Abstract：
Hypercyanotic spells are one of the defining clinical features of Tetralogy of Fallot (TOF). Limited data exist on peak Doppler right ventricular outflow tract (RVOT) gradient as a risk factor for the development of hypercyanotic spells, frequency of prophylactic use of propranolol based on peak RVOT gradient, and its impact on preventing the occurrence of hypercyanotic spells. We aimed to quantify peak RVOT gradients as measured on transthoracic echocardiography in infants with unrepaired TOF and assess for correlation with clinical symptoms of hypercyanotic spells. We also assessed the frequency of pre-operative use of propranolol, indication for medication initiation, and occurrence of hypercyanotic spells with or without propranolol use. Retrospective analysis was performed on patients at our institution who were born between February 1, 2011 and May 31, 2023. Patients were excluded if they were maintained on prostaglandin infusion or underwent palliative shunt placement or balloon valvuloplasty prior to complete surgical repair. Demographics, occurrence of hypercyanotic spells, propranolol use, peripheral oxygen saturation, age at surgical repair, and peak RVOT gradient at the time of propranolol initiation were collected from the electronic medical record. If no propranolol use was recorded, the single highest maximum RVOT gradient prior to surgery was collected. 203 patients were identified, of which 92 patients were included in analysis. Thirty-six (39%) patients received propranolol and 19% of patients developed hypercyanotic spells prior to surgery. Patients with higher peak RVOT gradients were more likely to be started on propranolol even in the absence of overt symptoms, and they also demonstrated more systemic desaturation. Additionally, peak RVOT gradient was found to be a poor predictor for the development of hypercyanotic spells. Wide clinical variation exists in the prophylactic use of propranolol for prevention of hypercyanotic spells. Peak RVOT gradient is not a reliable tool for prophylactic propranolol initiation to prevent hypercyanotic spells.
摘要：
紫红色过多是法洛四联症（TOF）的明确临床特征之一。关于多普勒右心室流出道（RVOT）峰值梯度的数据有限，这是发生紫红色过多法术的危险因素，基于峰值RVOT梯度的普萘洛尔预防性使用频率，以及它对防止紫红色过多法术发生的影响。我们旨在量化未修复TOF的婴儿经胸超声心动图测得的RVOT峰值梯度，并评估其与紫红色过多的临床症状的相关性。我们还评估了术前使用普萘洛尔的频率，开始用药的指征,以及在使用或不使用普萘洛尔的情况下出现紫红色过多现象。我们对2011年2月1日至2023年5月31日出生的患者进行了回顾性分析。如果在完成手术修复之前维持前列腺素输注或进行姑息性分流放置或球囊瓣膜成形术，则将其排除在外。人口统计,出现了紫红色过多的咒语,普萘洛尔的使用，外周血氧饱和度,手术修复的年龄，从电子病历中收集普萘洛尔开始时的RVOT峰值梯度。如果没有使用普萘洛尔的记录,收集手术前单个最高最大RVOT梯度.203名患者被确认，其中92例患者纳入分析.36例（39％）患者接受了普萘洛尔，19％的患者在手术前出现了紫红色过多的现象。即使没有明显症状，RVOT峰值梯度较高的患者也更有可能开始服用普萘洛尔。他们还表现出更多的系统性去饱和。此外,发现峰值RVOT梯度是高紫红色法术发展的不良预测指标。预防性使用普萘洛尔预防紫红色过多的法术存在广泛的临床差异。峰值RVOT梯度不是预防性启动普萘洛尔以预防紫红色过多的可靠工具。
