| Objective: The His bundle electrograms (HBE) was recorded firstly by the intracardiac bipolar catheter in 1969. HBE is very useful in locating the site of atrio-ventricular conduction block(AVB) and identifying other arrhythmia. As it is invasive the useage is limited in clinic. In 2003,a type of body surface beat to beat His Bundle Electrocardiogram(SHBE) recorder(mode ZTXD-1) is made in china, and its reliability is comfirmed by some research. However, it is not known whether the recorder is suitable or not for rabbits, and for other area, except AVB in clinical practice. The focus of present study on identifying the origin of wide QRS wave in fibrillation(Af) and evaluating the effect of propafenone and amiodarone on His- bundle conduction.Methods:ZTXD-1 mode SHBE recorder was used.1. Animal experimentAt first, to search for the optimal position of electrode by comparing the recording -s with different electrode sites, then 8 newzealand rabbits were administered by intra -venous injection propafenone (4mg/kg). Then the SHBE and the lead II electrocardio -gram (ECG II) were synchronously recorded before and at 10,15 ,20 mins after admi -nistrtion. Atrial-His interval (A-H), His interval (H) and His ventricular interval (H-V),V interval of SHBE and HR were obtained from the 5 beats measurement.2. Clinical research2.1 The effect of amiodarone on His- bundle conductionThis study was performed in persons both in sinus rhythm and in Af. In sinus rhythm, 22 health adults and 22 arrhythmic patients treated with routine dosage of amiodarone were included, and in Af, 10 patients treated and 10 patients not treated were included.SHBE were recorded 15 beats in sinus rhythm , and A-H,H, H-V ,V and HR were represented as mean value of 5 continuous cardiac cycles in sinus rhythm. In Af, SHBE were recorded for 120 seconds and the HV intervals of the 5 longest and 5 shortest R-R intervals were measured in each person.2.2 The value for identifying the site of AVB and origin of wide QRS in AfForty patients with different arrthymia, such as different kinds of premature complexes, escape complexes, cardiac pacemaker, were included. Statistics:The data of measurement were statistically analyzed with SPSS 10.0. Datas are expressed as M±SD, T test is used before and after drug administration. P<0.05 were considered significant, P<0.01 were considered very significant.Results:1. Animal experimentThe SHBE was recorded clearly in all rabbits. The A-H, H and H-V interval of rabbits were 182.8±6.4, 126.2±3.9 and 226.6±6.6 respectively.The parameters were prolonged obviously after intravenous injection at 15min.The AH,H and HV of rabbits were 193.1±2.8, 154.2±2.1 and 275.1±3.2 respectively. (P<0.05)2. Clinical research2.1 Whether in sinus or in Af, the H-V intervals in treated group with amiodarone were longer obviously than those in patients without.2.2 On SHBE, supraventrcular excitement had both H and V waves, and the ventricular excitement had V waves only, so the wide QRS waves in Af may be identified as ventricular premature complexes or aberration conduct.2.3 In Af, the H-V intervals at the longest and the shortest R-R intervals were similar in the same patients and in the patient group.Conclusion:1. The SHBE can be recorded conveniently in rabbits by ZTXD-1 SHBE recorder.2. Intravenous injection of propafenone may obviously prolong the H-V interval with the maximal effect at 15min.3. Routine dosage amiodarone treatment may prolong the H-V interval both in sinus rhythm and in Af patients.4. SHBE is useful for identifying the origin of wide QRS wave in patients with Af.5. The H-V interval is quite stable in the same patient with Af, whether with amiodarone treatment or without.
|
PDF Full Text Request