ABSTRACT
<p><b>OBJECTIVE</b>To analyze the extent of myocardium and coronary artery lesion post atrioventricular ring radiofrequency catheter ablation with different tip catheters.</p><p><b>METHODS</b>Twenty-one healthy dogs were randomly divided into 64 degrees C/50 W/100 s, 64 degrees C/100 W/100 s, 45 degrees C/45 W/100 s groups and ablated by 4 mm tip catheter, 8 mm tip catheter and irrigated tip catheter respectively. Left atrioventricular ring and right atrioventricular ring ablation were performed in all dogs. After ablation, myocardium lesion volume was calculated as 1/6pi x length x width x depth. Histological examinations were performed at the myocardium tissue at ablation sites.</p><p><b>RESULTS</b>The lesion depths post 8 mm tip catheter ablation (7.18 +/- 1.72) mm and irrigated tip catheter ablation (7.99 +/- 1.77) mm were similar and significantly deeper than that post 4 mm tip catheter ablation (4.54 +/- 1.38) mm, P < 0.01. Similar results were found in terms of lesion volume [(356.76 +/- 94.44) mm(3) post 8 mm tip catheter ablation, (391.69 +/- 109.54) mm(3) post irrigated tip catheter ablation and (191.34 +/- 74.52) mm(3) post 4 mm tip catheter ablation]. Five (5/42, 11.9%) transmural myocardium necrosis and 8 (8/42, 19%) coronary artery lesions were observed post ablations.</p><p><b>CONCLUSION</b>The extents of post ablation myocardium and coronary artery lesion were significantly higher induced by 8 mm tip catheter and irrigate tip catheter compared those by 4 mm tip catheter.</p>
Subject(s)
Animals , Dogs , Cardiac Catheterization , Catheter Ablation , Coronary Vessels , Pathology , Myocardium , PathologyABSTRACT
<p><b>BACKGROUND</b>Radiofrequency catheter ablation (RFCA) has been established as an effective and curative therapy for ventricular tachycardia (VT) and severely symptomatic premature ventricular contraction (PVC) from the outflow tract in structurally normal hearts. This study aimed to investigate electrophysiologic characteristics and effects of RFCA for patients with idiopathic VT and symptomatic PVC originating from the valve annulus.</p><p><b>METHODS</b>Characteristics of body surface electrocardiogram (ECG) and endocardiogram in a successful RFCA target were analyzed in 16 patients with idiopathic VT and symptomatic PVC originating from the valve annulus. Additionally, the ECG characteristics of VT or PVC were compared with those of manifest Wolff-Parkinson-White (WPW) syndrome originating from the same site of origin in 15 patients.</p><p><b>RESULTS</b>Thirteen patients were successful, 2 recurrent and 1 failed. The recurrent cases underwent successful ablation the second time guided by the Ensite 3000 mapping system. In all patients with the WPW syndrome, the characteristics of QRS morphology were well matched with those of the VT and PVC that originated from corresponding sites of origin.</p><p><b>CONCLUSIONS</b>RFCA is an effective curative therapy for VT and symptomatic PVC originating from the valve annulus. There are specific characteristics in ECG and the ablation site could be located by means of the WPW syndrome accessory pathway's algorithm.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Catheter Ablation , Methods , Electrocardiography , Mitral Valve , General Surgery , Tachycardia, Ventricular , General Surgery , Ventricular Premature Complexes , General SurgeryABSTRACT
Objective To observe the variation of enzymatic activity and areas and bulk of focus of heart injuries by using controllable catheter to ablate epicardial tmsue of rabbits and focus underneath atrioventrieular ring narcosis with 20% urethane(4 ml/kg)and divided into three groups.Each group included 7 rabbits.Anterior wallepieardium of left ventricle was ablated thirty seconds in each group(10,20 and 30 W)with self-made ablationspheroid microwave antenna,refilling with high pressure normal saline at same time.Then all of the rabbits were sacrificed respectively and their ventricular myocardium were taken out to undergo immunohistochemistry in order to display suceinate dehydrogenase(SDH).Also amplitude Wag measured in order to calculate areas of heart injuries.(8F)wag delivered to the pre-selected sites around atrioventricular ring of thirty-two healthy dogs,which had beenin intravenous narcosis with pentobarbital sodium(30 mg/kg).The dogs were divided into four groups(40,50,60 and 80 w) and two time points(60 and 120 s),by the combined method of X-ray and endocardial electrocardiograph,the microwave antenna could be confirmed to be located at the accurate position between anterior and posterior wall close to septum of left/right ventricle.After ventricular myocardium had been taken out,amplitude were measuredin order to calculate bulk of heart injuries by 1/6×3.14 x long×wide×deep.In addition.the histological changesand transmural injury were examined by optic microscope.Results In each group,the centre of injuries wagenzyme deficiency locus.The diameter and areag of heart injuries enlarged significantly(3.99.±0.41),(5.20±0.25),(6.31±0.37)mm and(12.53±2.56),(21.19±3.14),(30.96±3.76)mm2 with the increased microwave power level(10、20、30 W).Group comparison had statisficM significance(F＝76.8,58.5;P＜0.01 or ＜0.05).A total of 116points were ablated.The myocardial lesion showed ellipse in shape,and continuous symmetrical coagulationnecrosis under microscopic examination.There was a clear demarcated line around tlle myocardial tissue and fewparietal thmmbus.There were 16 transmura]injuries and five-with lung damage.The bulk of lesion aroundatrioventrieular ring hag been significantly enlarged(46.7±2.5),(51.1±2.7),(133.2±3.4),(141.8±3.9),(248.5±6.2),(260.3±6.5),(313.7±9.5),(327.4±10.5)with the increased microwave power level(40,50,60and 80 W)and/or distance of microwave ablation(60 and 120 s).Groups comparison had statistical significance(F＝31.16,27.85;all P＜0.01).In each time point,the lesion bulks had conspicuous distinction of statistics.In the same microwave power,the time wag longer,the bulk was larger(P＜0.01).Conclusions The more the microwave power level and time,the severe the heart injuries is.It is possible to use the microwave energy to ablate the deep focus under endocardium around atrioventricular ring.
ABSTRACT
Objective To find out pathologieal change and the expression of neuron specific enolage (NSE)in the hippocampus dentate gyrus granular cell layer of epilepsy patients,to investigate the relationship between the pathological change and the cause of the epilepsy.Methods The specimens of hippocampus were from 9 epilepsy patients and 20 normal persons and the pathological change were investigated under the staining of the hematoxylin and eosin staining.The expression of NSE in the hippocampns denmte gyrus granular cell layer of epilepsy patients was detected by immunohistochemistry(IHC)with specific antibody,and the rate of NSE positive nenrons was evaluated.Results The nuclear pyknosis was observed in all of hippocampus from the epilepsy patients and some neurons were swelling.The positive of NSE was showed to have yellow granule;the rate of NSE positive was 28.66%.The expression of NSE of the neurons in the hippocampus dentate gyrus granular cell layer was.significantly reduced in epilepsy patients(7.9±5.6)%.The normal neuron nuclear was big and round in the middle of the cell and the nucleolus could be seen easily.The expression of NSE of the neurons in the hippocampus dentate gyrus granular cell layer was(39.0±17.4)%.Compared with normal group,the number of neurons with yellow granule was reduced.The difference of the NSE expression rate between the two group was statistically significant(t＝-5.13,P＜0.01).Conclusions The result suggests that the pathological abnormality and the reduced expression of NSE on the hippocampus dentate gyrus granular cell layer neurons could be one of the main reasons of the occurring of epilepsy.
ABSTRACT
<p><b>OBJECTIVE</b>To observe the ECG and electrophysiological characteristic of patients with idiopathic ventricular tachycardia (VT) and premature ventricular contraction (PVC) originating from left (LVOT) and right (RVOT) ventricular outflow tracts and assess the clinical effect of radio frequency catheter ablation (RFCA) on these patients.</p><p><b>METHODS</b>RFCA was performed in 58 patients (10 with VT and 48 with PVC, 5 patients with VT from RVOT under the guidance of non-contact mapping system Ensite3000). VT or PVC originated from LVOT in 15 patients (12 out of 15 from left sinus of Valsalva) and RVOT in 43 patients.</p><p><b>RESULTS</b>(1) R wave in II, III, aVF leads was the common characteristics of VT or PVC originated from LVOT and RVOT and difference in wave duration index and R/S-wave amplitude ratio in V(1) or V(2) could be used to define VT and PVC originated from LVOT or RVOT. (2) Ablation was successful in 55 out of 58 patients (9 patients with the 2nd ablation, evaluated as arrhythmia-free at 3 months post ablation without medication) and failed in 3 patients. One patient developed pericardial tamponade during ablation and recovered without complication after related treatments.</p><p><b>CONCLUSIONS</b>RFCA is an effective, safe and curative therapy for VT or PVC originated from LVOT and RVOT. Non-contact mapping system (Ensite3000) is a safe and reliable tool to guide mapping and ablation in patients with complex VT and unstable hemodynamics.</p>
Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Catheter Ablation , Tachycardia, Ventricular , Therapeutics , Ventricular Outflow Obstruction , Ventricular Premature Complexes , TherapeuticsABSTRACT
<p><b>BACKGROUND</b>Atrial electrical remodeling (AER) contributes to the maintainance of atrial fibrillation (AF). This study was to compare the effects of Losartan with those of Diltiazem on tachycardia-induced acute AER in rabbits.</p><p><b>METHODS</b>Twenty-one rabbits paced with maximal atrial capture rate for 3 hours in the right atrium (RA) were randomly divided into saline group, Diltiazem group and Losartan group. After autonomic blockage, we measured atrial effective refractory period (AERP), AERP rate adapting feature, AERP dispersion and RA conduction time at basic cycle lengths (BCLs) of 200 ms and 150 ms at baseline, 0.5 hour, 1 hour, 2 and 3 hours after rapid atrial pacing.</p><p><b>RESULTS</b>In the saline group, there was a prompt decrease in AERP as a result of rapid atrial pacing, and AERP200 and AERP150 were shortened sharply within 0.5 hour of pacing (30.2 +/- 10.5 ms and 24.1 +/- 9.1 ms, respectively). The AERP did not change dramatically in the Diltiazem and Losartan groups. In the saline group, the value of (AERP200-AERP150)/50 ms in high RA was 0.17 +/- 0.08 at baseline and became significantly smaller at 0.5 hour (0.08 +/- 0.06), 1 hour (0.09 +/- 0.06), 2 hours (0.08 +/- 0.04) and 3 hours (0.09 +/- 0.05) (all P < 0.05), suggesting a reduction of rate adaptation of AERP. The value of (AERP200-AERP150)/50 ms in high RA did not change during the 3 hours of pacing in both Diltiazem and Losartan groups. In the saline group, AERP dispersion increased significantly at 2 and 3 hours (P < 0.05). However, Diltiazem could not prevent the increase of AERP dispersion at 3 hours (P < 0.05). During Losartan infusion, the AERP dispersion was no longer increased after rapid atrial pacing. There was no significant difference in RA conduction time among the three groups.</p><p><b>CONCLUSION</b>Like calcium antagonist Diltiazem, Losartan could prevent AERP shortening and preserve rate adaptation of AERP after rapid atrial pacing. Losartan is more effective than Diltiazem in inhibiting the increase of AERP dispersion.</p>