Amiodarone is poorly effective for the acute termination of ventricular tachycardia. Ann Emerg Med ; Ortiz M et al.
Randomized comparison of intravenous procainamide vs. Eur Heart J Tomlinson DR et al. Intravenous amiodarone for the pharmacological termination of haemodynamically-tolerated sustained ventricular tachycardia: is bolus dose amiodarone an appropriate first-line treatment? Emerg Med J ; Louis, Mosby, Inc. His interests are in resuscitation medicine, resident education and cutting the knowledge translation window.
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Note: this service is provided by a third party, we do not collect your information in any way. Consequently we do not recommend a particular position for electrode placement over another. A final point should be made about the use of antiarrhythmic drugs prior to attempted cardioversion. While evidence is limited, in patients who have been pretreated with amiodarone , ibutilide , propafenone or sotalol , the restoration of a sinus rhythm from AF required less electrical energy, fewer attempts and lower number of recurrences.
Among the various cardiac pathologies complicating pregnancy, arrhythmias are the most common. Often diagnosed for the first time during pregnancy, tachyarrhythmias are the commonest form of arrhythmias reported during pregnancy.
Cardioversion and defibrillation during pregnancy is relatively safe without documented adverse effects to the fetus. However, antepartum fetal monitoring is recommended to monitor fetal heart rate during the procedure. Special consideration of the duration of pregnancy should be made while choosing drugs used for sedation pre-procedure, for example, avoid midazolam. Since the implantation of the first ICD in , there has been a great increase in the use of these instruments and their presence in ICU patients.
Occasionally patients continue to have unstable tachyarrhythmias despite having a functioning device. In certain instances, the ICD can be successfully reprogrammed to deliver the shock internally or implement tachycardia-pacing strategies for managing tachyarrhythmia. The application of electrical current during synchronized and unsynchronized cardioversion in patients with an ICD or permanent pacemaker can potentially cause damage to the ICD circuit and cause malfunction of these devices.
However, hemodynamically unstable tachyarrhythmias that are not being controlled by the implanted device need to be treated without hesitation in a manner similar to any other patient in the ICU.
As a strategy for minimizing risk of device damage, it is recommended to place the pads at least 12 cm away from the pulse generator and to use the anteroposterior positioning of electrodes.
All ICDs and permanent pacemakers should be interrogated after cardioversion is performed to ensure the proper functioning of these devices. An initial study from revealed a significant increase in the incidence of serious postcardioversion ventricular ectopy in patients that had ECG evidence of digitalis toxicity precardioversion.
Subsequent studies have confirmed that sustained ventricular ectopy post cardioversion is exceedingly rare and tends to occur with higher energy cardioversion along with other concomitant factors such as hypokalemia. As with all tachyarrhythmias it is important to identify and treat the underlying cause.
If cardioversion is deemed necessary it should be carried out starting with a lower energy level and ensuring the correction of any electrolyte abnormalities. Complications of cardioversion include skin burns, transient hypotension commonly from sedation , and EKG changes such as nonspecific ST-T wave changes or transient ST segment elevation.
High-energy shocks may also result in myocardial necrosis, which may present as a small rise in cardiac enzymes. Myocardial dysfunction may also occur due to myocardial stunning and is usually related to ischemia during cardiac arrest. This complication usually improves in 24 to 48 hours post resuscitation.
Rarely, pulmonary edema may occur as a result of left atrial standstill or LV dysfunction after cardioversion in patients with longstanding AF. The two most common potentially life-threatening complications associated with cardioversion and defibrillation are arrhythmia and thromboembolism.
Arrhythmias include sinus tachycardia, non-sustained VT, bradycardia and occasionally complete heart block that may require temporary cardiac pacing. Clinically significant VT or VF may also occur infrequently. Previous studies in patients with atrial fibrillation have reported a post cardioversion stroke risk of 1. Much of these studies are retrospective analyses of data from emergency room visits and their results have not been reproduced in the ICU setting.
The benefits of cardioversion in unstable AF outweighs the risk of clot embolization and therefore, urgent synchronized cardioversion should not be delayed in these patients. This div only appears when the trigger link is hovered over.
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Murtagh Collection. About Search. Enable Autosuggest. You have successfully created a MyAccess Profile for alertsuccessName. Home Books Critical Care. Previous Chapter. Next Chapter. Gupta R. Gupta, Rohit R. Cardioversion and Defibrillation. Oropello J. John M. Oropello, et al. Critical Care.
McGraw Hill;. Accessed November 13, Cardioversion and defibrillation. McGraw Hill. Download citation file: RIS Zotero. Reference Manager. Autosuggest Results. Download Section PDF. Table Graphic Jump Location Table 92—1 Initial energy requirements commonly used during cardioversion.
View Table Download. Figure 92—1 Placement of the pads in an A anterolateral configuration and B anteroposterior configuration. If it is fine v-fib, you may terminate the rhythm; however, if the rhythm is asystole, defibrillation will be ineffective and you can follow the asystole protocol with confidence. Supraventricular tachycardia, or SVT, is far different than the rhythms discussed above, which originate in the ventricles. Patients in a supraventricular tachycardia will have a rapid rhythm with a heart rate greater than beats per minute and a stimulus that originates above the ventricles.
Patients with an SVT may be relatively stable with few symptoms, or profoundly unstable with severe signs and symptoms related to the rapid heart rate. Patients who are unstable, or who do not respond to medication will require electrical therapy.
In this case, synchronized cardioversion, rather than defibrillation, is performed. Sedation should be provided if the patient is conscious as cardioversion is painful. You May Also Like.
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