A response to the letter on electrical cardioversion resulting in death from synchronization failure

Rodney H. Falk

doi:10.1016/S0002-9149(99)80610-9

$Electrical Cardioversion Resulting in Death from Synchronization Failure observation by a cardiologist in private practice. Thomas E. Layman, Iowa City. 20 July MD low 1994 The recent article by Ebrahimi and Rubin in The American .kournal c@â Cardiology@ (Electrical Cardioversion Resulting in Death from Synchronization Failure. 1994;74: 100-102) makes a case for being alert to synchronization of directcurrent cardiovcrsion shocks to the QRS and not to the T wave. I would like to suggesteven more strongly that the fact that a 50 Wsecondsshock was used contributed more to the problem than did synchronization on the T wave. It has been my experience in 28 years of practicing cardiology that the only cases of ventricular fibrillation or ventricular tachycardia that have been induced by direct-current cardiovcrsion have been those which were low energy, such as the SOWseconds pulse which they used on their patient. It is my presumption, for which I have no proof, that such shocks will produce a partial depolarization of the myocardium and allow a circus movement phenomenon to occur, resulting in ventricular tachycardia, or worse, ventricular fibrillation. It has been my policy to use no less than 100 W-seconds (and more commonly, 200 W-seconds)as a beginning cardioverting energy. With such a policy, I have performed an almost equal number of cardioversions using synchronized and unsynchronized discharges over my Z-year practice. I have had no untoward efrects using the larger shocks and would encourage the use of higher energies to avoid the problems rcported in the authorsâ article. It stems to be the practice today to teach residents to use the smallest amountof energy available to achieve cardioversion. I believe this is a serious mistake that will lead to morbidity and mortality which could be avoided by using higher energies. 1would invite other readersâcomments, as this is strictly an unproved Letters ~icular the (with wriucn (from article the United SEWS) concerning a parof typein 771~ .?VW~CUII be received and publication. cxccptions) Two copies with a rapid, pre-excited ventricular response)has been suggestedto represent an anatomically long left lateral bypass tract with a short refractory period,2 and 1wonder where the autopsy located these tracts. Rodney Boston. H. Folk, MD Massachusetts 20 July 1994 JN. lârwioitation of 1. !vI&ovcn~ B. (Saran II. Ruskm Jmwtral of Car. 2 months lx limited should dio/o~qy~ must articleâs rare pages. within to 2 double-spaced must be submitted. The casereport by Ebrahimi and Rubin (Am.I Curdiol 1994;74: 101-102) is at once interesting and disturbing. While it illustrates the importance of the use of more than 1 lead for optimal R-wave detection during cardioversion, it also raises questions rcgarding the therapy given to this unfortunate 29-year-old patient with Wolff-Parkinson-White syndrome and atria1 fibrillation. The authors point out that the electrocardiogram ârevealed a wide complex tachycardia of irregular pattern that was diagnostic of atria1 fibrillation with Wolff-Parkinson-White syndrome,â but then state that âvarious vagal maneuversand intravenous medications failed to restore a more stable rhythm.â No medications are documented. I am puzzled as to why vagal maneuversmight be considered in a patient with this diagnosis, and wonder whether the diagnosis was as obvious to the emergency room physicians as is implied. It is critical in a cast report like this to state what the intravenous medications were, since verapamil is a widely used drug in emergencyrooms and is well recognized to have a serious potential for provoking cardiovascular collapse and/or ventricular fibrillation in patients with pre-excitated atria1fibrillation.â It is also possible that the medications administered before the arrest played a role in the inability to resuscitate this young patient with iatrogcnic ventricular fibrillation. One final and intriguing point about this case is the near-normal electrocardiogram in sinus rhythm despite a rapid. wide complex vcntricular responseduring atrial fibrillation. This contrasts with the more usual finding of a clear-cut delta wave during sinus rhythm. This combination (minimal pre-excitation during sinus rhythm and atria1 fibrillation 104:791--794. 2. Rohinwn K. Ro\~land E. Kriklcr DM. la~cnt DI%- Complications of Cardioversion The recent article by Ebrahimi and Rubin, âElectrical Cardioversion Resulting in Death from Synchronization Failureâ in the July 1, 1994issue of the Journal, pages 100 to 102, is somewhat misleading and incomplete. The catastrophic result of cardioversion in this patient did not occur due to synchronization failure but to misjudgment by the operator performing the cardioversion. Figure 2 in the article clearly shows that synchronization by the machine occurred on the top of the T wave with the expected result of ventricular fibrillation after administration of the shock. It is not the machine that should exert judgment of where to synchronize but the physician performing the cardioversion. It therefore is not a failure of the device âto behaveappropriatelyâ but insu@cicnt attention to detail by the operator of the equipment. It is true that in most articles in reference to cardioversion, the need for detailed attention to synchronization is not stressedsufficiently. It should be reiterated that the lead with the tallest R wave should be selectedfor monitoring and to apply synchronization. This is mandatory for anyone trying to perform cardioversion in a synchronized mode. In addition, I question the brief casereport. After the SOW-second cardioversion synchronized to the T wave resulted in ventricular fibrillation, the authors state âdespite advanced cardiac life support, numerous attempts to restore a stable rhythm were unsuccessful and the patient died.â The$

DeepDyve - Search, Rent, Read
The easiest way for you to get scholarly articles:

A response to the letter on electrical cardioversion resulting in death from synchronization failure

Falk, Rodney H.

Follow The American Journal of Cardiology , Volume 75 (7) Elsevier – Mar 1, 1995

Advanced Filters:

Specific Data Sources:

DeepDyve - Search, Rent, ReadThe easiest way for you to get scholarly articles:

A response to the letter on electrical cardioversion resulting in death from synchronization failure

Falk, Rodney H.

Follow The American Journal of Cardiology , Volume 75 (7) Elsevier – Mar 1, 1995

DeepDyve - Search, Rent, Read
The easiest way for you to get scholarly articles: