Editing Cardioversion (section)

== Procedure ==

=== Preparation ===

Cardioversion for restoration of sinus rhythm from an atrial rhythm is largely a scheduled procedure. In addition to cardiology, anesthesiology is also usually involved to ensure comfort of the patient for the duration of the shock therapy. The presence of registered nurses, physician associates, or other medical personnel may also be helpful during the procedure.

Before starting the procedure, the patient's chest and back will be prepped for electrode placement. The skin should be free of any oily substances (e.g., lotions) and hair which may otherwise interfere with adhesion of the pads.<ref>{{cite journal | vauthors = Sado DM, Deakin CD, Petley GW, Clewlow F | title = Comparison of the effects of removal of chest hair with not doing so before external defibrillation on transthoracic impedance | journal = The American Journal of Cardiology | volume = 93 | issue = 1 | pages = 98–100 | date = January 2004 | pmid = 14697478 | doi = 10.1016/j.amjcard.2003.09.020 }}</ref> Once this is complete, the medical team will adhere the pads to the patient using a rolling motion to ensure the absence of air pockets. ''(see details on pad placement below)''. The anesthesiology team will then administer a general anesthetic (e.g., [[Propofol]]) in order to ensure patient comfort and amnesia during the procedure. Opioid analgesics (e.g., Fentanyl) may be combined with Propofol, although anesthesiology must weigh the benefits against adverse effects including apnea.<ref>{{cite journal | vauthors = Wafae BG, da Silva RM, Veloso HH | title = Propofol for sedation for direct current cardioversion | journal = Annals of Cardiac Anaesthesia | volume = 22 | issue = 2 | pages = 113–121 | date = 2019 | pmid = 30971591 | pmc = 6489399 | doi = 10.4103/aca.ACA_72_18 | doi-access = free }}</ref> Bite blocks and extremity restraints are then utilized to prevent self-injury during cardioversion. Once these medications are administered, the [[glabellar reflex]] or [[Guedel's classification|eyelash reflex]] may be used to determine the patient's level of consciousness.

The pads are connected to a machine that can interpret the patient's cardiac rate and rhythm and deliver a shock at the appropriate time. The machine should synchronize ('sync') with the [[R wave]] of the rhythm strip. Although uncommon, sometimes the machine will unintentionally sync to high amplitude T waves, so it is important to ensure that the machine is synced appropriately to R waves.<ref name = "Goyal_2022">{{cite book | vauthors = Goyal A, Sciammarella JC, Chhabra L, Singhal M | chapter = Synchronized Electrical Cardioversion |date=2022 |url=http://www.ncbi.nlm.nih.gov/books/NBK482173/ | title = StatPearls |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=29489237 |access-date=2022-08-12 }}</ref> Interpretation of the patient's rhythm is imperative when using cardioversion to restore sinus rhythm from less emergent arrhythmias where a pulse is present (e.g., [[atrial flutter]], [[atrial fibrillation]]). However, if a patient is confirmed to be in [[Ventricular tachycardia|pulseless ventricular tachycardia]] "v-tach" or [[ventricular fibrillation]] "v-fib", then a shock is delivered immediately upon connection of the pads. In this application, electrical cardioversion is more properly termed [[defibrillation]].<ref name = "Goyal_2022" />
[[File:LIFEPAK_20e_Defibrillator_and_Monitor_displaying_synchronization_with_QRS_complexes._(arrowheads).jpg|thumb|[[:File:LIFEPAK 20e Defibrillator and Monitor displaying synchronization with QRS complexes. (arrowheads).jpg|LIFEPAK 20e Defibrillator and Monitor displaying synchronization with QRS complexes. (arrowheads)]]]]

=== Cardioversion ===

Once the machine is synced with the patient's cardiac rhythm, the machine must be charged. To determine the amount of energy (measured in joules "J") the patient requires, many factors are considered. As a rule of thumb, recent-onset atrial arrhythmias require less energy compared to persistent atrial arrhythmias. If the cardiologist suspects that the patient may be less respondent to cardioversion, a higher energy may be utilized. Once the machine is synced and charged, a shock can be delivered to the patient.<ref>{{cite journal | vauthors = Sirna SJ, Ferguson DW, Charbonnier F, Kerber RE | title = Factors affecting transthoracic impedance during electrical cardioversion | journal = The American Journal of Cardiology | volume = 62 | issue = 16 | pages = 1048–1052 | date = November 1988 | pmid = 3189167 | doi = 10.1016/0002-9149(88)90546-2 }}</ref>

====Recommended Energy Levels====
* ''Atrial Flutter and SVT: '''50-100 J''' for biphasic devices; 100 J for monophasic devices''
* ''Atrial Fibrillation: '''120-200 J''' for biphasic devices; 200 J for monophasic devices''
* ''Ventricular Tachycardia (with a pulse): '''100 J''' for biphasic devices; 200 J for monophasic devices''
* ''Pulseless Ventricular Tachycardia and Ventricular Fibrillation: '''120-200 J''' for biphasic devices; 360 J for monophasic devices''<ref>{{cite journal | vauthors = Fuster V, Rydén LE, Cannom DS, Crijns HJ, Curtis AB, Ellenbogen KA, Halperin JL, Le Heuzey JY, Kay GN, Lowe JE, Olsson SB, Prystowsky EN, Tamargo JL, Wann S, Smith SC, Jacobs AK, Adams CD, Anderson JL, Antman EM, Halperin JL, Hunt SA, Nishimura R, Ornato JP, Page RL, Riegel B, Priori SG, Blanc JJ, Budaj A, Camm AJ, Dean V, Deckers JW, Despres C, Dickstein K, Lekakis J, McGregor K, Metra M, Morais J, Osterspey A, Tamargo JL, Zamorano JL | display-authors = 6 | title = ACC/AHA/ESC 2006 Guidelines for the Management of Patients with Atrial Fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Revise the 2001 Guidelines for the Management of Patients With Atrial Fibrillation): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society | journal = Circulation | volume = 114 | issue = 7 | pages = e257–e354 | date = August 2006 | pmid = 16908781 | doi = 10.1161/circulationaha.106.177292 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Zipes DP, Camm AJ, Borggrefe M, Buxton AE, Chaitman B, Fromer M, Gregoratos G, Klein G, Moss AJ, Myerburg RJ, Priori SG, Quinones MA, Roden DM, Silka MJ, Tracy C, Smith SC, Jacobs AK, Adams CD, Antman EM, Anderson JL, Hunt SA, Halperin JL, Nishimura R, Ornato JP, Page RL, Riegel B, Blanc JJ, Budaj A, Dean V, Deckers JW, Despres C, Dickstein K, Lekakis J, McGregor K, Metra M, Morais J, Osterspey A, Tamargo JL, Zamorano JL | display-authors = 6 | title = ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (writing committee to develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society | journal = Circulation | volume = 114 | issue = 10 | pages = e385–e484 | date = September 2006 | pmid = 16935995 | doi = 10.1161/CIRCULATIONAHA.106.178233 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Link MS, Atkins DL, Passman RS, Halperin HR, Samson RA, White RD, Cudnik MT, Berg MD, Kudenchuk PJ, Kerber RE | display-authors = 6 | title = Part 6: electrical therapies: automated external defibrillators, defibrillation, cardioversion, and pacing: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care | journal = Circulation | volume = 122 | issue = 18 Suppl 3 | pages = S706–S719 | date = November 2010 | pmid = 20956222 | doi = 10.1161/CIRCULATIONAHA.110.970954 | doi-access = free }}</ref>

=== After cardioversion ===

Following electrical cardioversion, the cardiologist will determine if sinus rhythm has been restored. To confirm sinus rhythm, a distinct [[P wave (electrocardiography)|P wave]] should be seen preceding each QRS complex. Additionally, each [[R-R interval]] should be evenly spaced. If sinus rhythm is restored, the pads may be disconnected, and any other medical equipment is removed from the patients (e.g., bite blocks, restraints, etc.). The patient will regain consciousness soon thereafter (the effects of Propofol generally last for only 3–8 minutes). However, if the arrhythmia is persistent, the machine may be re-charged to a higher energy level, and the cardioversion attempt may be repeated. It is recommended to wait 60 seconds between subsequent cardioversion attempts, but this amount of time may be adjusted based on the patient and/or provider.