应用经胸冠状动脉血流显像技术评价支架术前后冠脉血流储备

目的采用经胸多普勒超声心动图冠状动脉血流显像技术观察支架术前后冠状动脉血流速度的变化，评价其对冠状动脉血流储备（CFR）的影响。方法22例冠心病患者(男18例，女4例),平均年龄（53.2±6.7）岁。对狭窄的冠状动脉行经皮冠状动脉腔内成形术（PTCA）后各置入一枚支架。分别于木前、术后72h内采用经胸多普勒冠状动脉血流显像技术记录狭窄远端静息舒张期血流峰速(r-Vd)、注射潘生丁及等长握力实验时最大舒张期血流峰速(d-Vd)及CFR。结果22例患者行支架术均获成功,狭窄率由术前(83.5±8.9)%,降至术后(5.2±9)%(P<0.05)。20支冠脉获得理想多普勒频谱（检出率90.9％）；支架术后r-Vd较术前r-Vd有增加趋势，但无统计学意义;术后静脉注射潘生丁后最大d-Vd及CFR均较术前明显增加［（0.92±0.22)m/svs(0.52±0.18)m/s,2.94±1.16vs1.88±0.40,P均<0.01］。30％患者术后CFR仍<2.0，此组与CFR≥2.0患者组比较，支架术后r-Vd明显增高［(0.45±0.19)m/svs(0.27±0.12)m/s,P<0.05］。少数患者(约18%，4／22)术前出现心绞痛，头昏等不适，静注氨茶碱或(和)含化硝酸甘油可迅速缓解。结论支架术能明显增加冠状动脉血流储备。采用经胸多普勒冠脉血流显像技术结合潘生丁、握力试验是一可行的无创性评价冠心病患者冠脉血流储备及介入治疗疗效的新方法。

Noninvasive assessment of coronary flow reserve using transthoracic coronary flow imaging before and after successful coronary stent implantation

Objective　To Determine: (1) Whether transthoracic Doppler may detect coronary flow velocity changes in patients undergoing coronary angioplasty and stenting to assess coronary flow reserve (CFR), and (2) whether this technique may help to evaluate noninvasively the results of the procedure. Methods　Twenty-two patients with single-vessel disease (LAD 17, RCA 4, LCX 1) undergoing stent implantation were studied with transthoracic pulsed Doppler guided by color flow imaging by recording coronary diastolic peak velocity at rest (r-Vd) and maximal vasodilation by intravenous dipyridamole and isometric handgrip (d-Vd), and CFR before and <72 hours after the interventional procedure. Results　Coronary flow velocity signals were successfully obtained in 20/22 patients (90.9%). Narrowing percent in diameter for 22 coronary arteries decreased from 83.5%±8.9% before to 5.2±9% after stenting (P<0.05). Both maximal d-Vd and CFR significantly increased after stenting (0.92±0.22 m/s vs 0.52±0.18 m/s, 2.94±1.16 vs 1.88±0.40, both P<0.01). After stenting, r-Vd tended to increase (0.35±0.17 m/s vs 0.26±0.09 m/s, P>0.05). Impaired CFR after successful stenting (30%, 6/20) was related to an increased resting flow velocity. Patients with an increase of CFR after stenting were characterized by an unaltered resting flow velocity and an increased dipyridamole-induced maximal flow velocity. Conclusion　In patients with coronary artery stenosis, transthoracic coronary flow imaging combined with intravenous dipyridamole and isometric handgrip shows improvement in coronary flow reserve after successful stent implantation. This new method may be feasible and promising technique for assessing CFR with a totally noninvasive approach.