一位 85 歲有慢性冠狀動脈疾病史女性因昏厥入急診。她嗜睡、冒冷汗、血壓 70/40 mmHg。心電圖顯示 P 波規律，QRS 寬大且獨立以每分 30 次跳動（三度房室阻滯）。優先介入為何？
An 85-year-old female with chronic coronary artery disease is brought to the ED after syncope. She is lethargic, diaphoretic, and hypotensive at 70/40 mmHg. ECG shows P waves at a regular rate but wide QRS complexes occurring independently at 30/min (third-degree AV block). What is the priority intervention?
- APush high-dose IV atropine, expecting it to permanently restore conduction.推注高劑量靜脈注射阿托品，預期其能永久恢復傳導。
- BAdminister high-dose IV amiodarone via central line.透過中心靜脈管給予高劑量靜脈注射胺碘酮。
- CHave the client cough and bear down repeatedly to convert the rhythm.讓病人反覆咳嗽並用力屏氣以轉換心律。
- DApply external pacer pads and initiate transcutaneous pacing (TCP) immediately.✓ 正解貼上外部節律器電極片並立即開始經皮節律器（TCP）。
三度房室阻滯（complete heart block）合併血流動力學不穩，是緊急且需立即電氣治療的心律。 選項 D 正確：經皮心律調節器（TCP）能直接驅動心室收縮、維持心輸出量。雖會疼痛但救命。後續多需植入永久性節律器。 選項 A 錯誤：Atropine 對三度阻滯多無效（阻滯位於 His 束以下）。 選項 C 錯誤：咳嗽用力動作（cough CPR）對阻滯性心律無用。 選項 B 錯誤：Amiodarone 是抗心律不整藥，會抑制傳導使阻滯更嚴重。
Third-degree (complete) AV block with hemodynamic instability is an emergency requiring immediate electrical therapy. C correct: Transcutaneous pacing directly captures the ventricles and restores cardiac output. Painful but lifesaving; permanent pacemaker usually follows. A incorrect: Atropine is usually ineffective in third-degree block (block is below His bundle). B incorrect: Cough CPR doesn't address conduction block. D incorrect: Amiodarone suppresses conduction—worsens the block.
「3rd degree complete heart block (第三度完全阻滯) = Transcutaneous Pacing (貼上貼片外部起搏) + Call doctor for Permanent Pacemaker」。這題是 ACLS 執照考最強紅線，如果在遇到三度阻滯時選擇給 Atropine(阿托品)，在全美跟台灣都是不及格的死刑。