Medrano G A, de Micheli A
Arch Inst Cardiol Mex. 1985 Jul-Aug;55(4):305-8.
Atrial QT(QTa) was measured in lead II, in right thoracic leads V4R, V3R and V1 as well as in five direct atrial unipolar leads in 40 dogs. Atrial damage of right or left atrium was provoked by infiltration of 96 degree alcohol in 30 dogs Premature right atrial beats were induced till one was blocked and A-V block was provoked in 10 other normal dogs as well as in those with right atrial damage. Control QTa was observed to include the terminal QRS notch and the proximal irregularity on ventricular ST interval that was better seen in direct leads with sinus rhythm and confirmed later in A-V block and blocked atrial premature beats. It was concluded that normal corrected QTa (QTac) can be obtained by QTac = 0.32 2 square root P-P +/- 0.02. In atrial damage the value increases beyond + 0.04 inclusive + 0.013 with the greater values in the right atrial unipolar. This formula allow us to recognize normal or abnormal QTac duration and to be acquainted that the terminal notch of QRS is produced by the final forces of atrial recoviry in some cases as well as to determine the position of vulnerable atrial period on the ST ventricular segment with and without atrial damage.
在40只犬中，于II导联、右胸导联V4R、V3R和V1以及5个直接心房单极导联测量心房QT（QTa）。在30只犬中，通过注入96度酒精诱发右心房或左心房损伤。在另外10只正常犬以及有右心房损伤的犬中，诱发右心房早搏直至其中一个发生阻滞，并诱发房室传导阻滞。观察到对照QTa包括终末QRS切迹和心室ST段近端不规则，这在窦性心律的直接导联中更易观察到，随后在房室传导阻滞和阻滞的心房早搏中得到证实。得出结论，正常校正QTa（QTac）可通过QTac = 0.32 √P-P ± 0.02获得。在心房损伤时，该值增加超过+0.04（含+0.013），右心房单极导联中的值更大。该公式使我们能够识别正常或异常的QTac持续时间，并了解在某些情况下QRS终末切迹是由心房恢复的最终力量产生的，以及确定有或无心房损伤时心室ST段上易损心房期的位置。
