DeCampli William M, Tsai Felix W, Argueta-Morales I Ricardo, Smith Cathy, Munro Hamish M
Cardiothoracic Surgery, The Heart Center at Arnold Palmer Hospital for Children, Orlando, FL, USA.
World J Pediatr Congenit Heart Surg. 2013 Oct;4(4):373-9. doi: 10.1177/2150135113490760.
Indirect clinical evidence suggests that coronary blood flow (CBF) is altered in patients palliated with systemic-to-pulmonary artery shunts (SPSs). The addition of epinephrine may exert additional effects.
A total of 11 newborn piglets underwent placement of a 3.5- to 4-mm graft between the innominate artery and the pulmonary artery. Doppler probes measured flow continuously in the aorta (aortic flow [AoF]), pulmonary artery and left coronary artery at baseline (SPS closed), SPS open, and during epinephrine administration (SPS closed and open). Each animal served as its own control. Systolic and diastolic CBF, resistance (coronary vascular resistance index [CVRI]), and myocardial oxygen supply demand ratio were calculated.
Opening the SPS increased AoF and decreased systolic and diastolic pressure from baseline, with and without the presence of epinephrine. The CBF and CVRI decreased on opening the SPS in the presence of epinephrine. The decrease occurred only in diastole and was proportional to pulmonary-to-systemic flow ratio (Qp/Qs). Epinephrine infusion itself reduced CVRI with SPS closed, but there was little further decrease on opening SPS. Myocardial oxygen supply-demand ratio decreased on opening SPS at baseline and with epinephrine.
This study suggests that SPS decreases CBF, especially in the presence of a higher Qp/Qs and epinephrine. The mechanism is largely due to the decrease in diastolic pressure and the inability of the coronary arteries to compensate with vasodilation.
间接临床证据表明，接受体肺分流术（SPS）姑息治疗的患者冠状动脉血流（CBF）发生改变。添加肾上腺素可能会产生额外影响。
总共11只新生仔猪在无名动脉和肺动脉之间植入了3.5至4毫米的移植物。多普勒探头在基线时（SPS关闭）、SPS开放时以及肾上腺素给药期间（SPS关闭和开放）连续测量主动脉（主动脉血流[AoF]）、肺动脉和左冠状动脉的血流。每只动物作为自身对照。计算收缩期和舒张期CBF、阻力（冠状动脉血管阻力指数[CVRI]）以及心肌氧供需比。
无论有无肾上腺素，打开SPS均会使AoF增加，并使收缩压和舒张压较基线降低。在有肾上腺素存在的情况下，打开SPS时CBF和CVRI降低。这种降低仅发生在舒张期，且与肺循环与体循环血流量之比（Qp/Qs）成正比。在SPS关闭时，肾上腺素输注本身会降低CVRI，但打开SPS时进一步降低的幅度很小。在基线时以及使用肾上腺素时，打开SPS会使心肌氧供需比降低。
本研究表明，SPS会降低CBF，尤其是在Qp/Qs较高且存在肾上腺素的情况下。其机制主要是由于舒张压降低以及冠状动脉无法通过血管舒张进行代偿。
