首医学生心电图（优选）首医学生心电图频发持续存在的房性早搏ASD、TOF、DORV其他药物如奎尼丁、肾上腺素、锑剂中毒、氨茶碱、咖啡因、某些麻醉药。正常的心电传导与心电图形成风湿性心脏病，先天性心脏病、心脏肿瘤、右心室发育不良、心力衰竭、长Q-T综合征、二尖办脱垂及左室假腱索等。切迹少见多见房室交界区:40-60bpm其他：由于过劳、精神紧张、胃肠道疾病、胆道感染或植物神经紊乱等所引起。环路：功能性或解剖性，如：双径路、旁道各部自律细胞频率正常范围分级心电图特点0无室性早搏25mv（肢导），>=0.II、III、aVF明显兼有LAE和RAE的特点起源于心房下部的房性早博RightAxisDeviation&RAE(PPulmonale):LeadsI,II,IIIRightVentricularHypertrophy(RVH)&RightAtrialEnlargement(RAE)RightAtrialEnlargement(RAE)&RightVentricularHypertrophy(RVH)右房肥大的临床意义左房肥大（LAE）II左房肥大的临床意义双房肥大左室肥大（LVH）振幅>=20mm<10mm舒张期早搏：T终末至QRS起点，4相PR间期：120-200毫秒（0.V3：R＋S>6.II、III、aVF呈巨大R波出现提前QRS波群，形态与窦性相同或因室内差异传导发生畸形；频发持续存在的房性早搏RightVentricularHypertrophy(RVH)&RightAtrialEnlargement(RAE)25mv（肢导），>=0.LVHwith"Strain"各部自律细胞频率正常范围RightVentricularHypertrophy(RVH)&RightAtrialEnlargement(RAE)占全部心律失常的37．7％出现提前QRS波群，形态与窦性相同或因室内差异传导发生畸形；LVH:LimbLeadCriteriaInthisexampleofLVH,theprecordialleadsdon'tmeettheusualvoltagecriteriaorexhibitsignificantSTsegmentabnormalities.LVH&PVCs:PrecordialLeadsLVH:LimbLeadCriteriaInthisexampleofLVH,theprecordialleadsdon'tmeettheusualvoltagecriteriaorexhibitsignificantSTsegmentabnormalities.Thefrontalplaneleads,however,showvoltagecriteriaforLVHandsignificantSTsegmentdepressioninleadswithtallRwaves.Thevoltagecriteriainclude1)RinaVL>11mm;2)RinI+SinIII>25mm;and3)(RI+SIII)-(RIII+SI)>17mm(LewisIndex).LVH:LimbLeadCriteriaInthisexampleofLVH,theprecordialleadsdon'tmeettheusualvoltagecriteriaorexhibitsignificantSTsegmentabnormalities.Thefrontalplaneleads,however,showvoltagecriteriaforLVHandsignificantSTsegmentdepressioninleadswithtallRwaves.Thevoltagecriteriainclude1)RinaVL>11mm;2)RinI+SinIII>25mm;and3)(RI+SIII)-(RIII+SI)>17mm(LewisIndex).LVH-BestseeninthefrontalplaneleadsLVH-BestseeninthefrontalplaneleadsLVH:Strainpattern+LeftAtrialEnlargement左室肥大临床意义右室肥大（RVH）RVHwithRightAxisDeviationNotetheqRpatterninrightprecordialleads.Thissuggestsrightventricularpressuresgreaterthanleftventricularpressures.ThepersistentSwavesinlateralprecordiall