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Temporary Postoperative Epicardial Pacing Electrodes
Temporary Postoperative Epicardial Pacing Electrodes Their Value and Management After Open-Heart Surgery Robert P. Hodam, M.D., and Albert Starr, M.D.
S
ince 1964, temporary epicardial pacemaking electrodes have been placed routinely at the time of operation in most patients undergoing open-heart surgery at this institution and at St. Vincent Hospital. This practice was initiated as a precaution against postoperative heart block in isolated cases involving repair of tetralogy of Fallot or correction of ventricular septa1 defects. As our experience grew, however, we came to realize the frequent value of these electrodes in establishing a stable cardiac rhythm during the postoperative period. Friesen et al. [l] subsequently showed the value of atrial pacing in increasing postoperative cardiac output. Consequently, for the past two years most patients except those with long-standing atrial fibrillation have had both atrial and ventricular pacing wires placed prior to closure of the chest. The purpose of this paper is to describe our method of placement and the subsequent management of these temporary pacing wires. TECHNIQUE The wire electrodes used are Teflon-coated myocardial electrodes with swaged-on stainless-steel needles.* The electrodes are joined via standard insulated wire to a male connector, as shown in Figure 1. They are then connected when needed to an external battery-powered pacemakert using an intervening “pigtail.” Ventricular electrodes are placed on the anterior surface of the right ventricle just prior to defibrillation, before the patient is removed from cardiopulmonary bypass. The swaged-on needle is passed partially through the wall of the ventricle, and part of the uninsulated wire is pulled through the myocardium. The needle is cut off and the bare wire looped back over itself and sutured loosely to the epicardium with a 5-0 silk, as shown in Figure 2. Two electrodes are placed on the ventricular surface in this manner. Three precautions are taken in their placement. Care is taken to avoid branches of the coronary arteries that might be From the Department of Cardiopulmonary Surgery, University of Oregon Medical School, Portland, Ore. Accepted for publication June 4, 1969. Address reprint requests to Dr. Hodam, University of Oregon Medical School, 3181 S.W. Sam Jackson Park Road, Portland, Ore. 97201. ‘Manufactured by Electrodyne Company, Inc., Wcstwood, Mass. tMedtronic, Medtronic Inc., Minneapolis, Minn.
506
THE ANNALS OF THORACIC SURGERY
Postoperative Epicardial Pacing
Conne Elec
FIG. 1. Teflon-insulated stainless-steel electrode with swaged-on needles attached to a male connector. T h e intervening connecting wire allows rapid con-
nection to the external pacemaker.
torn when the wires are removed; an attempt is made to pass the needle parallel to the myocardial fibers to minimize chances of myocardial tearing at the time of removal; and finally, the wires are placed at least 2 cm.apart so that their tips do not touch. We have found that this method of placement usually allows us to remove the wires while leaving the retaining sutures behind with a minimal chance of myocardial damage. Atrial wires are placed at the end of the procedure, just prior to closure of the incision. We have had greatest success in achieving atrial pacing when the electrodes have been positioned so that the stimulus passes across the region of the S-A node. One wire is positioned so that its tip lies free within the right atrial cavity near the junction of the superior vena cava. This is accomplished by passing the needle into the lower portion of the superior vena cava and bringing it out the anterior wall about one cm. lower toward the atrium. The wire is then pulled through and cut off to leave 2 mm. of bare wire exposed beyond the end of the Teflon insulation. The tip of the wire is pulled back into the lumen of
$
?
"
FZG. 2. Placement of atrihl k n d ventricular pacing electrodes. VOL.
8,
NO.
6, DECEMBER, 1969
507
HODAM AND STARR the superior vena cava and advanced downward into the upper portion of the right atrium. The Teflon-insulated wire is then looped back on itself and fixed loosely to the adventitia of the vena cava with a 5-0 suture, as shown in Figure 2. Occasionally, it is necessary to place a hemostatic suture in the site of exit of the needle. The second atrial wire may be placed in several positions, either on the right atrial wall or in the subcutaneous tissue of the chest wall. We have obtained the most reliable pacing by suturing the bare wire of the second electrode loosely to the adventitia of the superior vena cava between the vena cava and the aorta. Placement of the second electrode on the lateral atrial wall has resulted OCcasionally in stimulation of the phrenic nerve and contraction of the diaphragm. SUBSEQUENT MANAGEMENT Both atrial and ventricular wires are brought out through the lower end of the incision, identified with colored tape, and fixed to the patient’s chest wall in such a way that they will not be disturbed by removal of the gauze dressing over the incision. The gauze dressing is generally removed in 24 to 36 hours, and the incision is sprayed with a plastic film. A small gauze bandage is left around the wire sinus tract. This bandage is changed daily by the nursing staff. At this time, the small amount of exudate around the wires is cleansed away, and topical bacitracin and neomycin antibiotic ointment (Spectrocin) is applied to the wire sinus. When not in use, the wires are coiled and taped lightly to the patient’s chest or abdominal wall. When pacing is desired, the wires are connected to the external pulse generator, which is suspended from an I.V. stand or carried in the pocket of the patient’s robe if he is ambulatory. The wires are usually left in place for from 5 to 7 days postoperatively. I n patients who have undergone prosthetic valve replacement and are being started on long-term anticoagulant therapy on the sixth postoperative day, we recommend removal of the wires prior to the achievement of therapeutic anticoagulation. On rare occasions it has been necessary to maintain external pacing in the presence of adequate anticoagulation. Removal of the wires in these instances has not resulted in any complications, but in general we do not recommend this practice. Removal of the electrodes is accomplished by a slow, steady, firm pull on all wires at the same time. Usually, the rhythmic counterpull of the beating heart will be felt easily. A steady, firm pull on the wires, however, will allow the wires to slide free with little, if any, discomfort to the patient. After removal of the wires, the sinus tract is covered for a day or two with an occlusive gauze dressing. COMPLICATIONS Since 1964, pacing wires have been placed in more than 1,000 patients. There have been no deaths attributable to these wires. Four complications have been noted: two bleeding episodes requiring reoperation, one pneumothorax, and one pneumomediastinum following removal of the pacing wires. The first bleeding episode occurred early in our experience after removal of the pacing wires on the seventh postoperative day. Continued loss of arterial blood from the wire sinus tract necessitated reexploration. The bleeding source was found to be a small branch of a coronary artery, and the bleeding was controlled without difficulty. Subsequently, care in avoiding these branches during electrode placement has prevented further complications from this cause. The second bleeding episode occurred in the recovery room immediately after operation. At reexploration a small hole was found in the ascending aorta near the site of placement of the atrial electrode. This hole was presumed to have resulted from erosion of the wire tip through the aorta.
508
THE ANNALS OF THORACIC SURGERY
Postoperatiue Epicardial Pacing One patient developed a right pneumothorax several hours aft pacing wires on the seventh postoperative day. A second patient asymptomatic pneumomediastinum which was found on roentgen0 moval of his pacing wires. Both these complications are believed to have resulted from leakage of air into the thorax through the wire sinus tract. Our practice of draining the pericardium into the right pleural space allowed collapse of the right lung in the case cited. Since these two complications, we have placed small occlusive dressings over the sinus tract for a day or two until it seals. Occasionally, serosanguineous drainage from the sinus tract will be noted for a few days after removal of the wires. In all cases, however, this drainage has ceased spontaneously and no infection that appears related to the wires has occurred in the wound, sternum, or mediastinum.
COMMENT
We have found the temporary epicardial pacing electrodes to be of value in numerous situations common to the postoperative, period following open-heart surgery. Atrial pacing has been found valuable in stabilizing such supraventricular arrhythmias as slow sinus rhythm with nodal escape beats or PVC’s, sinus arrest, PAC’s precipitating atrial tachycardia, and in nodal rhythms with retrograde conduction, A-V dissociation, or atrial standstill. Previous work from this department [2, 31 has emphasized the value of paced atrial contractions in maintaining a more optimal cardiac output following operation. An added value of the intracavitary atrial wire is its ability to function as an atrial electrocardiogram lead for the diagnosis of supraventricular tachycardias. In several instances, patients with atrial fibrillation preoperatively have returned from the operating room in sinus rhythm. Through atrial pacing it has been possible to maintain the sinus rhythm throughout the postoperative period. Ventricular pacing wires originally were used only in patients with complete heart block or in those in whom temporary postsurgical heart block was feared. Experience has proved, however, that these wires are only very rarely needed for such situations, but are commonly of value in other situations. We find the most common use of ventricular pacing to be in patients with slow atrial fibtillation with PVC’s. Ventricular pacemaking in these situations usually will elimihate the PVC’s and allow us to administer digitalis preparations more ”freely if we think the patient’s condition warrants it. SUAIMARY A N D CONCLUSIONS
Temporary atrial or ventricular epicardial pacing electrodes, or both, have been used routinely after open-heart surgery at the University of Oregon Medical School since 1964. These electrodes have proved of value on numerous occasions in stabilizing cardiac rhythm, improving cardiac output, and aiding in the diagnosis of supraventricular VOL.
8,
NO.
6,
DECEMBER,
1969
509
HODAM AND STARR
tachycardias. Our method of placement and subsequent management of these electrodes have been described in detail. In more than 1,000 cases no deaths have resulted from the use of these temporary electrodes. Two bleeding episodes, one pneumothorax, and one pneumomediastinum have been the only four complications. We believe that the value of these temporary epicardial electrodes and the minimal morbidity associated with them warrants their continued use. REFERENCES 1. Friesen, W. G., Woodson, R. D., Ames, A. W., Herr, R. H., Starr, A., and Kassebaum, D. G. A hernodynamic comparison of atrial and ventricular pacing in postoperative cardiac surgical patients. J . Thorac. Cardiovasc. Surg. 55:271, 1968.
2. Woodson, R. D., Friesen, W. G., Herr, R. H., and Starr, A. Postoperative atrial pacing: A new adjuvant in mitral valve surgery. Surg. Forum 19:103, 1968.
3. Woodson, R. D., and Starr, A. Atrial pacing after mitral valve surgery. Arch. Surg. (Chicago) 97:984, 1968.
510
THE ANNALS OF THORACIC SURGERY
S
ince 1964, temporary epicardial pacemaking electrodes have been placed routinely at the time of operation in most patients undergoing open-heart surgery at this institution and at St. Vincent Hospital. This practice was initiated as a precaution against postoperative heart block in isolated cases involving repair of tetralogy of Fallot or correction of ventricular septa1 defects. As our experience grew, however, we came to realize the frequent value of these electrodes in establishing a stable cardiac rhythm during the postoperative period. Friesen et al. [l] subsequently showed the value of atrial pacing in increasing postoperative cardiac output. Consequently, for the past two years most patients except those with long-standing atrial fibrillation have had both atrial and ventricular pacing wires placed prior to closure of the chest. The purpose of this paper is to describe our method of placement and the subsequent management of these temporary pacing wires. TECHNIQUE The wire electrodes used are Teflon-coated myocardial electrodes with swaged-on stainless-steel needles.* The electrodes are joined via standard insulated wire to a male connector, as shown in Figure 1. They are then connected when needed to an external battery-powered pacemakert using an intervening “pigtail.” Ventricular electrodes are placed on the anterior surface of the right ventricle just prior to defibrillation, before the patient is removed from cardiopulmonary bypass. The swaged-on needle is passed partially through the wall of the ventricle, and part of the uninsulated wire is pulled through the myocardium. The needle is cut off and the bare wire looped back over itself and sutured loosely to the epicardium with a 5-0 silk, as shown in Figure 2. Two electrodes are placed on the ventricular surface in this manner. Three precautions are taken in their placement. Care is taken to avoid branches of the coronary arteries that might be From the Department of Cardiopulmonary Surgery, University of Oregon Medical School, Portland, Ore. Accepted for publication June 4, 1969. Address reprint requests to Dr. Hodam, University of Oregon Medical School, 3181 S.W. Sam Jackson Park Road, Portland, Ore. 97201. ‘Manufactured by Electrodyne Company, Inc., Wcstwood, Mass. tMedtronic, Medtronic Inc., Minneapolis, Minn.
506
THE ANNALS OF THORACIC SURGERY
Postoperative Epicardial Pacing
Conne Elec
FIG. 1. Teflon-insulated stainless-steel electrode with swaged-on needles attached to a male connector. T h e intervening connecting wire allows rapid con-
nection to the external pacemaker.
torn when the wires are removed; an attempt is made to pass the needle parallel to the myocardial fibers to minimize chances of myocardial tearing at the time of removal; and finally, the wires are placed at least 2 cm.apart so that their tips do not touch. We have found that this method of placement usually allows us to remove the wires while leaving the retaining sutures behind with a minimal chance of myocardial damage. Atrial wires are placed at the end of the procedure, just prior to closure of the incision. We have had greatest success in achieving atrial pacing when the electrodes have been positioned so that the stimulus passes across the region of the S-A node. One wire is positioned so that its tip lies free within the right atrial cavity near the junction of the superior vena cava. This is accomplished by passing the needle into the lower portion of the superior vena cava and bringing it out the anterior wall about one cm. lower toward the atrium. The wire is then pulled through and cut off to leave 2 mm. of bare wire exposed beyond the end of the Teflon insulation. The tip of the wire is pulled back into the lumen of
$
?
"
FZG. 2. Placement of atrihl k n d ventricular pacing electrodes. VOL.
8,
NO.
6, DECEMBER, 1969
507
HODAM AND STARR the superior vena cava and advanced downward into the upper portion of the right atrium. The Teflon-insulated wire is then looped back on itself and fixed loosely to the adventitia of the vena cava with a 5-0 suture, as shown in Figure 2. Occasionally, it is necessary to place a hemostatic suture in the site of exit of the needle. The second atrial wire may be placed in several positions, either on the right atrial wall or in the subcutaneous tissue of the chest wall. We have obtained the most reliable pacing by suturing the bare wire of the second electrode loosely to the adventitia of the superior vena cava between the vena cava and the aorta. Placement of the second electrode on the lateral atrial wall has resulted OCcasionally in stimulation of the phrenic nerve and contraction of the diaphragm. SUBSEQUENT MANAGEMENT Both atrial and ventricular wires are brought out through the lower end of the incision, identified with colored tape, and fixed to the patient’s chest wall in such a way that they will not be disturbed by removal of the gauze dressing over the incision. The gauze dressing is generally removed in 24 to 36 hours, and the incision is sprayed with a plastic film. A small gauze bandage is left around the wire sinus tract. This bandage is changed daily by the nursing staff. At this time, the small amount of exudate around the wires is cleansed away, and topical bacitracin and neomycin antibiotic ointment (Spectrocin) is applied to the wire sinus. When not in use, the wires are coiled and taped lightly to the patient’s chest or abdominal wall. When pacing is desired, the wires are connected to the external pulse generator, which is suspended from an I.V. stand or carried in the pocket of the patient’s robe if he is ambulatory. The wires are usually left in place for from 5 to 7 days postoperatively. I n patients who have undergone prosthetic valve replacement and are being started on long-term anticoagulant therapy on the sixth postoperative day, we recommend removal of the wires prior to the achievement of therapeutic anticoagulation. On rare occasions it has been necessary to maintain external pacing in the presence of adequate anticoagulation. Removal of the wires in these instances has not resulted in any complications, but in general we do not recommend this practice. Removal of the electrodes is accomplished by a slow, steady, firm pull on all wires at the same time. Usually, the rhythmic counterpull of the beating heart will be felt easily. A steady, firm pull on the wires, however, will allow the wires to slide free with little, if any, discomfort to the patient. After removal of the wires, the sinus tract is covered for a day or two with an occlusive gauze dressing. COMPLICATIONS Since 1964, pacing wires have been placed in more than 1,000 patients. There have been no deaths attributable to these wires. Four complications have been noted: two bleeding episodes requiring reoperation, one pneumothorax, and one pneumomediastinum following removal of the pacing wires. The first bleeding episode occurred early in our experience after removal of the pacing wires on the seventh postoperative day. Continued loss of arterial blood from the wire sinus tract necessitated reexploration. The bleeding source was found to be a small branch of a coronary artery, and the bleeding was controlled without difficulty. Subsequently, care in avoiding these branches during electrode placement has prevented further complications from this cause. The second bleeding episode occurred in the recovery room immediately after operation. At reexploration a small hole was found in the ascending aorta near the site of placement of the atrial electrode. This hole was presumed to have resulted from erosion of the wire tip through the aorta.
508
THE ANNALS OF THORACIC SURGERY
Postoperatiue Epicardial Pacing One patient developed a right pneumothorax several hours aft pacing wires on the seventh postoperative day. A second patient asymptomatic pneumomediastinum which was found on roentgen0 moval of his pacing wires. Both these complications are believed to have resulted from leakage of air into the thorax through the wire sinus tract. Our practice of draining the pericardium into the right pleural space allowed collapse of the right lung in the case cited. Since these two complications, we have placed small occlusive dressings over the sinus tract for a day or two until it seals. Occasionally, serosanguineous drainage from the sinus tract will be noted for a few days after removal of the wires. In all cases, however, this drainage has ceased spontaneously and no infection that appears related to the wires has occurred in the wound, sternum, or mediastinum.
COMMENT
We have found the temporary epicardial pacing electrodes to be of value in numerous situations common to the postoperative, period following open-heart surgery. Atrial pacing has been found valuable in stabilizing such supraventricular arrhythmias as slow sinus rhythm with nodal escape beats or PVC’s, sinus arrest, PAC’s precipitating atrial tachycardia, and in nodal rhythms with retrograde conduction, A-V dissociation, or atrial standstill. Previous work from this department [2, 31 has emphasized the value of paced atrial contractions in maintaining a more optimal cardiac output following operation. An added value of the intracavitary atrial wire is its ability to function as an atrial electrocardiogram lead for the diagnosis of supraventricular tachycardias. In several instances, patients with atrial fibrillation preoperatively have returned from the operating room in sinus rhythm. Through atrial pacing it has been possible to maintain the sinus rhythm throughout the postoperative period. Ventricular pacing wires originally were used only in patients with complete heart block or in those in whom temporary postsurgical heart block was feared. Experience has proved, however, that these wires are only very rarely needed for such situations, but are commonly of value in other situations. We find the most common use of ventricular pacing to be in patients with slow atrial fibtillation with PVC’s. Ventricular pacemaking in these situations usually will elimihate the PVC’s and allow us to administer digitalis preparations more ”freely if we think the patient’s condition warrants it. SUAIMARY A N D CONCLUSIONS
Temporary atrial or ventricular epicardial pacing electrodes, or both, have been used routinely after open-heart surgery at the University of Oregon Medical School since 1964. These electrodes have proved of value on numerous occasions in stabilizing cardiac rhythm, improving cardiac output, and aiding in the diagnosis of supraventricular VOL.
8,
NO.
6,
DECEMBER,
1969
509
HODAM AND STARR
tachycardias. Our method of placement and subsequent management of these electrodes have been described in detail. In more than 1,000 cases no deaths have resulted from the use of these temporary electrodes. Two bleeding episodes, one pneumothorax, and one pneumomediastinum have been the only four complications. We believe that the value of these temporary epicardial electrodes and the minimal morbidity associated with them warrants their continued use. REFERENCES 1. Friesen, W. G., Woodson, R. D., Ames, A. W., Herr, R. H., Starr, A., and Kassebaum, D. G. A hernodynamic comparison of atrial and ventricular pacing in postoperative cardiac surgical patients. J . Thorac. Cardiovasc. Surg. 55:271, 1968.
2. Woodson, R. D., Friesen, W. G., Herr, R. H., and Starr, A. Postoperative atrial pacing: A new adjuvant in mitral valve surgery. Surg. Forum 19:103, 1968.
3. Woodson, R. D., and Starr, A. Atrial pacing after mitral valve surgery. Arch. Surg. (Chicago) 97:984, 1968.
510
THE ANNALS OF THORACIC SURGERY