Effects of the Berlin Heart biventricular assist device on microvascular responses in pre-transplant patients.
Microcirculatory forearm cutaneous blood flow was monitored continuously and noninvasively by laser doppler flow-metry (LDF) in 15 patients treated with the Berlin Heart biventricular assist device system (BVAD) for end-stage heart failure under stable hemodynamic states (BVAD pts, n = 10) and norepinephrine therapy (BVAD nor pts, n = 5). Ten healthy human subjects served as controls (C). Cutaneous blood flow was measured before, during, and after external brachial artery occlusion to evaluate the post-occlusive reactive hyperemia (PORH) as a standardized response. To examine microvascular responses to macrohemodynamic changes, the cardiac output (CO) was decreased by a 20% reduction in BVAD pump rate. No significant differences in baseline LDF measurements (in millivolts) were observed among the three groups (C, 470.7 mV +/- 177.3; BVAD pts, 328.0 mV +/- 122.7; BVAD nor pts, 360.0 mV +/- 160.0). After cuff pressure release (1 min later), a significant (p < 0.004) three-fold to four-fold blood flow increase (PORH) occurred in each group (C, 1113.6 mV +/- 469.2; BVAD pts, 813.0 mV +/- 190.1; BVAD nor pts, 498.0 mV +/- 191.8). The difference in PORH between the BVAD pts and BVAD nor pts was significant (p < 0.01), and the time to peak PORH values was different (p < 0.05) among the three groups (C, 22.2 s +/- 10.7; BVAD pts, 11.3 s +/- 12.5; BVAD nor pts, 7.0 s +/- 5.8). A markedly delayed return to baseline occurred in the BVAD pts. The 20% reduction in BVAD pump rate decreased CO significantly (p < 0.05) and increased (p < 0.01) systemic vascular resistance (SVR).(ABSTRACT TRUNCATED AT 250 WORDS)
Bittner
H B
HB
German Heart Institute, Department of Cardiothoracic Surgery, Berlin.
Diemel
K D
KD
Böttner
W
W
Friedel
N
N
Stengele
B
B
Hetzer
R
R
D000328:Adult; D002303:Cardiac Output, Low / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D005542:Forearm / Q000098:blood supply*; D016027:Heart Transplantation; D006353:Heart-Assist Devices; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation; D008991:Monitoring, Physiologic; D011300:Preoperative Care; D012039:Regional Blood Flow