The Journai of Emergency Medione, Vol 8, pp. 209-210. 1990 PrInted I” the USA CopyrIght C 1990 Pergamon Press plc

0 Conversion of Acute Atria1 Fibrillation with Procainamide

I read with interest the case report by de Haas et al. (1) on conversion of acute atria1 fibrillation with intravenous procainamide. Despite this and other articles in the cardiology and anesthesiology literature (2-4), the treat- ment is seldom employed. I reviewed the records of our emergency department over a two-year period, October 1986 to October 1988, for cases of acute atria1 fibrilla- tion. Sixteen patients with new onset atria1 fibrillation were treated with the procainamide infusion protocol (20 mg/min up to 1,000 mg). Ages ranged from 38 to 83. Of these 16 patients, 12 converted to sinus rhythm, the majority at procainamide doses of between 400 and 700 mg. We gave the procainamide only in cases where overt myocardial ischemia, hypoxemia, or hemodynamic com- promise were absent. One patient became mildly hy- potensive; her infusion rate was slowed, and she converted

to a sinus rhythm. All patients had Sentron blood pressure monitoring and close nursing standby. No significant QRS widening or Q-T prolongation occurred. Of the four patients failing to convert, two did so “spontaneously” at 2 and 5 hours after procainamide infusion. One other nonconverter received only 500 mg of procainamide. All patients who converted to sinus rhythm were discharged home; whereas only two of four remaining in atria1 fibrillation went home. The use of verapamil and digoxin helped slow ventricular response rates in most patients.

The case report and my review suggest that procain- amide is an extremely efficacious drug in converting acute onset atria1 fibrillation. The safety and ease of administration make this drug a standard for treatment of this problem in our emergency department.

Marilyn Geninatti, MD

Thunderbird Samaritan Hospital Glendale, Arizona

REFERENCES

1. de Haas DD. Taliaferro EH, Amin NM. Intravenous procainamide for the conversion of new onset atria1 fibrillation in the emergency department setting. J Emerg Med. 1988;6: 1 X5-7.

2. Fenster PE, Comess KA, Marsh R, Katzenberg C, Hager WD. Conversion of atria1 fibrillation to sinus rhythm by acute intrave-

0 Procainamide Conversion of Acute Atria1 Fibril- lation

Intravenous procainamide for the conversion of new onset atria1 fibrillation as outlined in our case report (1) is a very safe and effective regimen. Dr. Geninatti’s data emphasize this point, and she echoes our concern that this treatment is not utilized more often in the emergency department setting.

When our protocol (1,2) has been strictly adhered to

nous procainamide infusion. Am Heart J. 1983;106:501~. 3. Nolan PE Jr, Fenster PE. Letter to the Editor. Heart & Lung.

1983;14:314. 4. Fulham MJ, Cookson WOC, Sher M. Procainamide infusion and

acute atria1 fibrillation. Anaesth Inten Care. 1984: 12: 12 14.

with respect to patient selection and dosing, our success rate has approached 90% for conversion to sinus rhythm during procainamide infusion. This is consistent with the data presented by Dr. Geninatti where only 4 of her 16 patients did not convert. Of these, one did not receive an adequate dose. Two other “failures” who “spontane- ously” converted after infusion probably also received inadequate dosing, as we are recommending a 20 mg/kg maximum dose whereas only a 1000 mg dose was used. We believe that these three patients also could have

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210 The Journal of Emergency Medicine

converted during infusion per our protocol. If so, 15 out of 16 patients could have attained a sinus rhythm after procainamide infusion. These are similar to the results we have attained. This regimen is much more effective than any of the currently utilized “standard” emergency department interventions (i . e . , verapamil , digoxin, or beta-blockers) which tend to slow the ventricular re- sponse in atria1 fibrillation, but have a low incidence of conversion to sinus rhythm (3). The “standard” inter- ventions may even be dangerous if used in “pre- excited” atria1 fibrillation (4), whereas intravenous pro- cainamide is the treatment of choice.

In the past, we, as emergency physicians, have felt that our job was completed when the ventricular re- sponse rate in new onset atria1 fibrillation was con- trolled, and we have left the ultimate responsibility for cardioversion to our internal medicine or cardiology colleagues. We argue that this does our patients a disservice. It has been shown (5) that the longer a patient is in atria1 fibrillation, the more difficult conversion becomes. In addition, there is an increased risk of systemic embolization after conversion of patients who have been in atria1 fibrillation for prolonged periods. Cerebral blood flow and cardiac index (6) are also decreased with this rhythm. Finally, as mentioned by Dr. Geninatti, selected patients-those less than 65 years of

age without clinical or historical evidence of organic heart, lung, or thyroid disease (1,2)-who have been cardioverted may be considered for discharge home with further workup as outpatients.

The use of intravenous procainamide for conversion of new onset atria1 fibrillation is conspicuously absent from the emergency medicine literature, although the emergency department is where procainamide use could be of greatest benefit. Our hope is that physicians such as Dr. Geninatti and her colleagues at Thunderbird Samar- itan Hospital will continue to “spread the word.”

David Dana de Haas, MD

Department of Emergency Medicine Anaheim Memorial Hospital

Clinical Instructor, Division of Emergency Medicine

University of California, Irvine College of Medicine

Ellen H. Taliaferro, MD, FACEP

Emergency Medicine Services San Francisco General Hospital

Associate Professor of Surgery University of California,

San Francisco

REFERENCES

de Haas DD, Taliaferro EH, Amin NM. Intravenous procainamide for the conversion of new onset atria1 fibrillation in the emergency department setting. J Emerg Med. 1988;6:185-7. de Haas DD, Taliaferro EH, Kamnakar ARSR, Amin NM, Borgs- dorf LR, Caldwell JW. Protocol for management of new onset atria1 fibrillation in the emergency department. Unpublished prospective study protocol. Located at Department of Emergency Medicine, Anaheim Memorial Hospital, Anaheim, California. Platia EV, Michelson EL, Porterfield JK, Das G. Esmolol vs verapamil in the acute treatment of atria1 fibrillation or atria1 flutter.

Am J Cardiol. 1989;63:925-9. Garratt C, Ward D, Antonio A, Camm AJ. Misuse of verapamil in pre-excited atria1 fibrillation. Lancet. 1989;1:867-9. Fenster PE. Comess KA. Marsh R, Katzenberg C, Hager WD. Conversion’ of atria1 fibrillation to sinus rhythm-by acute intrave- nous procainamide infusion. Am Heart J. 1983;106:5014. Orlando JR, Van Herick R, Aronow WS, Olson HG. Hemodynam- its and echocardiograms before and after cardioversion of atria1 fibrillation to normal sinus rhythm. Chest. 1979;76:521-6.