Clinical Center of the Republic of Srpska, Faculty of Medicine, University of Banja-Luka, Banja-Luka, Bosnia and Herzegovina -
Department of Cardiac, Thoracic, and Vascular Surgery, S. Orsola-Malpighi Polyclinic Hospital, Bologna University, Bologna, Italy.
Minerva Cardioangiol. 2020 Jun;68(3):249-257. doi: 10.23736/S0026-4725.20.05093-8. Epub 2020 Feb 25.
A blunted heart rate reserve (HRR) during dipyridamole stress echocardiography (DSE) is a prognostically unfavorable sign of cardiac autonomic dysfunction. Short-term adjustments of heart rate (HR) are thought to rise from changes in neural input to the heart. DSE is applied in potential heart donors to rule out underlying coronary artery disease and left ventricular dysfunction. The aim of this study is to assess HRR during DSE in brain death.
We enrolled two groups: group 1 (N.=49, 22 men, 54.6±8.8 years) with patients in brain death enrolled in the nationwide marginal donor heart recruiting program; group 2 (N.=49, 18 men, 66.4±12.0 years) referred to DSE for suspected or known coronary artery disease. All underwent DSE (0.84 mg/kg in 6') by quality-controlled readers certified via web-based training (1487/CE Lazio-1). We assessed left ventricular contractile reserve (LVCR) as stress/rest ratio of force (systolic blood pressure/end-systolic volume). HRR was calculated as the peak/rest HR ratio from 12-lead EKG.
The two study groups were similar for prevalence of inducible ischemia (4/49 vs. 9/49, P=NS). Group 1 showed higher resting HR (group 1: 88.1±15.5 bpm vs. group 2: 66.5±11.5 bpm, P<0.01) and similar peak HR (group 1: 94.7±15.3 bpm vs. group 2: 89.5±19.3 bpm, P=0.144), with blunted HRR (group 1: 1.08±0.10 bpm vs. group 2: 1.36±0.31 bpm, P<0.01). HRR was unrelated to LVCR.
HRR is almost abolished and unrelated to LVCR in brain-dead patients during DSE. The modulation of neural input to the heart is essential to determine HRR, and plays no significant role in determining the inotropic response during DSE.
在双嘧达莫负荷超声心动图（DSE）中，心率储备（HRR）减弱是心脏自主神经功能障碍的预后不良标志。心率（HR）的短期调整被认为源于心脏神经输入的变化。DSE 应用于潜在的心脏供体中，以排除潜在的冠状动脉疾病和左心室功能障碍。本研究的目的是评估脑死亡患者在 DSE 期间的 HRR。
我们纳入了两组患者：第 1 组（N=49，22 名男性，54.6±8.8 岁），为全国性边缘供体心脏招募计划中脑死亡患者；第 2 组（N=49，18 名男性，66.4±12.0 岁），因疑似或已知冠状动脉疾病而行 DSE。所有患者均由经过网络培训认证的有资质的读者（1487/CE Lazio-1）进行 DSE（0.84mg/kg，持续 6'）。我们评估了左心室收缩储备（LVCR）作为压力（收缩压/收缩末期容积）的应激/休息比值。HRR 通过 12 导联心电图计算为峰值/休息 HR 比值。
两组患者的可诱导缺血发生率相似（4/49 例 vs. 9/49 例，P=NS）。第 1 组静息 HR 较高（第 1 组：88.1±15.5 bpm vs. 第 2 组：66.5±11.5 bpm，P<0.01），而峰值 HR 相似（第 1 组：94.7±15.3 bpm vs. 第 2 组：89.5±19.3 bpm，P=0.144），HRR 减弱（第 1 组：1.08±0.10 bpm vs. 第 2 组：1.36±0.31 bpm，P<0.01）。HRR 与 LVCR 无关。
在 DSE 期间，脑死亡患者的 HRR 几乎完全消失，与 LVCR 无关。心脏神经输入的调节对于确定 HRR 至关重要，而在 DSE 期间确定正性肌力反应时，其作用并不显著。
