通过刺激自主神经结丛建立持续局灶性心房颤动动物模型

Relationship between right atrium ganglionated plexus and atrial fibrillation: A new canine model for sustained focal atrial fibrillation

目的探讨一种通过刺激自主神经结丛来建立持续局灶性心房颤动(房颤)动物模型的新方法。方法共选取20只雄性杂交狗,随机分为乙酰胆碱(Acetylcholine)组(10只)和卡巴胆碱(Carbachol)组(10只)。用苯巴比妥钠麻醉,行右侧开胸及心包切开手术,暴露出右肺静脉与右心房之间的脂肪垫,将一注射针插入该脂肪垫中,以备注入乙酰胆碱或卡巴胆碱。将多电极导管(CordisWebster公司,美国)缝合在右上肺静脉、右心房、左心房上。分别在给药前后(乙酰胆碱组:10 mmol/L乙酰胆碱0.5 mL;卡巴胆碱组:10 mmol/L卡巴胆碱0.5 mL),于右心房处行程序期前刺激,来测定有效不应期及诱发房颤,刺激强度分别采用2倍、4倍、10倍及20倍起搏域值,如出现房颤,则记录房颤持续最长时间及房颤时心房电活动的平均周期。结果向右心房脂肪垫注射乙酰胆碱或卡巴胆碱后可明显缩短心房有效不应期,增加诱发房颤最大与最小偶联间期之差,延长房颤持续的时间,缩短房颤时心房电活动的平均周期。乙酰胆碱组,未注射乙酰胆碱时,在刺激强度为2倍、4倍、10倍及20倍起搏域值时,在右心房处所测心房有效不应期分别为(116.3±17.8)ms,(102.3±22.7)ms,(91.7±21.9)ms和(80.0±23.0)ms,注入乙酰胆碱后则分别缩短为(103.8±26.1)ms(P>0.05),(94.7±21.9)ms(P<0.05),(74.3±20.0)ms(P<0.01)和(65.5±17.8)ms(P<0.05)。未注射乙酰胆碱或卡巴胆碱时,所诱发房颤均为短阵性房颤,持续时间为(9.7±6.0)s(乙酰胆碱组)和(10.4±8.0)s(卡巴胆碱组),心房平均电活动周期为(122.0±9.0)ms(乙酰胆碱组)和(120.0±8.0)ms(卡巴胆碱组);注入乙酰胆碱后持续时间延长为(596.7±281.0)s(P<0.01),心房平均电活动周期缩短为(76.0±32.0)ms(P<0.05);注入卡巴胆碱后则诱发出频率极快、持续时间更长的房颤,持续时间延长为(2 364.0±1169.0)s(P<0.01),心房平均电活动周期缩短为(39.0±12.0)ms(P<0.01)。结论向狗右心房脂肪垫注射卡巴胆碱可成功建立持续性房颤的动物模型。

Objective The study try to establish a new model of focal atrial fibrillation （AF） by stimulating the ganglionated plexus （GP） located at the base of the pulmonary veins （PVs）. Methods The dogs were divided into 2 groups randomly （ 10 for Ach group and 10 for c^hol group）. The right lateral thoracotomy and pericardiotomy were made to expose the fat pad （FP） between right pulmonary vein （PV） and right atrium （RA）. A needle was inserted in the fat pad for the injection of acylcholine and carbachol. Several octapolar electrode catheters were attached by sutures to contact the right superior pulmonary vein （RSPV）, right atrium and left atrium. The measurements were made of refractory periods using programmed premature stimulation in the right atrium both before and after ths administeration （Ach group： 10 mnol/L acylcholine 0.5 mL; carbachol group： 10 mmol/L carbachol 0.5 mL）. Premature beats were delivered at 2 × , 4 × , 10 × , 20 × threshold at coupling intervals starting at 150 msec down to refractoriness and the ERP was recorded at each level. If AF occurred, the longest duration of AF and the average f wave duration were recorded. Results In Ach group, the ERP recorded at RA with 2× , 4× , 10× and 20× threshold stimuli were （116.3± 17.8）ms, （102.3± 22.7）ms, （91.7± 21.9）ms and （80.0± 23.0）ms before the injection of acylcholine respectively. After the injection of acylcholine, the ERP were shortened to （ 103.8 ± 26.1 ）ms（ P 〉 0.05）, （94.7 ± 21.9）ms（ P 〈 0.05）, （74.3 ± 20.0）ms（ P 〈0.01） and （65.5 ± 17.8）ms（ P 〈 0.05） respectively. Before the application of acylcholine or Carbachol, the duration of AF was （9.7 ± 6.0） s in Ach group and （ 10.4 ± 8.0） s in Carbachol group. The mean f-f period was （122.0±9.0） ms in Ach group and （120.0± 8.0） ms in Carbachol group. The duration of AF prolonged to （596.7 ± 281. 0） s（ P 〈 0. 01 ） and the mean f-f period became （76.0 ±32. 0） ms（ P 〈 0. 05） after the injection of acylcholine. On the other hand, the duration of AF was （2 364.0± 1 169.0） s（ P 〈 0.01） and the mean f-f period was （39.0 ± 12.0） ms（ P 〈 0.01 ） after the injection of Carbachol. Conclusion Injection of carbachol into the fat pad at the base of RSPV can induce and maintain fecal AF with very long duration, which is very useful for the establishment of AF model.