Fangzhou Liu

Incidence and outcomes of cerebrovascular events complicating catheter ablation for atrial fibrillation

AIMS Cerebrovascular complications are relatively uncommon, but severe adverse events are associated with catheter ablation of atrial fibrillation (AF). This study aimed to investigate the incidence, risk factors, and hospital outcomes of cerebrovascular events complicating AF ablation. METHODS AND RESULTS Cerebrovascular complications occurring during the procedure or hospitalization after AF ablation were assessed. Cerebrovascular events occurred in 9 of 1946 consecutive procedures (0.46%). Seven patients (0.36% per procedure) were diagnosed with ischaemic stroke and two patients (0.1% per procedure) with intracranial haemorrhage (ICH). Six events (6/9, 66.7%) occurred during the ablation and the remainders within 24 h after the ablation. Multivariable analysis revealed that previous ischaemic stroke [odds ratio (OR) 10.549; 95% confidence interval (CI) 2.551-43.625, P = 0.001] and mechanical valve replacement (OR 3.261; 95% CI 1.337-7.953, P = 0.009) were independent predictors. In a separate model, CHA2DS2-VASc score ≥3 (OR 7.992; 95% CI 2.046-31.215, P = 0.003) and mechanical valve replacement (OR 4.104; 95% CI 1.644-10.245, P = 0.002) were significantly associated with cerebrovascular complications. All patients survived to discharge except the two cases with ICH. CONCLUSION Cerebrovascular complications related to catheter ablation of AF are relatively infrequent and typically occur early either during the procedure or within the first 24 h after AF ablation. Previous ischaemic stroke, mechanical valve replacement, and CHA2DS2-VASc score ≥3 are independent predictors of such complications. The majority of these events are ischaemic stroke with a benign clinical outcome, while ICH may correlate with poor prognosis.

Five-year epidemiological survey of valvular heart disease: changes in morbidity, etiological spectrum and management in a cardiovascular center of Southern China

OBJECTIVE The objective of the present study is to analyze the epidemiological profile of patients with abnormal valvular structure and function and highlight the etiological spectrum and management of valvular heart disease (VHD) in a single cardiovascular center of Southern China in five years. METHODS The retrospective study included 19,428 consecutive patients (9,441 men and 9,987 women with a mean age of 52.03±20.50 years) with abnormal valvular structure and function who were screened by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE) at the in-patient department of Guangdong General Hospital from January 2009 to December 2013. Data on baseline characteristics, potential etiology, treatment strategies and discharge outcomes were collected from electronic medical records. RESULTS There were 13,549 (69.7%) patients with relatively definite etiology for VHD. VHD was rheumatic in 7,197 (37.0%) patients, congenital in 2,697 (13.9%), degenerative in 2,241 (11.5%), ischemic in 2,460 (12.7%). The prevalence decreased significantly in rheumatic VHD from 2009 to 2013 (from 42.8% to 32.8%, P<0.001), but increased markedly in congenital VHD (from 9.0% to 12.3%, P<0.001), ischemic VHD (from 9.2% to 11.3%, P=0.003) and degenerative VHD (from 8.8% to 14.5%, P<0.001). Meantime, the prevalence of ischemic VHD increased after the age of 45, similar to that of degenerative VHD. From 2009 to 2013, the proportion of patients with VHD undergoing open cardiac valvular surgery decreased (from 49.5% to 44.3%, P<0.001) and that of patients treated with general medication increased (from 49.2% to 54.1%, P<0.001). However, there was markedly increment in video-assisted thoracoscopic surgery (VATS) from 2009 to 2013 (from 0.3% to 4.4%, P<0.001). Increasing tendencies were showed in aortic mechanical valve replacement (from 32.1% to 34.5%, P=0.001) and double mechanical valve replacement (from 20.9% to 22.3%, P=0.035), especially in mitral valvuloplasty (from 8.5% to 15.7%, P<0.001). However, the proportion of patients undergoing bioprosthetic valve replacement decreased from 2009 to 2013 (from 26.3% to 15.5%, P<0.001). CONCLUSIONS Despite a significant shift from rheumatic towards degenerative etiology from 2009 to 2013, rheumatic VHD remains the leading etiology in Southern China, with a significant increase in the prevalence of ischemic, congenital and degenerative VHD. General medication and cardiac valvular surgery remain the main treatment options. The proportion of VATS increased markedly from 2009 to 2013, and mechanical valve replacement and mitral valvuloplasty showed an increasing tendency.

Long-Term Outcomes of Radio-Frequency Catheter Ablation on Ventricular Tachycardias Due to Arrhythmogenic Right Ventricular Cardiomyopathy: A Single Center Experience

Aims To summarize our experience of radiofrequency catheter ablation (RFCA) for recurrent drug-refractory ventricular tachycardias (VTs) due to arrhythmogenic right ventricular cardiomyopathy (ARVC) in our center over the past 11 years and its related factors. Methods and Results We reviewed 48 adults (mean age 39.9 ± 12.9 years, range: 14 to 65) who met the present ARVC diagnostic criteria and accepted RFCA for VTs from December 2004 to April 2016. The patients received a total of 70 procedures using two ablation approaches, the endocardial approach in 52 RFCAs, and the combined epicardial and endocardial approach (the combined approach) in 18 RFCAs. Kaplan-Meier survival analysis showed that the combined approach achieved better acute procedural success (p = 0.003) and better long-term outcomes (p = 0.028) than the endocardial approach. Patients who obtained acute procedural success with non-inducibility had better long-term outcomes (p < 0.001). COX regression of multivariate analysis showed that procedural success was the only factor that benefited long-term outcome, irrespective of the endocardial or the combined approach (p = 0.001). The rate of sudden cardiac death (SCD) in patients without procedural success was significantly higher than that in patients with procedural success (p = 0.005). All patients without implantable cardioverter defibrillator (ICD) implantation who had successful final RFCA survived. Conclusions The combined approach resulted in better procedural success and long-term VT-free survival compared with the endocardial approach in ARVC patients with recurrent VTs. Acute procedural success with non-inducibility was strongly related to better long-term VT-free survival and reduced SCD, irrespective of whether this was achieved by the endocardial approach or the combined approach.

Experimental, Pathologic, and Clinical Findings of Radiofrequency Catheter Ablation of Para-Hisian Region From the Right Ventricle in Dogs and Humans

Background— Ablation of para-Hisian accessory pathway (AP) poses high risks of atrioventricular block. We developed a pacing technique to differentiate the near-field (NF) from far-field His activations to avoid the complication. Methods and Results— Three-dimensional mapping of the right ventricle was performed in 15 mongrel dogs and 23 patients with para-Hisian AP. Using different pacing outputs, the NF- and far-field His activation was identified on the ventricular aspect. Radiofrequency application was delivered at the NF His site in 8 (group 1) and the far-field His site in 7 dogs (group 2), followed by pathologic examination after 14 days. NF His activation was captured with 5 mA/1 ms in 10 and 10 mA/1 ms in 5 dogs. In group 1, radiofrequency delivery resulted in complete atrioventricular block in 3, right bundle branch block with HV (His-to-ventricular) interval prolongation in 1, and only right bundle branch block in 2 dogs, whereas no changes occurred in group 2. Pathologic examination in group-1 dogs showed complete or partial necrosis of the His bundle in 4 and complete necrosis of the right bundle branch in 5 dogs. In group 2, partial necrosis in the right bundle branch was found only in 1 dog. Using this pacing technique, the APs were 5.7±1.2 mm away from the His bundle located superiorly in 20 or inferiorly in 3 patients. All APs were successfully eliminated with 1 to 3 radiofrequency applications. No complications and recurrence occurred during a follow-up of 11.8±1.4 months. Conclusions— Differentiating the NF His from far-field His activations led to a high ablation success without atrioventricular block in para-Hisian AP patients.

Myocyte-specific enhancer factor 2C: a novel target gene of miR-214-3p in suppressing angiotensin II-induced cardiomyocyte hypertrophy.

The role of microRNA-214-3p (miR-214-3p) in cardiac hypertrophy was not well illustrated. The present study aimed to investigate the expression and potential target of miR-214-3p in angiotensin II (Ang-II)-induced mouse cardiac hypertrophy. In mice with either Ang-II infusion or transverse aortic constriction (TAC) model, miR-214-3p expression was markedly decreased in the hypertrophic myocardium. Down-regulation of miR-214-3p was observed in the myocardium of patients with cardiac hypertrophy. Expression of miR-214-3p was upregulated in Ang-II-induced hypertrophic neonatal mouse ventricular cardiomyocytes. Cardiac hypertrophy was attenuated in Ang-II-infused mice by tail vein injection of miR-214-3p. Moreover, miR-214-3p inhibited the expression of atrial natriuretic peptide (ANP) and β-myosin heavy chain (MHC) in Ang-II-treated mouse cardiomyocytes in vitro. Myocyte-specific enhancer factor 2C (MEF2C), which was increased in Ang-II-induced hypertrophic mouse myocardium and cardiomyocytes, was identified as a target gene of miR-214-3p. Functionally, miR-214-3p mimic, consistent with MEF2C siRNA, inhibited cell size increase and protein expression of ANP and β-MHC in Ang-II-treated mouse cardiomyocytes. The NF-κB signal pathway was verified to mediate Ang-II-induced miR-214-3p expression in cardiomyocytes. Taken together, our results revealed that MEF2C is a novel target of miR-214-3p, and attenuation of miR-214-3p expression may contribute to MEF2Cexpressionin cardiac hypertrophy.

Predictive Value of Serum uric acid on Left Atrial Spontaneous Echo Contrast in Non-Valvular Atrial Fibrillation Patients

Objectives To investigate the relationship between serum uric acid (SUA) and left atrial spontaneous echo contrast (LA-SEC) in non-valvular atrial fibrillation (AF) patients. Methods We retrospectively screened 1,476 consecutive hospitalized patients with AF who underwent transesophageal echocardiography prior to radiofrequency catheter ablation, left atrial appendage closure and electric cardioversion at Guangdong General Hospital. Data on the clinical baseline characteristics of all patients were collected from electronic medical records and analyzed. Results After exclusion of patients with left atrial thrombus, 1,354 patients entered into present study and 57 were LA-SEC. The mean female SUA level (380.88 ± 94.35 µmol/L vs. 323.37 ± 72.19 µmol/L, P < 0.001) and male SUA level (416.97 ± 98.87 µmol/L vs. 367.88 ± 68.50 µmol/L, P = 0.008) were both significantly higher in patients with LA-SEC than in the controls. The mean left atrial dimension (41.32 ± 5.12 mm vs. 36.12 ± 5.66 mm, P < 0.001) was markedly larger in patients with LA-SEC. In multivariate regression analysis, SUA level was an independent risk factor for LA-SEC (OR: 1.008, P < 0.001). In receiver operating characteristic curve analysis, the corresponding area under the curve for SUA predicting LA-SEC in female and male were 0.670 and 0.657, respectively. SUA level is significantly higher in non-valvular AF patients with LA-SEC. Conclusion SUA level is an independent risk factor and has a moderate predictive value for LA-SEC among non-valvular AF patients in Southern China.

Predictive effect of hyperuricemia on left atrial stasis in non-valvular atrial fibrillation patients

OBJECTIVES To investigate the relationship between hyperuricemia and left atrial thrombus (LAT)/spontaneous echo contrast (SEC) and to determine the predictive value of hyperuricemia in non-valvular (NV) atrial fibrillation (AF) patients. METHODS The study retrospectively reviewed 1198 consecutive patients (male 801, female 397, and mean age of 56.84 ± 12.22) who were diagnosed with AF and accepted transesophageal echocardiography (TEE) prior to catheter ablation, appendage occlusion and electrical cardioversion using a single-center database. The clinical baseline characteristics were collected from medical record review and analyzed. Patients were categorized into an LAT/SEC group and a normal group. RESULTS According to the TEE examination, there were 97 (8.1%) patients with abnormality; of these, 49 were with LAT and 48 with SEC. The mean serum uric acid (SUA) level and hyperuricemia proportion were markedly higher in patients with LAT/SEC. The significant predictive effect was observed in the SUA level (OR = 1.006) and hyperuricemia (OR = 2.04). After adjustment for persistent/permanent-AF, age, gender, LA dimension > 40 mm, previous stroke, hypertension and diabetes, the SUA level (OR = 1.004) and hyperuricemia (OR = 1.69) were independent predictors for LAT/SEC. The SUA level (OR = 1.004) and hyperuricemia (OR = 1.69) were independent predictors for LAT/SEC, Further subgroup analysis in different CHA2DS2-VASc categories, it might be helpful to refine the LAT/SEC risk via combination area CHA2DS2-VASc score and hyperuricemia, especially in those with CHA2DS2-VASc score < 2. CONCLUSIONS The SUA level and hyperuricemia proportion are closely associated with LA stasis. Hyperuricemia might independently predict and refine LA stasis risk among NVAF patients, especially in those with CHA2DS2-VASc score < 2.

Catheter ablation of right-sided para-Hisian ventricular arrhythmias using a simple pacing strategy

BACKGROUND Ablation of para-Hisian ventricular arrhythmias (PH-VAs) is challenging because of the close relationship of the origin site and His bundle. Using pacing techniques to differentiate the near-field from far-field His activations, thereby avoiding atrioventricular block, has been reported in patients with para-Hisian accessory pathways. OBJECTIVES We applied the same pacing technique and 3-dimensional mapping to guide radiofrequency (RF) ablation in patients with right-sided PH-VAs and investigated the clinical outcome of such cases. METHODS Fourteen patients with right-sided PH-VAs were included in this study. The earliest activation sites were confirmed in the right ventricle on the 3-dimensional map. Pacing with different outputs was performed at the largest His potential site (P1) and the earliest activation site (P2). If the minimum His bundle-right bundle branch-captured output at P2 was higher than that at P1, RF ablation was performed at the site. RESULTS All the patients in this study had monomorphic premature ventricular contractions (PVCs) with a mean QRS duration of 118.3 ± 8.1 ms. A His-right bundle branch potential with an amplitude of 0.05 ± 0.02 mV was recorded at P2, with a mean distance of 5.97 ± 1.84 mm away from P1. PVCs were successfully eliminated in 13 of 14 patients (92.9%). One patient exhibited persistent right bundle branch block after ablation, and 1 recurrence of ablated PVCs occurred during a median follow-up period of 15 months. CONCLUSION Using a simple pacing technique to evaluate the safety of RF energy application led to a high success rate of RF catheter ablation of right-sided PH-VAs without atrioventricular block.

Trans-subclavian Approach for Radiofrequency Ablation of Atrioventricular Accessory Pathway Associated with Coronary Sinus Diverticulum

A 20-year-old Chinese male presented with narrow-complex tachycardia related to type B pre-excitation pattern (Figure 1A and 1B). During the electrophysiological study, the earliest ventricular and atrial activation was adjacent to the coronary sinus (CS) electrode 9,0 during sinus rhythm and 7,8 during ventricular pacing (Figure 1D, 1E and 1G), respectively. An orthodromic atrioventricular reentry tachycardia could be induced reproducibly. Subsequently, a conventional 4 mm tip ablation catheter (Triguy, APT Medical, PRC) was introduced into the right ventricle via a long sheath (SR0, St. Jude Medical, USA). Repeated radiofrequency (RF) energy (50 W at 55 8C) delivery at the target site failed to eliminate the antegrade accessory pathway (AP) conduction due to rising impedance and poor power delivery. Considering the possibility of the AP located at the epicardium, coronary sinus angiography was implemented by Amplatz left 1 catheter. Two CS diverticula were identified near the ostium (Figure 1G, Online Video 1 and 2). A salineirrigated ablation catheter (Triguy, APT Medical, PRC) was reintroduced into the CS via the right femoral vein