380 BRIEF REPORTS

FIGURE 2. Two pieces of thrombus retrieved from the bypass graft with 2 separate passes Of the guiding catheter.

script; and to Susan Kasdan for preparation of the manuscript.

1. Hart&r GO, Rutherford BD, McConahay DR, Johnson WL Jr, McCallister BD, Gura GM Jr, Conn RC, Crockett JE. Percutaneous transluminal coronary angioplasty with and without thrombolytic therapy for treatment of acute myocardial infarction. Am Heart J 1983;106:965-973. 2. Mathey DG, Kuck KH, Tilsner V, Krebber HJ, Bleifeld W. Nonsurgical coronary artery recanalization in acute transmural myocardial infarction. Circulation 1981;63:489-497. 3. Greenfield LJ. Pulmonary embolism: diagnosis and management. Curr Probl Surg 1976:13:1-z?. 4. Mgore JH Jr, Koolpe AJ, Carabasi A, Yang SL, Jarrell BE. Transvenous catheter pulmonary emholectomy. Arch Surg 1985;126:1372-1375. 5. Sniderman KW, Bodner L, Saddekni S, Srur M, SOS TA. Percutaneous embolectomy by transcatheter aspiration. Radiology 1984;150:357-361. 6. Starck EE, McDermott JC, Crummy AB, Turnipseed WD, Acher CW, Bur- gess JH. Percutaneous aspiration thromboembolectomy. Radiology 1985;156: 61-66.

Defibrillation of High-Risk Patients During Coronaiy Jngiography

Using Self-Adhesive, Preapplied Electrode Pads

ROBERT F. WILSON, MD SARA SIRNA, MD

CARL W. WHITE, MD RICHARD E. KERBER, MD

D irect-current shocks for ventricular fibrillation or ventricular tachycardia have traditionally been ad- ministered using hand-held “paddle” electrodes. Hur- ried, incorrect paddle electrode placement during emergency cardioversion or defibrillation and poor contact between the paddle electrode and skin may be responsible for failure of electrical shocks to terminate arrhythmias.lJ Additionally, when shocks are given in the cardiac catheterization laboratory, the need to re- move sterile drapes and radiographic equipment and the presence of intravascular (and often intracoronary) catheters makes defibrillation during angiography at least cumbersome, and may cause important delays in shock delivery. Moreover, sterile fields are often con- taminated during defibrillation attempts using hand- held paddle electrodes.

Self-adhesive, preapplied electrode pads have been successfully used in place of hand-held paddle electrodes for elective cardioversion and for out-of- hospital defibrillation. 3,4 However, the foil electrodes of such preapplied defibrillation pads may interfere with radiographic visualization of the heart. Recently, to overcome this potential visualization problem, a new, commercially available version of the self-adhe-

On arrival at the cardiac catheterization laborato- ry, the self-adhesive electrode pads were applied in

From the Cardiovascular Center and Department of Internal Medicine, University of Iowa Hospitals, Iowa City, Iowa 52242. Reprint requests to Dr. Kerber. This work was supported by the American Heart Association, Iowa Affiliate, Des Moines, Iowa. Manuscript received December 22, 1986; revised manuscript received March 30,1987, accepted Anril2.1987.

sive electrode pads was introduced. The modified self- adhesive pads consist of an apical electrode, which is half-circular in order to avoid obscuring the heart, and a fully circular electrode, which is placed in the right parasterngl position. We report our experience with use of these self-adhesive, preapplied electrodes dur- ing angiographic procedures in high-risk patients in whom serious ventricular arrhythmias requiring di- rect-current shocks are likely to develop.

The pads evaluated in this study consisted of foil electrodes covered by a sodium chloride gel (R2:Cath Pads, model 414; R2 Corp.]. The gel served as’ the interface between the foil electrode and the chest wall. The pad backing was composed of nonconduc- tive foam with an adhesive outer ring. The pad elec- trode placed at the cardiac base was 12 cm in diameter [area 123 cm2]. The apex pad’s outer diameter was 8 cm, but its foil electrode was a half circle with Q 4-cm radius (area 25 cmz].

The copper conductors leading to the self-adhesive pad electrode were connected to a Hewlett-Packard defibrillator (model 78670A). The connecting cable contained 4 pushbutton switches mounted on a small box (Fig. I). After the defibrilfator was charged, the current could be transmitted to the electrodes only when the operator simultaneously pressed all 4 push buttons, a safety feature to prevent inadvertent shock delivery.

Clinical data were collected prospectively from pa- tients undergoing cardiac CQth&?riZQtiOII and coro- nary angiography at the University of Iowa between December 1985 and June 1986. The pads were applied just before the start of the catheterization in 31 patients felt by the attending cardiologist to be at higher than normal risk for serious tachyarrhythmia or ventricu- lar fibrillation during the procedure; 21 were within the initial 8 hours of acute myocardial in@ction, 3 had unstable angina and 7 had other illnesses that might have resulted in hemodynamic instability (purulent pericarditis, pulmonary embolism, complex coronary angioplasty).

August 1, 1987 THE AMERICAN JOURNAL OF CARDNXOGY Voiume 60 381

an apical-anterior position. The anterior pad -was placed just inferior to the right clavicle and adjacent to the right upper sternum (Fig. I). The apex pad was placed over the cardiac apex. The foil of the apex electrode (displayed diagrammatically on the backing of the pad] was placed in a caudal-posterior fashion to minimize the likelihood of its being within the radio- graphic field.

Thirty of the 31 patients then underwent coronary cineangiography using a Siemens Angioskop C-arm system; in 1 patient angiography was not performed because of rapid clinical deterioration. Multiple angu- lated views of both the left and right coronary arteries were obtained in most patients; shutters were routine- ly set as close to the cardiac border as possible.

I,f ventricular fibrijlation or tachycardia occurred, a 200-J shock was initially administered. A second shock of 200 or 300 J and subsequent shocks of 300 J were administered if required.

In 7 of the 31 patients ventricular fibrillation or polymorphous, rapid ventricular tachycardia devel- oped during the procedures. A total of 42 shocks were administered. One patient received 26 shocks: 23 for ventricular fibrillation and 3 for ventricular tachycar- dia during a prolonged procedure. The 6 other pa- tients received 15 shocks for ventricular fibrillation and 1 shock for ventricular tachycardia. In each of the 7 patients in whom these lethal ventricular arrhyth- mias developed, shocks delivered via self-adhesive

pads terminated the arrhythmia at least once. Twen- ty-nine of the 42 shocks (69%) administered were suc- cessful: 7 of 12 (63%) 200-I shocks and 22 of 31 (73%) 300-J shocks.

Cineangiograms of the coronary circulation were recorded in 30 of 31 patients. In alI but I patient, the pads were not visible at all on the cinangiograms de- spite wide caudal-cranial angulation [range 90° left anterior oblique to 64’ right anterior oblique, 48O cra- nial to 32’ caudal angulation (Fig. 2). In 1 patient, the base pad could be seen in 1 angiographic view (31’ rught anterior oblique angulation), but it did not over- Iie or obscure the coronary vasculature.

Our major finding is that use of self-adhesive preapplied electrode pads for defibrillation in high- risk patients during coronary angiography is clinically feasible, facilitates emergency shock delivery and does not impair angiographic image quality.

These self-adhesive preapplied electrode pads for defibrillation during coronary angiography offer 5 po- tential advantages over standard hand-held paddle electrodes. First, proper placement of the electrodes before emergency (and often harried] shock delivery in the catheterization laboratory should improve the likelihood of effecting defibrillation.lJ

Second, shocks can be delivered via the preapplied pads without removing or contaminating the sterile drapes used in the catheterization laboratory. Conse- quently, the risk of infection should be lower and necessity of replacing contaminated catheters is obviated.

Third, the time required for shock delivery should be reduced by the use of these preapplied pads. Radio-

FIGURE 1. Self-adhesive electrode pads in the apex-anterior orien- tation on a patient. The location of the half-circular foil electrode in the apex pad is indicated on the nonconductive backing. The pad is placed so that the foil electrode is oriented caudal-posterior to minimize the likelihood of its being within the cineangiographic field and obscuring the heart.

FIGURE 2. Cineangiograms obtained in the 44’ right anterior oblique, 22O caudal angulation view (fop /eff), the 40” left anterior oblique (LAG), 30” caudal angulation (fop righf), the 80” LAO angulation (boffom right), and 40” LAO with 41’ cranial angulation (boftom left). The self-adhesive foil electrode pads are not visible in any view.

382 BRIEF REPORTS

graphic equipment need not be moved aside and pad- dle electrodes need not be grasped, covered with con- ductive paste, and placed on the patient’s chest. This procedural simplification, in our experience, great- ly facilitates administration of the shocks during cath- eterization. It is especially helpful when repeated shocks are necessary; one of our patients required 26 shocks during 1 procedure.

Fourth, high-quality stable electrocardiographic monitoring can be performed using the large pad elec- trodes. This avoids the loose-lead artifact frequent- ly encountered with the usual small monitoring electrodes.

Finally, the electrode pads reduce the chance of accidental shock to the operator by allowing him or her to stand well away from the patient and catheteriza- tion table during shock delivery.

The clinical efficacy of self-adhesive pads was sim- ilar to that of the traditional hand-held paddles: 7 of 11 ZOO-J shocks (63%) using the pads terminated the ar- rhythmia, as did 22 of 31 300-J shocks (73%). These results are similar to those reported by other investiga- tors using hand-held paddle electrodes and energies of 200 J or higher.5-8 However, direct comparison of our patients with previous reports is difficult because few patients in the previous studies were undergoing cardiac catheterization and angiography.

The primary potential disadvantage of using these pads during coronary angiography is that they might interfere with radiographic visualization of the coro- nary vasculature. This can be prevented by proper placement. In our study, the pads were only visible within the cineangiographic field in 1 patient, and in

this patient they did not overlie the heart. On fluoros- copy we frequently did see the pads; they were suffi- ciently radiolucent to permit the viewing of catheters as they were manipulated into place.

Another potential disadvantage of the small apical pad may be higher current density traversing the myo- cardium, possibly causing myocardial injury. The good rate of shock success we observed does not support this possibility, but it cannot be excluded.

After shocks, an area of mild erythema around the site of the electrode pad developed in most patients. These areas were similar to the erythema often seen after hand-held paddle electrode shocks. No skin sloughing or other serious skin problems were encountered.

Acknowledgment: We thank the R2 Corporation for donating the electrode pads used in this study.

1. DeSilva RA. Hypothesis for low energy tronsthoracic defibrillation. Br Heart r 1979;42:495-496, 2. Crampton RA. Accepted, controversial and speculative aspects of ventricu- lar defibrillation. Prog Cardiovasc Dis 1980:23:X7-186 3. Kerber RE, Martins JB, Kelly KJ, Ferguson DW, Jensen S, Newman B, Parke JD, Kieso R. Melton J. Self-adhesive preapplied electrode pads for defibrilla- tion and cardioversion. JACC 1984;3:815-820. 4. Stults KR. Brown DD, Kerber RE. Self-adhesive monitor/defibriilation pads: prehospitol use (abstr]. JACC 1986;7:241A. 5. Patton JN, Pantridge JF. Current required for ventricular defibrillation. Br Med / i979;1:513-515. 6. Gascho JA, Crampton RS, Cherwek ML, Sipes JN, Hunter FP, O’Brien WM. Determinants of ventricular defibrillation in adults. Circulation 1979;60:231- 240. 7. Weaver WD, Cobb LA, Copass MK, Hallstrom AP. Ventricular defibrilla- tion-a comparative trial using 175 J and 320 J shocks. N Engl J Med 1982; 307:1101-1106. 8. Kerber RE, Jensen SR, Gascho JA. Grayzel J, Hoyt R, Kennedy J. Determi- nants of defibrillation: prospective analysis of 183 patients. Am J Cardiol 1983;52:739-745.

Relation Between left Atrial Dimension and Duration

of Atrial Fibrillation

PALLE PETERSEN, MD JENS KASTRUP, MD

KIM BRINCH, MD JOHN GODTFREDSEN, MD, PhD

GUDRUN BOYSEN, MD, PhD

A trial fibrillation (AF) is a common finding, especial- ly in elderly patients.l It is widely accepted that the left atrium is dilated in AF, but whether left atria1 (LA] enlargement is a cause or a consequence of the ar- rhythmia is still debated.2-4 The present study deter- mines the LA dimension in patients with AF of short and of long duration.

From the Department of Neurology, Rigshospitalet, and Depart- ment of Cardiology, Herlev Hospital, University of Copenha- gen, Copenhagen, Denmark. Manuscript received January 23, 1987; revised manuscript received and accepted March 16,1987.

The study was performed from January to Decem- ber 1986. All patients were referred from their family physician to the outpatient clinic for routine electro- cardiography. When an electrocardiogram showed AF the patient was invited to participate in the study. The patients were separated into 2 groups according to history and previous electrocardiographic findings. Group 2 consisted of 36 patients (13 men, 23 women, mean age 72 years, range 47 to 87) with AF less than 3 months in duration as judged by previous electrocar- diograms, a careful clinical history including symp- toms of heart failure, palpitations, chest pain and a review of ail medical charts and records from the family physician and, in some cases, from hospital admissions. To confirm that the arrhythmia was chronic, 3 electrocardiograms were recorded, with an interval of about 1 week between each recording. Group 2 consisted of 34 patients (14 men, 20 women, mean age 73 years, range 62 to 86) with AF for at least 3 year, verified according to the same criteria as de- scribed earlier. Finally, a normal control group con- sisting of 32 healthy persons (23 men, 18 women, mean age 73 years, range 58 to 84) who had participated in the Copenhagen City Heart Study5 was included