University of British Columbia, Vancouver, BC, Canada.
Circ Arrhythm Electrophysiol. 2012 Oct;5(5):933-40. doi: 10.1161/CIRCEP.112.973230. Epub 2012 Sep 3.
Epinephrine infusion may unmask latent genetic conditions associated with cardiac arrest, including long-QT syndrome and catecholaminergic polymorphic ventricular tachycardia (VT).
Patients with unexplained cardiac arrest (normal left ventricular function and QT interval) and selected family members from the Cardiac Arrest Survivors with Preserved Ejection Fraction Registry (CASPER) registry underwent epinephrine challenge at doses of 0.05, 0.10, and 0.20 μg/kg per minute. A test was considered positive for long-QT syndrome if the absolute QT interval prolonged by ≥ 30 ms at 0.10 μg/kg per minute and borderline if QT prolongation was 1 to 29 ms. Catecholaminergic polymorphic VT was diagnosed if epinephrine provoked ≥ 3 beats of polymorphic or bidirectional VT and borderline if polymorphic couplets, premature ventricular contractions, or nonsustained monomorphic VT was induced. Epinephrine infusion was performed in 170 patients (age, 42 ± 16 years; 49% men), including 98 patients with unexplained cardiac arrest. Testing was positive for long-QT syndrome in 31 patients (18%) and borderline in 24 patients (14%). Exercise testing provoked an abnormal QT response in 42% of tested patients with a positive epinephrine response. Testing for catecholaminergic polymorphic VT was positive in 7% and borderline in 5%. Targeted genetic testing of abnormal patients was positive in 17% of long-QT syndrome patients and 13% of catecholaminergic polymorphic VT patients.
Epinephrine challenge provoked abnormalities in a substantial proportion of patients, most commonly a prolonged QT interval. Exercise and genetic testing replicated the diagnosis suggested by the epinephrine response in a small proportion of patients. Epinephrine infusion combined with exercise testing and targeted genetic testing is recommended in the workup of suspected familial sudden death syndromes. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00292032.
肾上腺素输注可能会揭示与心搏骤停相关的潜在遗传疾病，包括长 QT 综合征和儿茶酚胺多形性室性心动过速（VT）。
来自心脏骤停存活者射血分数保留登记处（CASPER）登记处的不明原因心搏骤停（左心室功能和 QT 间期正常）且具有特定家族史的患者接受了肾上腺素 0.05、0.10 和 0.20μg/kg/min 的剂量挑战。如果在 0.10μg/kg/min 时绝对 QT 间期延长≥30ms，则认为长 QT 综合征检测阳性，如果 QT 延长为 1 至 29ms，则为边界阳性。如果肾上腺素引起≥3 次多形性或双向 VT，则诊断为儿茶酚胺多形性 VT，边界阳性则为多形性成对、室性早搏或非持续单形性 VT。在 170 例患者（年龄 42±16 岁，49%为男性）中进行了肾上腺素输注，其中 98 例为不明原因心搏骤停。31 例（18%）患者长 QT 综合征检测阳性，24 例（14%）患者为边界阳性。在接受肾上腺素阳性反应的患者中，42%的患者运动试验引起 QT 反应异常。儿茶酚胺多形性 VT 的检测阳性率为 7%，边界阳性率为 5%。在长 QT 综合征患者中，有 17%的异常患者和 13%的儿茶酚胺多形性 VT 患者进行了靶向基因检测，结果阳性。
肾上腺素激发试验在很大一部分患者中引起异常，最常见的是 QT 间期延长。在一小部分患者中，运动和基因检测复制了肾上腺素反应提示的诊断。建议在疑似家族性猝死综合征的检查中采用肾上腺素输注联合运动试验和靶向基因检测。
临床试验注册- URL：http://www.clinicaltrials.gov。唯一标识符：NCT00292032。
