Optimal lead positioning for postoperative atrial pacing.

Temporary atrial pacing leads have uncontested utility for diagnosis and treatment of postoperative supraventricular arrhythmias. Sensing and capture thresholds may be inconsistent, however. We evaluated intraoperative atrial sensing amplitude and capture thresholds in 25 patients after coronary bypass using six bipolar and four unipolar lead combinations based on four lead positions: A, atrial appendage; B, 1 cm above the presumed sinoatrial node at the atrial-superior-vena caval junction; C, interatrial groove at the right superior pulmonary vein; and D, caudal inferolateral free wall. Unipolar lead B and bipolar lead B-D had the best voltage pacing threshold and system resistance (p less than 0.05). The lowest current was also observed with unipolar lead B and bipolar lead B-D, but the difference was not significant (p greater than 0.05). P-wave amplitude was not significantly different for any lead combination. Location C, in unipolar or bipolar combinations, frequently paced the phrenic nerve. These data provide new guidelines for establishment of postoperative temporary atrial pacing leads.     

Sensing and pacing with floating electrodes in the right atrium and right atrial appendage

Unipolar and bipolar floating atrial electrograms from 58 pacemaker patients were recorded and compared. Twenty-four floating unipolar electrodes and 29 floating bipolar electrodes were used at mid-right atrial level and five orthogonal atrial J leads within the right atrial appendage. Each signal was analyzed in the time domain: peak to peak deflection of P wave and QRS complex, duration of P wave and QRS complex and slew rate; and in the frequency domain: maximum of the energy spectrum and frequency at which a decrease of 3 dB from the maximal amplitude occurred. Atrial P (1.31 +/- 0.94 mV, mean +/- SD) and QRS (1.0 +/- 0.56 mV) waves from unipolar floating electrodes were comparable, whereas they were significantly different from bipolar floating electrodes (1.15 +/- 0.77 mV and 0.25 +/- 0.39 mV). Amplitudes of P waves from orthogonal J leads were largest (3.1 +/- 2.6 mV) and QRS complexes (0.21 +/- 0.13 mV) smallest. The P waves had the highest frequency content (17.1 +/- 19.4 Hz). It is concluded that atrial electrograms from orthogonal electrodes (bipolar or orthogonal J) offer superior sensing characteristics because of the large amplitude P wave and discriminating power between P and QRS waves (P/QRS voltage 15:1). An orthogonal J lead can thus be used for P synchronous pacing at the atrial level, whereas an orthogonal ventricular lead can be used for rate-response pacing systems.     

Clinical experience with transvenous atrial pacing

Twelve patients were paced with a transvenous J-shaped bipolar electrode positioned in the right atrial appendage. All had chronic sinoatrial dysfunction and 5 had paroxysmal atrial arrhythmia: 2 had recent myocardial infarction, 1 angina decubitus, and 1 ventricular pre-excitation. Atrioventricular sequential pacing was employed in this last patient and this mode of pacing was substituted for atrial pacing in one other. The remaining 10 patients were paced from the atrium only. Electrode displacement occurred in 2 patients and 2 others had a rise in pacing threshold. After repositioning the electrode or substituting a more powerful pacemaker, sustained atrial capture was achieved in 3 of these 4. Sensing of spontaneous P waves was present constantly in 4 and variably in 3 of 9 patients. Symptomatic improvement was obtained in 10 patients. A bipolar pacemaker with a variable output voltage and a relatively high demand sensitivity is optimal for atrial pacing. Measurements of intra-atrial voltage with various electrode configurations in 7 patients suggest that atrial sensing may more often be achieved when the reference electrode is situated in the upper part of the right atrium than when it is close to the electrode tip in the atrial appendage.     

Clinical experience with transvenous atrial pacing.

Twelve patients were paced with a transvenous J-shaped bipolar electrode positioned in the right atrial appendage. All had chronic sinoatrial dysfunction and 5 had paroxysmal atrial arrhythmia: 2 had recent myocardial infarction, 1 angina decubitus, and 1 ventricular pre-excitation. Atrioventricular sequential pacing was employed in this last patient and this mode of pacing was substituted for atrial pacing in one other. The remaining 10 patients were paced from the atrium only. Electrode displacement occurred in 2 patients and 2 others had a rise in pacing threshold. After repositioning the electrode or substituting a more powerful pacemaker, sustained atrial capture was achieved in 3 of these 4. Sensing of spontaneous P waves was present constantly in 4 and variably in 3 of 9 patients. Symptomatic improvement was obtained in 10 patients. A bipolar pacemaker with a variable output voltage and a relatively high demand sensitivity is optimal for atrial pacing. Measurements of intra-atrial voltage with various electrode configurations in 7 patients suggest that atrial sensing may more often be achieved when the reference electrode is situated in the upper part of the right atrium than when it is close to the electrode tip in the atrial appendage.     

The sequence of retrograde atrial activation in the canine heart. Correlation with positive and negative retrograde P waves.

The relationship of P-wave polarity and morphology in leads II, III, and aVF to the sequence of atrial activation was studied in the canine heart when the atria were paced from the region of the sinus node or the posterior-inferior left atrium and when retrograde activation of the atria occurred with right ventricular epicardial pacing. Deeply negative P waves in leads II, III, and aVF which occurred when the posterior-inferior left atrium was paced were associated with true retrograde activation of the atria. Positive P waves recorded in leads II, III, and aVF during retrograde atrial capture with right ventricular pacing were associated with rapid retrograde spread of the impulse in the interatrial septum to the region of Bachmann's bundle from which site the impulse spread to depolarize significant portions of both atria in a manner similar to that demonstrated during pacing from the region of the sinus node. When the atria were paced from a site just anterior to the coronary sinus ostium, positive P waves recorded in leads II, III, and aVF were associated with early activation in the vicinity of Bachmann's bundle and later activation of the posterior-inferior left atrium. When the atria were paced from a site just posterior to the coronary sinus ostium, negative P waves in leads II, III, and aVF were associated with early activation of the posterior-inferior left atrium and later activation in the vicinity of Bachmann's bundle. It was concluded that the time of arrival of the impulse at Bachmann's bundle relative to that at the posterior left atrium and the direction of spread of the impulse from and within Bachmann's bundle are critical in determining P-wave polarity and morphology.     

Clinical significance of prolonged P wave width after right atrial appendage pacing in sick sinus syndrome.

The present study investigated both the clinical significance of atrial fibrillation (AF) before right atrial appendage (RAA) pacing and the influence of prolonged P wave on AF occurrence in RAA-paced patients with sick sinus syndrome (SSS). Fifty-seven patients (age 68+/-10 years; 19 men, 38 women) with SSS who underwent RAA pacing were divided into 2 groups: 23 patients without AF before pacing (I + II; Rubenstein I or II) and 34 patients with AF before pacing (III; Rubenstein III). The P wave duration in intrinsic rhythm and with RAA pacing were measured on the standard electrocardiography in leads II and V(1) with the use of a digitizing tablet. Group III was further subdivided into 2 groups: 20 patients (IIIb) with a paced P wave >130 ms in both leads II and V(1) and the other 14 patients (IIIa). The duration of the intrinsic P wave in leads II and V(1) was significantly greater in group III than in group I + II (119+/-20 vs 108+/-21 ms, p=0.0417, 106+/-16 vs 95+/-21 ms, p=0.0258, respectively). During the follow-up of 40+/-21 months, AF recurrence was significantly higher in group IIIb than in groups IIIa and I + II (17/20 vs 5/14 vs 2/23 p<0.0001). A few occurrences of AF were observed by conventional RAA pacing in patients without AF before pacing. However, SSS with AF before pacing caused a significant intra-atrial conduction disturbance and a high incidence of AF recurrence after implantation of RAA pacing, especially in patients with a prolonged paced P wave, in whom new pacing modalities may be needed to shorten paced P wave duration and prevent AF.     

Electrocardiographic characteristics in low atrial septum pacing

AIM: The aim of the study was to compare P-wave morphology and duration in pacing from the low right atrial septal wall and the high right atrial appendage (RAA). METHODS: The electrocardiogram (ECG) of 50 patients with low atrial septum (LAS) pacing and that of 50 patients with RAA pacing were compared with their electrocardiogram during sinus rhythm. RESULTS: In the frontal plane, patients with LAS pacing showed a superior P-wave axis between -60 degrees and -90 degrees . In all patients with RAA pacing, a P-wave axis between 0 degrees and +90 degrees was observed as in sinus rhythm. In the horizontal plane, all patients with LAS pacing had an anterior P-wave axis between +90 degrees and +210 degrees , whereas all patients with RAA pacing had a posterior P-wave axis between -30 degrees and -90 degrees . The terminal part of biphasic P waves in lead V 1 in LAS pacing was always positive, a pattern that was never observed in P waves of sinus origin or in RAA pacing. P-wave duration was longer with RAA pacing compared with LAS pacing (115 +/- 19 vs 80 +/- 14 milliseconds [ P < .01]). CONCLUSION: The total atrial activation time during LAS pacing is shorter than that during RAA pacing. The electrical atrial activation sequences in LAS pacing and RAA pacing are significantly different. The morphology of biphasic P waves in lead V1 during LAS pacing suggests that the initial part of activation occurs in the left atrium and the terminal part in the right atrium.     

Problems of artificial pacemaker therapy

Four hundred and sixty-seven cases with implantation of an artificial pacemaker were studied. The postoperative survival rate was 63% for 15 years. Seventy-two percent of type III patients of the sick sinus syndrome were free from postoperative thromboembolism and the lowest of the three types of the sick sinus syndrome. Comparing postoperative physical activity, cardiothoracic ratio and exercise tolerance time, physiological pacing was superior to ventricular pacing in hemodynamic effects and clinical symptoms. In a hundred cases of physiological pacing, complications and problems of physiological pacing were discussed. Atrial sensing failure and over-sensing were observed in seven and two cases respectively. A low amplitude of atrial potential and use of unipolar atrial leads were considered to be the main causes of these complications. Bipolar lead should be used as the atrial lead to avoid such complications, because the atrial potential by bipolar leads is not less than that by unipolar leads. Atrial sensing may be more sensitive without electromagnetic interference. The fixed A-V delay time whenever the atrium is sensed or paced, often results in a ventricular fusion beat and hemodynamic change on every beat, according to the interval of atrial and ventricular contractions. The A-V delay time should be changed in accordance with atrial sensing or pacing.     

Regional control of atrial fibrillation by rapid pacing in conscious dogs

BACKGROUND. In five chronically instrumented conscious dogs, we studied the effects of rapid pacing on sustained electrically induced atrial fibrillation. METHODS AND RESULTS. Twenty-three unipolar atrial electrograms were recorded simultaneously from the bundle of Bachmann and the lateral wall of the right and left atria. During sustained atrial fibrillation, the surface electrocardiogram showed continuous irregularities of the baseline without P or F waves as well as an irregular ventricular rhythm with narrow QRS complexes. The atrial electrograms showed rapid irregular activity with a median cycle length of 85 +/- 8 msec and a range (P5-95) of 33 +/- 18 msec. Overdrive pacing of atrial fibrillation was performed using symmetric biphasic rectangular stimuli (2-msec duration, sixfold that of threshold) applied to a pair of stimulating electrodes at the left atrial appendage. Stimulation was started at pacing intervals of about 10 msec longer than the local median fibrillation interval and subsequently shortened in steps of 1 msec. At a critical pacing interval slightly shorter than the median fibrillation interval, the atrium around the pacing site was suddenly captured by the electrical stimuli. The area of local capture had a diameter of 6.1 +/- 1.6 cm. The time window of capture was 12 +/- 4 msec. CONCLUSIONS. These observations show that during electrically induced atrial fibrillation in chronically instrumented conscious dogs, a short excitable gap is present, permitting regional control of the fibrillatory process by rapid pacing.     

Latest generation of unipolar and bipolar steroid eluting leads: long-term comparison of electrical performance in atrium and ventricles.

One hundred and seventy-three patients, mean age 74 years permanently paced with 123 atrial (53 unipolar, 70 bipolar) and 143 ventricular (73 unipolar, 70 bipolar) pacing leads were included in this study. The pacing leads were recent generation low surface area steroid eluting leads from one manufacturer: leads with silicone and polyurethane insulation were studied, and they were combined with generations of one pacemaker family from the same manufacturer permitting identical measurements to be made over a follow-up of 2 years. Pacing threshold was measured using pulse duration at a fixed voltage of 1.5 V: peak to peak P and R wave amplitude and pacing impedance at 2.5 V and 0.5 ms were all measured using the manufacturer's standard programmer. Although many significant differences, in the parameters measures, existed between atrium and ventricle and unipolar and bipolar configurations, none was felt to be of clinical significance. These data permit the physician to choose the lead type with regard to sensing performance and long-term lead integrity.     

Acute changes in pacing threshold and R- or P-wave amplitude during permanent pacemaker implantation

This study examines the changes in pacing threshold and R- or P-wave amplitude during the first 30 minutes after implantation of tined and screw-in leads. The leads examined were those of 1 manufacturer (Medtronic) and consisted of 3 ventricular pacing leads (model numbers 6957 unipolar screw-in [11 patients], 6961 unipolar tined [12 patients] and 6962 bipolar tined [7 patients]) and 1 atrial lead (model number 6957J unipolar screw-in [10 patients]). After optimal lead position was obtained fluoroscopically in the right ventricular apex or right atrium, the pacing threshold and R- or P-wave amplitudes were measured at 5-minute intervals for 30 minutes. The acute ventricular pacing threshold with the screw-in lead was significantly higher than with the tined lead (0.84 +/- 0.17 vs 0.58 +/- 0.15 volts; p less than 0.001). There was a significant (p less than 0.001) acute decrease in the ventricular pacing threshold with both lead types, with the maximum decrease occurring 5 minutes after lead implantation. There was a significant acute increase in R-wave size with the ventricular screw-in lead that peaked 20 minutes after lead implantation (11.9 +/- 3.0 to 14.7 +/- 4.1 mV; p less than 0.001). The atrial screw-in lead behaved in a manner identical to its counterpart in the ventricle. In conclusion, there are acute changes in the pacing threshold and R- or P-wave amplitude obtained with tined and screw-in pacing leads.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical Validation of New Pacing-Sensing Configurations for Atrial Automatic Capture Verification in Pacemakers

INTRODUCTION: This study evaluated an atrial automatic capture verification scheme based on atrial evoked response (AER). Atrial pacing was between Atip and Can (Atip-Can) using different coupling capacitances (CCs). Independent pairs of sensing electrodes between Aring and Vtip (Aring-Vtip) or between Aring and a separate indifferent electrode (Aring-Indiff) were used to reduce pacing-induced afterpotentials. METHODS AND RESULTS: A custom-made external pacing system was used to perform automatic step-up and step-down pacing (0.1 to 7.1 V at 0.5 msec, step size of 0.1 V) using different CCs (2 or 15 microF). Intracardiac signals from Aring-Indiff and Aring-Vtip were independently recorded and analyzed both in real time and off-line to detect AER. Every paced beat also was visually inspected and compared with surface ECG to verify the captures. With the intracardiac signals properly filtered, AER detection was based on the signal within a window of 12 to 65 msec after the stimulus. Data from 27 patients (4 chronic and 23 acute implantations; age 65.6+/-13.9 years) were analyzed. Bipolar atrial lead measurements using a standard pacing system analyzer were as follows (mean +/- SD): impedance 695+/-227 ohms, P wave amplitude 4.2+/-2.3 mV, slew rate 1.1+/-0.9 V/sec, and pacing threshold at 0.5 msec 1.0+/-0.5 V. The results with CC = 2 microF showed that of 9,500 atrial paced beats, correct capture verification rates were 99.8% (Aring-Indiff) and 99.4% (Aring-Vtip). Similar results were achieved with CC = 15 microF (99.7% and 99.5%, respectively). CONCLUSION: AER can be reliably detected using independent pacing (Atip-Can) and sensing (Aring-Vtip or Aring-Indiff) electrodes. Therefore, atrial automatic capture verification by AER detection is feasible.     

P waves during ectopic atrial rhythms in man: a study utilizing atrial pacing with fixed electrodes.

Threshold bipolar pacing was performed from one of 12 selected atrial sites with temporary implanted electrodes in 69 patients following open-heart surgery in order to study P wave polarity and morphology and the P-R interval during paced ectopic atrial rhythms. A negative P wave was recorded in lead I only with pacing the left atrium and only when pacing near the left pulmonary veins. A positive bifid P wave in V1 was recorded only with left atrial pacing and only when pacing was near the inferior pulmonary veins and coronary sinus. P wave polarity and morphology were otherwise of no use in localization of the origin of the impulse in these studies. The pacing stimulus to P wave interval was found to vary between 10 and 54 msec, making the duration of the P-R interval an unreliable indicator of the site of origin of the paced impulse. Although the relation of these paced rhythms to spontaneously occurring ectopic rhythms is unclear, the previously published criteria for localizing ectopic atrial rhythms are again demonstrated to be unreliable. P wave polarity and morphology and the P-R interval are of limited value in ascertaining the origin of ectopic atrial rhythms in man.     

Discrimination of antegrade and retrograde atrial depolarization by electrogram analysis

The inability of cardiac pacemakers to selectively reject retrograde P waves limits the usefulness of dual-chamber pacemakers (because of the possibility of endless loop tachycardias) and of antitachycardia devices which use a dual-chamber sensing algorithm. In order to determine selective sensing parameters, amplitude, slew rate, and configuration of antegrade and retrograde atrial electrograms were measured in 34 patients undergoing dual-chamber pacemaker implant--31 with unipolar and three with bipolar units. All antegrade and retrograde pairs were measurably different. All 34 cases had measurable antegrade/retrograde amplitude differences; 30 of the unipolar cases (96.8%) and all bipolar cases displayed antegrade/retrograde amplitude differences of at least 0.25 mV. Thirty of the unipolar cases (96.8%) and two bipolar cases had measurable slew rate differences. Configuration differed in 14 of 31 (45.2%) of unipolar and in two bipolar cases. A combined criterion with 0.25 mV sensitivity steps (available in at least two presently available pacemakers) and 0.5 V/sec slew rate gradations (through the use of externally programmable filters) would allow the discrimination of retrograde from antegrade depolarizations in all 34 cases. With the use of amplitude and slew rate differences, it is therefore possible to reject retrograde P waves while sensing antegrade P waves with current technology.     

起搏器植入术中双极导线单、双极模式参数的比较

目的比较起搏器植入术中双极导线单、双极模式的参数。方法共入选117例患者,术中共植入78根心房双极导线和117根心室双极导线,以Medtronic 5318起搏分析仪测试起搏参数,固定脉宽为0.42 ms。结果术中双极导线单极模式与双极模式的起搏阈值无差异(P均>0.05);双极模式的P/R波振幅高于单极模式(P均<0.01);心房、心室双极模式的阻抗均大于单极模式(P均<0.05)。术后随访无1例有阈值异常增高,导线脱位或断裂发生。结论双极导线单、双极模式的起搏阈值无差异;双极模式的感知优于单极模式,而阻抗较单极模式高。     

Enalapril preserves sinus node function in a canine atrial fibrillation model induced by rapid atrial pacing

METHODS AND RESULTS: Seventeen beagles were pretreated with either placebo (group I, n = 9) or enalapril 1 mg/kg/day (group II, n = 8) and paced at 500/min from the right atrial appendage for 4 weeks. Every week, corrected sinus node recovery time (CSNRT) and sinus cycle length (SCL) were measured. Quantitative analysis of interstitial fibrosis (IF) and adipose tissue (AT) in the SN was performed with Masson's trichrome stain, and apoptosis of the sinus nodal cells were detected with terminal deoxynucleotidyl transferase nick end-labeling. In group I, rapid atrial pacing prolonged both CSNRT and SCL. After 4 weeks of pacing, CSNRT and SCL were significantly shorter in group II (CSNRT, 410 +/- 37 msec; SCL, 426 +/- 34 msec) than in group I (CSNRT, 717 +/- 52 msec, P < 0.005; SCL, 568 +/- 73 msec, P < 0.05). Both IF and AT of the SN were greater in group I (IF, 9.7 +/- 1.9%; AT, 32.6 +/- 5.9%) than in seven sham dogs (IF, 2.4 +/- 0.9%, P < 0.05; AT, 4.0 +/- 1.7%, P < 0.05) and in group II dogs (IF, 4.0 +/- 2.0%, P < 0.05; AT, 4.0 +/- 1.7%, P < 0.05). End-labeling assay was positive in three of nine dogs in group I, but negative in group II and sham dogs. CONCLUSIONS: Rapid atrial pacing impaired SN function through IF and AT of the SN. Enalapril prevented these pacing-induced degenerative changes and improved SN function.     

Acute and chronic stability of atrial screw-in leads

The purpose of this study was to evaluate the acute and chronic stability of the atrial screw-in lead. In this study, we used CPI model 4165, 4166, and 4266 porous tip screw-in leads in 32 patients (12 for AAI pacing and 20 for DDD pacing). All of these leads were fixed to the free wall of the right atrium and used as the unipolar type. Acute voltage and current thresholds, lead impedance, P-wave amplitude, and chronic threshold were measured. Early and late complications were also investigated. The average acute stimulation thresholds at 0.6 msec pulse width were 0.82 +/- 0.43 V and 1.1 +/- 0.6 mA. Mean lead impedance was 627.2 +/- 83.1 ohms, and mean P wave amplitude was 3.1 +/- 1.1 mV. After an average follow-up period of 32 months (range: 2-72 months), we found the results of the chronic threshold study to be satisfactory. The thresholds were usually below 0.1 msec pulse width with the nominally programmed pacemaker output. Only one patient required a higher output due to an increased threshold. With regard to complications, neither lead dislodgment nor cardiac perforation was observed. In conclusion, acute and chronic thresholds were satisfactory and no serious complications occurred. Therefore the atrial screw-in lead has long-term reliability and stability.     

Electrical characteristics of low atrial septum pacing compared with right atrial appendage pacing.

AIM: The study was designed to compare the electrical characteristics of atrial leads placed in the low atrial septum (LAS) with those placed in the right atrial appendage (RAA) associated with dual chamber pacing. METHODS: In 86 patients an active-fixation (St. Jude Medical's Tendril DX model 1388T) atrial lead was positioned in RAA and in 86 patients the same model atrial lead was placed in the LAS. Pacing thresholds, sensing thresholds, impedances and the Far Field paced R-Wave (FFRW) amplitude and timing were compared at 6 weeks and at 3 and 6 months. RESULTS: The pacing threshold did not differ between groups. Sensed voltage of the P-wave was higher in the LAS compared with the RAA at 3 and 6 months (P=0.004). Impedance was higher in the LAS at 6 weeks and 3 months (P=0.002) but this difference was no longer significant at 6 months (P=0.05). The atrial sensed FFRW voltage was significantly higher in the LAS position compared with the RAA at 3 and 6 months follow-up (P=0.0002). FFRW voltage>1 mV was seen in 87% of the RAA pacing group and in 94% of the LAS pacing group (P=ns). The time between the ventricular pacing stimulus and the sensed FFRW in the atrium, (V spike-FFRW) in RAA was longer than in LAS at all follow-up measurements (P=0.006). CONCLUSIONS: The electrical characteristics of LAS pacing makes this alternative position in the atrium safe and feasible. Though statistical differences were found in P-wave sensing (LAS higher voltage than in the RAA) and FFRW sensing was higher in the LAS compared with the RAA this did not interfere with the clinical applicability of the LAS as alternative pacing site.     

Long-term assessment of unipolar and bipolar stimulation and sensing thresholds using a lead configuration programmable pacemaker

Acute and long-term pacing thresholds were measured prospectively in 74 patients with a unipolar/bipolar multiprogrammable pacemaker. At implantation, mean current threshold was 0.48 +/- 0.16 mA with unipolar mode and 0.55 +/- 0.16 mA bipolar mode (p less than 0.01). R wave amplitude at implantation was 7.78 +/- 2.4 mV with unipolar and 7.67 +/- 2.1 mV in bipolar mode (p = NS). During long-term follow-up (mean 9.3 months; range 3 to 24), no clinically significant differences in pacing or sensing thresholds were observed between bipolar and unipolar configurations. Lead configuration was changed 23 times in 11 patients. Symptomatic myopotential inhibition was corrected in two patients by reprogramming to the bipolar pacing mode. High thresholds and loss of capture were corrected in two patients by reprogramming to the unipolar pacing mode. The remaining configurational changes were made for improved sensing or pacing thresholds. This study documents, in a large group of patients, the equivalence of long-term unipolar and bipolar pacing and sensing thresholds and, in addition, demonstrates that lead configuration programmability offered some advantage in a subgroup of patients and may have prevented reoperation in five patients.     

食管心房调搏对阵发性室上性心律失常的诊断意义

目的探讨食管心房调搏对阵发性室上性心律失常的诊断意义。方法应用食管导联心电图对82例各类阵发性室上性心律失常的检出率对照分析。结果房室结双径路在双极食管导联的检出率为82.57%,单极食管导联的检出率为57.3%（P〈0.01）;预激综合征（WPW）合并房室折返性心动过速在双极食管导联的检出率为11.46%,单极食管导联的检出率为10.98%（P〈0.05）。室性心动过速伴房室分离在双极食管导联的检出率为2.75%,单极食管导联心电图的检出率为1.22%（P〈0.05）;室性心动过速与心房扑动并存在双极食管导联的检出率为2.29%,单极食管导联心电图的检出率为1.22%（P〈0.05）;室性心动过速伴1：1室房逆传在双极食管导联的检出率为1.83%,单极食管导联心电图的检出率为1.22%（P〈0.05）。结论双极食管导联对阵发性室上性心律失常的检出率比单极食管导联的检出率高,安全、可靠、实用、能定位、对射频消融术前病例的筛选具有重要作用。