Evaluation and Initial Treatment of Supraventricular Tachycardia

2012;367:1438-48.

CLINICAL PRACTICE

Atrial fibrillation (AF)

Underlying causes

Cardiac disease, pulmonary disease, pulmonary embolism, hyperthyroidism, postoperative

RegularityIrregular

Rate (bpm)100-220

OnsetSudden or gradual (if in chronic AF)

Response to AdenosineTermination of tachycardia

Atiral Activity and P:QRS RelationshipFibrillatory waves, no relationship to QRS

ECG

Multifocal atrial tachycardia (MAT)

Underlying causes

Pulmonary disease, theophylline therapy

RegularityIrregular

Rate (bpm)100-150

OnsetGradual

Response to AdenosineNone

Atiral Activity and P:QRS RelationshipChanging P morphologic features before QRS

ECG

Frequent atrial premature contractions

Underlying causes

Caffeine, stimulants

RegularityIrregular

Rate (bpm)100-150

OnsetGradual

Response to AdenosineNone

Atiral Activity and P:QRS RelationshipP before QRS

ECG

Sinus tachycardia

Underlying causes

Sepsis, hypovolemia, anemia, pulmonary embolism, pain, fear, fright, exertion, myocardial ischemia, hyperthyroidism, heart failure

RegularityRegular

Rate (bpm)220 minus the patient’s age

OnsetGradual

Response to AdenosineTransient slowing

Atiral Activity and P:QRS RelationshipP before QRS

ECG

Atrial flutter (AFL)

Underlying causes

Cardiac disease

RegularityRegular (occasionally irregular if variable AV conduction)

Rate (bpm)

150

OnsetSudden

Response to AdenosineTransient slowing of ventricular rate

Atiral Activity and P:QRS RelationshipFlutter wave, usually 2:1

ECG

AV nodal reentrant tachycardia (AVNRT)

Underlying causesNon

RegularityRegular

Rate (bpm)150-250

OnsetSudden

Response to AdenosineTermination of tachycardia

Atiral Activity and P:QRS RelationshipNo apparent atrial activity or R’ at termination of QRS

ECG

AV reciprocating tachycardia (AVRT)

Underlying causesRarely, Ebstein’s anomaly

RegularityRegular

Rate (bpm)150-250

OnsetSudden

Response to AdenosineTermination of tachycardia

ECGIn narrow complex, P after QRS

In wide complex, P rarely observed

In irregular rhythm (Afib), no apparent P wave

Atrial tachycardia (AT)

Underlying causesCardiac disease, pulmonary disease

RegularityRegular

Rate (bpm)150-250

OnsetSudden

Response to AdenosineTermination of tachycardia

Atiral Activity and P:QRS RelationshipP before QRS

ECG

Irregular SupraventricularTachycardiasRegularSupraventricularTachycardias

Differential Diagnosis of Supraventricular Tachycardias

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

The regular supraventricular tachycardias include sinus tachycardia, atrial flutter, atrioventricular nodal reentrant tachycardia, atrioventricular reciprocating tachycardia, and atrial tachycardia.

The irregular supraventricular tachycardias are atrial fibrillation, atrial flutter with variable atrioventricular block, and multifocal atrial tachycardia; multiple atrial premature contractions can cause a similar presentation.

Differential Diagnosis of Supraventricular Tachycardias

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

Differential Diagnosis of Supraventricular Tachycardias

Adenosine blocks the atrioventricular node and is useful in distinguishing among supraventricular tachycardias 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 atrioventricular nodal reentrant tachycardia, atrioventricular reciprocating tachycardia, and some atrial tachycardias.

Differential Diagnosis and Treatment of Narrow-Complex Tachycardias.

Narrow-complex tachycardia

Regular rhythm Irregular rhythm

Sudden onset Gradual onset HR <150 bpm HR 150 bpm≧�

Adenosine ST AF, MAT, NSR,or ST with APCs

AF, AFL withvariable block

Termination No termination Treat underlying cause

AVNRT, AVRT, AT

AT, AFL (ST,less frequently)

Rate control with β-blocker, verapamil, diltiazem; if unstable condition, cardioversion, procainamide, ibutilde

Differential Diagnosis and Treatment of Wide-Complex Tachycardias.

Wide-complex tachycardia

Underlying heart disease

No Yes

Irregular rhythm Regular rhythm

Unstable condition Stable condition Stable condition Unstable condition

PolymorphicVT, VF

AF with WPW

AF with aberrancyor AF with benignWPW

Adenosine

Termination No termination VTCardioversion–defibrillation

SVT with aberrancy,AVRT (WPW),idiopathic VT

Cardioversion; IVprocainamide,sotalol, lidocaine,or amiodarone