심실 재분극에 대한 흡연의 급성 효과- QT 분산과 관상동맥 혈류 예비력의 관계 - = The Acute Effects of Cigarette Smoking on the Heterogeneity ofVentricular Repolarization in Healthy Subjects- The Relationship between QT Dispersion and Coronary Flow Reserve -

다국어 초록 (Multilingual Abstract)

Background and Objectives：Although cigarette smoking is a known risk factor for sudden cardiac death, littleis known about the effects of smoking on the heart. The QT interval and QT dispersion prolongation have beenassociated with a lower ventricular fibrillation threshold and the occurrence of sudden cardiac death. Smokinghas an unfavorable influence on the autonomic balance and myocardial blood flow. The objective of the currentstudy was to evaluate the relationship between the QT dispersion and coronary flow reserve (CFR) in healthyyoung male subjects. Subjects and Methods：The study included a sample of 30 healthy young male cigarettesmokers. The catecholamines level, QTc dispersion, heart rate variability and myocardial blood flow weremeasured, immediately before and 5 minutes after and during the smoking of 3 cigarettes. Results：Short-termsmoking caused significant increases in the serum cortisol (10.9±4.9 vs. 15.0±7.0 μg/dL, p<0.01), serumepinephrine (0.038±0.026 vs. 0.046±0.026 ng/mL, p=0.044), heart rate (78±9 vs. 85±8 beats/min, p<0.01), maximal QTc interval (412±22 vs. 435±20 ms, p<0.01), QTc dispersion (43±14 vs. 62±17 ms,p<0.01), LFnu (68±9 vs. 78±6%, p<0.01), LF/HF (3.25±2.15 vs. 5.22±1.89, p<0.01) and peak diastolicvelocity (21.7±3.9 vs. 23.9±5.5 cm/sec, p=0.005), and a decrease in the CFR (3.71±0.56 vs. 3.42±0.76,p=0.024). The change in the QTc dispersion was closely related to the change in the CFR (r=-0.357, p=0.043).Conclusion：The present study is the first to demonstrate that the impaired coronary flow reserve after smokingmay contribute to the increased inhomogeneity of ventricular repolarization in healthy young male smokers

국문 초록 (Abstract)

배경 및 목적：
흡연에 의한 심실 재분극의 비균일성 증가는 심실내 부정맥 및 돌연사의 발생을 유발시킬 수 있는 요인으로 생각하고 있다. 이러한 재분극 비균일성 증가는 심장에서 자율신경의 부조화에 기인하는 것으로 생각되며, 그 외에도 흡연은 혈관내피세포의 손상과 지질에 대한 작용으로 동맥경화를 촉진시키며, 혈소판의 응집, 혈관의 수축 등을 유발한다. 본 연구에서는 건강한 성인에서 흡연에 의한 심실 재분극의 이상을 관찰하고자 하였고, 흡연 후 QT 분산 변화 정도와 카테콜아민, LFnu, CFR의 변화 정도와의 연관성을 알아보고자 하였다.방 법：건강한 성인 남자 30명(평균 연령: 26±2세)을 대상으로오전 11시에서 오후 1시 사이에 개방되고 조용한 방에서 10분 정도 안정 후 시행하였다. 흡연 전후에 혈중 코티솔, 에피네프린, 노르에피네프린 농도 측정을 위한 혈액 채취, QT분산을 확인하기 위한 12 유도 심전도, 그리고 경흉부 심초음파를 이용한 관상동맥 혈류 측정을 각각 시행하였고, 심박수 변이도를 분석하기 위한 3-channel SEER MC Digital 기록기를 이용한 20분간 심전도 기록을 흡연 전과 흡연 동안에 기록하였다.결 과：흡연 후 혈중 코티솔 농도(10.9±4.9 vs 15.0±7.0 ug/dL, p<0.01), 에피네프린 농도(0.038±0.026 vs 0.046±0.026 ng/mL, p=0.044), 심박수(78±9 vs 85±8 beats/min, p<0.01), 최대 QTc 간격(412±22 vs 435±20 ms,p<0.01)과 QTc 분산(43±14 vs 62±14 ms, p<0.01), Lfnu(68±9 vs 78±6%, p<0.01), LF/HF(3.25±2.15 vs 5.22±1.89, p<0.01), PDV(21.7±3.9 vs 23.9±5.5 cm/sec,p=0.005)은 유의하게 증가하였으며, CFR(3.71±0.56 vs3.42±0.76, p=0.024)은 감소하였다. 흡연 후 QT 분산의변화 정도와 CFR의 변화 정도는 유의한 음의 상관관계가 있었다(r=-0.357, p=0.043).결 론：건강한 성인 남자에서 흡연은 교감신경계의 항진과 함께 심실 재분극의 불균일성, 관상동맥 혈류의 증가 그리고 관상동맥 혈류 예비력의 감소를 일으킨다. 관상동맥 혈류 예비력의 감소가 심실 재분극 불균일성에 기여할 가능성이 있을 것으로 생각된다.

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