Differential Response to Afterload in Axial and Centrifugal Continuous Flow Left Ventricular Assist Devices (CV-LVAD)

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• 作者：B.C. Lampert¹ ; C. Eckert¹ ; M.A. Shullo² ; A. Scanlon¹ ; S. Weaver¹ ; J. Bhama¹ ; C. Bermudez¹ ; R. Kormos¹ ; J.J. Teuteberg¹
• 刊名：The Journal of Heart and Lung Transplantation
• 出版年：2013
• 出版时间：April, 2013
• 年：2013
• 卷：32
• 期：4_supp_S
• 页码：S57
• 全文大小：269 K

文摘

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Purpose

CF-LVADs generate a specific flow for a given pressure differential across the pump. Implications of difference between afterload sensitivity of axial and centrifugal pumps has not been previously described.

Methods and Materials

All CF LVAD at a single center from 5/06 to 10/11, supported >30 days and managed with a standardized blood pressure (BP) protocol with target mean ¡Ü 80 mmHg. Mean number of data points per patient was 318. Contour mapping compared speed, pressure, and power.

Results

There were 96 CF-LVADs with mean support of 262 days. Patient demographics: age 55 years, male 80 % , white 79 % , ischemic 50 % , BTT 55 % , 61 axial & 35 centrifugal LVAD. Mean BP was near goal and not different between axial and centrifugal devices (). No BP meds at end of follow-up: 25 patients, 14 of whom died on device. Of patients on therapy, 38 were managed on 1 medication and 33 on 2+ medications. As expected, for each pump type at the same BP (afterload), power consumption and thus flow, increased with increasing pump speed. However, pump types differed somewhat in their response to increased afterload (). For axial pumps, at a given pump speed there was little change in pump power over clinically relevant ranges of afterload. In contrast, centrifugal pumps had more afterload dependence with a decrease in pump power with increasing afterload.

Conclusions

In the setting of aggressive BP control, axial and centrifugal pumps demonstrated a differential response to increasing afterload, with centrifugal pumps having greater afterload dependence. BP control is important in all patients with CF-LVADs, but poorly controlled BP may impair pump flow to a greater degree in patients with centrifugal devices.