In order to accurately detect the occasional negative R waves in electrocardiography （ECG） signals, the positive-negative adaptive threshold method is adopted to determine the positive R waves and the negative R wav...In order to accurately detect the occasional negative R waves in electrocardiography （ECG） signals, the positive-negative adaptive threshold method is adopted to determine the positive R waves and the negative R waves, according to difference characteristics of ECG signals. The Q and S waves can then be accurately positioned based on the basic characteristics of QRS waves. Finally, the algorithm simulation is made based on the signals from MIT-BIH database with MATLAB. The ex- perimental results show that the algorithm can improve the detection accuracy rate to 99. 91% and o- vercome the problem of larger computation load for wavelet transform and other methods, so the al- gorithm is suitable for real-time detection.展开更多
BACKGROUND Most Mahaim fibers are right free-wall atriofascicular accessory pathways with only antegrade conduction.Concealed Mahaim fiber is not very rare;however,concealed nodoventricular fiber is a very rare kind o...BACKGROUND Most Mahaim fibers are right free-wall atriofascicular accessory pathways with only antegrade conduction.Concealed Mahaim fiber is not very rare;however,concealed nodoventricular fiber is a very rare kind of retrograde accessory pathway in supraventricular tachycardia with atrioventricular(AV)dissociation.Only a few cases about successful ablation of the nodoventricular accessory pathway have been reported.We describe the case of a 32-year-old woman who underwent an electrophysiology study and radiofrequency(RF)ablation of a rare narrow QRS tachycardia with AV dissociation.CASE SUMMARY A 32-year-old woman with a history of paroxysmal palpitation was admitted to our hospital for RF ablation.Electrocardiography revealed a narrow QRS complex tachycardia with the same morphology in sinus rhythm.Echocardiography showed no structural heart disease.A right-sided concealed AV accessory pathway and a right-sided concealed nodoventricular accessory pathway were involved in the orthodromic atrioventricular reciprocating tachycardia.His bundle-ventricular interval during tachycardia was the same as that in sinus rhythm.The tachycardia could be initiated and entrained by ventricular pacing.Premature right ventricular stimulus introduced during the His-bundle refractory period when tachycardia occurred was able to advance the next atrial potential.The earliest atrial activation was mapped near the proximal slow AV nodal pathway.RF ablation of both accessary pathways was successfully performed under the guidance of a three-dimensional mapping system by recording the earliest retrograde atrial potential,and tachycardia could no longer be induced.CONCLUSION Narrow QRS tachycardia with AV dissociation is inducible by concealed nodoventricular fiber and ablated by recording the earliest retrograde atrial potential.展开更多
文摘In order to accurately detect the occasional negative R waves in electrocardiography （ECG） signals, the positive-negative adaptive threshold method is adopted to determine the positive R waves and the negative R waves, according to difference characteristics of ECG signals. The Q and S waves can then be accurately positioned based on the basic characteristics of QRS waves. Finally, the algorithm simulation is made based on the signals from MIT-BIH database with MATLAB. The ex- perimental results show that the algorithm can improve the detection accuracy rate to 99. 91% and o- vercome the problem of larger computation load for wavelet transform and other methods, so the al- gorithm is suitable for real-time detection.
文摘BACKGROUND Most Mahaim fibers are right free-wall atriofascicular accessory pathways with only antegrade conduction.Concealed Mahaim fiber is not very rare;however,concealed nodoventricular fiber is a very rare kind of retrograde accessory pathway in supraventricular tachycardia with atrioventricular(AV)dissociation.Only a few cases about successful ablation of the nodoventricular accessory pathway have been reported.We describe the case of a 32-year-old woman who underwent an electrophysiology study and radiofrequency(RF)ablation of a rare narrow QRS tachycardia with AV dissociation.CASE SUMMARY A 32-year-old woman with a history of paroxysmal palpitation was admitted to our hospital for RF ablation.Electrocardiography revealed a narrow QRS complex tachycardia with the same morphology in sinus rhythm.Echocardiography showed no structural heart disease.A right-sided concealed AV accessory pathway and a right-sided concealed nodoventricular accessory pathway were involved in the orthodromic atrioventricular reciprocating tachycardia.His bundle-ventricular interval during tachycardia was the same as that in sinus rhythm.The tachycardia could be initiated and entrained by ventricular pacing.Premature right ventricular stimulus introduced during the His-bundle refractory period when tachycardia occurred was able to advance the next atrial potential.The earliest atrial activation was mapped near the proximal slow AV nodal pathway.RF ablation of both accessary pathways was successfully performed under the guidance of a three-dimensional mapping system by recording the earliest retrograde atrial potential,and tachycardia could no longer be induced.CONCLUSION Narrow QRS tachycardia with AV dissociation is inducible by concealed nodoventricular fiber and ablated by recording the earliest retrograde atrial potential.
