Temporary<unk>  cardiac<unk> , also called endocardial<unk> , is a potentially life saving intervention used primarily to correct profound bradycardia. It can be used to treat symptomatic bradycardias that do not respond to transcutaneous<unk>  or to drug therapy.<unk>  is acheieved by threading a<unk>  electrode through a vein into the right atrium, right ventricle, or both.
This means of<unk>  the heart is not as popular as other means of<unk>  (see transcutaneous<unk> , implanted pacemaker, epicardial<unk>  because it is a temporary solution to pace the heart and yet involves a similar level of risk of bleeding as a more permanent solution like<unk>  an implanted pacemaker.
For patients who present in an emergency setting with symptomatic bradycardias, usually drugs like atropine or sympathomimetic drugs (e.g. epinephrine, vasopressin, etc.) can be used to increase the heart rate to an adequate level until the underlying cause of the bradycardia can be isolated and then, possibly, a permanent pacemaker can be placed.  In most patients, transcutaneous<unk>  would be attempted before<unk>  because of the ease and speed of its application and its relative lack of risk.
For patients for whom<unk>  is chosen, the procedure is done at the bedside with a local anesthetic alone or in conjunction with conscious sedation.  The<unk>  electrode is advanced through the vein to the heart with the guidance of an electrocardiogram and sometimes with ultrasonography.  An x-ray after the procedure is always obtained to confirm placement of the<unk>  electrode.
The greater use of atropine and epinephrine or external<unk>  may obviate the need for<unk>  by stabilizing patients early in the process of caring for the patient.  Some debate exists over the efficacity and reliability of<unk> , especially if the need for permanent<unk>  is anticipated.
Transvenous pacing
Transcutaneous pacing
AVNRT cardioversion
Pericardial window
AV nodal ablation
Implantable cardioverter defibrillator
Atrial fibrillation cardioversion
Pulseless ventricular tachycardia interventions