1700627950
1700627951
已经证明,心外膜及M层心肌细胞动作电位上1位相终末部位上的切迹,反映心外膜及M层心肌细胞的全或无复极形式,以及2相折返倾向。
1700627952
1700627953
2相折返是1993年由Antzelevitch和Di Diego等提出的,是指在缺血或药物作用下,心外膜及M层心肌细胞表现为全或无的复极形式。动作电位的平台期被抑制或消失,使动作电位时程缩短约40%~70%。此时,动作电位的平台期丢失区和正常区之间电的异质性,导致2相折返。一般的折返激动,都是0相去极化电流所致,而这种2相折返是由2相复极电流折返引起的。2相折返途径可与0相折返一致,亦可与此不同,但肯定不是解剖依赖性。
1700627954
1700627955
因此,体表心电图上的J波,可以作为诊断和预测2相折返倾向的重要指标。最近的资料显示,Brugada综合征的发生机制,可能亦和2相折返有关。心外膜动作电位的平台期的丢失,引起相应部位ST段抬高,这和Brugada综合征的表现相同。事实上,所谓的Brugada综合征的图形和J波亦有明显的相同之处。
1700627956
1700627957
乙酰胆碱由于抑制Ica内向电流,使平台期消失;β受体兴奋剂则增加Ica,使平台恢复;钠阻滞剂使平台期消失,因此钠通道阻滞剂虽然抑制了0相折返,但同时又诱发了2相折返;兴奋迷走神经和Ⅰ类抗心律失常药加重相应部位ST段抬高,因此也有可能诱发2相折返;β受体阻滞剂则使相应部位ST段抬高减少,从而抑制2相折返。但Brugada最近报道,β受体阻滞剂并不能有效预防Brugada综合征病人的猝死。
1700627958
1700627959
【思考题】
1700627960
1700627961
1.试述心脏性猝死的处理流程及心肺复苏新进展。
1700627962
1700627963
2.常用的心脏性猝死相关的心电信息检测手段有哪些?各有何特点。
1700627964
1700627965
3.何谓Brugada综合征。
1700627966
1700627967
参考文献
1700627968
1700627969
[1] S G Priori, E Aliot, C Blømstrom-Lundqvist, et al. Task force on sudden cardiac death of the European society of cardiology. Europace, 2002, 4(1)
:3-18.
1700627970
1700627971
[2] ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. J Am Coll Cardiol, 2006, 48
:247-346.
1700627972
1700627973
[3] 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation, 2005, 112 [Suppl].
1700627974
1700627975
[4] Hallstrom AP, Ornato JP, Weisfeldt M, et al. Public access defibrillation and survival after out of hospital cardiac arrest. N Engl J Med, 2004, 351(7)
:637-646.
1700627976
1700627977
[5] Ganz LI. Primary prevention of sudden cardiac death. Curr Cardiol Rep, 2004, 6(5)
:339-347.
1700627978
1700627979
[6] Yoshio H, Shimizu M, Sugihara N, et al. Assessment of autonomic nervous activity by heart rate spectral analysis in patients with variant angina. Am Heart J, 1993, 125(2 Pt 1)
:324-329.
1700627980
1700627981
[7] 徐征,葛霁光,徐秋萍,等. 心率的Poincarè散点图量化指标. 生物医学工程学杂志,2000,17(4)
:433-436.
1700627982
1700627983
[8] Josephson ME, Horowitz LN, Farshidi A, et al. Recurrent sustained ventricular tachycardia. Endocardial mapping. Circulation, 1978, 57(3)
:440-447.
1700627984
1700627985
[9] Hombach V, Hopp HW, Braun V, et al. Significance of post excitation potentials within the ST segment in the surface ECG of patients with coronary heart disease(author’s transl). Dtsch Med Wochenschr, 1980, 105(42)
:1457-1462.
1700627986
1700627987
[10] Mehra R E, Sherif N. Signal averaging of electrocardiographic potentials: a review. Acupunct Electrother Res, 1982, 7(2-3)
:133-155.
1700627988
1700627989
[11] Simson MB, Kanovsky MS, Dresden CA, et al. Signal averaging methods to select patients at risk for lethal arrhythmias. Cardiovasc Clin, 1985, 15(3)
:145-153.
1700627990
1700627991
[12] McLaughlin NB, Campbell RW, Murray A. Comparison of automatic QT measurement techniques in the normal 12 lead electrocardiogram. Br Heart J, 1995,(1)
:84-89.
1700627992
1700627993
[13] Day CP, McComb JM, Campbell RW. QT dispersion: an indication of arrhythmia risk in patients with long QT intervals. Br Heart J, 1990, 63(6)
:342-344.
1700627994
1700627995
[14] Hii JT, Wyse DG, Gillis AM, et al. Precordial QT interval dispersion as a marker of torsade de pointes. Disparate effects of class Ia antiarrhythmic drugs and amiodarone. Circulation, 1992, 86(5)
:1376-1382.
1700627996
1700627997
[15] Brugada P, Brugada J. Right bundle branch block, persistent ST segment elevation and sudden cardiac death: a distinct clinical and electrocardiographic syndrome. A multicenter report. J Am Coll Cardiol, 1992, 20(6)
:1391-1396.
1700627998
1700627999
[16] Brugada J, Brugada P, Brugada R. The syndrome of right bundle branch block ST segment elevation in V1 to V3 and sudden death the Brugada syndrome. Europace, 1999, 1(3)
:156-166.
[
上一页 ]
[ :1.70062795e+09 ]
[
下一页 ]