Wisheart J D, Wright J E, Rosenfeldt F L, Ross J K
Thorax. 1973 Jan;28(1):9-14. doi: 10.1136/thx.28.1.9.
The effect of cardiac pacing, through a wide range of pacing rates, has been studied in 13 patients in stable sinus rhythm within 24 hours of operation. Using first atrial and then ventricular pacing, the cardiac rate was raised to 60% above control value. The effects of atrial and ventricular pacing were compared by observing the differences in the various parameters measured at corresponding paced heart rates. With atrial pacing there was no significant difference in the cardiac output, mean aortic pressure, mean left atrial pressure, or left ventricular work. During ventricular pacing there were significant falls in cardiac output (p<0·05), mean aortic pressure (p<0·01), and left ventricular work (p<0·01). There was a significant rise in mean left atrial pressure (p<0·01). In this study atrial pacing had no significant effect on the parameters measured, through a wide range of cardiac rates. An inotropic effect resulting from increase of rate was not seen. Reported increases in cardiac output following pacing must therefore have resulted from correction of a dysrhythmia. Ventricular pacing incurs a definite haemodynamic penalty if used in patients with an intact atrioventricular conducting pathway. If atrial pacing is not available, this penalty must be balanced against the possible haemodynamic advantage of suppressing a dysrhythmia.
在13例术后24小时内窦性心律稳定的患者中，研究了在较宽起搏频率范围内心脏起搏的效果。先进行心房起搏，然后进行心室起搏，将心率提高到高于对照值60%。通过观察在相应起搏心率下测量的各种参数的差异，比较心房起搏和心室起搏的效果。心房起搏时，心输出量、平均主动脉压、平均左心房压或左心室作功无显著差异。心室起搏时，心输出量（p<0.05）、平均主动脉压（p<0.01）和左心室作功（p<0.01）显著下降。平均左心房压显著升高（p<0.01）。在本研究中，在较宽的心率范围内，心房起搏对所测量的参数无显著影响。未观察到因心率增加而产生的变力作用。因此，报道的起搏后心输出量增加一定是由于心律失常得到纠正。如果在房室传导通路完整的患者中使用心室起搏，会产生明确的血流动力学代价。如果无法进行心房起搏，则必须在这种代价与抑制心律失常可能带来的血流动力学优势之间进行权衡。
