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Objective To explore the clinical effect of transesophageal atrial pacing (TEAP) in the diagnosis of unexplained tachycardia in children. Methods The results of TEAP in 28 children with unexplained tachycardia diagnosed and treated from September 2017 to August 2019 were retrospectively analyzed and were compared with the intracardiac electrophysiological study. Results A total of 28 children (19 boys; 9 girls) with an average age of 10.8±3.7 years were treated with TEAP .There were 15 cases of atrioventricular reentrant tachycardia (AVR7)，8 cases of atrioventricular node reentrant tachycardia (AVNR7)，and 2 cases of intra-atrial reentrant tachycardia (IAR7)，and a diagnostic rate was 89.29% (25/28).The ectopic tachycardia was not induced in 3 cases. Intracardiac electrophysiological study (IEPS) was performed in 21 patients. One patient had no ectopic tachycardia induced by TEAP and was diagnosed with idiopathic right ventricular outflow tract ventricular tachycardia (RVOT-VT) by IEPS. One case of left bypass atrioventricular reentrant tachycardia (LP-AVRT) was misdiagnosed of atrial tachycardia (AT).The diagnosis results of other patients using IEPS were consistent with TEAP, and a coincidence rate was 90.48% (19/21). Conclusions The diagnosis of tachycardia by TEAP is highly consistent with the results of IEPS. TEAP is recommended for children with clinically unexplained tachycardia, so as to clarify the diagnosis and classification of tachycardia and provide evidence for further diagnosis and treatment.
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Objective To explore the value of transesophageal atrial pacing (TEAP) and temporary cardiac pacing in the treatment of acute intractable tachyarrhythmia in children. Method The clinical data of children with acute intractable tachyarrhythmia treated with TEAP (48 cases) or temporary cardiac pacing (6 cases) from January 2014 to December 2017 were retrospectively analyzed. Results In the 48 cases aged 1 day to 13 years (28 males and 20 females) treated with TEAP, 25 cases had paroxysmal supraventricular tachycardia, in which there were 15 cases of rapid atrial flutter, 5 cases of atrial tachycardia and 3 cases of left ventricular idiopathic bundle branch reentrant tachycardia. The rates of successful cardioversion to sinus rhythm through TEAP were 84％, 80％, 20％ and 100％ respectively. In the 6 cases aged 2 to 10 years (1 male and 5 females) treated with temporary cardiac pacing, there were 5 cases of fulminant myocarditis and 1 case of noncompaction of the ventricular myocardium and their conditions were well controlled after treatment. Conclusion TEAP and temporary cardiac pacing have good curative effect in the treatment of acute intractable tachyarrhythmia in children. However, temporary electricity therapy can only temporarily rectify the hemodynamic abnormality threatening the life of children, and active comprehensive treatment for the primary diseases should be carried out simultaneously.
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Objective To explore the value of transesophageal atrial pacing (TEAP) in assessing the mechanism of paroxysmal supraventricular tachycardia (PSVT) in children. Methods The electrophysiological data of 50 children with PSVT who had undergone TEAP and, at a later stage, radio-frequency catheter ablation (RFCA) examination were retrospectively analyzed from January 2008 to December 2013. Results When using the intracardiac electrophysiological study (IEPS) as the diagnostic gold standard, the sensitivity of TEAP for atrioventricular nodal reentrant tachycardia (AVNRT), left accessory pathway (LAP) and right accessory pathway (RAP) was 92.9%, 83.1%and 90%respectively;the speciifcity was 86.4%, 100%and 95%respectively;the accuracy was 90%, 96%, and 94%respectively. The diagnostic accuracy of TEAP for AVNRT was 92.9%(26/28), the diagnosis accuracy for slow-fast AVNRT was 100%, but 2 cases of fast-slow AVNRT were both misdiagnosed as AVRT. The diagnostic accuracy of TEAP for AVRT was 86.4%(19/22) and 3 cases were misdiagnosed as slow-fast AVNRT. Conclusions TEAP has good clinical value in ifnding the mechanism of PSVT and its preliminarily location in children, but it has some limitations for some types of PSVT.
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Objective To evaluate the clinical application value of transesophageal atrial pacing (TEAP) combined with atropine load experiment in the diagnosis of the lesions of sinoatrial node and atrioventricular node.Methods One hundred and forty-four cases selected from the outpatient and hospitalized patients in the People's Hospital of Changji Hui Autonomous Prefecture from September 2009 to December 2012,who with dizziness, syncope and other clinical symptoms and electrocardiogram showe.TEAP combined with atropine load experiment were given to these patients.Results (1) The authors detected in all patients,83 cases (57.6％) were positive, among which, 48 cases (57.8％) male, 35 cases (42.2％) female.(2) The authors detected 57 cases(39.6％) non-increased vagus nerve tension cases in 83 positive cases,among which 33 cases (57.9％) male, 24 cases (42.1％) female;Among which 29 cases (20.1％) were sinoatrial node hypofunction, and 16 cases(55.2％) male;8 cases(5.6％) were atrioventricular node hypofunction,and 4 cases(50％) male;14 cases(9.7％) were double node hypofunction, and 10 cases (71.4％) male;6 cases (4.2％) were tachycardia-bradycardia syndrome, and 3 cases (50％) male;among which, a long interval of greater than 3 seconds appeared when we stimulate one 84 years old man with S1S1 stimulate way, immediately pressed protective pacemaker until his own sinus rhythm was restored, as a safety precaution, stoped further examination and classified him as sick sinus group.Conclusion Detect the common causes of slow sinus and atrioventricular block,such as the sinoatrial node dysfunction, atrioventricular node dysfunction, double node dysfunction and increased vagus nerve tension through TEAP combined with atropine load experiment.Consider that this methods have the best diagnostic value in decreasing its rate of false positivity,and should be used as a necessary check before implantation of pacemaker in such patients, suitable used in clinical, especially in basic general hospitals.
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Objective To identify the charactor of wide QRS complex tachycardia( WCT)throuGh transesophaGeal atrial pacinG( TEAP ). Methods TEAP and intracadiac electrophysioloGical examination infoamation of l2 cases WCT were collected and analyzed from January to February in 20l2 of Wuhan Asia Heart Hospital. Results Comparison of TEAP and intracadiac electrophysioloGical examination showed that l0 in l2 patients were match. Conclusion TEAP is a rapid and convenient method to diaGnose most WCT.
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[Abstract ] Objective Modern pharmacological studies confirmed Zhigancao Decoction total extract, single active ingredients and their combinations could obviously inhibit arrhythmia.This study was to investigate the effects of Zhigancao Decoction medicated serum combined with myocardial tissue/silicon substrate microelectrode arrays (MEA) on rapid atrial pacing(RAP). Methods New Zealand white rabbits were randomly divided into normal control group, normal serum control group, Zhigancao Decoction medica-ted serum group and water decoction group, 8 in each group.After the establishment of an atrial fibrillation rabbit model, the field ac-tion potential duration ( fAPD) of the right atrial appendage ( RAA ) tissue was measured and the effections of Zhigancao Decoction medicated serum and water decoction on the fAPD of RAA were observed. Results The successful modeling of rapid atrial pacing induced atrial fibrillation in rabbits contributed to the significant shortening of fAPD 12 h after pacing compared to that before pacing ([174.30 ±1.36]ms vs[162.48 ±0.88]ms, P<0.05).After giving 10%~25% Zhigancao Decoction medicated serum and water decoction, the fAPDs of RAA tissue in rabbits with atrial fibrillation were prolonged, which represented positive dose-response relation-ship.The fAPDs of the rabbits given serum containing 10%, 15%, 20%and 25%Zhigancao Decoction were respectively (170.81 ± 0.61)ms, (171.00 ±0.46)ms, (179.08 ±0.67)ms, (179.76 ±2.26)ms, which were longer than those of water decoction group ([163.82 ±0.780]ms, [163.66 ±0.95]ms, [174.06 ±1.32]ms, [176.84 ±1.19]ms), and the difference was statistically sig-nificant (P<0.05). Conclusion The fAPD can be taken as one index of cardiac electrophysiological change, and 10%~25%Zh-igancao Decoction medicated serum can lead to fAPD extension in rabbit model of atrial fibrillation, which might be the electrophysio-logical mechanism of anti-atrial fibrillation.
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Objective In this research we established rapid atrial pacing rabbit models, to investigate the effects of simvastatin on changes of early atrial effective refractory period (AERP) and protein expression of atrial α1c sub-unit of L-type calcium channel on atrial remodeling. Methods 42 rabbits were randomly divided into 3 groups:control group,rapid pacing group and simvastatin group,simvastatin 5 mg/( kg·d) was given intragastrically daily for two weeks before electrophysiology study in simvastatin group, normal saline was given intragastrically in control and rapid pacing group instead. Control group with no pacing, in simvastatin group and rapid pacing group, right atrium was paced at 800 beats/min for 8 hours to establish acute atrial fibrillation models, right atrial effective re-fractory period(AERP)was measured at the basic cycle length of 200 ms and 150 ms before pacing and 1,2,4,6, and 8 hours after the onset of the pacing, the changes of rate adaptation of AERP (AERP200-AERP150) were ana-lyzed . Right atrium tissue was obtained for measurement of protein expression of atrialα1 c subunit of L-type calcium channel by Western blot. Simultaneously,lipid levels in each group was examined. Results No significant differ-ence in lipid levels among three groups was observed. The AERP was shortened and the rate adaptation of AERP (AERP200-AERP150) disappeared during pacing compared with those before pacing(P<0.05). The shortening of AERP was reversed and AERP200-AERP150 was maintained in simvastatin group. Compared with the control group,the protein expression levels of atrial α1c subunit of L-type calcium channel decreased significantly after 8 hours pacing in rapid pacing group(P<0.01). The protein expression levels of simvastatin group decreased insig-nificantly . Conclusion Atrial rapid pacing can induce the shortening of the AERP and the losing of adaptability to the frequency of AERP,pretreatment with simvastatin can improve the degree significantly and maintain the adapta-bility to frequence basically. The protein expression levels of atrial α1c subunit of L-type calcium channel de-creased significantly after 8 hours pacing,pretreatment with simvastatin can prevent this change without lowering the lipid levels,thus contributing to the ionic mechanism of simvastatin for antiarrhythmia.
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Once considered as nothing more than a nuisance after cardiac surgery, the importance of postoperative atrial fibrillation (POAF) has been realized in the last decade, primarily because of the morbidity associated with the condition. Numerous causative factors have been described without any single factor being singled out as the cause of this complication. POAF has been associated with stroke, renal failure and congestive heart failure, although it is difficult to state whether POAF is directly responsible for these complications. Guidelines have been formulated for prevention of POAF. However, very few cardiothoracic centers follow any form of protocol to prevent POAF. Routine use of prophylaxis would subject all patients to the side effects of anti-arrhythmic drugs, while only a minority of the patients do actually develop this problem postoperatively. Withdrawal of beta blockers in the postoperative period has been implicated as one of the major causes of POAF. Amiodarone, calcium channel blockers and a variety of other pharmacological agents have been used for the prevention of POAF. Atrial pacing is a non-pharmacological measure which has gained popularity in the prevention of POAF. There is considerable controversy regarding whether rate control is superior to rhythm control in the treatment of established atrial fibrillation (AF). Amiodarone plays a central role in both rate control and rhythm control in postoperative AF. Newer drugs like dronedarone and ranazoline are likely to come into the market in the coming years.
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Adrenergic beta-Antagonists/therapeutic use , Anti-Arrhythmia Agents/therapeutic use , Atrial Fibrillation/etiology , Atrial Fibrillation/physiopathology , Atrial Fibrillation/prevention & control , Atrial Fibrillation/therapy , Calcium Channel Blockers/therapeutic use , Cardiac Pacing, Artificial , Cardiac Surgical Procedures , Electric Countershock , Electrophysiological Phenomena , Humans , Postoperative Complications/physiopathology , Postoperative Complications/therapy , Predictive Value of Tests , Risk Factors , Treatment OutcomeABSTRACT
We report a case of Mobitz type I atrioventricular block induced by atrial pacing in a 60 year old woman undergoing off-pump coronary artery bypass surgery. Reversible ischemic damage to the conduction system might be associated with this phenomenon.
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Female , Humans , Atrioventricular Block , Coronary Artery Bypass, Off-Pump , Myocardial IschemiaABSTRACT
Aim To determine the effects of sodium tashinoneⅡA sulfonate(TSN) on monophasic action potential(MAP) and tachycardia-induced electrical remodeling of rabbit atria in vivo.Methods Twenty-four rabbits were equally divided into two groups randomly: control group and TSN group.Electrical catheters were localized in the right atrium through right internal jugular vein.Right atrial MAP was recorded by multiple channel recording. ERP of right atrial(AERP) was assessed by programmed electrical stimulation before pacing and from 0～8 hours after the onset of the pacing.Results The AERP_(200 ms) of control group was shortened from (105.9?3.8) ms to(114.7?7.2) ms and the rate-dependent of control group's atrium was lost through the pacing process compared with TSN group before pacing(P
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Objective To investigate the indications to use a temporary pacemaker for bifascicular block in perioperative period.Methods The treatment for 40 patients with heart bifascicular block and a special case were retrospectively studied.All cases,according to their disease history,clinical symptoms,physical ability and atrio-ventricular conduction ability,were divided into two groups:P group(prophylactic insertion of a temporary pacemaker) and N group(without inserting a pacemaker).During operation,we observed whether atrio-ventricular block occurs,the performance of pacemaker and atropine's therapeutic efficacy to bradycardia.Results Anesthesia was postponed in one case because of acute left bundle branch block(LBBB) and the patient died with severe myocardium damage soon after failed resuscitation.All other cases went through anesthesia and operation smoothly.Bradycardia and hypotension could be relieved somewhat by medication in operation,and no complete atrio-ventricular block developed.Conclusion There is no need inserting a temporary pacemaker for chronic bifascicular block if asymptomatic and no atrio-ventricular block.Transesophageal atrial pacing is an easy way to evaluate in quantification atrio-ventricular conduction ability.
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PURPOSE: We intended to find out the role of transesophageal atrial pacing in evaluation of infants and children with palpitation of unknown origin. METHODS: We tried transesophageal atrial pacing study in 69 infants and children with palpitation, in whom tachycardia wasn't documented in electrocardiogram and reviewed retrospectively the records of transesophageal pacing and medical records of theses patients to find out the induction rate of tachycardia by transesophageal atrial pacing and the possible mechanism of tachycardia if induced. RESULTS: In 70.1% infants and children with palpitation, tachycardia was induced, so we could conclude that tachycaridia was the cause of palpitation in these cases. In most cases, tachycardia was induced by rapid atrial pacing, and in 21% by using isoproterenol. Tachycardia induction rate was higher in or =6-year-old children(P<0.05). In cases of the induced, we reviewed the mechanism of tachycardia. Of these induced tachycardias, 53.2% is atrioventricular reentry tachycardia, 34.0% were atrioventricular nodal reentry tachycardia, and 12.8% were idiopathic left ventricular tachycardia. Invasive electrophysiologic study was done to 10 patients of those induced. The results of electrophysiologic study and transesophageal pacing and recording were the same except for one patient. CONCLUSION: Transesophageal atrial pacing and recording is a less invasive, safe and useful method to find out the cause of palpitation and the mechanism of tachycardia in infants and children.
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Infant , Child , Male , Female , HumansABSTRACT
Objective To explore the causes of short P R interval syndrome.Methods 15 patients of short P R interval syndrome were tested with transesophageal atrial pacing (TEAP),and then the results and the parameters of TEAP were analyzed.Results The detection rates of dual atrioventricular nodal pathways(DAVNP),L G L syndrome and latent preexcitation syndrome were 66.67%(10/15),26.67%(4/15)and 6.67%(1/15)respectively.Conclusion The most common causes of short P R interval syndrome are DAVNP and the L G L syndrome
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Obiective To investigate the influence of rapid atrial pacing(RAP)on the expression of ?1c subunit of L-type calcium channel,and the protective effect of verapamil.Methods 30 rabbits were randomly assigned into RAP group and verapamil pre-conditioned group.Each group was further divided into 5 subgroups(n=3 for each subgroup).Electrode was embedded in the right atrium through right external jugular vein.Pacing was performed for 6h,12h,24h and 48h in different subgroups.No pacing in the sham operation group.For verapamil pre-conditioned group,the drug was intravenously administered(0.2mg/kg)30 minutes before the initiation of rapid atrial pacing.Right atrium tissue was harvested for determination of mRNA and protein expression of L-type calcium channel subunits by reverse transcription polymerase chain reaction(RT-PCR)and Western blot.Results The mRNA level of ?1c subunit started to be reduced 6h after rapid atrial pacing(RAP)and continued to decline as pacing continued,and the expression of protein was parallel with mRNA.Otherwise,the mRNA level of ?1c subunit started to decrease 24h after RAP and continued to decline while pacing continued,and the expression of protein paralleled with that of mRNA in verapamil pre-conditioned group.Verapamil can attenuate the down-regulation of L-type calcium channel of the atrium induced by RAP only at 24h after RAP,but the effect was less intent.Conclusion mRNA and protein expression level of L-type calcium channel subunits decreased after RAP,The calcium channel blocker verapamil can attenuate the down-regulation of L-type calcium channel of atrium induced by RAP resulting in a decrease or postponement of calcium overload in atrial myocytes,thus exerting protective effects on atrial electrical remodeling,but such effects vanished after prolonged pacing.
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AIM: To investigate the potassium channel gene expression of myocardial sleeves of pulmonary vein and effects of amiodarone on rabbits with rapid atrial pacing.METHODS: Rabbits were divided into three groups(n=10),(1) the control group with sham operation and placebo;(2) the right atrial pacing(RAP) group at 600 beats/min with the placebo;(3) the amiodarone group treated for seven days with oral amiodarone at 100 mg ? kg-1 ? d-1.Based on RAP simultaneously,the messenger ribonucleic acid(mRNA) of specimen was measured by reverse transcription-polymerase chain reaction.RESULTS: Compared with the control group,Kv4.3(transient outward K+ current,Ito1) mRNA expression in RAP group was reduced by 51%(P
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BACKGROUND: Pacing-induced atrial electrical remodeling (AER) is characterized by shortening of atrial effective refractory period (A-ERP) and its altered rate adaptation. In paroxysmal atrial fibrillation (AF), periods of AF occur with interveneing normal sinus rhythm (NSR) when atria recover from the preceding AER. Previous episodes of AF may precondition the atrial myocardium and cause different time course of AER in subsequent episodes of AF. But the influence of the preceding AER on the subsequent AER has not been described. METHODS: Four mongrel dogs were anesthetized with enflurane. After thoracotomy, silicon band with 3 pairs of electrodes was sutured to the lateral wall of the left atrium. Atrial pacing was performed after 2 wks of recovery and autonomic blockade. Pacing protocol consisted of rapid atrial pacing (RAP) at 500 bpm (for 60 min) and recovery in NSR (for 60 min) which was repeated three times. A-ERP was measured every 10 min. The same pacing protocol was repeated after pretreatment with verapamil (0.1 mg/kg/hr). RESULTS: 1) With 60 min of RAP, A-ERP decreased significantly (126+/-6 ms vs. 105+/-7 ms, p<0.005). 2) After cessation of pacing, A-ERP returned to 98% of baseline value in 15 minutes. Recovery from AER occurred faster than AER (78 vs 21 ms/h). 3) After pretreatment with verapamil, RAP decreased A-ERP from 127+/-5 ms to 116+/-5 ms. AER, the reduction in A-ERP, was significantly attenuated by pretreatment with verapamil (deltaERp=17+/-7 vs. 9+/-0.2 %, p<0.05). 4) When RAPs were repeated, AER showed a tendency of acceleration, but it was not statistically significant (deltaERp=22 ms, 24 ms, 28 ms at the end of 60 min pacing for the 1st, 2nd, 3rd pacing). CONCLUSION: RAP induced AER in conscious dog atria and it was reduced by pretreatment with calcium channel blocking agent, verapamil. Upon repeated atrial stimulations, AER did not accelerate or decelerate when the atria recovered from the preceding AER.
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Animals , Dogs , Acceleration , Atrial Fibrillation , Atrial Remodeling , Calcium , Calcium Channels , Electrodes , Enflurane , Heart Atria , Myocardium , Silicones , Thoracotomy , VerapamilABSTRACT
BACKGROUND: In aerometabolic process, the human heart mainly utilizes free acid as fuel. During anaerobic process, lactate production by the myocardium is increased and accumulates in the myocardium. Thus it decreases the contractility of myocadium. Therefore in patients with ischemic heart disease, lactate prodution must be increased by the myocardium during myocardial ischemia. During paroxysmal supraventricular tachycardia, patients frequently experience chest pain and ST segment depression suggesting acute myocardial ischemia. However it occurs on a physiologic basis independent of ischemia. The purpose of this study was to assess whether tachycardia induced by artial pacing produces myocardial ischemia in patients without evidence of ischemic heart disease. METHODS: Between May 28, 1996 and August 13, 1996, at the University of Keimyung, Dong-San Medical center, 15 patients(male 9, female 6, mean age of 38 years) with palpititation underwent electrophysiologic testing and had radiofrequency cather ablation. There were no evidence of ischemic heart disease. Right artrial pacing was done with lengths of 500msec, 400msec and 350msec in each 5 patients. A 12 lead electrdcardiogram, left ventricular enddiastolic pressure, blood from femoral artery and coronary sinus for lactate determinations and blood gas analysis were dbtained simultaneously. They were obtained at baseline, at 1, 5, 10 and 15 minute of atrial pacing and at 1, 5, 10 minute after cessation of pacing. RESULT: Significant changes were not observed in , , concentration of , pH and saturation. In all patients, mean percent lactate extraction was above 10% and not significantly changed during atrial pacing. However ST segment depression was significantly progressive during atrial pacing and according to decrease the cycle length(p<0.05), also left ventricular end-diastolic pressure was significantly decreased during atrial pacing(p<0.05). Conclusion: Therefore tachycardia induced by atrial pacing for 15 minutes did not produce myocardial ischemia in patients without evidence of ischemic heart disease. Depression of STsegment during supraventricular tachycardia or atrial pacing, in patient without underlying heart disease is necessary to inveestigate what makes this phenomenon.
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Female , Humans , Blood Gas Analysis , Blood Pressure , Chest Pain , Coronary Sinus , Depression , Femoral Artery , Heart , Heart Diseases , Hydrogen-Ion Concentration , Ischemia , Lactic Acid , Metabolism , Myocardial Ischemia , Myocardium , Tachycardia , Tachycardia, SupraventricularABSTRACT
PURPOSE--To evaluate the mechanisms and dynamics of episodes of progression to high degree (HD) atrioventricular (AV) block (B) analyzed during incremental atrial pacing (St), in patients with previous 2:1 His-Purkinje (HP) AVB. METHODS--Data from 4 patients were analyzed. All of them with history of syncope and ECG exhibiting 2:1 AVB with wide QRS pattern. The AVB was in the HP system (HPS) in all. Every patient was submitted to electrophysiologic study with incremental atrial pacing, by which the conduction sequences and the AV conduction ratios (AVR) were analyzed. The basal (B) cycle length (CL) was defined as the shortest interval between two conducted beats (spontaneous or pacing-induced). The incremental atrial stimulation was performed beginning with CL 10 msec shorter than BCL until reaching 250 msec. RESULTS--Nineteen episodes of progression to HD-AVB were seen. A) With StCL between 31 and 26 of BCL, AVR were 3:1, 4:1 and 5:1, with only one blocking zone (BZ) in the HPS; B) with StCL between 24 and 22 of BCL, AVR were 5:1, 7:2, 9:2e11:3. In this situation a 2nd BZ ensues-on proximal, site of a decremental conduction, situated in the AV node (AVN) or in the HPS, and the other (distal level) always in HPS; C) with StCL between 24 and 16 of BCL, AVR were 5:1, 6:1, 10:2, 11:2 and 12:3. Here, these AVR were explained by postulating 3 BZ where 2 were in AVN and 1 in HPS, or inversely with 1 in AVN and 2 in HPS. The decremental conduction occurred in 1 or 2 out 3 BZ and an integral conduction (like 2:1 or 3:1) in the others. CONCLUSION--The BCL is the determinant of the AVR observed. As the StCL is shortened (< 26 BCL) a 2nd or 3rd BZ in the AVN or in the HPS ensues. These observations suggest that the mechanisms and dynamics of progression to HD-AVB apply only during incremental atrial pacing and there is a clear difference with what has been observed with the progression occurring exclusively at AV node.
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Humans , Male , Female , Middle Aged , Heart Block/physiopathology , Atrioventricular Node/physiopathology , Purkinje Fibers , Electrocardiography , Heart Block/therapy , Cardiac Pacing, Artificial , Bundle of His/physiopathologyABSTRACT
Atrial flutter, a common rhythm disturbance, was first described over 80 years ago. Despite extensive investigations, several important issues remain unresolved concerning its exact mechanism and management. Present therapeutic strategies often appear effective to prevent and terminate atrial flutter. However, controlled trial and definitive studies comparing the various treatment options are surprisingly scarce. Here we report on a study of 9 episodes of spontaneous atrial flutter(AF)(flutter wave cycle length 224+/-39 msec) treatedd by transesophageal atrial pacing(TAP) in 9 patients(7 men and 2 women; mean age 56.9 yrs). TAP was effective in 5 patients : sinus rhythm resumption was immediate in 3 patients and followed a short period of atrial fibrillation in 2 patients. TAP was unsuccessful in 4 patients. All the patients tolerated the procedure well. These data strongly support the immediate first choice use of TAP in AF therapy.
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Female , Humans , Male , Atrial Fibrillation , Atrial FlutterABSTRACT
The study group consisted of 50 normal children. The determination of Sinus node func- tions included SNRT, CSNRT, SNRTI, SACT, IHR and autonomic nervous system tone. The A-V conduction system function was evaluated by measurement of wenckeback point and 2:1 point of A-V conduction system. Each parameter was determined before and after com- bined autonomic blockade. Before combined blockade, the Wenckeback point and 2:1 point appeared at the HR of 175-220 bpm were 90% of the cases and 98% of the cases respectively, after combined block- ade, they were 98% of the cases and 100% of the cases respectively. It also showed the domi- nant vagus had effect on A-V node.