Supraventricular Tachycardia: Evaluation and Initial Treatment

Evaluation and Initial Treatment of Supraventricular Tachycardia from Sun YaiCheng

Evaluation and Initial Treatment of Supraventricular Tachycardia

N Engl J Med 2012;367:1438-48.

Differential Diagnosis of Supraventricular Tachycardias (SVT)

• The initial differential diagnosis of SVT should focus on the ventricular response characteristics of regularity, rate, and rapidity of onset, not on the atrial depolarization from the ECG.

• The regular SVT include sinus tachycardia, atrial flutter, AV nodal reentrant tachycardia, AV reciprocating tachycardia, and atrial tachycardia.

• The irregular SVT are atrial fibrillation, atrial flutter with variable AV block, and multifocal atrial tachycardia; multiple atrial premature contractions can cause a similar presentation.

• Sudden onset and termination are characteristic of acute atrial fibrillation and atrial flutter, AV nodal reentrant tachycardia, AV reciprocating tachycardia, and atrial tachycardia.

• Gradual onset and recession occur with sinus tachycardia, chronic atrial fibrillation and atrial flutter, multifocal atrial tachycardia, and atrial premature contractions.

• Adenosine blocks the AV node and is useful in distinguishing among SVT but should not be given in the case of irregular wide-complex tachycardias, since it may render these rhythms unstable.

• After administration of adenosine, slowing of the heart rate is consistent with a diagnosis of sinus tachycardia, atrial tachycardia, atrial fibrillation, or atrial flutter, whereas termination of tachycardia points to AV nodal reentrant tachycardia, AV reciprocating tachycardia, and some atrial tachycardias.

Differential Diagnosis and Treatment of Narrow-Complex Tachycardias


Differential Diagnosis and Treatment of Wide-Complex Tachycardias

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101年 急診專科醫師考題

關於 wide QRS tachycardia 的敘述，下列何者錯誤？

1. 若有 ventriculo - atrial dissociation，表示為 ventricular origin
2. 若為 polymorphic ventricular tachycardia 且先前EKG 有 QTc prolongation 或鎂離子濃度偏低的情形，可考慮直接給予 MgSO4
3. 若有高度一致性之 QRS complex 但規律性極不規則，加上間歇出現 narrow QRS complexes，應考慮為 atrial fibrillation 合併 WPW syndrome
4. 若血行動力學不穩定，則宜以同步電擊治療
5. 若血行動力學穩定，不宜使用adenosine 治療

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