Synchronized and Unsynchronized Cardioversion
Synchronized vs. Unsynchronized Cardioversion
Ever wondered what the difference between synchronized and unsynchronized cardioversion is?
Synchronized cardioversion is a LOW ENERGY SHOCK that uses a sensor to deliver electricity that is synchronized with the peak of the QRS complex (the highest point of the R-wave). When the “sync” option is engaged on a defibrillator and the shock button pushed, there will be a delay in the shock. During this delay, the machine reads and synchronizes with the patients ECG rhythm. This occurs so that the shock can be delivered with the peak of the R-wave in the patients QRS complex.
Synchronization avoids the delivery of a LOW ENERGY shock during cardiac repolarization (t-wave). If the shock occurs on the t-wave (during repolarization), there is a high likelihood that the shock can precipitate VF (Ventricular Fibrillation).
The most common indications for synchronized cardioversion are unstable atrial fibrillation, atrial flutter, atrial tachycardia, and supraventricular tachycardias. If medications fail in the stable patient with the before mentioned arrhythmias, synchronized cardioversion will most likely be indicated.
Unsynchronized cardioversion (defibrillation) is a HIGH ENERGY shock which is delivered as soon as the shock button is pushed on a defibrillator. This means that the shock may fall randomly anywhere within the cardiac cycle (QRS complex). Unsynchronized cardioversion (defibrillation) is used when there is no coordinated intrinsic electrical activity in the heart (pulseless VT/VF) or the defibrillator fails to synchronize in an unstable patient.
For cases where electrical shock is needed, if the patient is stable and you can see a QRS-t complex use (LOW ENERGY) synchronized cardioversion. If the patient is pulseless, or if the patient is unstable and the defibrillator will not synchronize, use (HIGH EVERGY) unsynchronized cardioversion (defibrillation).
thank you very much.after several years i could solve my problem in this field:-)
now it clear my dout. Thank u
Statement made “patient unstable and the defibrillator will not synchronize,use high energy unsynchronized cardop-version” Why would the defibrillator not synchronize? Is there another
reason besides the machine does not have that capability/function?
During synchronized cardioversion, the defibrillator attempts to sync with the patient’s heart rhythm. This occurs so that the shock can be delivered with the peak of the R-wave in the patients QRS complex. So the main reason why the defibrillator would not be able to sync would be an inability for the machine to recognize an R-wave. This can occur with some types of tachycardia.
Kind Regards,
Jeff
thank you so much
thanks for the information i actually confuse the two
Thanks so much for this up-to-date and concise information. I appreciate it.
this is awesome….thanx for sharing…
is amiodarone contraidicated to pregnant?
Amiodarone is pregnancy Category D which states:
“There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.”
Kind regards,
Jeff
Best learning material ever ,thanks for putting this together .
Jeff, can you defibrilate a pregnant patient or do you have to deliver the baby before defribrilating the mother? Also I know you cannot give amiodarone to a pregnant woman, what can be used until the baby is delivered or should you just wait for the baby to be delivered and then give amiodarone?
Thanks
You can defibrillate a pregnant patient without danger to the unborn child. Here is a diagram that explains the AHA information on the treatment of maternal cardiac arrest.
Kind regards, Jeff
Really good information