Waldo A L, Vitikainen K J, Kaiser G A, Malm J R, Hoffman B F
Departments of Pharmacology and Surgery, College of Physicians and Surgeons, Columbia University, Surgical Service, Presbyterian Hospital, New York, New York, USA.
Circulation. 1970 Oct;42(4):653-71. doi: 10.1161/01.cir.42.4.653.
The atria of 37 patients were paced from selected sites during cardiac surgery. When the atria were paced from endocardial sites low in the right atrium, the P waves in ECG leads II, III, and aVF were shown to be either negative, biphasic, or positive, depending on the site paced. When the endocardial sites were paced, the P-R intervals were, almost without exception, less than 0.12 sec. When those endocardial sites closest to the A-V junction were paced, the P-R intervals were always less than 0.12 sec. When the atria were paced, from the epicardial sites, the P-R intervals were always greater than 0.12 sec. Negative P waves in ECG leads II, III, and aVF were recorded when the atria were paced from the postero-inferior left atrium and the caudal right atrium. The P-R interval did not always reflect the initial period of atrial activation because an isoelectric interval, generally of 0.01 to 0.025 sec, was frequently present between the onset of atrial stimulation and the first clear evidence of the P wave in the ECG. The implications of these results are discussed.
37例患者在心脏手术期间从选定部位进行心房起搏。当从右心房低位的心内膜部位进行心房起搏时，心电图导联II、III和aVF中的P波显示为负向、双向或正向，这取决于起搏部位。当进行心内膜部位起搏时，P-R间期几乎无一例外都小于0.12秒。当起搏最靠近房室交界的那些心内膜部位时，P-R间期总是小于0.12秒。当从心外膜部位进行心房起搏时，P-R间期总是大于0.12秒。当从左心房后下壁和右心房尾部进行心房起搏时，心电图导联II、III和aVF中记录到负向P波。P-R间期并不总是反映心房激动的起始期，因为在心房刺激开始与心电图中P波的首个明确证据之间经常存在一个通常为0.01至0.025秒的等电位间期。讨论了这些结果的意义。
