioversion of persistent atrial fibrillation during radiofrequency ablation / 中华心血管病杂志

<p><b>OBJECTIVE</b>The aim of this study was to investigate the efficiency and safety of ibutilide for cardioversion of persistent atrial fibrillation (AF) during radiofrequency ablation.</p><p><b>METHODS</b>Eighteen patients (16 males) with persistent atrial fibrillation were enrolled in this study. All patients underwent circumferential pulmonary vein ablation guided by a Carto three-dimensional mapping system. In addition, linear ablation at the top of the left atrium and the isthmus of mitral valves and complex fractionated atrial electrogram (CAFE) ablation were performed. All patients were still in either atrial fibrillation or atrial flutter after ablation, the patients were treated with 1 mg intravenous ibutilide injection within 10 minutes after unsuccessful ablation. Intravenous injection was stopped in case of sinus rhythm (SR) restoration or occurrence of severe adverse reactions such as ventricular tachycardia. Cardioversion rate within 30 min and adverse reactions within 4 h were observed. Patients were divided into either conversion group or non-conversion group according to whether AF was converted to sinus rhythm within 30 minutes after injection.</p><p><b>RESULTS</b>Eleven patients (61.11%) converted to SR after ibutilide injection. There were no significant differences in gender, age, body mass index, left atrium and left ventricular function between conversion group and non-conversion groups. The average conversion time was (13.80 ± 7.64) min, left atrium scar area ratio was significantly larger in non-conversion group (12.40 ± 11.03)% than in conversion group (5.12 ± 3.83)%, P < 0.05. Ibutilide significantly prolonged the average wavelength of the AF wave (171.8 ± 29.5) ms vs. (242.0 ± 40.0) ms at baseline, P < 0.01. The QT interval at 30 min after ibutilide injection (0.39 ± 0.21) s was significantly longer than before injection (0.51 ± 0.08) s, P < 0.05. There was no serious arrhythmias or other adverse reactions post ibutilide injection.</p><p><b>CONCLUSIONS</b>Ibutilide is highly effective and safe agent for cardioversion in patients underwent unsuccessful ablation. Left atrium scar area ratio is an important determinant for the conversion rate in this cohort.</p>

Restitution of atrial repolarization and atrial fibrillation in canine atrium / 中华心血管病杂志

<p><b>OBJECTIVE</b>Electrical restitution was believed to be a determinant responsible for the stability of heart rhythm. Although numerous studies focused on the role of action potential duration restitution (APDR) in the initiation and maintenance of ventricular fibrillation (VF), the relationship between atrial APDR and atrial fibrillation (AF) has not been fully understood. This study aims to investigate the characteristics of APDR of left atrium (LA) and right atrium (Rs) in canines and the relevance to induction of AF.</p><p><b>METHODS</b>Monophasic action potential (MAP) was recorded from LA and RA in 14 canines using the MAP recording-pacing combination catheter. APDR, plotted as action potential duration (APD) on the preceding diastolic interval (DI), was assessed by use of programmed stimulation with a single extrastimulus (S1S2) at LA and RA. Episodes of AF were recorded and analyzed.</p><p><b>RESULTS</b>APD90 was significantly shorter in the LA than that in the RA [(157.4 +/- 43.5) ms vs. (170.9 +/- 37.9) ms, P < 0.05]. The mean slope of the APDR curve by S1S2 in the LA was significantly greater than that in the RA (1.3 +/- 0.4 vs. 0.9 +/- 0.3, P < 0.05). The incidence of induced AF was significantly higher in the LA than in the RA (11/18 vs. 7/18, P < 0.05).</p><p><b>CONCLUSIONS</b>The APDR and MAP characteristics are not uniform between atrium, which may be one of the important mechanisms responsible for the initiation of AF. Heterogeneity of APDR between LA and RA might create critical gradients or a dispersion of repolarization and substrate for re-entrant arrhythmias and vulnerability to AF.</p>

Effect of ablation of complex fractionated atrial electrogram on vagal modulation in dogs / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Clinical observations have shown that the complex fractionated atrial electrogram (CFAE) associates with ganglionated plexus activity in the cardiac autonomic nervous system. This study aimed to investigate the impact of CFAE ablation on vagal modulation to atria and vulnerability to develop atrial fibrillation (AF).</p><p><b>METHODS</b>Ten adult mongrel dogs were involved. Cervical sympathovagal trunks were decentralized and sympathetic effects were blocked. CFAE was color tagged on the atrial 3-dimensional image and ablated during AF induced by S1S2 programmed stimulation plus sympathovagal trunk stimulation. Atrial effective refractory period (ERP) and vulnerability window (VW) of AF were measured on baseline and at vagal stimulation at 4 atrium sites. Serial tissue sections from ablative and control specimens received hematoxylin and eosin staining for microscopic examination.</p><p><b>RESULTS</b>Most CFAE areas were localized at the right superior pulmonary quadrant, distal coronary sinus (CS(d)) quadrant, and proximal coronary sinus (CS(p)) quadrant (21.74%, separately). Sinus rhythm cycle length (SCL) shortening did not decrease significantly after ablation at the sites, including right atrial appendage, left atrial appendage, CS(d), and CS(p) (P > 0.05). ERP shortening during vagal stimulation significantly decreased after ablation (P < 0.01); the VW to vagal stimulation significantly decreased after ablation (P < 0.05). The architecture of individual ganglia altered after ablation.</p><p><b>CONCLUSIONS</b>CFAE has an autonomic basis in dogs. The decreased SCL and ERP shortening to vagal stimulation after CFAE ablation demonstrate that CFAE ablation attenuates vagal modulation to the atria, thereby suppressing AF mediated by enhanced vagal activity. CFAE ablation could suppress AF mediated by enhanced vagal activity.</p>

Chronic outcome of patients with paroxysmal atrial fibrillation post catheter ablation / 中华心血管病杂志

<p><b>OBJECTIVE</b>High short-term successful rate was reported for catheter ablation in patients with paroxysmal atrial fibrillation (AF), we analyzed the long-term outcome (success rate, anticoagulation therapy and embolism event, anti-arrhythmic therapy and death post procedure) of catheter ablation for paroxysmal AF in this study.</p><p><b>METHODS</b>From January 2000 to December 2004, 106 consecutive patients with drug-refractory paroxysmal AF underwent catheter ablation and were followed-up for (60.7 + or - 11.8) months. Segmental pulmonary vein isolation (SPVI) was routinely performed by radiofrequency energy under the guidance of circular mapping catheter. The patients were followed up with 24 h-holter, ECG, telephone or letter. Data on recurrence of AF, the anticoagulation medication and the incidence of embolism, anti-arrhythmic therapy were obtained.</p><p><b>RESULTS</b>There were 9 patients lost to follow up. In the remaining 97 patients [65 males, (54.8 + or - 11.2) years old], 3 cases died from cancer, sinus rhythm was maintained in 68 patients (Group S, 72.3%) and AF recurrence evidenced in 26 patients (Group R, 27.7%). In Group S, 56 patients (82.4%) discontinued anticoagulation medication, and 12 patients continued to take aspirin. There was no embolism event in Group S during follow-up. In Group R, 1 patient continued to take warfarin; 11 patients continued to take aspirin and 2 patients suffered from cerebral embolism. Anticoagulation medication was discontinued in 14 patients (53.8%) and 1 patient suffered form cerebral embolism. The incidence of embolism event in Group R is significantly higher than in Group S (P < 0.01). More patients discontinued anti-arrhythmic medication in Group S than in Group R (80.9% vs. 56.0%, P < 0.05).</p><p><b>CONCLUSION</b>Catheter ablation is associated with satisfactory long-term success rate, reduced anti-arrhythmia medication, improved quality of life in patients with paroxysmal AF.</p>