Cardiac electrical and mechanical synchrony of super-responders to cardiac resynchronization therapy / 中华医学杂志(英文版)

BACKGROUND@#Super-responders (SRs) to cardiac resynchronization therapy (CRT) regain near-normal or normal cardiac function. The extent of cardiac synchrony of SRs and whether continuous biventricular (BIV) pacing is needed remain unknown. The aim of this study was to evaluate the cardiac electrical and mechanical synchrony of SRs.@*METHODS@#We retrospectively analyzed CRT recipients between 2008 and 2016 in 2 centers to identify SRs, whose left ventricular (LV) ejection fraction was increased to ≥50% at follow-up. Cardiac synchrony was evaluated in intrinsic and BIV-paced rhythms. Electrical synchrony was estimated by QRS duration and LV mechanical synchrony by single-photon emission computed tomography myocardial perfusion imaging.@*RESULTS@#Seventeen SRs were included with LV ejection fraction increased from 33.0 ± 4.6% to 59.3 ± 6.3%. The intrinsic QRS duration after super-response was 148.8 ± 30.0 ms, significantly shorter than baseline (174.8 ± 11.9 ms, P = 0.004, t = -3.379) but longer than BIV-paced level (135.5 ± 16.7 ms, P = 0.042, t = 2.211). Intrinsic LV mechanical synchrony significantly improved after super-response (phase standard deviation [PSD], 51.1 ± 16.5° vs. 19.8 ± 8.1°, P < 0.001, t = 5.726; phase histogram bandwidth (PHB), 171.7 ± 64.2° vs. 60.5 ± 22.9°, P < 0.001, t = 5.376) but was inferior to BIV-paced synchrony (PSD, 19.8 ± 8.1° vs. 15.2 ± 6.4°, P = 0.005, t = 3.414; PHB, 60.5 ± 22.9° vs. 46.0 ± 16.3°, P = 0.009, t = 3.136).@*CONCLUSIONS@#SRs had significant improvements in cardiac electrical and LV mechanical synchrony. Since intrinsic synchrony of SRs was still inferior to BIV-paced rhythm, continued BIV pacing is needed to maintain longstanding and synchronized contraction.

Microvolt T-wave alternans complemented with electrophysiologic study for prediction of ventricular tachyarrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy: a long-term follow-up study / 中华医学杂志(英文版)

Background@#The long-term predicted value of microvolt T-wave alternans (MTWA) for ventricular tachyarrhythmia in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) remains unclear. Our study explored the characteristics of MTWA and its prognostic value when combined with an electrophysiologic study (EPS) in patients with ARVC.@*Methods@#All patients underwent non-invasive MTWA examination with modified moving average (MMA) analysis and an EPS. A positive event was defined as the first occurrence of sudden cardiac death, documented sustained ventricular tachycardia (VT), ventricular fibrillation, or the administration of appropriate implantable cardioverter defibrillator therapy including shock or antitachycardia pacing.@*Results@#Thirty-five patients with ARVC (age 38.6 ± 11.0 years; 28 males) with preserved left ventricular (LV) function were recruited. The maximal TWA value (MaxValt) was 17.0 (11.0–27.0) μV. Sustained VT was induced in 22 patients by the EPS. During a median follow-up of 99.9 ± 7.7 months, 15 patients had positive clinical events. When inducible VT was combined with the MaxValt, the area under the curve improved from 0.739 to 0.797. The receiver operating characteristic curve showed that a MaxValt of 23.5 μV was the optimal cutoff value to identify positive events. The multivariate Cox regression model for survival showed that MTWA (MaxValt, hazard ratio [HR], 1.06; 95% confidence interval [CI], 1.01–1.11; P = 0.01) and inducible VT (HR, 5.98; 95% CI, 1.33–26.8; P = 0.01) independently predicted positive events in patients with ARVC.@*Conclusions@#MTWA assessment with MMA analysis complemented by an EPS might provide improved prognostic ability in patients with ARVC with preserved LV function during long-term follow-up.

Microvolt T-wave alternans complemented with electrophysiologic study for prediction of ventricular tachyarrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy: a long-term follow-up study / 中华医学杂志(英文版)

BACKGROUND@#The long-term predicted value of microvolt T-wave alternans (MTWA) for ventricular tachyarrhythmia in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) remains unclear. Our study explored the characteristics of MTWA and its prognostic value when combined with an electrophysiologic study (EPS) in patients with ARVC.@*METHODS@#All patients underwent non-invasive MTWA examination with modified moving average (MMA) analysis and an EPS. A positive event was defined as the first occurrence of sudden cardiac death, documented sustained ventricular tachycardia (VT), ventricular fibrillation, or the administration of appropriate implantable cardioverter defibrillator therapy including shock or anti-tachycardia pacing.@*RESULTS@#Thirty-five patients with ARVC (age 38.6 ± 11.0 years; 28 males) with preserved left ventricular (LV) function were recruited. The maximal TWA value (MaxValt) was 17.0 (11.0-27.0) μV. Sustained VT was induced in 22 patients by the EPS. During a median follow-up of 99.9 ± 7.7 months, 15 patients had positive clinical events. When inducible VT was combined with the MaxValt, the area under the curve improved from 0.739 to 0.797. The receiver operating characteristic curve showed that a MaxValt of 23.5 μV was the optimal cutoff value to identify positive events. The multivariate Cox regression model for survival showed that MTWA (MaxValt, hazard ratio [HR], 1.06; 95% confidence interval [CI], 1.01-1.11; P = 0.01) and inducible VT (HR, 5.98; 95% CI, 1.33-26.8; P = 0.01) independently predicted positive events in patients with ARVC.@*CONCLUSIONS@#MTWA assessment with MMA analysis complemented by an EPS might provide improved prognostic ability in patients with ARVC with preserved LV function during long-term follow-up.

Catheter ablation of epicardial accessory pathway associated with coronary sinus musculature / 中华心血管病杂志

<p><b>OBJECTIVE</b>To report the single-center clinical experience of catheter ablation of epicardial accessory pathway associated with coronary sinus musculature.</p><p><b>METHODS</b>The data of 721 cases of left sided accessory pathway ablation were retrospectively analyzed. Ablation in the coronary sinus was performed in 17 (2.4 %) cases [11 males, mean age (37 ± 11) years].</p><p><b>RESULTS</b>Among the 17 cases, the accessory pathway was successfully ablated in middle cardiac vein and posterior lateral coronary sinus in 11 and 6 cases, respectively. Deverticulum of middle cardiac vein was seen in 2 cases. Mean time required to block the accessory pathway was (4.7 ± 2.7) s. An accessory pathway potential could be recorded at the target site in 10 out of 17 patients (59%). During a mean (21 ± 16) months follow up, only one patient experienced recurrence who was successfully cured by a second ablation session. No procedure related complication was reported.</p><p><b>CONCLUSION</b>About 2.4% of left accessory pathway may have epicardial connection locating at middle cardiac vein or lateral part of the coronary sinus and require epicardial ablation. The epicardial ablation is safe and effective, warrants an excellent long-term results.</p>

Catheter ablation of focal atrial tachycardia:the topographic distribution and long-term outcome / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the topographic distribution and long-term outcome of catheter ablation for focal atrial tachycardia (AT).</p><p><b>METHOD</b>The data of 207 patients who underwent electrophysiologic study for AT were retrospectively analyzed.</p><p><b>RESULTS</b>A total of 200 AT were identified in 185 patients. The most common site for AT was ostium of the coronary sinus (23.8%), followed by crista terminalis (20.5%), perinodal area (20.0%), cava vena (17.8%), annulus (13.0%), and appendage (10.3%). Eighty percent AT originated from the right atrium, 17.8% originated from the left atrium. AT originated from the left atrium was more common in male than in female (25.0% vs. 13.3%, P = 0.042), while AT originated from the right atrium was more common in female than in male (69.4% vs. 86.7%, P = 0.004). Among the 185 patients, acute success ablation rate was 93.5% (n = 173). The acute success rate in the conventional mapping group was lower than that in the three-dimensional mapping group (79.3% vs. 96.5%, P < 0.01). During a median of 36 months follow up, the AT recurred in 20 patients (success ablation rate 88.4%). Success ablation rate was similar between the conventional mapping group and the three-dimensional mapping group (P > 0.05).</p><p><b>CONCLUSIONS</b>Focal AT commonly originates from ostium of coronary sinus, crystal terminalis, perinodal area, and cava veins. There is a gender related difference in the distribution of focal AT. The radiofrequency catheter ablation yields a satisfying success rate and very low complication rate and could be the first line choice for treating ATs in experienced electrophysiological center.</p>

Impact of metoprolol use in the treatment of patients with electrical-storm after cardioverter defibrillators implantation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the effectiveness of the metoprolol dosage adjustment on reducing the incidence of electrical-storm (ES) in patients with Implantable Cardioverter Defibrillators (ICDs).</p><p><b>METHODS</b>Data from patients with ICD implantation between Jan, 2003 and Jun, 2006 in our hospital were retrospectively analyzed. ES was defined as either ≥ 3 times of ventricular tachyarrhythmias (VTAs) resulting in ICD therapy or VTAs lasting more than 30 s detected by ICD without any therapy within 24 hours.</p><p><b>RESULTS</b>During a follow-up period of (27.5 ± 21.2) months, ES was recorded in 39 cases [34 males, average age (52.0 ± 13.1) years] out of 119 patients (32.8%) and 9 patients died after ES. During the period of storm attack, ES was successfully controlled in 25/30 patients by various interventions, including predisposing factors corrected in 5 cases, ICD reprogramming and antiarrhythmic drugs therapy optimized in 16 cases (one received intravenous injection of metoprolol), and VTAs eliminated by catheter ablation in 4 cases. ES was spontaneously resolved in the remaining 5 cases. In the chronic phase, 2 patients with Brugada syndrome were treated with Quinidine mono-therapy while the dosage of metoprolol was adjusted in the remaining 23 patients and the dosage of metoprolol was increased gradually from (26.8 ± 13.9) mg/d to (88.9 ± 53.5) mg/d without any adverse effects (9 patients received also oral amiodarone 200 mg/d). Post dosage adjustment, the total VTA episodes [(1.9 ± 1.7) times/month vs. (0.8 ± 0.6) times/month, P = 0.004], incidence of antitachycardia pacing therapies [(4.2 ± 3.8) runs/month vs. (2.3 ± 2.0) runs/month, P = 0.003], as well as electrical cardioversion or defibrillation [(1.1 ± 0.9) times/month vs. (0.4 ± 0.2) times/month, P = 0.001] were significantly decreased. ES was not controlled until a extremely high dosage [225 - 300 (255.3 ± 41.7) mg/d] of metoprolol was reached in the remaining 5 patients.</p><p><b>CONCLUSIONS</b>Metoprolol use is essential and its dosage should be individualized in the majority of ICD recipients with ES. In approximately 1/6 patients, the dosage of metoprolol should be higher than 200 mg/d.</p>

Clinical characteristics of congenital ventricular aneurysm and diverticula in inland China / 中华心血管病杂志

<p><b>OBJECTIVE</b>To summarize the clinical characteristics of congenital ventricular aneurysm and diverticula in inland China.</p><p><b>METHODS</b>To identify the literature of congenital aneurysm and diverticula from Wanfang, China National Knowledge Infrastructure (CNKI) and PubMed databases, and to analyze the clinical characteristics of congenital aneurysm and diverticula from January of 2001 to December of 2009.</p><p><b>RESULTS</b>A total of 116 patients [78 men, 1 - 80 (33.5 ± 21.3) years old] with congenital aneurysm or diverticula were included in 109 articles. Twenty-five patients (13 men) were congenital ventricular aneurysm, including a family of 4 patients. Ninety-one patients (65 men) were congenital ventricular diverticula. One hundred patients were detected by echocardiography during medical examination, 34 patients combined with other cardiac anomalies, 4 of which with extracardiac structures. There were 8 patients with ventricular arrhythmia, 8 patients with thrombosis, 2 patients died of cardiac rupture, 4 patients died of sudden death, surgical operation was performed in 46 patients and 3 patients received ablation procedure. All patient did not receive implantable cardioverter defibrillator (ICD) implantation.</p><p><b>CONCLUSIONS</b>Congenital ventricular aneurysm or diverticulum is a rare cardiac malformation. Most congenital left ventricular aneurysms and diverticula are asymptomatic and detected by echocardiography. Congenital ventricular aneurysm or diverticulum may cause ventricular tachycardia, ventricular wall rupture, systemic embolization or sudden death, which had to be treated individually.</p>

Evaluation of the traditional Chinese Medicine Shensongyangxin capsule on treating premature ventricular contractions: a randomized, double-blind, controlled multicenter trial / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Premature ventricular contraction (PVC) is one of the most common kinds of arrhythmias for which the treatment falls into dilemma. Previous clinical application showed that the traditional Chinese Medicine Shensongyangxin (SSYX) capsule is efficacious for the treatment of PVCs. This randomized clinical trial aimed to further evaluate the efficacy and safety of SSYX capsule on treating PVC.</p><p><b>METHODS</b>The subjects who had frequent PVCs with or without organic heart disease and normal cardiac function were enrolled in the study. The primary endpoint was the change of PVC numbers after eight-week medication with SSYX capsule. The secondary endpoints included change of clinical symptoms related to PVCs and the safety evaluation of SSYX capsule. Totally 188 PVC patients were randomly enrolled in the non-organic heart disease PVCs trial and orally took either SSYX capsules or analogues (three times per day, 4 capsules one time). A total of 671 PVCs patients were randomly enrolled in the organic heart disease PVCs trial, and orally took either SSYX capsules (three times per day, 4 capsules one time) or mexiletine tablet (three times per day, 150 mg one time). The PVCs were monitored and calculated with 24-hour Holter electrocardiogram. Routine blood, liver and kidney function were tested before and after medication with SSYX capsule.</p><p><b>RESULTS</b>SSYX capsules significantly decreased the PVCs numbers and alleviated the related symptoms in patients with or without organic heart disease. In non-organic heart disease group, SSYX capsules and the placebos decreased the PVCs from 12,561.34 ± 9,777.93 to 4,806.87 ± 6,507.17, and 12,605.69 ± 8,736.34 to 10,364.94 ± 9,903.41, respectively. The total effective rate was 74.2% and 28.9% in SSYX and placebo groups (P < 0.001). In organic heart disease group, SSYX capsule and mexiletine decreased the PVCs from 8,641.01 ± 8,923.57 to 3,853.68 ± 7,096.42, 8,621.61 ± 8,367.74 to 5,648.29 ± 8,667.38, respectively. The total effective rate was 65.8% and 50.7% in SSYX and mexiletine groups (P < 0.001). In addition, SSYX capsule significantly alleviated PVCs-related symptoms such as palpitations, chest tightness, insomnia, fatigue, and night sweats. No adverse cardiac events were observed except some slight gastrointestinal side effects during the study.</p><p><b>CONCLUSIONS</b>Compared with placebo or mexiletine, SSYX capsules have significant therapeutic efficacy in reducing PVCs numbers and alleviate PVCs-related symptoms.</p>

Prevalence of Epsilon wave in patients with arrhythmogenic right ventricular cardiomyopathy / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the prevalence of Epsilon wave in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC).</p><p><b>METHODS</b>The epsilon wave was detected in 32 patients [24 men, mean age (42.3 +/- 13.3) years] with ARVC using three different electrocardiography (ECG) recording methods: standard twelve leads ECG (S-ECG), right precordial leads ECG (R-ECG) and Fontaine bipolar precordial leads ECG (F-ECG). The Epsilon wave was defined as wiggler, small spike wave and smooth potential between the end of the QRS complex and the beginning of the ST segment.</p><p><b>RESULTS</b>Epsilon wave was detected in 37.5%, 37.5% and 50.0% patients with ARVC by S-ECG, R-ECG and F-ECG respectively. The detection rates derived from the three recording methods were similar (P > 0.05). The Epsilon wave was only detectable by S-ECG in one case, by R-ECG in three cases, and by F-ECG in five cases. The detection rate of Epsilon wave was 50.0% by combined use of S-ECG and R-ECG (SR-ECG), 56.3% by combined use of S-ECG and F-ECG (SF-ECG), and 65.6% by combined use of the three recording methods (SRF-ECG). The detection rate was significantly higher by SF-ECG (56.3%) and SRF-ECG (65.6%) than by S-ECG alone (37.5%, all P < 0.05). Most Epsilon waves detected by the S-ECG, R-ECG and F-ECG were small spiked waves.</p><p><b>CONCLUSION</b>Combined use of S-ECG, F-ECG and R-ECG could increase the detection rate of Epsilon wave in patients with ARVC.</p>

Detection of gene mutations of SCN5A in 7 patients with Brugada syndrome / 中华心血管病杂志

<p><b>OBJECTIVE</b>Brugada syndrome is linked to sodium channel mutations and could induce arrhythmias that even lead to sudden death. The purpose of this study was to detect if there was gene mutation of SCN5A in 7 patients with Brugada syndrome and explore the molecular genetic characteristics of this disease.</p><p><b>METHOD</b>Genomic DNA was extracted from peripheral blood of all 7 patients with Brugada syndrome and 41 pairs of PCR primers were designed to amplify all the 28 exons of SCN5A.</p><p><b>RESULT</b>There was no novel mutation in exons of Gene SCN5A in these patients with Brugada syndrome.</p><p><b>CONCLUSION</b>Brugada syndrome might associated gene mutation or other mechanisms independent of SCN5A gene mutation.</p>

Electrophysiological findings and ablation strategies in patients with atrial tachyarrhythmias after left atrial circumferential ablation in the treatment of atrial fibrillation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To report the electrophysiological findings and the ablation strategies in patients with atrial tachyarrhythmias (ATAs) or atrial fibrillation (AF) recurrence after left atrial circumferential ablation (LACA) in the treatment of AF.</p><p><b>METHODS</b>91 patients with AF had LACA procedure from April 2004 to May 2006, 19 of which accepted the second ablation procedure due to ATAs or AF recurrence. In all the 19 patients [17 male, 2 female, age 25 - 65 (53 +/- 12) years], 11 presented with paroxysmal AF before the first ablation procedure, 2 with persistent AF and 6 with permanent AF. Pulmonary vein potentials (PVP) were investigated in both sides in all the patients.</p><p><b>RESULTS</b>Delayed PVP was identified inside the left circular line in 5 patients, in the right in 1 and both in 2 during sinus rhythm. "Gap" conduction was found and successfully closed guided by circular mapping catheter. In 3 cases, irregular left atrial tachycardia was caused by fibrillation rhythm inside the left ring via decremental "gap" conduction. Reisolation was done successfully again guided by 3-D mapping and made the left atrium in sinus rhythm but the fibrillation rhythm was still inside the left ring. Pulmonary vein tachycardia with 1:1 conduction to the left atrium presented in one case and reisolation stopped the tachycardia. No PVP was discovered in both sides in 4 patients but other tachycardias could be induced, including two right atrial scar related tachycardias, two supraventricular tachycardias mediated by concealed accessory pathway, one cavo-tricuspid isthmus dependent atrial flutter and one focal atrial tachycardia near the coronary sinus ostium. All the tachycardias in these 4 patients were successfully ablated with the help of routine and 3-D mapping techniques. In the rest 3, which were in AF rhythm, LACA was successfully done again. After a mean follow-up of 4 - 26 (11.5 +/- 8.5) months, 16 patients were symptom free without anti-arrhythmic drug therapy; 1 of them had frequent palpitation attack with Holter recording of atrial premature contractions; 2 of them with permanent AF became paroxysmal in one, and still in AF in the other.</p><p><b>CONCLUSIONS</b>Reconduction between the left atrium and the pulmonary veins is the dominant factor for post-LACA ATAs and AF recurrence. Other forms of atrial tachycardias or supraventricular tachycardias may coexist with AF or sometimes trigger AF. LACA can not sufficiently modify AF substrate in some permanent AF patients.</p>

Tpeak-Tend interval and risk of cardiac events in patients with Brugada syndrome / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the possible association between Tpeak-Tend (Tp-e) interval in surface standard ECG and cardiac events in patients with Brugada syndrome (BrS).</p><p><b>METHOD</b>Tp-e interval in surface standard ECG was compared between BrS patients (n = 23, all males) and paroxysmal supraventricular tachycardia (PSVT) patients (n = 20, all males) as well as between BrS patients with (n = 16) or without (n = 7) cardiac events.</p><p><b>RESULTS</b>There was significant difference in Tp-e interval between BrS patients and PSVT patients [(109.57 +/- 22.86) ms vs. (88.50 +/- 13.08) ms, P < 0.05]. Tp-e interval was also significantly longer in BrS patients with cardiac events (syncope, clinical ventricular fibrillation and induced VF during electrophysiological study) than BrS patients without cardiac events [(118.12 +/- 20.40) ms vs. (90.00 +/- 15.27) ms, P < 0.05] while Tp-e interval was similar between BrS patients without cardiac events and PSVT patients (P > 0.05).</p><p><b>CONCLUSION</b>The prolongation of Tp-e (> or = 120 ms) was associated with higher cardiac events in BrS patients.</p>

Time distribution of ventricular arrhythmias in patients with Brugada syndrome / 中华心血管病杂志

<p><b>OBJECTIVE</b>To study the characterization of time distribution of ventricular arrhythmias in patients with Brugada syndrome (BrS) using Holter monitoring and ICD follow-up.</p><p><b>METHODS</b>Patients with BrS [all male, mean age (41.07 +/- 11.49) years], were divided into ventricular fibrillation (VF) group (n = 7) and no ventricular fibrillation (N-VF) group (n = 7). Premature ventricular capture (PVC) and VF episodes were detected by Holter monitoring and ICD recording.</p><p><b>RESULTS</b>The 24 hours total number of PVCs ranged from 0 to 74 (mean 9.61 +/- 17.23) in most of the patients and were similar between VF group and N-VF group. The percentage of PVC episodes in VF group was significantly higher than that in N-VF group from nocturnal time to early morning (22:00 to 7:00, 98.67% vs. 44.14%, P < 0.01). There were total 75 VF episodes during (23.18 +/- 17.96) months' follow-up in 5 patients with BrS, 93.3% of which occurred from nocturnal time to early morning (22:00 to 7:00).</p><p><b>CONCLUSIONS</b>The episodes of PVC were enriched from nocturnal time to early morning in BrS patients, this time distribution could be a new noninvasive risk stratification factor for BrS. The episodes of VF in BrS patients were also enriched from nocturnal time to early morning and this time characteristic of episodes of VF could be used to guide drug therapy.</p>

Left atrium linear lesion encircling pulmonary veins guided by EnSite-NavX and double-Lasso technique for paroxysmal atrial fibrillation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy of left atrium linear lesion encircling pulmonary veins (PV) guided by EnSite-NavX and double-Lasso technique for paroxysmal atrial fibrillation (PAF).</p><p><b>METHODS</b>Twenty-two patients (male 19, mean age of 48.5 years +/- 11.4 years) with symptomatic PAF were enrolled. After a geometry of the left atrium was reconstructed by EnSite-NavX system, PV ostia were marked on the map based on venography. Two Lasso catheters were placed within the ipsilateral superior and inferior PVs. Irrigated radiofrequency energy was applied at 0.5-1.0 cm of distance from the PV ostia. Continuous linear lesion was done to obtain the disappearance of pulmonary vein potentials. Patients were on propafenone and perindopril for three months after the procedure.</p><p><b>RESULTS</b>The endpoint for ablation was reached in 21 Patients and 1 patient was not successful because of cardiac tamponade. The mean procedure time was 6.6 h +/- 1.3 h and the mean X-ray exposure time was 56.1 min +/- 18.0 min. After a mean 5.3 months +/- 2.7 months of follow-up, 10 patients were free of symptoms. Two patients had no PAF recurrence after the second procedure. Three patients had clinical recurrence of PAF in the first month. The total success rate in this study was 81% (17/21). Mortality was 0% and the overall complication rate was about 9% (2/22).</p><p><b>CONCLUSION</b>Left atrium circumferential linear ablation surrounding PV ostia guided by EnSite-NavX and double-Lasso technique is effective in PAF, but some patients will need more than one procedure in order to achieve a success.</p>

The electrophysiological study and implantable cardioverter defibrillator therapy for the patients with Brugada syndrome / 中华心血管病杂志

<p><b>OBJECTIVE</b>Clinical observation of electrophysiological study and implantable cardioverter defibrillator (ICD) therapy in patients with Brugada syndrome.</p><p><b>METHODS</b>Ten patients (all male) with Brugada wave (spontaneous or propafenone test positive in ECG) underwent electrophysiological study (EPS). The mean age was (41 +/- 10) years. They had no structural heart disease with echocardiogram and the angiogram work-up. The ICD implanted in the patients with EPS-induced ventricular fibrillation in those who were available.</p><p><b>RESULTS</b>Three patients had the history of familial sudden cardiac death (SCD). Four patients had repeated syncope episodes, two of them had documented ventricular fibrillation during syncope episodes. The AH and HV intervals were 50 - 124 (86 +/- 21) ms and 41 - 84 (58 +/- 15) ms. The ventricular fibrillation was induced in four patients with syncope and atrioventricular reentry tachycardia in one patient with palpitation. Three patients had spontaneous or inducible atrial fibrillation. The ICD implanted in three patients with inducible ventricular fibrillation. Due to economic issue, one patient without ICD implantation had got SCD during follow-up. The patient with atrioventricular reentry tachycardia underwent a successful left atrioventricular accessory pathway ablation.</p><p><b>CONCLUSION</b>The Brugada patients with syncope and high rate of inducible ventricular fibrillation in EPS are the high risk population for SCD, in whom ICD should implant promptly to prevent SCD.</p>

Application of dynamic substrate mapping in ablation of ventricular tachycardias in arrhythmogenic right ventricular cardiomyopathy / 中华心血管病杂志

<p><b>OBJECTIVE</b>To study the application of abnormal electrophysiological substrate mapping for guiding ablation of ventricular tachycardias in arrhythmogenic right ventricular cardiomyopathy (ARVC-VTs) using a non-contact mapping system.</p><p><b>METHODS</b>Dynamic substrate mapping was performed in three male ARVC patients during sinus rhythm. The sites of the earliest activation, exit point and activation sequence were mapped for each induced VT.</p><p><b>RESULTS</b>Three different patterns of substrates were determined in 3 patients, which located in right ventricular outflow tract, anterior right ventricular wall, and anterolateral right ventricular wall, respectively. Five different clinical VTs [mean CL (348 +/- 65) ms] were induced. Of 5 VTs, three were originated from substrate or boundary of substrate, and two had a remote origin. One VT conducted through the substrate. Linear ablations were created between the sites of the earliest ventricular activation and the VT exit point, or across the critical isthmus. The five clinical VTs were successfully ablated. There were no VT recurrences during 20 months of follow-up.</p><p><b>CONCLUSIONS</b>Defining the abnormal electrophysiologic VT substrates is useful for understanding the mechanisms of ARVC-VTs and determining an ablation strategy. Linear ablation across a critical isthmus or between the earliest activation and the exit point can effectively cure these arrhythmias.</p>

Adenosine-5'-triphosphate test for the noninvasive diagnosis of AV nodal dual pathways(AVNDP) and assessment of results of slow pathway ablation in patients with AV nodal reentrant tachycardia / 中国临床药理学与治疗学

Aim To assess the value of the administration of adenosine-5'-triphosphate (ATP) during sinus rhythm for noninvasive diagnosis of AV node dual pathways(AVNDP) and abolition or modification of the slow pathway (SP) after radiofrequency(RFCA) in patients with inducible sustained AVNRT. Methods Incremental doses of ATP were intravenously administrated during sinus rhythm to patients with spontaneous or inducible sustained AVNRT(study group, n=45)and to patients with no evidence of AVNDP or inducible AVNRT (control group, n=37) until ECG signs of AVNDP( 50 ms increase or decrease in P-R interval in two consecutive beats, or occurrence of AVNRT) or second-degree AV block were observed. Results Four patients (two in study patients and two in control patients) could not complete the trial and were excluded from analysis. AVNDP was observed by ATP in 36(84%) study patients, whereas it was diagnosed by electrophysiology criteria in 38(88%) patients. AVNDP was observed only in 1(3%) control patient. AVNDP by ATP test was disappeared in 18(90%) of 20 patients who underwent SP abolition and in 3(38%) of 8 patients who underwent SP modification. Conclusion ATP test during sinus rhythm enables noninvasive diagnosis of AVNDP in a high percentage of patients with inducible AVNRT and reliably confirms the results of RFCA of the SP.