| Objective: Paroxysmal Supraventricular Tachycardia (PSVT) is mainlycause of automaticity and reentrant movement, and above all, reentrantmovement is the capital etiological factor. The reentrant circle of PSVT canoccurrence between atrium and atrium, or atrium and atrioventricular node, orinternodal bundle and atrioventricular, as well as in the sinoatrial node oratrioventricular node. According which, PSVT can be distinguished asAtrioventricular Reentrant Tachycardia (AVRT) and Atrioventricular NodalReentrant Tachycardia (AVNRT). The tachycardia which is caused byPreexcitation Syndrome (or Wolf-Parkinson-White Syndrome) is AVRT, thereentrant circle occurrence between the common conduction pathway andaccessory atrioventricular pathways. Otherwise, the accessory atrioventricularpathways participate the formation of reentrant circle in AVRT. And based onwhether the accessory pathways can conduct forward or not, AVRT is dividedas dominant and recessive preexcited.Para-Hisian bundle accessory pathways is the accessory pathways thatcan record the His bundle amplitude in the electrophysiological examination,including both left and right accessory pathways. Normally, right anteroseptalaccessory pathways that ablation distance within5mm of the Hisian bundlecatheter are counted. As the anatomical location of para-Hisian bundle locatedclose to His bundle, it gets a very high probability to induce atrioventricularblock in catheter ablation procedure, even may lead to completelyatrioventricular block. And no matter the procedure through sinus rhythm orpacing ventricle proceed in catheter ablation carry out difficulty. Thatprimarily judgment via tests without invasive if the accessory pathways arepara-Hisian pathways is a very hot topic in medical area. And the tests themselves are worth to investigation and think highly of in clinical. Over thelast2decades, several attempts have been made to correlateelectrocardiographic (ECG) findings with precise anatomic locations ofaccessory pathways. However, no single published algorithm offers extremelyhigh sensitivity/specificity for all pathway locations. Specifically, the ECGcriteria to identify a para-Hisian accessory pathway are based on a small seriesof patients. In fact, the presence of a negative delta wave in the rightprecordial leads V1and V2has been proposed as a classic, noninvasive markerof para-Hisian accessory pathways. However, these criteria were based on theobservation of a small series of patients. Otherwise, to make a definitediagnosis of para-Hisian accessory pathways, electrophysiology is the goldenstandard apparently. However, to proceed an electrophysiological procedurehas a very strict requirement of the skill of the man and environment of theprocedure. It will be very helpful to the clinical doctors if the doctors get aprimary judgment of the accessory pathway which is para-Hisian accessorypathway or not before the next treatment plan was made. This retrospectivestudy analyzes112dominant Preexcitation Syndrome patients’ ECG beforethe catheter ablation procedure. And the aim of this retrospective study is tosummarize the characters of para-Hisian accessory pathways, through analysisthe polarity of Delta waves, whether the ST segment of lead aVR elevated, thepolarity of P wave in lead V1, the precordial leads that R/S=1occurrence,whether the ST-T transformed in lead Ⅱ and Ⅲ and aVF betweenpara-Hisian accessory pathway patients and other AVRT patients.Methods: A total of158subjects who underwent treatment and clinicaldiagnosed as AVRT in the second Hospital of Hebei Medical University fromJuly2011to December2013was retrospectively analyzed, of whom112individuals fulfilled the inclusion criteria of our study. Of all these112enrolled subjects,69cases (61.6%) are male, and43cases (38.4%) are female,with the age of10-72years (39±15years). After the patients or the familysign the agreement for the catheter ablation procedure, theelectrophysiological examination and catheter ablation were performed. And routinely located the mapping electrode catheter, the result of theelectrophysiological examination should be analyzed by at least twoexperienced associate chief doctors. A para-Hisian accessory pathway isdefined as one situated in the His bundle area with a His bundle potential,including both left and right. ECG recordings were obtained in all patientsbefore the invasive electrophysiological procedure. The ECGs were recordedat a paper speed of25mm/s and an amplification of10mm/mV. All ECGsshowed a clear delta wave, with a combined delta and QRS width of at least120ms. Preexcited12-lead ECGs were obtained during sinus rhythm. Theinitial40ms of the preexcited QRS complex in each leads were taken as thedelta wave. If the delta wave was above the baseline without any part belowthe baseline in a given lead, it was designated as positive for that lead. If thedelta wave was below the baseline without any part above the baseline, it wasdesignated as negative. The whole delta wave on the baseline or the deltawave that was composed of both positive and negative deflections or the deltawave that was from deflections back to the baseline before the QRS complexstarted was designated as isoeletric. The standard of the elevated ST segmentin aVR lead was the deflection distance from baseline was over0.1mVpersisting60ms after the J point. If the ratio that the amplitude of R wave andS wave was equal to1occurrence before V1, it was designated as preV1. If theratio that the amplitude of R wave and S wave was equal to1occurrence inprecordial lead V1, it was designated as V1. If the ratio that the amplitude of Rwave and S wave was equal to1occurrence in precordial lead V2, it wasdesignated as V2. If the ratio that the amplitude of R wave and S wave wasequal to1occurrence in precordial lead V3, it was designated as V3. If the ratiothat the amplitude of R wave and S wave was equal to1occurrence inprecordial lead V4, it was designated as V4. If the P wave in V1was above thebaseline of ST segment, it was designated as positive. If the P wave in lead V1was below the baseline of ST segment, it was designated as negative. If theelevated and depression ST segments and inversion T waves occurred in leadsⅡ, Ⅲ, and aVF, it was designated as transformed ST-T positive. If the elevated and depression ST segments and inversion T waves did not occur inleads Ⅱ, Ⅲ, and aVF, it was designated as transformed ST-T negative.Statistical analysis was performed with SPSS16.0software. Parametricvariables were expressed as mean±standard deviation (SD), and t test wasused to indicate the differences. Categorical variables were expressed aspercentages (%), of which Chi-square test was used to indicate differences.Fisher exact test were used to compare differences between groups (if1≤expect count T<5). The consistency of diagnostic methods was analysis byKappa values, and the accuracy was represented by the area under the curve(AUC). A P value less than0.05was accepted as statistically significantdifference.Results: Finally112individuals were included in our study,69of themwere male (61.6%), and43subjects were female (38.4%), with a mean age of39±15years (ranging from10to72years) at the time of analysis. And75.0%patients with para-Hisian accessory pathways had a predominantly negativedelta wave in lead V1, where as this was observed in just22.1%patients in thecontrol group (P=0.002). Therefore, this ECG finding led to sensitivity,specificity, and positive, and negative predictive values of75.0%,77.8%,20.7%, and97.6%, respectively, for a para-Hisian accessory pathway location.However,100.0%patients with para-Hisian accessory pathways had atransformed ST-T in leads Ⅱ, Ⅲ, and aVF, where as this was observed injust8.7%patients in the control group (P<0.001). This ECG finding led tosensitivity, specificity, and positive, and negative predictive values of100.0%,91.3%,47.1%, and100.0%, respectively, for a para-Hisian accessory pathwaylocation. Otherwise, the other observation markers did not show anystatistically significant difference. And three brand new methods of diagnosiswere compared to the classical method via Kappa values, which turned out tobe negtive. Otherwise, AUC of lead Ⅱ, Ⅲ, and aVF showed the maximumvalue, while the classical method the minimum.Conclusion: The classical finding of a negative delta wave in the firstprecordial lead V1shows a positive predictive value and high sensitivity, specificity and negative predictive to detect accessory pathways with adefinition of para-Hisian location, as well as a transformed ST-T in leads Ⅱ,Ⅲ, and aVF. However, the latter observation marker does a little better inpositive predictive value.A transformed ST-T in leads Ⅱ, Ⅲ, and aVF shows a highly accuracydetect accessory pathways with a definition of para-Hisian location in thisvery study. |
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