Jung Mette H, Hassager Christian, Balling Louise, Russell Stuart D, Boesgaard Soeren, Gustafsson Finn
From the *Department of Cardiology, Rigshospitalet, Copenhagen, Denmark; and †Department of Cardiology, Johns Hopkins Hospital, Baltimore, Maryland.
ASAIO J. 2015 May-Jun;61(3):307-12. doi: 10.1097/MAT.0000000000000194.
Pulmonary capillary wedge pressure (PCWP) is the key to describing left ventricular (LV) unloading; however, the relation between pressure and the echocardiography-derived surrogate of LV volume (LV end-diastolic diameter [LVEDD]) as a function of pump speed (revolutions per minute [RPM]) in continuous-flow LV assist device (CF-LVAD) patients is unknown. In this study, the pressure-volume relation as a function of RPM during ramp testing was investigated by simultaneously measuring PCWP by Swan-Ganz catheter and LVEDD by echocardiography. The ramp protocol started at usual pump setting (ramp-base) and then went from 8,000 RPM (ramp-low) increasing by 400 RPM/5 minutes until reaching 12,000 RPM or suction/arrhythmic event (ramp-high). The study was finalized by a 25 Watt exercise test at two ramp steps. Ten patients with ramp-base of 9,300 ± 241 RPM (at which 3 of 10 had aortic valve opening) were examined. At ramp-low, ramp-base, and ramp-high, PCWP was 20 ± 4, 14 ± 4, and 7 ± 3 mm Hg (p < 0.001 for all comparisons) and LVEDD 6.6 ± 1.0, 6.7 ± 0.9, and 5.5 ± 1.7 cm (p < 0.05 for all comparisons but ramp-low versus ramp-base). Correlation between PCWP and LVEDD slopes; R = 0.53 (p = 0.02). In conclusion, PCWP as a function of RPM is weakly correlated with changes in LVEDD. Thus, LVEDD is not an accurate measure of unloading in CF-LVAD patients.
肺毛细血管楔压(PCWP)是描述左心室(LV)卸载情况的关键指标;然而,在持续流左心室辅助装置(CF-LVAD)患者中,压力与通过超声心动图得出的左心室容积替代指标(左心室舒张末期直径[LVEDD])之间随泵速(每分钟转数[RPM])变化的关系尚不清楚。在本研究中,通过使用Swan-Ganz导管同步测量PCWP以及通过超声心动图测量LVEDD,研究了斜坡测试期间压力-容积关系随RPM的变化情况。斜坡方案从通常的泵设置(斜坡基线)开始,然后从8000 RPM(斜坡低)开始,以每分钟400 RPM的速度增加,持续5分钟,直至达到12000 RPM或出现抽吸/心律失常事件(斜坡高)。该研究通过在两个斜坡步骤进行的25瓦运动测试完成。对10名斜坡基线为9300±241 RPM(其中10人中有3人主动脉瓣开放)的患者进行了检查。在斜坡低、斜坡基线和斜坡高时,PCWP分别为20±4、14±4和7±3 mmHg(所有比较p<0.001),LVEDD分别为6.6±1.0厘米、6.7±0.9厘米和5.5±1.7厘米(除斜坡低与斜坡基线比较外,所有比较p<0.05)。PCWP与LVEDD斜率之间的相关性;R = 0.53(p = 0.02)。总之,PCWP随RPM的变化与LVEDD的变化呈弱相关。因此,LVEDD并非CF-LVAD患者卸载情况的准确测量指标。