Katoh H, Sano K, Inoue S, Hirano T, Tahara H, Sakane T, Kitamura J, Yoshitomi H, Shimada T, Murakami R
Fourth Department of Internal Medicine, Shimane Medical University.
J Cardiol. 1999 Oct;34(4):199-205.
Atrial fibrillation with organic heart disease shows a steady value for the time constant of left ventricular isovolumetric relaxation (TC), whereas left ventricular contractility varies from beat to beat. However, there is no report on left ventricular relaxation in lone atrial fibrillation. This study assessed left ventricular relaxation in 5 patients with lone atrial fibrillation, 3 with ischemic heart disease and one with hypertrophic cardiomyopathy. Left ventricular pressure was recorded at 3 msec intervals, with a high fidelity micromanometer-tipped catheter. Maximal positive dP/dt (dP/dtmax) and TC of isovolumetric left ventricular relaxation period [P(t) = (P0-P infinity) exp (-t/TC) + P infinity] were measured as indices of left ventricular contractility and left ventricular relaxation, respectively. Correlation coefficients of dP/dtmax and TC versus the ratio of the preceding to the pre-preceding RR-interval (RR2/RR1) were calculated. A good correlation was found between dP/dtmax and RR2/RR1 in all patients (r = 0.71-0.84, p < 0.0001). No correlation between TC and RR2/RR1 was found in patients with atrial fibrillation with organic heart disease, but a good correlation was found between TC and RR2/RR1 in patients with lone atrial fibrillation (r = 0.74-0.95, p < 0.0001). The correlation between TC and RR2/RR1 is well preserved in lone atrial fibrillation. The mechanism of the variation of TC with the RR2/RR1 interval in lone atrial fibrillation may be similar to the change of TC in postextrasystolic potentiation, which is attributed to the change of intracellular Ca2+ concentration. Absence of correlation between TC and RR2/RR1 interval may indicate that left ventricular relaxation is disturbed in patients with atrial fibrillation with organic heart disease.
伴有器质性心脏病的心房颤动患者，其左心室等容舒张时间常数（TC）保持稳定，而左心室收缩性逐搏变化。然而，关于孤立性心房颤动患者左心室舒张功能的研究尚无报道。本研究评估了5例孤立性心房颤动患者、3例缺血性心脏病患者和1例肥厚型心肌病患者的左心室舒张功能。使用高保真微测压导管，每隔3毫秒记录一次左心室压力。分别测量左心室收缩性指标最大正向dP/dt（dP/dtmax）和左心室等容舒张期的TC [P(t) = (P0 - P∞) exp (-t/TC) + P∞]。计算dP/dtmax和TC与前一个RR间期和前前一个RR间期比值（RR2/RR1）之间的相关系数。所有患者的dP/dtmax与RR2/RR1之间均存在良好的相关性（r = 0.71 - 0.84，p < 0.0001）。伴有器质性心脏病的心房颤动患者中，TC与RR2/RR1之间无相关性，但孤立性心房颤动患者中，TC与RR2/RR1之间存在良好的相关性（r = 0.74 - 0.95，p < 0.0001）。在孤立性心房颤动中，TC与RR2/RR1之间的相关性良好。孤立性心房颤动中TC随RR2/RR1间期变化的机制可能类似于期前收缩后增强中TC的变化，这归因于细胞内Ca2+浓度的改变。TC与RR2/RR1间期缺乏相关性可能表明伴有器质性心脏病的心房颤动患者左心室舒张功能受到干扰。
