Rosenquist R, Gobel F L, Wang Y
Am Heart J. 1975 Feb;89(2):144-52. doi: 10.1016/0002-8703(75)90038-1.
Increasing the heart rate to near normal in patients with complete heart block (CHB) and slow ventricular rates may lead to greater improvement in ventricular function than when the heart rate is increased from normal to more rapid heart rates. Improvement in ventricular function is usually manifested by a decrease in left ventricular end-diastolic pressure (LVEDP) and volume and by an increase in contractility. In patients with both CHB and valvular heart disease improvement in ventricular function during pacing may be modified by the nature of the valvular disease. Hemodynamic data from six patients with both valvular heart disease and CHB were compared with those from ten patients with CHB and normal cardiac valves. Hemodynamic studies were performed at slow or idioventricular rates and again after increasing the heart rate to more nearly normal levels by ventricular pacing. When obstruction to left ventricular inflow (mitral stenosis) co-existed with CHB, increasing the heart rate resulted in a reduction of an elevated LVEDP to normal. This resulted in only a small increase in left atrial pressure in spite of a striking increase in the mean left atrial-ventricular gradient. When obstruction to left ventricular outflow prevailed (aortic stenosis), improvement in cardiac function was manifested mainly by a decrease in LVEDP and was accompanied by a decrease in left ventricular stroke work. When a large regurgitant volume (aortic insufficiency) was added to a ventricle which has enlarged subsequent to CHB, there was striking elevation in ventricular filling pressures which returned to more nearly normal levels when the heart rate was increased. This was accompanied by a reduction in regurgitant stroke volume in the patient in whom it was measured. Thus, an increase in heart rate may be especially beneficial to those patients with CHB who also have valvular lesions which contribute to an increase in LVEDP and end-diastolic volume. Careful hemodynamic evaluation is helpful in determining appropriate therapy in these patients.
在完全性心脏传导阻滞（CHB）且心室率缓慢的患者中，将心率提高至接近正常水平可能比将心率从正常提高到更快心率时能使心室功能得到更大改善。心室功能的改善通常表现为左心室舒张末期压力（LVEDP）和容积降低以及收缩力增加。在患有CHB和瓣膜性心脏病的患者中，起搏期间心室功能的改善可能会因瓣膜疾病的性质而有所改变。将6例患有瓣膜性心脏病和CHB的患者的血流动力学数据与10例患有CHB且心脏瓣膜正常的患者的数据进行了比较。在缓慢或心室自身心律时进行血流动力学研究，然后通过心室起搏将心率提高到更接近正常水平后再次进行研究。当左心室流入道梗阻（二尖瓣狭窄）与CHB并存时，心率增加会使升高的LVEDP降至正常。尽管平均左心房 - 心室梯度显著增加，但这仅导致左心房压力小幅升高。当左心室流出道梗阻为主（主动脉瓣狭窄）时，心脏功能的改善主要表现为LVEDP降低，并伴有左心室每搏功减少。当在CHB后已扩大的心室中增加大量反流容积（主动脉瓣关闭不全）时，心室充盈压力会显著升高，当心率增加时会恢复到更接近正常的水平。在测量反流每搏量的患者中，这伴随着反流每搏量的减少。因此，心率增加可能对那些患有CHB且同时伴有瓣膜病变导致LVEDP和舒张末期容积增加的患者特别有益。仔细的血流动力学评估有助于确定这些患者的适当治疗方法。
