Rinkenberger R L, Polumbo R A, Bolton M R, Dunn M
Cathet Cardiovasc Diagn. 1978;4(1):63-70. doi: 10.1002/ccd.1810040109.
Electrical alternans concomitant with pericardial effusion has been considered a pathognomonic sign suggestive of a large effusion with cardiac tamponade, particularly if there is P wave alternans as well as QRS alternans. However, the mechanism of this phenomonon remains controversial. A patient with pericardial effusion secondary to adenocarcinoma of the lung with metastases, pericardial effusion, electrical alternans, and cardiac tamponade was studied by echocardiography, right and left heart catheterization, and pericardiocentesis. Hemodynamic data were consistent with cadiac tamponade. The echocardiogram demonstrated a large anterior and posterior pericardial effusion. Noncongruous motion of the septum and posterior wall was pericardial effusion. Noncongruous motion of the septum and posterior wall was recorded at a rate equal to the heart rate. In addition, congruous motion of the septum and posterior wall was recorded at a rate that was half the heart rate and corresponded to the electrical alternans. The congruous movement disappeared after pericardiocentesis, as did the electrical alternans. The electrical alternans is synchronous with and due to the pendulous movement of the heart within the pericardial sac, as demonstrated by echocardiogram and cineangiograms.
伴有心包积液的电交替一直被认为是提示大量积液伴心脏压塞的一个特征性体征，尤其是存在P波电交替以及QRS波电交替时。然而，这种现象的机制仍存在争议。对一名继发于肺腺癌伴转移、心包积液、电交替和心脏压塞的患者进行了超声心动图、左右心导管检查及心包穿刺术研究。血流动力学数据与心脏压塞相符。超声心动图显示大量心包前后积液。记录到室间隔和后壁的不协调运动，其频率与心率相等。此外，还记录到室间隔和后壁的协调运动，其频率为心率的一半，且与电交替相对应。心包穿刺术后，协调运动消失，电交替也消失。如超声心动图和心血管造影所示，电交替与心脏在心包腔内的摆动运动同步且由其所致。
