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Arrhythmia (III)atrial fibrillation(AF)/atrial flutter(AFL)台北醫學大學台北醫學大學張念中張念中 教授教授Lead IIIIatrial fibrillation with rapid ventricular response (R.V.R.)atrial fibrillation(AF) Multiple areas of reentry within atria, or Multiple ectopic foci AF with rapid ventricular response =VR 100 bpm electrical activity is very rapid (每分約 400-700), 每個electrical impulse只造成小區域的 depolarization。這些multiple atrial impulses有一些只傳入 AV node,而不通過AV node，即在 AV node內 block，這種 nonconducted impulse 造成 AV node的 overall refractoriness。 75 yrs者 10% 有 AF All CVA有 50% due to thromboembolism as a result of AF AF常發生在有 valvular, hypertensive, and ischemic heart dx. AF without structural heart dx.= lone AF. 原因： 在 acute ischemic heart disease時，因 ischemia 引起的 CHF將造成 LAP ,這種 LAP是誘發 AF 的原因 sick sinus syndrome hypoxia pericarditis normal heart 另 other transient and reversible: cardiac surgery, hypertension, acute alcohol, theophylline, endocrinopathy (hypothyroidism, hyperthyroidism, and pheochromocytoma) 可能有 fibrillatory waves或只有 chaotic electrical activity AF 造成 Hypotension: usu.在 AMI或 abnormal vent. filling，例：HOCM or MS AF 若伴有規則 QRS: complete AV block or non- paroxysmal junctional tachycardia (accelerated junctional rhythm)；通常是 due to digitalis中毒 LA愈大 Convert rhythm 48 hrs(adequate anticoagulation, then,pharmacologic cardioversion; but no cardioversion) AF/AFL +LVEF 48 hrs:adequate anticogulation,then cardioversion -(no propafenone or betablocker) WPW+AF/ AFL+normal LV:(orthodromic:narrow QRS),and antidromic(wideQRS) Control rate:cardioversion or propafenone or amiodarone Convert rhythm48hrs:adequate anticoagulation,then, cardioversion WPW + AF/AFL + LVEF 48 hrs:adequate anticoagulation, then, cardioversion -(no propafenone) impaired LV定義：clinical CHF或 LVEF 48 hrs:電擊易造成 thromboembolism) 電擊 (同步 ) : AF: 100-200J, AFL及 PSVT 50-100JCardioversion in AF/AFL Acute AF/AFL with RVR in ongoing myocardial ischemia, MI, hypotension, marked CHF (hemodynamically unstable): 不論有無 anticoagulation立即電 同步 cardioversion (AF: 100-200;AFL 50-100) or pharmacologic (chemical) cardioversion 48 hrs or unknown duration: early cardioversion:先給 heparin24hrs後 ,TEE to exclude atrial clot, then, cardioversion後 ,抗凝劑 for 4 wks. Delayed cardioversion:anticogulation x 3 wks, cardioversion, then anticoagulation x 4wks (國考 )Cardioversion is deferred in digitalis intoxication,hyperthyroidism, paroxysmal tachy.without antiarrhythmic agent to prevent recurrence: 即 antiarrhythmic agents用到 therapeutic range才電 . 另 : Functionally euthyroid後才電 to limit the likelihood of recurrence. Indication of anticoagulation in AF/AFL All tachyarrhythmia都不需 anticoagulant except AF/FL:因只有 AF/AFL才有可能持續 48 hrs後才來醫院 , 且 AF/FL 是發生於心房 , 心房壁比心室壁較會造成血栓附著所以只有 AF/AFL才有使用 anticoagulant與否的問題 .(其它的 tachyarrhythmia,若持續 , 在 75, and CAD: 若 AF/AFL已 48 hrs, 而要選用amiodarone做 chemical cardioversion時 ,若有這些 risks建議與 heparin x 24 hrs併用後才電 (then, coumardin x 4 wks); 若無這些 risks,則直接用 ; AF/AFL 48 hrs,要電一定需先 heparin x 24 hrs後才電 , except AF/AFL的心室速率很快且 hemodynamically 已 unstable. LA-SEC（ SEC: spontaneous echo contrast; 做心超發現 LA內有煙霧狀物飄動表示血球黏在一起，是易發生血栓之狀態） : increased risk, but lack of large trial Chronic warfarin is most effective Rx. for attenuating risk of stroke associated with AF/AFL 有上述之危險因子建議用 warfarin Contraindication to warfarin 時 : ASA; if ASA intolerant, change to ticlopidine or clopidogrel. 65 yrs with no risks for thromboembolic events: the need for anticoagulation and the role of ASA are controversial. 原則上任一種方式的 Cardioversion: 電 , chemical, or overdrive atrial pacing皆須 anticoagulation. (但要參考上述之不同狀態 ) 電擊前 :鎮靜 :Propofol(Diprivan): short-acting iv anaesthetic agent;0.5-1 mg/Kg, (以理想體重決定劑量 )加D5W後成 20 cc, 建議濃度 2 mg/cc; iv push for 1 min, onset 1 min, duration 3-10 mins; (1A=20 cc, 1 cc=10 mg),輕微止痛效果 ,有 呼吸抑制及 bp下降 作用 ;+/-止痛 :alfantanil(Rapifen),(1A=2 ml=1 mg), narcotic analgesic, 1/2A,iv. *Propofol除 ICU插管病人外需自費1A=約 260元 同步電擊 (synchronous cardioversion)一次後機器會自動變回 unsynchronized mode,故若需再電時須再 set 一次 . Test問題 1: 請問這段 Holter EKG之診斷是 ? (1) Sinus tachycardia, (2) Atrial Flutter, (3) Atrial fibrillation, (4) Ventricular tachycardia, (5) Ventricular fibrillationLead ILead IILead III問題 2: 有此段 EKG之病人 ， 本來健康 48歲女性 , 由 3個月前開始常突發心悸合併体重減少 5公斤及失眠 , neck前方有收縮期雜音 . BP