Sekine Takako, Kodama Takahide, Kondo Takeshi, Fujimoto Shinichiro, Matsutani Hideyuki, Arai Takehiro, Morita Hitomi, Sano Tomonari, Saito Yuji, Takase Shinichi
Department of Radiological Technology, Takase Clinic, Japan.
Nihon Hoshasen Gijutsu Gakkai Zasshi. 2010 Dec 20;66(12):1539-47. doi: 10.6009/jjrt.66.1539.
A low heart rate (HR), associated with a prolonged slow filling phase (SF), is necessary to obtain a high quality coronary CT at a low radiation dose with conventional 64 multidetector-row computed tomography (MDCT). The purpose of our study was to confirm the safety of injecting propranolol (2-10 mg) into the vein for lowering heart rate in patients requiring MDCT and to document the effect of the drug on HR, PQ and SF.
Of 1290 consecutive patients who were initially considered for enrollment in the coronary MDCT study, 40 patients with atrial fibrillations, 3 with atrial flutters, and 13 with artificial pacemakers were excluded. Of the remaining 1234 patients (M/F=714/520), 331 had already taken an oral beta-blocker before the CT examination, and were included in the study. In patients with no contraindications, propranolol was aggressively injected (2-10 mg) into the vein to reduce the HR.
In patients not taking an oral beta blocker, 2 mg propranolol reduced the HR by -10±5 bpm and 10 mg, by -20±7 bpm. However, in patients taking an oral beta-blocker, the decrease in HR by propranolol was minimal (2 mg, -6±4 bpm; 10 mg, -10±6 bpm). Propranolol significantly prolonged the PQ interval (from 169±27 to 179±29 ms, P<0.0001), and SF (from 125±69 to 264±79 ms, P<0.0001). Adverse effects of propranolol injection were observed in only 3 [2 mild hypotension and 1 paroxysmal atrial fibrillation (recovered to sinus rhythm by DC counter shock)] of 3212 patients. All 3 patients became stable after 1 or 2 hours of rest and could return home.
Propranolol injection was a relatively safe and useful method to reduce HR and prolong SF, necessary for obtaining high quality coronary MDCT with a low radiation dose.
在使用传统64排多层螺旋CT（MDCT）进行低辐射剂量的高质量冠状动脉CT检查时，低心率（HR）以及随之延长的缓慢充盈期（SF）是必要条件。我们研究的目的是证实对需要进行MDCT检查的患者静脉注射普萘洛尔（2 - 10毫克）降低心率的安全性，并记录该药物对心率、PQ间期和缓慢充盈期的影响。
在最初考虑纳入冠状动脉MDCT研究的1290例连续患者中，排除了40例心房颤动患者、3例心房扑动患者和13例植入人工起搏器的患者。在其余1234例患者（男/女 = 714/520）中，331例在CT检查前已服用口服β受体阻滞剂，将其纳入研究。对于无禁忌证的患者，静脉快速注射普萘洛尔（2 - 10毫克）以降低心率。
在未服用口服β受体阻滞剂的患者中，2毫克普萘洛尔使心率降低 - 10±5次/分钟，10毫克使心率降低 - 20±7次/分钟。然而，在服用口服β受体阻滞剂的患者中，普萘洛尔导致的心率降低幅度很小（2毫克， - 6±4次/分钟；10毫克， - 10±6次/分钟）。普萘洛尔显著延长了PQ间期（从169±27毫秒延长至179±29毫秒，P<0.0001）以及缓慢充盈期（从125±69毫秒延长至264±79毫秒，P<0.0001）。在3212例患者中，仅3例（2例轻度低血压和1例阵发性心房颤动，经直流电复律恢复为窦性心律）出现了普萘洛尔注射的不良反应。所有3例患者在休息1或2小时后情况稳定并可回家。
注射普萘洛尔是一种相对安全且有用的降低心率和延长缓慢充盈期的方法，这对于以低辐射剂量获得高质量冠状动脉MDCT检查是必要的。
