Second-Degree Atrioventricular Block in the His-Purkinje System Following Acute Myocardial Infarction: Clinical Observations on Its Evolution

摘要: The evolution of second-degree atrioventricular block in the His-Purkinje system was studied four patients with acute myocardial infarction, utilizing continuous electrocardiographic monitoring and serial His bundle recordings. Three had anterior wall infarction; all developed right bundle-branch two also showed a left hemiblock one to hours prior onset block. fourth patient an old anteroseptal infarction chronic hemiblock; he following lateroposterior infarction. electrograms were obtained during insertion temporary ventricular pacemaker within first 24 chest pain. A second electrogram removal 7 14 days after recording. In cases localized system. three recording minimal increment delay conduction (3 10 msec) blocked beat (equivalent Mobitz type 2 block). development significant (35 210 Wenckebach conduction). illustrated reverse order observations seen other three. resumption 1:1 conduction; however, when challenged rapid atrial pacing, repetitive