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No evidence for the comparison between monophasic DC shock and biphasic DC shock in the acute management of supraventricular tachycardia

Three Part Question

In [adults with supraventricular tachycardia] is [monophasic shock or biphasic shock] more efficient at [restoring sinus rhythm]

Clinical Scenario

A 48 year old female with a known history of recurrent paroxysmal supraventricular tachycardia arrives in A & E complaining of dizziness and palpitations. An ECG reveals a 160 bpm regular rhythm with visible p waves distorting the start of the QRS complex. Physical manoeuvres are attempted unsucessfully and an adenosine bolus is given. The tachycardia appears to be refractory to treatment and the lady goes into shock. A decision to electrically cardiovert is made. The physician on-call wonders which waveform would be more efficient at restoring sinus rhythm.

Search Strategy

Medline using the OVID interface 1966 to June Week 4 2005
EMBASE using the OVID interface 1980 to 2005 Week 27
CINAHL using the OVID interface 1982 to June Week 4 2005
[(exp Supraventricular Tachycardia/) OR (exp Tachycardia, Atrioventricular Nodal Reentry/) OR (supraventricular OR (narrow complex tachycardia) OR narrow-complex tachycardia) OR (junctional] AND [(exp Electric Countershock/) or (cardiover$.mp.) AND (] AND [(exp Electric Countershock) OR (cardiover$.mp.) AND (]

Search Outcome

No relevant papers were found with either of the searches above. Papers concerning the comparison of monophasic vs biphasic cardioversion were related to elective cardioversion in atrial fibrillation and/or atrial flutter.


There was no evidence in the available literature that compaired the efficacy between monophasic vs biphasic dc cardioversion in restoring sinus rhythm in haemodinamically unstable patients due to narrow complex tachycardia. However, evidence was found suggesting that biphasic shocks are superior to monophasic shocks in restoring sinus rhythm in patients with atrial fibrillation, atrial flutter or ventricular fibrillation/tachycardia.

Clinical Bottom Line

A clinical bottom line could not be produced since there are no papers produced concerning this topic. Local advice should be followed.