Bashore T M, Walker S, Van Fossen D, Shaffer P B, Fontana M E, Unverferth D V
Ohio State University Hospitals.
Cathet Cardiovasc Diagn. 1988;14(1):24-32. doi: 10.1002/ccd.1810140106.
To assess the effect of rapid preload reduction on left ventricular performance in nonischemic cardiomyopathy, 11 patients were studied during inferior vena caval (IVC) balloon occlusion. Five developed sustained pulsus alternans. During pulsus alternans, the strong beats demonstrated systolic performance characteristics similar to baseline values, despite a drop in both left ventricular (LV) end-diastolic diameter (66 +/- 13 to 61 +/- 13 mm; p less than 0.05) and LV end-diastolic pressure (21 +/- 8 to 9 +/- 6 mmHg; p less than 0.05). In contrast, the weak beats demonstrated a reduction in peak systolic pressure (130 +/- 36 to 109 +/- 33 mmHg; p less than 0.02), fractional shortening (20% +/- 4% to 17% +/- 9%; p less than 0.05) and peak positive dP/dt (1,006 +/- 224 to 921 +/- 287 mmHg; p less than 0.05). Measures of diastolic performance (peak negative dP/dt, the time constant of LV relaxation, the length of diastasis, and LV end-diastolic stress) were not different between baseline beats and the strong beats; and only LV end-diastolic stress differed when baseline beats were compared to the weak beats. When the strong beats were compared to the weak beats during induced pulsus alternans, significant differences were observed in peak systolic pressure, peak positive dP/dt, and fractional shortening, but no differences in any measured diastolic parameter was observed. A slight difference was noted in the left ventricular end-diastolic diameters, with the weak beat consistently beginning at a slightly smaller diameter (61 +/- 13; mm vs 59 +/- 13; p less than 0.05). In summary, these data are consistent with an augmentation and deletion of intrinsic contractile forces in association with an alternation in preload on a beat-to-beat basis as best describing left ventricular performance during pulsus alternans.
为评估快速降低前负荷对非缺血性心肌病左心室功能的影响，对11例患者在进行下腔静脉（IVC）球囊闭塞期间进行了研究。5例出现持续性交替脉。在交替脉期间，尽管左心室（LV）舒张末期直径下降（从66±13降至61±13mm；p<0.05）和左心室舒张末期压力下降（从21±8降至9±6mmHg；p<0.05），但强搏动的收缩功能特征与基线值相似。相比之下，弱搏动的收缩压峰值降低（从130±36降至109±33mmHg；p<0.02），缩短分数降低（从20%±4%降至17%±9%；p<0.05），以及峰值正dP/dt降低（从1,006±224降至921±287mmHg；p<0.05）。舒张功能指标（峰值负dP/dt、左心室舒张时间常数、舒张期长度和左心室舒张末期应力）在基线搏动和强搏动之间无差异；仅在将基线搏动与弱搏动进行比较时，左心室舒张末期应力存在差异。当在诱发交替脉期间将强搏动与弱搏动进行比较时，在收缩压峰值、峰值正dP/dt和缩短分数方面观察到显著差异，但在任何测量的舒张参数方面未观察到差异。左心室舒张末期直径存在轻微差异，弱搏动始终始于稍小的直径（61±13mm对59±13mm；p<0.05）。总之，这些数据与逐搏前负荷交替时内在收缩力的增强和减弱相一致，这最能描述交替脉期间的左心室功能。
