의학 저널 번역 연습 교재 기립성 저혈압 심방세동 발병률 높여 누운 자세 에서 갑자기 일어났 을 때 수축 기 혈압 이 떨어지 는 기립성 저혈압 이 심방세동 발병 과 연관 이 있 는 것 으로 나타났 다 . 미국 존스 홉킨스 의대 수닐 아가르왈 ( Sunil K . Agarwal ) 교수 는 죽상 경화증 위험 연구 에 등록 된 45 ~ 64 세 흑백 인 남녀 12 , 071 명 을 대상 으로 18 년 간추 적 조사 한 결과 를 PLoS one 에 발표 했 다 . 기립성 저혈압 을 수축 기 혈압 20 mmHg 이상 , 확 장기 혈압 10 mmHg 이상 으로 정의 해 분석 한 결과 , 총 603 명 에서 기립성 저혈압 이 관찰 됐으며 1 , 438 명 이 심방세동 진단 을 받 았 다 . 분석 결과 , 기립성 저혈압 이 없 는 사람 보다 있 는 사람 에서 심방세동 발생 률 이 더 높 게 나타났 다 ( 6 . 3 대 9 . 3 ) . 성별 이나 인종 , 연령 등 기타 위험 인자 를 고려 해도 기립성 저혈압 군 의 심방세동 발병 위험 이 1 . 62 배 더 높 은 것 으로 조사 됐 다 . 아가르왈 교수 는 " 기립성 저혈압 이 심방세동 발병률 을 높이 는 것 으로 나타났 다 . 하지만 반대 로 기립성 저혈압 이 떨어지 면 심방세동 발병률 도 줄어드 는지 는 추가 연구 가 필요 하 다 " 고 말 했 다 . Orthostatic ( 기립성 ) Change inBlood Pressure and Incidence of Atrial Fibrillation : Results from a Bi - Ethnic ( 인종 간 ) PopulationBased Study 기립성 혈압 변화 와 심방 세동 의 발병률 : 인종 집단 연구 결과 Abstract ( 초록 ) Background ( 배경 ) Autonomic fluctuations are associated withthe initiation and possibly maintenance of atrial fibrillation ( AF ) . However , little is known about the relationship between orthostatic blood pressurechange , a common manifestation of autonomic dysfunction , and incident AF . 어휘 Autonomic nervous system : 자율 신경 계 atrial : 심방 의 fibrillation : 세동 manifestation : 징후 Supine : 반듯이 누운 . / Parasympathetic tone : 부 교감 신경 긴장도 sympathetic tone : 교감 신경 긴장 lower limb : 하 지 / capacitance vessel : 수용 혈관 redistribution of blood : 혈액 의 재 공급 / dysregulation : 조절 장애 progressive study : 전향 적 연구 / hypotension ; 저혈압 , hypertension : 고 혈압 자율 신경 요동 은 심방 세동 ( AF ) 의 발병 과 혹시 모를 병세 에 관련 있 다 . 그러나 자율 신경 계 장애 의 징후 인 기립성 혈압 변화 와 AF 의 발병 사이 의 관계 는 거의 알려져 있 지 않 다 . MethodsWe examined whether supine - to - standingchanges in systolic blood pressure ( SBP ) are associated with incident AF in 12 , 071 African American and white men and women aged 45 – 64 years , enrolled inthe Atherosclerosis Risks in Communities ( ARIC ) study . Orthostatic hypotension ( OH ) was defined as a supine - standing drop in SBP by ≥ 20 mmHg or diastolicblood pressure by ≥ 10 mmHg . AF cases were identified based on study scheduled 12 - lead ECG , hospital discharge ICD codes , and death certificates through 2009 . 어휘 Systolic : 심장 수축 의 / systolic blood pressure ( SBP ) ; 수축 기 혈압 . Atherosclerosis : 죽상 경화증 , 동맥 경화증 / agents in atherosclerosis : 동맥 경화증 치료제 . Diastolic : 심장 확장 의 ResultsOH was seen in 603 ( 5 %) atbaseline . During an average follow - up of 18 . 1 years , 1438 ( 11 . 9 %) studyparticipants developed AF . Incident AF occurred more commonly among those withOH than those without , a rate of 9 . 3 vs . 6 . 3 per 1000 person years , ( p < 0 . 001 ) . The age , gender , and race adjusted hazard ratio ( 95 % CI ) of AFamong those with OH compared to those without was 1 . 62 ( 1 . 34 , 2 . 14 ) . Thisassociation was attenuated after adjustment for common AF risk factors to HR 1 . 40 ( 1 . 15 , 1 . 71 ) , a strength similar to that of diabetes or hypertension withAF in the same model . A non - linear relationship between orthostatic change inSBP and incident AF was present after multivariable adjustment . Incident : 당연히 따르 는 , 부수 하 는 , 부대 하 는 Person year : 인년 . attenuate : 가늘 어 지 다 . 묽 어 지 다 , 약해 지 다 . Follow - up : 추적 검사 , 추적 조사 Develop : 나타내 다 . 발병 하 다 . Multivariable : 다 변량 , 다변수 . ConclusionsOHis associated with higher AF incidence . Whether interventions that decrease OHcan reduce AF risk remains unknown . I n t r o ductionAtrialfibrillation ( AF ) affects approximately 3 million North Americans and theprevalence is projected to double by 2050 . [ 1 ] , [ 2 ] AF shares common risk factors with other cardiovascular diseases ( CVD ) including age , obesity , hypertension , diabetes , cigarette smoking , andpreexisting heart disease . [ 3 ] , [ 4 ] However , not all individuals who develop AF have CVD risk factors , and inyounger individuals as many as 45 % may not have underlying CVD . [ 5 ] Furthermore , both divisions branches of the autonomic nervous system ( ANS ) i . e . , sympathetic and parasympathetic may be strong modulators of the AFsubstrate , leading to the initiation and / or maintenance of AF [ 6 ] . Thus , constructs of neuro - humoral system dys - regulation may provide additional , patho - physiological insights and also help assist in identifying individuals atrisk for developing AF . Autonomic nervous system : 자율 신경 계 TheANS plays an important role in complex mechanisms involved in maintaining bloodpressure . During a change from supine or seated to standing position , aninitial withdrawal of parasympathetic tone followed by an increase insympathetic tone in response to the redistribution of blood in the capacitancevessels of the lower limbs is seen [ 7 ] . The measurement of orthostatic blood pressure change is an easy , inexpensive , and relatively quick procedure that can provide some information about anindividual ’ s ANS dys - regulation [ 8 ] . Prospective studies report that those with a substantial drop in their bloodpressure upon standing categorized as orthostatic hypotension ( OH ) havereportedly a two - fold higher stroke risk , [ 9 ] and a 50 – 100 % increased mortality rate than those without OH . [ 10 ] , [ 11 ] However , there is limited information from population based studies to describethe association between OH and AF incidence . [ 12 ] We hypothesize that individuals who have either a drop or an increase in bloodpressure upon standing may be at an increased risk of AF . Supine : 반듯이 누운 . / Parasympathetic tone : 부 교감 신경 긴장도 sympathetic tone : 교감 신경 긴장 lower limb : 하 지 / capacitance vessel : 수용 혈관 redistribution of blood : 혈액 의 재 공급 / dysregulation : 조절 장애 progressive study : 전향 적 연구 / hypotension ; 저혈압 , hypertension : 고 혈압 MethodsStudy SampleTheARIC Study enrolled 15 , 792 men and women ages 45 – 64 years sampled from fourU . S . communities using area - probability sampling from Washington County , Minneapolis , Jackson , and Winston Salem . The ARIC study has been approved bythe Institutional Review Boards ( IRB ) of all participating institutions , including the IRBs of the University of Minnesota , Johns Hopkins University , University of North Carolina , University of Mississippi Medical Center , andWake Forest University . All participants gave written informed consent in eachone of the study visits . Baseline examinations of the cohort were conductedfrom 1987 to 1989 to collect standardized information on socioeconomicindicators , medical history , family history , CVD risk factors , serumchemistries , electrocardiograms ( ECGs ) , medication use , and anthropometrics . Three follow up examinations ( visits ) followed the baseline visit , as well asannual telephone interviews and active surveillance of hospitalizations anddeath . A complete description of the ARIC communities and of the design hasbeen published elsewhere . [ 13 ] . Institutional Review Boards ( IRB ) : 임상 시험 심사 위원회 . baselineexamination : Clinical practice A physical exam which is part of aninitial Pt - physician contact , and designed to assess a Pt ' s eligibility forenrollment in a clinical trial and produce requisite baseline data . 임상 시험 등록 기준 을 심사 하 기 위한 기초 검사 . 임상 시험 적합 성 검사 . 기초 심사 검사 . Medical history : 병력 . Serum chemistry : 혈청 화학 검사 Electrocardiograms : 심전도 Anthropometrics : 인체 측정 . 인체 계측 . 인체 측정학 . Forthis analysis , participants were excluded if they were either missing or hadpoor quality data on postural change in blood pressure measured at studybaseline ( n = 2555 ) , prevalent AF or atrial flutter identified from ECGs atbaseline ( n = 37 ) , other abnormalities in heart rhythm ( advanced AV blocks , pacemakers , wandering atrial beats , supra - ventricular or ventriculartachycardia ; n = 242 ) , self - identified race as neither African American norCaucasian ( n = 48 ) , were African Americans from Minnesota or Washington county ( n = 55 ) , or were missing important covariates ( n = 1238 ) . Data from theremaining 12 , 071 study participants were included in the analyses . Fibrillation : fluctuation , flutter . / 세동 AV blocks : 방실 차단 ( atrio - venticularblock , AVB ) ; 방실 차단 은 동방 결절 에서 발생 된 충격파 가 방실 결절 과 His bundle 통과 할 때 지연 되 거나 차단 되 는 경우 를 말 한다 . AdvanceAV blocks : 진행 된 방실 차단 . 방실 차단 의 존재 . 방실 차단 . Pacemaker : 페이스메이커 , 심장 의 동방 결절 , 방실 결절 . Supra - ventricular : 상실 성 빈맥 / ventricular tachycardia : 심실성 빈맥 Covariate ; 공 변량 / 실험 결과 의 독립 변수 이외 에 종속 변수 에 영향 을 줄 수 있 는 잡음 인자 를 연구자 가 통제 하 고자 하 는 변수 을 공 변량 ( covariate ) 이 라고 한다 Ascertainment of AFElectrocardiograms ( ECGs ) during the baseline visit were used to exclude individuals withprevalent AF or atrial flutter . Incident AF cases through December 31 , 2009 were identified from 3 sources : 1 ) study scheduled ECGs that were recordedtriennially through 1998 , 2 ) hospital discharge records using ICD codes through 2009 , and 3 ) death certificates through 2009 . ECGswere recorded using MAC PC Personal Cardiographs ( Marquette Electronics , Inc . , Milwaukee , WI ) and were then transmitted to the ARIC ECG Reading Center forcomputer coding and verified by trained experts to confirm the diagnosis of AF . [ 14 ] . Ascertainment ; 확인 , 검진 Triennially : 3 년 마다 의 . Annualfollow - up telephone calls made to cohort participants identified anyhospitalizations or vital status . In addition , local hospitals records and theNational Death Index were surveyed to ascertain cardiovascular events or death . Hospital discharge records were abstracted from all p a rticipanthospitalizations and AF was identified as an ICD - 9 discharge code of 427 . 31 or 427 . 32 for atrial flutter at any position . AF was also identified by thepresence of ICD - 9 code 427 . 3 or ICD - 10 code I 48 at any position in the deathcertificate . 14 AF occurring simultaneously with heartrevascularization surgery or other cardiac surgery involving heart valves orsepta was not considered an incident event and follow - up was continued beyondthat surgical AF related event . More than 99 % of the AF cases were identifiedat hospitalization . Within the ARIC cohort , the sensitivity and specificity ofa hospital discharge diagnosis for AF was found to be 84 % and 98 %, respectively . [ 15 ] . Cohort : ( 인구 통계 에서 ) 코호트 ( 통계 인자 를 공유 하 는 집단 ; 동시 출생 집단 등 ) Hospitalization : 입원 , 입원 기간 . Revascularization 혈관 재 형성 , 혈관 이식 . Heart valve : 심장 판막 . Septa ( septus 의 복수 형 ) : 격막 , 격벽 Orthostatic Changes in Blood Pressure : 기립성 혈압 변화 Atthe baseline examination , after 20 minutes of resting in the supine position , blood pressure was measured in the study participants approximately every 30 seconds for 2 min ( 2 – 5 measurements , 90 % had ≥ 4 measurements ) using Dinamap 1846 SX , automated oscillometric device . Participants were then asked to stand , and BP measurements were repeated during the first 2 min after standing ( 2 – 5 measurements , 91 % had ≥ 4 measurements ) . BP change was defined as the differencebetween the average standing and average supine after excluding the 1 ststanding measurement , as BP homeostasis occurs during the first 30 s afterstanding [ 16 ] . Postural hypotension was defined as a systolic blood pressure ( SBP ) drop of ≥ 20 mmHg or diastolic blood pressure ( DBP ) of ≥ 10 mmHg when changing position fromsupine to standing . Baseline examination : 기준 검사 . Supine position : 누운 자세 . Homeostasis ; 항상성 Other Covariates : 기타 공 변수 Race , education attainment , cigarette smoking status , pack - years of smoking , andalcohol drinking status were determined by self - report . Body mass index ( BMI ) was calculated as weight ( in kilograms ) divided by height ( in meters ) squared . Diabetes was defined as fasting glucose ≥ 126 mg / dL , non - fasting glucose of ≥ 200 mg / dL , self - report of a physician diagnosis or current use of glucose loweringmedications . Participants ’ sitting blood pressure was measured at baseline 3 times , with the mean of the last 2 measurements used . Hypertension , defined asSBP of ≥ 140 mmHg , DBP ≥ 90 mmHg , or the use of a blood pressure medication in thepast 2 weeks . Prevalent CHD was defined as the presence of a self - report of myocardialinfarction ( MI ) , coronary artery bypass , angioplasty , or MI based on thebaseline ECG . Prevalent Heart Failure ( HF ) was identified by the Gothenburgcriteria or self - report use of HF medication use in the past 2 weeks . [ 17 ] Medication history was obtained by self - report of medication intake during lasttwo weeks and by reviewing medication brought by participants to their visit . Each medication was coded by trained and certified interviewers with the use ofa computerized medication classification system . Medications in the classes ofanti - hypertensive , anti - depressants , anti - psychotics , anti - cholinergics , sedatives , narcotics , and nitro compounds were grouped together as medicationwith potential to induce orthostatic hypotension . Pack - years of smoking : 흡 연력 . 하루 몇 갑 x 햇수 Determine ; examine , survey . Body mass index : 체질량 지수 ( 키 와 뭄무 게 를 이용 해 지방 의 양 을 추정 하 는 비만 측 정법 ) , 체중 을 신장 의 제곱 으로 나눈 비만도 지수 Square : 을 제곱 하 다 , ~ 의 면적 을 구하 다 . Fasting glucose : 공복 혈당 . Non fasting glucose : 식후 혈당 . Coronary artery bypass : 관상 동맥 우회술 . Angioplasty : 혈관 형성 ( 술 ) . Statistical Methods 통계 방법 Theanalysis was performed using SAS version 9 . 1 . 3 ( SAS Institute , Cary , NC ) . Cumulative AF proportions during follow up time were estimated using KaplanMeier methods , and a graph with 1 - survival ( t ) by OH status was generated . Coxproportional hazards models were used to estimate multivariable adjusted hazardratios of AF by OH status with varying degrees of adjustment for potentialconfounders . We examined the possibility of a non - linear relationship betweenorthostatic changes in SBP and AF incidence using restricted cubic splines fororthostatic BP change as a continuous variable with no change as reference . [ 18 ] A partial likelihood ratio test using models with only linear terms wascompared to a model containing both linear and the cubic spline terms , whichsuggested a non - linear association with increased risk ( though statisticallynon - significant ) in those with increase in SBP upon standing . Therefore , inaddition to focusing on OH which is an easily available clinical measure , weestimated risk of AF at either ends of orthostatic SBP change while consideringthose between the 5 th and 95 th percentile as thereferent . Also , we also examined its association with between OH and AFstratified by several risk groups including race , gender , diabetes , hypertension , intake of medications that may predispose to OH , and history ofCHD . Analysis restricted to those without diabetes , hypertension , heartfailure , and CHD were also conducted . The proportional hazards assumption waschecked for OH and there was no gross violation ( p value for time interactionterm = 0 . 34 ) . A p value of < 0 . 05 on a two tailed test was consideredsignificant for the analysis and a p < 0 . 1 was considered significant forinteractions . ResultsWeanalyzed data from 12 , 071 ARIC cohort participants of whom 55 % were female and 25 % African Americans . At baseline , 5 % of participants had orthostatichypotension , 34 % had hypertension , 9 % had diabetes , 5 % had CHD , and 4 % had HF . The distribution of orthostatic change in blood pressure on changing positionfrom supine to standing is presented at the bottom of Figure 1 . They were followed up for an average of 18 years with a cumulative follow up of 220 , 000 person - years . During this time 1 , 438 ( 11 . 9 %) of the study participantsdeveloped AF . The differences in participant baseline characteristics arepresented in Table 1 stratified by incident AF . Those who developed AF were older , had a higherburden of traditional CVD risk factors , a higher prevalence of low formaleducation attainment , higher alcohol consumption , and were more likely to haveorthostatic hypotension . Orthostatic Hypotension and AFIncidentAF occurred more commonly among those who had OH at baseline than those without ( 18 . 4 % vs . 11 . 6 %, p < 0 . 001 ) . The cumulative event proportion curve ( 1 - survival at time t ) graph showed higher rate of AF among those with OHthroughout the study period ( log - rank test p < 0 . 001 , Figure 2 ) . The age adjusted incidence rate of AF was also higher among those with OHcompared to those without OH 9 . 3 ( 95 % CI : 7 . 7 , 11 . 2 ) vs . 6 . 3 ( 95 % CI : 5 . 9 , 6 . 6 per 1000 person - years . The unadjusted hazard ratio of AF among those withorthostatic hypotension compared to those without was 2 . 22 ( 95 % CI 1 . 80 – 2 . 65 ) . Adjustment for age , gender , race , and study center attenuated the relation to 1 . 62 ( 95 % CI 1 . 34 – 2 . 14 ) , which was further attenuated to a HR 1 . 40 ( 95 % CI 1 . 15 – 1 . 71 ) after additional adjustment with common AF risk factors includingBMI , heart rate , SBP , DBP , anti - hypertensive medications intake , diabetes , smoking status , alcohol consumption , HDL - C , LDL - C , CHD , and heart ( Table 2 ) . Thestrength of this association is similar to the association of diabetes ( 1 . 42 ; 95 % CI : 1 . 21 – 1 . 66 ) or hypertension ( 1 . 38 ; 95 % CI : 1 . 20 – 1 . 59 ) with AF in thesame multivariable model that includes OH and other potential confounders . Inadditional analyses that excluded those with diabetes , hypertension , or CHD , associations persisted . Orthostatic Hypotension and AF by SubgroupsWealso performed several stratified analysis to better assess the putativerelationship by several sub - groups ( Table 3 ) . The association of OH with AF was stronger in women than in men . Similarly , individuals taking medications that may increase the risk of OH showed astronger association between OH and AF , whereas no association was seen amongthose not taking these medications ( HR ( 95 % CI ) of 1 . 66 ( 1 . 26 , 2 . 19 ) vs . 1 . 08 ( 0 . 76 , 1 . 54 ) ; p for interaction = 0 . 03 ) . Therewas no significant difference in the association of OH with AF risk between theother sub - groups including no differences between whites and blacks . SBP Change upon Standing and AFTherelationship of continuous change in SBP with AF was non - linear ( Figure 1 ) . We found an asymmetrical reversed J - shaped relationship with the SBP changes ateither extreme showing a higher risk of AF as compared to the majority of the samplein the middle . This relationship retained its shape after multivariableadjustment but those with an increase in SBP were not significantly differentthan those with no change . As compared to those with SBP change within 5 thto 95 th centile ( referent group ) , those with SBP decrease ( > 19 mmof Hg or more ) had a higher risk of AF with a HR of 1 . 58 ( 95 % CI : 1 . 30 – 1 . 91 ) . However , compared to the same referent those with SBP increase ( > 16 mm of Hgor more ) did not have significantly higher risk of AF with a HR of 1 . 13 ( 95 % CI : 0 . 90 – 1 . 41 . Diastolic BP change when standing from supine was more narrowlydistributed than systolic BP change . Though its association with AF was similarto systolic BP ; it was not statistically significant ( data not shown ) . DiscussionInthis prospective analysis of a large population based cohort , we found a 40 % higher risk of AF among those with OH , compared to those without , independentof several potential confounders . The strength of this association is similarto the association of diabetes or hypertension with AF in the multivariablemodel that includes OH and other potential confounders . The association wasalso found to be non - linear . Whileboth experimental and human studies point to a role of autonomic perturbationsand modulations in initiation , maintenance , and treatment of AF [ 19 ] , [ 20 ] [ 21 ] , only one other population based study has examined the association between OHand AF [ 12 ] . Contrary to the previous study , we found a similar association among those withand without hypertension , and similar to that study the association showedabout 30 – 40 % increased risk , and we have extended the study by exploring therelationship over the range of SBP change [ 12 ] . Notably , the estimated effect size is likely smaller than the true value as thereliability of single measurement is moderate , [ 22 ] and the follow up is lengthy in both studies . There was no association observedin the subgroup that did not take orthostatic inducing medications . one canonly contemplate that those with OH in this group may be less exposed to itseffect than those on medications . Importantly , this association persisted withsimilar strength in those without prevalent HF or CHD or hypertension ordiabetes ( 60 % of the cohort ) , although it was statistically non - significant . Interestingly , we noted a small signal of increased risk for AF in participants who had a risein SBP upon standing ( though statistically non - significant in multivariablemodel as compared to those without change ) . Also , a U shaped relationshipbetween orthostatic change in blood pressure and silent cerebrovascular diseasehas been reported [ 12 ] . Based on our results it is hard to say that the non - significant signal seen atthis tail of SBP change is a true effect and would need examination in otherstudies . Asustained decrease or increase in blood pressure upon standing may reflectamong other causes , an inability of the ANS to come to a balance quickly . Interestingly , both renal artery denervation ( sympathetic ) [ 23 ] or wide circumferential ablation ( parasympathetic ) [ 24 ] , when done in addition to pulmonary vein isolation , has been associated with alower recurrence of AF in those with paroxysmal / refractory AF , suggesting thatan imbalance may lead to fluctuations in ANS leading to initiation of AF andthat such wide fluctuations may be reflected in the orthostatic change in bloodpressure . Understanding of interventions that may improve OH , except in thesettings of severe autonomic dysfunction , is limited . A deeper understanding ofthese interventions as well as whether they improve long term cardiovascularoutcomes may benefit a large proportion of the general population . Strengthsof this study include being a community based sample of biracial middle aged menand women with long term follow up and a characterization of importantpotential confounders at baseline . There are several limitations such as , a ) the moderate reliability of orthostatic blood pressure change reading at onevisit only and its potential misclassification over time , which may drive theeffect estimate towards null ; b ) we will miss those with paroxysmal AF ormanaged in outpatient settings and who did not have a hospital admissionthrough the end of follow up – this is unlikely to differ by OH status and thuswe do not expect a large bias from this . Also , it is unlikely that these freedwelling community participants were meaningfully dehydrated during a fieldcenter visit . Measures of peripheral neuropathy were not available . Lastly , cardiacstructural and functional measures such as left ventricular mass , leftventricular ejection fraction , or pulmonary artery pressures were not availableand may act as potential confounders . Inconclusion , we found that orthostatic hypotension , a simple clinicalmeasurement , is associated with an elevated AF risk by 40 % during an averagefollow up of 18 years . The strength of this a relationship is similar to thatof diabetes or hypertension with AF . Future studies examining mechanismslinking orthostatic change in BP with AF including a closer look at autonomicfunction by measures such as heart rate variability may improve ourunderstanding . Though causal association is difficult to prove , researchexploring whether interventions to prevent and treat OH may improvecardiovascular outcomes merit attention .