Saratov Research Institute of Cardiology, Saratov, Russia.
J Cardiovasc Med (Hagerstown). 2012 Aug;13(8):491-8. doi: 10.2459/JCM.0b013e3283512199.
Selection of the optimal dose of beta-blocker treatment in myocardial infarction (MI) patients is problematic because of a lack of well-established guidelines.
We evaluated changes in synchronization between 0.1 Hz oscillations in heart rate (HR) and plethysmographic peripheral microcirculation in response to a tilt-table test and to 3-month treatment with the highest tolerated beta-blocker (metoprolol) dose in 43 patients aged between 41 and 77 years with acute MI 6 months prior to the start of the study. Before the study the patients were treated with small doses of beta-blocker. Phase differences between HR and peripheral microcirculation oscillations were used to measure the degree of synchronization (S), and relative change in S from horizontal position was used to characterize the response to vertical tilt.
Two groups of MI patients matched for clinical characteristics were identified on the basis of the results. The first group was composed of patients with decreased S as a response to vertical tilt at the beginning of the study. The patients with increased S during vertical tilt before treatment with the highest tolerated beta-blocker dose were attributed to the second group. The response to vertical tilt in the first group of patients was postulated to indicate the need to increase beta-blocker dose, and in turn, the response in the second group to indicate an already adequate beta-blocker dose.
Assessment of synchronization of 0.1 Hz HR and peripheral microcirculation oscillations as a response to a tilt test can possibly be used as a guideline for selecting beta-blocker dose in post-MI patients.
由于缺乏完善的指南，选择心肌梗死（MI）患者β受体阻滞剂治疗的最佳剂量存在问题。
我们评估了 43 例年龄在 41 至 77 岁之间的急性 MI 患者在研究开始前 6 个月对倾斜试验和最高耐受剂量的β受体阻滞剂（美托洛尔）治疗 3 个月的反应中，心率（HR）和容积描记外周微循环之间的 0.1Hz 振荡之间同步性的变化。在研究之前，患者接受了小剂量的β受体阻滞剂治疗。使用 HR 和外周微循环振荡之间的相位差来测量同步程度（S），并使用 S 从水平位置的相对变化来描述对垂直倾斜的反应。
根据研究结果，确定了两组临床特征匹配的 MI 患者。第一组由研究开始时垂直倾斜时 S 降低的患者组成。在接受最高耐受剂量的β受体阻滞剂治疗之前，S 在垂直倾斜期间增加的患者被归入第二组。假设第一组患者的垂直倾斜反应表明需要增加β受体阻滞剂剂量，而第二组的反应则表明已经有足够的β受体阻滞剂剂量。
评估 0.1Hz HR 和外周微循环振荡的同步性作为倾斜试验的反应，可能可以用作 MI 后患者选择β受体阻滞剂剂量的指南。
