Laskey W K, St John Sutton M, Untereker W J, Martin J L, Hirshfeld J W, Reichek N
Am J Cardiol. 1983 Oct 1;52(7):809-12. doi: 10.1016/0002-9149(83)90419-8.
Differences in the mechanics of strong and weak contractions during sustained pulsus alternans were studied in 4 patients with aortic valve stenosis (AS). No significant difference was observed between strong (S) and weak (W) beats in M-mode echographic end-diastolic minor-axis dimension or end-diastolic meridional wall stress. Peak systolic meridional stress (S:225 X 10(3) dynes/cm2; W:205 X 10(3) dynes/cm2), the time integral of left ventricular (LV) meridional systolic stress (S:5,000 X 10(3) dynes/cm2; W:4,500 X 10(3) dynes/cm2) and the area of a stress dimension loop (S:202 X 10(3) dyne/cm; W 165 X 10(3) dyne/cm) were all greater for strong beats. However, end-systolic meridional stress (S:100 X 10(3) dynes/cm2; W:115 X 10(3) dynes/cm2) and end-systolic minor-axis dimension (S:4.75 cm; W:5.0 cm) were significantly greater for weak beats. Stress-length relations, derived from resting and postnitroglycerin determinations, revealed higher end-systolic dimensions for weak beats at any level of limiting afterload, suggesting diminished contractile performance of weak beats. Additionally, fractional minor-axis shortening for weak beats was diminished, at any level of end-systolic stress, in comparison with that for strong beats. The results are supportive of theories suggesting alternating contractile performance during pulsus alternans.
对4例主动脉瓣狭窄（AS）患者持续交替脉期间强弱收缩机制的差异进行了研究。在M型超声心动图舒张末期短轴内径或舒张末期经壁应力方面，强（S）、弱（W）搏动之间未观察到显著差异。强搏动的收缩期峰值经壁应力（S：225×10³达因/平方厘米；W：205×10³达因/平方厘米）、左心室（LV）经壁收缩期应力的时间积分（S：5,000×10³达因/平方厘米；W：4,500×10³达因/平方厘米）以及应力-维度环的面积（S：202×10³达因/厘米；W：165×10³达因/厘米）均更大。然而，弱搏动的收缩末期经壁应力（S：100×10³达因/平方厘米；W：115×10³达因/平方厘米）和收缩末期短轴内径（S：4.75厘米；W：5.0厘米）显著更大。从静息和使用硝酸甘油后测定得出的应力-长度关系显示，在任何水平的极限后负荷下，弱搏动的收缩末期维度更高，提示弱搏动的收缩性能降低。此外，与强搏动相比，在任何收缩末期应力水平下，弱搏动的短轴缩短分数均降低。这些结果支持了提示交替脉期间收缩性能交替的理论。
