Comparison of left atrial and left ventricular performance in conscious dogs.
Comparison of left atrial and left ventricular performance in conscious dogs.
复制标题
清醒犬左心房和左心室性能的比较。
DOI：
10.1093/cvr/18.10.604
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发表时间：
1984
影响因子：
10.8
通讯作者：
Morkin,E
中科院分区：
文献类型：
--
作者：
Goldman,S;Olajos,M;Morkin,E
据报道，左心房（LA）的收缩速度比左心室（LV）更快，但在生理条件下，这两个腔室的收缩机制尚未进行比较。因此，sonomicometer晶体和固态压力传感器被用来测量LV和LA收缩功能，同时在七个清醒的狗。将两组晶体（LA-1、LA-2）垂直放置在LA上。以0.4 - 1.2 μg·kg-1·min-1递增剂量输注苯丙氨酸，以增加LV和LA后负荷。通过心房起搏维持恒定心率。结果表明，两种直径的左心房运动几乎相同。左心房短轴缩短率（0.07±0.01）和射血时间（0.057±0.002 s）明显小于心室值（分别为0.21±0.01和0.18±0.01 s）。LV的周向纤维缩短速度（Vcf）（1.16±0.05 circ·s-1）与LA-1 Vcf（1.19±0.09 circ·s-1）或LA-2 Vcf（1.22±0.08 circ·s-1）无显著差异。输注苯肾上腺素时，左室收缩压从120.0±3.4 mmHg升至190.8± 15.5 mmHg，左室舒张末期压从3.6± 0.3 mmHg升至27.7 ±2.7 mmHg。当绘制每个腔室的Vcf与该腔室的峰值收缩压时，LA曲线位于LV曲线的右上方。因此，在同一清醒动物的心脏中，LA和LV在静息时具有非常相似的壁速度，但LV缩短的速度对后负荷的增加更敏感。
The velocity of contraction has been reported to be more rapid in left atrium (LA) than left ventricle (LV), but the mechanics of contraction in these two chambers have not been compared under physiological conditions. Accordingly, sonomicrometer crystals and solid state pressure transducers were used to measure LV and LA systolic function simultaneously in seven conscious dogs. Two sets of crystals (LA-1, LA-2) were placed perpendicularly across the LA. Phenylephrine was infused at increasing doses from 0.4 to 1.2 μg·kg−1·min−1to increase LV and LA afterloads. Constant heart rates were maintained by atrial pacing. The results indicated that LA motion was virtually identical in both diameters. LA fractional shortening (0.07±0.01) and ejection time (0.057±0.002 s) were much smaller than the ventricular values (0.21±0.01 and 0.18±0.01 s, respectively). The velocity of circumferential fibre shortening (Vcf) for the LV (1.16±0.05 circ·s−1) was not significantly different from LA-1 Vcf(1.19±0.09 circ·s−1) or LA-2 Vcf(1.22±0.08 circ·s−1). During phenylephrine infusions, LV systolic pressure increased from 120.0±3.4 to 190.8± 15.5 mmHg and LV end-diastolic pressure increased from 3.6±0.3to27.7±2.7 mmHg. When Vcffor each chamber was plotted against the peak systolic pressure in that chamber, the curve of the LA was located upward and to the right of the LV curve. Thus in the heart of the same conscious animal, LA and LV have very similar wall velocities at rest, but the velocity of LV shortening was more sensitive to increases in afterload.