Bodenheimer M M, Banka V S, Helfant R H
Cardiovasc Res. 1976 May;10(3):336-40. doi: 10.1093/cvr/10.3.336.
The optimal heart rate in the immediate period following acute coronary occlusion has been controversial from the standpoint of arrhythmias and the extent of ischaemic injury. In the present study we have examined the effect of heart rate on both local myocardial contractile ability and ischaemia in 10 open chested dogs using strain gauge arches and epicardial electrograms. After sinus node destruction, atrial pacing was instituted for rate control at 100/min and increased randomly to 150, 175, and 200/min. Before coronary occlusion, total tension and rate of tension rise progressively increased at higher rates while ST segments demonstrated no significant changes. After coronary artery occlusion, total tension and rate of tension rise in the ischaemic zone decreased markedly and showed no significant change with increments in pacing rate. In the border zone, after the initial decrease in tension, pacing at 150 beats/min improved tension without a change in ST segments. However, when the rate was increased to 175 and 200 beats/min, although border zone tension increased further, ST segments rose significantly. Thus, a heart rate between 100-150/min provides the optimal range for increasing contractile ability in the nonischaemic and border zones without adversely affecting the degree of ischaemic injury.
从心律失常和缺血性损伤程度的角度来看，急性冠状动脉闭塞后即刻的最佳心率一直存在争议。在本研究中，我们使用应变片和心外膜电图，在10只开胸犬身上研究了心率对局部心肌收缩能力和缺血的影响。在破坏窦房结后，通过心房起搏将心率控制在100次/分钟，并随机增加到150、175和200次/分钟。冠状动脉闭塞前，较高心率时总张力和张力上升速率逐渐增加，而ST段无明显变化。冠状动脉闭塞后，缺血区的总张力和张力上升速率明显降低，且起搏频率增加时无明显变化。在边缘区，张力最初下降后，以150次/分钟起搏可改善张力，而ST段无变化。然而，当心率增加到175和200次/分钟时，尽管边缘区张力进一步增加，但ST段显著上升。因此，100 - 150次/分钟的心率为增加非缺血区和边缘区的收缩能力提供了最佳范围，而不会对缺血性损伤程度产生不利影响。
