Padeletti Luigi, Bagliani Giuseppe
Heart and Vessels Department, University of Florence, Largo Brambilla, 3, 50134 Florence, Italy; IRCCS Multimedica, Cardiology Department, Via Milanese, 300, 20099 Sesto San Giovanni, Italy.
Arrhythmology Unit, Cardiology Department, Foligno General Hospital, Via Massimo Arcamone, 06034 Foligno (PG), Italy; Cardiovascular Diseases Department, University of Perugia, Piazza Menghini 1, 06129 Perugia, Italy.
Card Electrophysiol Clin. 2017 Sep;9(3):345-363. doi: 10.1016/j.ccep.2017.05.009. Epub 2017 Jul 14.
The conduction system includes a primary pacemaker, the internodal tracts, the atrioventricular node, and the His bundle with the right and left branches. In "emergency" conditions, accessory pacemakers may be triggered. The conduction system produces very low-intensity currents; a surface electrocardiogram (ECG) detects only the big myocardial masses. Electrogenetic mechanisms are reduced automaticity and/or impaired conduction at the base of bradycardias. An increased automaticity and/or reentry phenomenon are at the base of ectopic beats and tachycardias. A "wide QRS" is a ventricular activation time of 120 milliseconds or more. The "laddergram" helps in the fast and reliable ECG interpretation.
传导系统包括一个主要起搏器、结间束、房室结以及带有左右分支的希氏束。在“紧急”情况下，辅助起搏器可能会被触发。传导系统产生的电流强度非常低；体表心电图（ECG）仅能检测到较大的心肌团块。电生理机制是心动过缓基础上的自律性降低和/或传导受损。异位搏动和心动过速的基础是自律性增加和/或折返现象。“宽QRS波”是指心室激动时间为120毫秒或更长。“梯形图”有助于快速且可靠地解读心电图。
