Chu Timothy, Azevedo Keith, Ernst Amy A, Sarangarm Dusadee, Weiss Steven J
From the Department of Emergency Medicine, University of New Mexico, Albuquerque.
South Med J. 2017 Jul;110(7):475-479. doi: 10.14423/SMJ.0000000000000674.
Patients with an alcohol use disorder experiencing acute intoxication or withdrawal may be at risk for electrocardiograph (ECG) abnormalities, including prolongation of repolarization (long QTc [corrected QT]) that may contribute to arrhythmias and may be associated with a threefold increase in the likelihood of sudden cardiac events. Patients with acute coronary syndrome may have prolonged QTc as well. To our knowledge, no previous studies have compared the QTc of ACS with acute ethanol (EtOH) withdrawal syndromes in the emergency department (ED). The purpose of our study was to compare the QTc of those with EtOH withdrawal emergencies with patients with ACS in our ED. Our hypothesis was that the QTc would be similarly prolonged in the two cohorts.
The study compared two cohort groups, those with ACS and those with EtOH withdrawal-related ED visits over a 1-year period. We compared ECG QTc, cardiac medication use, and electrolyte differences. We considered a QTc of >450 ms elevated for men and >470 ms elevated for women based on the literature. Fifty subjects in whom an ECG, serum osmolality, and EtOH level were recorded within 2 hours of one another and who were administered a Clinical Institute Withdrawal Assessment protocol were compared with 203 patients with ACS during the same period. We excluded patients with incomplete data. Medications compared included clopidogrel, acetylsalicylic acid, β-blockers, angiotensin-converting enzyme inhibitors, and statins. ECG QT and QTc, as well as electrolytes, were recorded and compared. Data were extracted by two investigators with a 20% sample re-evaluated by the other extractor as a reliability measure. Descriptive statistics including medians and interquartile ranges were measured for continuous variables. Comparisons were made using two-tailed tests for parametric data and the Mann-Whitney test for nonparametric data.
Agreement in the 20% sampling between investigators was high (96%). The mean QTc in the ACS group was 457 ms and the mean QTc in the EtOH withdrawal-related group was 468 ms (diff 11, not significant). Significantly more patients had a prolonged QTc in the EtOH withdrawal group than in the ACS group 62% vs 46%; diff 16; 95% CI (0.1, 30). There was significantly more use of clopidogrel, acetylsalicylic acid, angiotensin-converting enzyme inhibitors, and statins ( < 0.05 for all) in the ACS group compared with the EtOH withdrawal group; however, there was no difference in β-blocker usage. There was a significantly higher admission rate: 100% of ACS compared with 76% of the EtOH withdrawal group ( < 0.01, diff 24, 95% confidence interval 18-29). Electrolytes were not significantly different in the two groups.
More patients with EtOH withdrawal-related ED visits had a long QTc than patients presenting with ACS. ED physicians should carefully monitor patients experiencing EtOH withdrawal for cardiac arrhythmias and obtain an ECG. If any medications that prolong the QTc are considered, then an ECG should be obtained before administering medications that may affect the myocardium to make medication safer for the patient.
患有酒精使用障碍且处于急性中毒或戒断状态的患者可能存在心电图（ECG）异常风险，包括复极延长（校正QT间期延长，即长QTc），这可能导致心律失常，且可能使心脏性猝死事件的发生可能性增加两倍。急性冠状动脉综合征患者也可能出现QTc延长。据我们所知，此前尚无研究在急诊科（ED）比较急性冠状动脉综合征（ACS）与急性乙醇（EtOH）戒断综合征患者的QTc。本研究的目的是比较我院急诊科中EtOH戒断急诊患者与ACS患者的QTc。我们的假设是两组患者的QTc会出现相似程度的延长。
本研究比较了两个队列组，即1年内患有ACS的患者和因EtOH戒断到急诊科就诊的患者。我们比较了ECG的QTc、心脏用药情况及电解质差异。根据文献，我们将男性QTc>450 ms、女性QTc>470 ms视为QTc升高。将在2小时内依次记录心电图、血清渗透压和EtOH水平且接受临床研究所戒断评估方案的50名受试者与同期203例ACS患者进行比较。我们排除了数据不完整的患者。所比较的药物包括氯吡格雷、乙酰水杨酸、β受体阻滞剂、血管紧张素转换酶抑制剂和他汀类药物。记录并比较ECG的QT和QTc以及电解质。由两名研究人员提取数据，另一名提取人员对20%的样本重新评估以作为可靠性衡量。对连续变量测量包括中位数和四分位间距在内的描述性统计量。对参数数据使用双侧t检验，对非参数数据使用曼-惠特尼U检验进行比较。
研究人员之间20%抽样的一致性很高（96%）。ACS组的平均QTc为457 ms，EtOH戒断相关组的平均QTc为468 ms（差值为11，无统计学意义）。与ACS组相比，EtOH戒断组QTc延长的患者明显更多，分别为62%和46%；差值为16；95%置信区间（0.1，30）。与EtOH戒断组相比，ACS组使用氯吡格雷、乙酰水杨酸、血管紧张素转换酶抑制剂和他汀类药物的情况显著更多（所有P<0.05）；然而，β受体阻滞剂的使用情况无差异。ACS组的入院率显著更高：ACS组为100%，而EtOH戒断组为76%（P<0.01，差值为24，95%置信区间为18 - 29）。两组的电解质无显著差异。
与因ACS到急诊科就诊的患者相比，更多因EtOH戒断到急诊科就诊的患者存在长QTc。急诊科医生应仔细监测EtOH戒断患者是否有心律失常，并进行心电图检查。如果考虑使用任何可延长QTc的药物，那么在给予可能影响心肌的药物之前应进行心电图检查，以使药物对患者更安全。
