Objective To investigate the value of contrast enhancement T1 mapping in detection of diffuse myocardial fibrosis in cardiomyopathy, and the relationship between myocardial fibrosis and cardiac function. Methods From September 2013 to September 2014, 76 cases of cardiomyopathy patients (including myocarditis) and 33 cases of healthy controls were enrolled in our study. All the subjects underwent cardiac MR (CMR) examination. Scan sequences included cine MR, pre-contrast and post-contrast T1 mapping and late gadolinium enhancement (LGE) imaging. The pre-/post-contrast left ventricle average T1 value and cardiac function of patients and controls were measured and compared by using independent-samples t test. According to the LGE imaging, all the subjects were subsequently divided into LGE positive group, LGE negative group and control group. The myocardial average T1 value and cardiac function among the three sub-groups were compared by using one-way ANOVA, and the relationship among them were analyzed by using Pearson correlation. Results Among the 76 cases of non-ischemia cardiomyopathy patients, 51 cases (67.1%) had LGE. Compared with controls, cardiomyopathy patients presented with higher pre-contrast T1 value [(1 306.4 ± 84.6)ms vs. (1 266.6 ± 57.3)ms, t=2.10, P<0.05] and lower post-contrast T1 value [(483.6 ± 112.0)ms vs. (534.1 ± 92.7)ms,t=-0.27, P<0.05]. Pre-contrast and post-contrast average T1 value of LGE positive patients were (1 322.2 ± 85.8) and (459.7 ± 132.2)ms respectively;pre-contrast and post-contrast average T1 value of LGE negative patients were (1 267.0 ± 68.5) ms and (521.0±95.2)ms, there were statistical significant differences of T1 value between LGE positive and LGE negative patients (P<0.01), however, there were no statistical significant differences of T1 value between LGE negative patients and controls (P>0.05). There were correlation between pre-/post-contrast left ventricle T1 value and ejection fraction (EF) in cardiomyopathy patients (r=-0.252,-0.217, P<0.01), however no statistical correlation with other cardiac function parameters (P>0.05). Conclusions The average pre-/post-contrast T1 value in left ventricle myocardium are helpful for detection of diffuse fibrosis in cardiomyopathy patients. The LGE positive is a sign that can greatly change the T1 value of the myocardial tissue, meanwhile, myocardial fibrosis is negative correlated with ejection fraction in cardiomyopathy patients.

Objective:To investigate the relationship between serum procollagen Ⅲ amino terminal peptide (PIIINP), collagen I carboxyl terminal cross-linking peptide (CTXI), high-sensitivity C-reactive protein (hs-CRP) and cardiac magnetic resonance (CMR) T 1 mapping value in patients with lone atrial fibrillation (AF). Methods:Fifty-five patients with lone AF in Beijing Anzhen Hospital from July 2017 to June 2018 were prospectively enrolled. Another 20 healthy volunteers were examined at the same time to provide normal reference range. All patients completed PIIINP, CTXI, hs-CRP and CMR examination within one week. CMR examination including cine, pre-contrast T 1 mapping, and late gadolinium enhancement sequences. We used t test, Mann-Whitney U test or chi square test to compare the difference of the above indexes between AF patients and the control group. Spearman correlation analysis was used to determine the associations between left ventricular native T 1 value and blood biomarker in AF patients. Results:All the patients were paroxysmal AF with an average age of (48±10) years, of which 46 (83.6%) were male. The PIIINP, CTXI, hs-CRP, left ventricular native T 1 value of AF patients were 5.83 (3.52, 12.40) ng/ml, 4.63 (3.31, 6.82) μg/ml, 3.41 (1.72, 6.61) mg/L and (1 261±23) ms, respectively, which all significant higher than those in healthy subjects (all P<0.05). The native T 1 value of left ventricular myocardium was positively correlated with PIIINP ( r=0.492, P<0.05) and hs-CRP ( r=0.516, P<0.05), but not with CTXI ( r=0.021, P>0.05). Conclusions:The PIIINP, CTXI and hs-CRP increased in patients with lone AF, PIIINP and hs-CRP were correlated with elevated native T 1 value of left ventricular myocardium.

Objective To evaluate the diffuse myocardial fibrosis of the left ventricle (LV) in patients with atrial fibrillation (AF) by cardiac MR (CMR) T1 mapping methods.Methods Totally 60 subjects (30 paroxysmal AF patients and 30 persistent AF patients) and 59 normal control underwent MR cardiac cine,late gadolinium enhancement,and LV T1 mapping.For T1 mapping,modified Look-Locker inversion recovery sequence was used.Compared with control,pre-contrast ventricular T1 times were quantified and extracellular volume (ECV) was calculated.Results All subjects completed the CMR exam,no myocardial delay enhanced lesion was found.Pre-contrast ventricular T1 time in healthy controls was lower than that in patients with persistent and paroxysmal AF,and the pre-comrast ventricular T1 time in persistent AF patients was higher than that of paroxysmal AF patients (all P＜0.05).The mean LV myocardial ECV had no statistical difference between healthy controls and paroxysmal AF patients (P＞ 0.05),while lower than persistent AF patients (P ＜ 0.05).The mean LV myocardial ECV in patients with persistent AF was larger than that in patients with paroxysmal AF (P＜0.05).LV functional indexes were positive correlated with pre-contrast ventricular T1 time and ECV in patients with AF (all P＜0.05).Conclusion There is LV myocardial fibrosis in patients with AF,and the degree in patients with persistent AF is more severe than that in patients with paroxysmal AF.

To evaluate the feasibility of real-time myocardial contrast echocardiography (RTMCE) by quantitative analysis of myocardial perfusion in rabbits, transthoracic RTMCE was performed in 10 healthy rabbits by using continuous infusion of SonoVue into the auricular vein. The short axis view at the papillary muscle level was obtained. The duration of the time that the contrast took to appear in right heart, left heart and myocardium was recorded. The regional myocardial signal intensity (SI) versus refilling time plots were fitted to an exponential function: y(t) =A(1-e(-beta(t-t0))) + C, where y is SI at any given time, A is the SI plateau that reflects myocardial blood volume, and beta is the slope of the refilling curve that reflects myocardial microbubble velocity. The A, beta and Axbeta values at different infusion rate of SonoVue were analyzed and the A, beta and Axbeta values in each segment in the short axis view at the papillary muscle level were compared. All the animal experiments were successful and high-quality images were obtained. The best intravenous infusion rate for SonoVue was 30 mL/h. The contrast appeared in right heart, left heart and myocardium at 7.5+/-2.2 s, 9.1+/-2.4 s and 12.2+/-1.6 s respectively. After 16.6+/-2.3s, myocardial opacification reached a steady state. The mean A, beta and Axbeta value in the short axis view at the papillary muscle level were 9.8+/-3.0 dB, 1.4+/-0.5 s(-1) and 13.5+/-3.6 dBxs(-1) respectively. A, beta and Axbeta values showed no significant differences among 6 segments. It was suggested that RTMCE was feasible for quantitative analysis of myocardial perfusion in rabbits. It provides a non-invasive method to evaluate the myocardial perfusion in rabbit disease models.

OBJECTIVETo explore if CHA2DS2 VASc score can predict substrate for persistent atrial fibrillation ( AF) and outcome post catheter ablation of AF.

METHODSFrom January 2011 to December 2012,116 patients underwent catheter ablation of persistent AF in our department and were enrolled in this study. CHA2DS2VASc score was calculated as follows: two points were assigned for a history of stroke or transient ischemic attack and age ≥ 75 and 1 point each was assigned for age ≥ 65, a history of hypertension, diabetes,recent cardiac failure, vessel disease, female. Left atrial geometry ( LA) was reconstructed with a 3.5 mm tip ablation catheter with fill-in threshold 10 in CARTO system. The mapping catheter was stabled at each endocardial location for at least 3 seconds for recording. The electrogram recordings at each endocardial location were analyzed with a custom software embedded in the CARTO mapping system. Interval confidence level (ICL) was used to characterize complex fractionated atrial electrograms (CFAEs) . As the default setting of the software, ICL more than or equal to 7 was considered sites with a highly repetitive CFAEs complex. CFAEs index was defined as the fraction of area of ICL more than or equal to 7 to the left atrial surface. The CFAEs index and outcome of catheter ablation among different CHA2DS2VASc groups were compared.

RESULTSOf the 116 patients, CHA2DS2VASc was 0 in 33 patients, 1 in 31 patients and ≥ 2 in 52 patients. Left atrial surface ((121.2 ± 18.9) cm2, (133.6 ± 23.8) cm2, (133.9 ± 16.1) cm2, P = 0.008), left atrial volume ((103.6 ± 24.8) ml, (118.3 ± 27.8) ml, (120.9 ± 20.9) ml, P = 0.005) and CFAEs index (44.6% ± 22.4%, 54.2% ± 22.2%, 58.7% ± 23.1%, P = 0.023) increased in proportion with increasing CHA2DS2VASc. ICLmax, ICLmin and CFAEs spatial distribution were similar among the three groups. During the mean follow-up of (13 ± 8) months, the recurrence rate were 36.4%, 35.5%, 55.8% among the three groups (P = 0.025).

CONCLUSIONA high CHA2DS2VASc score is associated with extensive AF substrate and higher recurrence rate post catheter ablation of persistent AF.

Aged ; Atrial Fibrillation ; Catheter Ablation ; Electrophysiologic Techniques, Cardiac ; Female ; Heart Atria ; Heart Failure ; Humans ; Hypertension ; Recurrence ; Stroke ; Treatment Outcome

Objective Cryoballoon ablation of pulmonary vein (PV) ostia often induces a vagal response.This prospective study was designed to assess the effectiveness of prophylactic intravenous administration of atropine on hemodynamic impairment induced by cryoballoon ablation in patients with atrial fibrillation.Methods Twenty-five patients with paroxysmal atrial fibrillation undergoing cryoballoon ablation were prospectively enrolled and assigned to either the trial group on the control group.First twelve patients (the trial group) were administered 1 mg of atropine before deflation of the cryoballoon,while the following 13 patients (the control group) were given atropine only after the onset of the hemodynamic variation (decrease in heart rate and/or blood pressure).Treatment was considered effective when the hemodynamic variations were restored.Results In the trial group,three patients with transient hypotension did not require further supportive care throughout the procedures and one patient with hypotension required supportive management.In the control group,hypotension,bradycardia and mixed bradycardia with hypotension requiring supportive care occurred in six,three,and three patients,respectively.Overall,the rate of marked vagal responses was significantly lower when prophylactic atropine was administrated (4/12 vs.12/13 patients,P ＜ 0.01).Conclusions Atropine is effective in the prevention of all types of vasovagal responses induced by cryoballoon ablation in patients with atrial fibrillation.

Objective To investigate ablation characteristics of PVC/VT originating from left ventricle anterior papillary muscles.Methods This study included 10 patients of PVC/VT originating from left ventricle anterior papillary muscles from January 2015 to June 2016 in Beijing Anzhen Hospital.Electrophysiological mapping and radiofrequency ablation were completed using three-dimensional anatomical mapping system combined with three-dimensional intracardiac ultrasound technology.ECG and abaltion target diagram characteristics as well as the special anatomy were explored.Results All the 10 patients were successfully ablated and followed up for 12 months.One patient had recurrence within 12 months and no complications were recorded.The target sites localized at the tip (n =1),middle portion(n =4)or the base (n =5) of the LV-APM.Among 7 patients,the target sites were located at the anterior septal papillary muscle and in 3 patients were located in the free papillary muscle.9 patients were successfully ablated via anterograde trans-septal catheterization after the failure of retrograde approach.Premature QRS wave time were 152.80 ± 11.72 ms and 6 patients presented sharp potential at the targets during PVC/VT.Conclusions PVC/VT originating from left ventricle anterior papillary muscles have similar ECG and diagram characteristics that is different from which originating from left anterior fascicle.It is recommended to get the target via transseptalpuncure approach.Ablation target could be clearly positioned by three-dimensional intracardiac ultrasound technology.

Objective The recurrence of perimitral atrial tachycardia is common after initial ablation of persistent atrial fibrillation (AF). The aim of the study is to explore a preferable ablation approach for perimitral atrial tachycardia in the redo ablation of persistent AF. Methods Seventy-four patients with perimitral atrial tachycardia after initial ablation for persistent AF were included in our study. Patients were distinguished into either the group of having ablation during tachycardia (Group A) or the group having ablation after cardioversion to sinus rhythm (Group B) according to the different ablation strategies. The procedural endpoints were pulmonary vein isolation and bidirectional conduction block of all the ablated lines. The primary endpoint of the study was freedom from atrial tachyarrhythmia recurrence during the follow-up period. Results There were statistical differences in baseline clinical data between the 2 groups. During the redo procedure, conduction recovery rate across the mitral isthmus (MI),cavotricuspid isthmus and left atial roofline were 100％, 40.5％ and 48.6％ respectively. The procedural time, fluoroscopy time, mapping time were longer in the patients of group A. During a mean follow-up of (16.9±6.3) months, 31 (72.1％) patients in group A and 21(67.7％) patients in group B maintained in sinus rhythm in the absence of antiarrhythmic durgs (P =0.771) . Conclusion In patients with perimitral atrial tachycardia after initial ablation for persistent AF,ablation in sinus rhythm is a more simplified method and as effective as ablation during tachycardia.

Objective To observe the management and outcome of the cardiac tamponade patients during the ablation procedure using two different anticoagulation strategies. Methods All the patients developed tamponade during the ablation procedure were enrolled from January 2007 to December 2013 in our center. In group 1, warfarin was discontinued 3 to 5 days before the procedure and low molecular weight heparin (LMWH) was administered subcutaneously until ablation procedure day. In group 2, warfarin was not discontinued and the international normalized ratio INR was to maintained between 2 and 3. Results There were 27 patients (0.6%) developed cardiac tamponade out of a total 4487 patients received ablation in our center. The baseline clinical characteristics including age, left atrium, the heparin dose and ACT during the procedure had no signiifcant difference between the groups, except that the INR was higher in the group 2 (0.9±0.1 vs. 2.3±0.5, P<0.001). There was no signiifcant difference in the amount of pericardiac drainage between the two groups (365±222 ml vs. 506±300 ml, P=0.137). Two patients in group 1 patient (11.1%) and 1 in group 2 (11.1%) needed emergency surgical repair (P>0.999). The median hospital day was similar in the 2 groups [(9.6±3.3) d vs. (12.1±4.5) d, P=0.167]. There were no other serious complications and no hospital death. Conclusions Non-discontinuation of warfarin during peri-procedural catheter ablation of AF is not signiifcantly different to bridging with LMWH in the management and outcome of acute cardiac tamponade.

Objective Identify the mechanism of induced atrial arrhythmias after pulmonary vein isolation (PVI) in patients with paroxysmal atrial ifbrillation(PAF), and investigate its long-term prognosis. Methods All patients with PAF undergoing PVI and induction test afterwards between Feburary 2010 and October 2010 were included. The induction protocol was rapid pacing initiated at cycle length of 250 ms with progressive shortening in a decrement of 10 ms down to 180 ms or refractoriness. Isoproterenol of 2-4μg/min was administrated as well. Inducibility was deifned as induction of atrial arrhythmia lasting >1 min. The mechanism of induced tachycardia was identiifed by activation mapping and entrainment mapping under the guidance of CARTO system. All patients were followed up by 36 months. Results Forty-nine atrial tachycardia were induced in 39 (19.7%) patients, including 35 organized atrial tachycardia (OAT) and 14 atrial ifbrillation (AF). The LA diameter was signiifcantly larger in inducible group than non-inducible group (39.5±6.6 mm vs. 36.7±5.2 mm, P=0.004). Macroreentry was the most common mechanism in induced OATs (28, 80.0%), and mitral isthmus was the most common critical site (20, 40.8%), followed by cavo-tricuspid isthmus (12, 24.5%), PV (6, 12.2%), LA septum (4, 8.2%), superior vena cava (3, 6.1%) and LA roof (1, 2.0%). Conclusions The most common mechanism of induced tachycardia by IV isoproterenol and rapid pacing is MI and CTI dependent after PVI in PAF patients, which can be succssefully eliminated by liner ablation, not increasing long-term recurrence rate.