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Immediate postoperative digitalization in the prophylaxis of supraventricular arrhythmias following coronary artery bypass
J THORAC CARDIOVASC SURG 81:419-422, 1981
Immediate postoperative digitalization in the prophylaxis of supraventricular arrhythmias following coronary artery bypass Regimens of acute preoperative digitalization have been evaluated previously in the prophylaxis of supraventricular tachycardias (SVT) following coronary artery bypass operations, with equivocal results. This study assesses the effectiveness of immediate postoperative digitalization on the incidence of arrhythmias in 407 consecutive patients recovering from myocardial revascularization, In 137 patients treated by our regimen, which begins digitalization within 4 hours postoperatively, the incidence of supraventricular tachyarrhythmias was 2%, while the corresponding figure for 270 untreated patients was 15%. Digitalization reduced the incidence of supraventricular arrhythmias significantly (p < 0.01), whereas death, ventricular ectopy, and infarction rates were similar in the two groups. The few patients who did have supraventricular arrhythmias while receiving prophylactic digoxin were no more easily treated than patients in the undigitalized group. The timing of administration of digoxin for SVT prophylaxis may be more important than previously recognized. Immediate postoperative digitalization, theoretically preferable to preoperative regimens, is a safe, effective way to reduce the incidence of supraventricular arrhythmias following myocardial revascularization .
John F. Csicsko, M.D.,* Michael H. Schatzlein, M.D.,* and Robert D. King, M.D., Indianapolis, Ind.
Supraventricular tachyarrhythmias frequently complicate the early postoperative course of patients undergoing myocardial revascularization. Attempts to lower the incidence of supraventricular tachycardias (S VT) in these patients by acute preoperative digitalization have had mixed results, 1,2 and the controversy regarding the risk/benefit ratio of prophylactic digitalis in this setting continues. This study was undertaken to assess the effect of immediate postoperative digitalization (begun within the first 4 hours) on the incidence of SVT in patients undergoing coronary artery operations. Patients and methods The study included 407 consecutive patients undergoing elective coronary artery bypass without concomiFrom the Section of Cardiothoracic Surgery, Department of Surgery, Indiana University Medical Center, Indianapolis, Ind. 46202. Received for publication May 2, 1980. Accepted for publication Aug. 4, 1980. Address for reprints: Robert D. King, M. D., Professor of Surgery, Department of Surgery, Indiana University Medical Center, 1100 West Michigan 51., Indianapolis, Ind. 46202. *Present address: The Duemling Clinic, 2828 Fairfield Ave., Fort Wayne, Ind. 46807.
tant procedures (valve replacement, ventricular aneurysmectomy, or others) at the Indiana University Hospital. No patient had a history of treatment for any arrhythmia. Propranolol was discontinued at least I week preoperatively in those patients who had been receiving it, and patients who were receiving digitalis or antiarrhythmic drugs preoperatively were excluded from the study. All patients underwent myocardial revascularization employing cardiopulmonary bypass with topical hypothermia, moderate systemic hypothermia, and intermittent aortic cross-clamping with left ventricular decompression. The study was conducted prior to our adoption of hyperkalemic cold blood cardioplegia. Anesthesia was obtained with oxygen, nitrous oxide, and morphine. Group I patients (n = 137) received 0.5 mg of digoxin intravenously within 4 hours postoperatively, an additional 0.5 mg in divided doses intravenously over the next 12 hours, and 0.25 mg intravenously or by mouth each day for the next 5 weeks. Intravenous potassium chloride was given if necessary to correct the serum potassium level to at least 4.0 mEq/L prior to administration of digoxin. Group II patients (n = 270) received digoxin only as treatment for specific digitalis-
0022-5223/811030419+04$00.4010 © 1981 The C. V. Mosby Co.
419
The Journal of
420
Csicsko, Schatzlein, King
Thoracic and Cardiovascular Surgery
Table I. Population characteristics in 407 patients undergoing myocardial revascularization Group I: Digoxin prophylaxis (n = /37) No.
I
56.2 122 15 41 0
Mean age (yr) Male Female Previous myocardial infarction Prior treatment for supraventricular arrhythmia Prior treatment for ventricular arrhythmia Grafts/patient
Group 1/: No digoxin (n = 270) No.
%
89 II
30
I
55.4 237 33 75 0
0
0
2.4
2.4
%
88 12 28
Results
Table II. Preoperative electrocardiographic findings in 407 patients undergoing myocardial revascularization Group I: Digoxin prophylaxis (n = /37) No. Anterior ischemia Inferior ischemia Anterior infarction, old Inferior infarction, old Right bundle branch block Left bundle branch block Intraventricular conduction delay Sinus arrhythmia Atrial premature depolarization, occasional Ventricular premature depolarizaion, unifocal, occasional * Junctional premature depolarization, occasional First-degree atrioventricular block Pre-excitation, type A
I
Group 1/: No digoxin (n = 270)
%
No.
I
0.7
0 4 37 2 2 4
27 I.5
8 3 13 62
2.9
1.5 2.9
I
3 I 2
%
3.0 I.I 4.8 23 I.I 0.4 0.7 0.4 0.4
0 I
0.7
12
8.8
4
0.7
o
0.7
2
0
referred by one group of cardiologists and were operated upon by the one group of surgeons. Preoperative electrocardiographic findings were comparable between groups and are detailed in Table II. All patients underwent continuous electrocardiographic monitoring for at least 72 hours on units with automatic printout for tachyarrhythmias or bradyarrhythmias. Standard twelve-lead electrocardiograms were obtained preoperatively, daily for 3 days postoperatively, and on the day prior to discharge from the hospital. Following transfer from the intensive care unit and cessation of continuous monitoring, cardiograms and rhythm strips were obtained whenever the pulse became irregular or was recorded to be outside the range of 60 to 120 beats/min.
1.5
0.7 0.4
.p < 0.05 by Fisher's exact test (other differences not significant).
responsive arrhythmias. No patient in either group received propranolol during the period of this study. Group assignment was random, but not formally randomized. However, there were no significant differences between the groups on retrospective analysis of age, sex, history of previous myocardial infarction, or number of vessels bypassed (Table I). All patients were
The arrhythmias observed are presented in Table Ill. The incidence of SVT was 2% in patients receiving prophylactic digoxin (Group I) and 15% in those (Group II) who did not receive the drug (p < 0.01). There was no significant difference in the incidence of ventricular arrhythmia (6% in Group I and 8% in Group II), even though occasional unifocal ventricular premature depolarizations had been noted more frequently on the preoperative tracings of patients who ultimately received digoxin (Table II). Arrhythmias suggesting digitalis toxicity (bidirectional tachycardia, Mobitz I atrioventricular block, paroxysmal atrial tachycardia with block) were not observed in any patient. Perioperative infarction rates (as determined by the development of new Q waves in association with enzyme criteria) and death rates were similar in the two groups (Table IV).
Discussion Supraventricular tachycardias (S VT) complicate the postoperative course of 10% to 15% of patients undergoing myocardial revascularization.v 4 In view of the known beneficial effects of preoperative prophylactic digitalization on the incidence of S VT in patients undergoing general thoracic surgical procedures.v " and because digitalis is the drug of choice in the treatment of S VT, 9, 10 it was inevitable that this mode of therapy would be tried in an effort to reduce the incidence of this complication of coronary operations. Johnson and associates I noted a pronounced reduction in the incidence of S VT in a group of patients given digitalis prior to coronary artery bypass. On the other hand, several factors weigh against routine prophylactic digitalization immediately before cardiac operations. At least two studies have shown considerable variations in digoxin blood levels associated with cardiopulmonary bypass,": 12 and bypass-
Volume 81 Number 3 March,1981
related alterations in renal function have also been documented.'" The effects of cold potassium cardioplegia on myocardial digoxin levels have yet to be explored. Mason and colleagues H suggested increased myocardial sensitivity to the toxic effects of digitalis during bypass and the first 24 hours thereafter. Losses of potassium tend to occur as a result of the diuresis accompanying hemodilution perfusion, 11 and such losses may potentiate digitalis toxicity. H. 15 Krasula and associates 16 showed that acute digitalization leads to high myocardial concentrations of digoxin, which might potentiate irritability during intraoperative manipulation. Selzer and co-workers'? have made the point that the possibility of digitalis toxicity does not confuse the differential diagnosis of arrhythmia in the patient who has received no digitalis. Finally, Tyras and associates" recently reported a prospective study of acute preoperative digitalization of coronary bypass patients in which they found a significant increase in the incidence of SVT in the treated group. We felt that many of the objections to prophylactic digitalization could be overcome by deferring the administration of digitalis until the immediate postoperative period, beginning as soon as the patient's condition has stabilized off bypass and the serum potassium has been shown to be normal. This has provided excellent SVT prophylaxis, and toxicity has not been a problem. Although digitalis toxicity has been shown to cause virtually any and all arrhythmias, 10 our patients did not have problems in which the decision as to whether to withhold digitalis or give more of the drug was a difficult one. Routine use of temporary atrial pacing wires for recording the atrial electrogram, as described by Waldo and associates.!" has increased diagnostic accuracy for supraventricular versus ventricular arrhythmias, and all of the troublesome supraventricular arrhythmias in our series were associated with a rapid ventricular response indicating the need for more digitalis. While some authors" 6. 19 have reported greater ease of control of S VT which did develop in patients given digitalis prophylactically, this was not the case in our patients. Atrial arrhythmias were rare in patients receiving digitalis, but when they did occur they necessitated repeated additional doses of digoxin, quinidine, and/or cardioversion. Conversely, ventricular arrhythmias in our patients, whether given digitalis or not, responded readily to lidocaine. In conclusion, we feel that the conflicting data regarding the efficacy of digoxin prophylaxis in coronary bypass patients may be related at least in part to the timing of the digitalization. Immediate postoperati ve treatment with digoxin in the dosage schedules outlined
Supraventricular arrhythmias after coronary bypass
42 1
Table III. Postoperative arrhythmias in 407 patients undergoing myocardial revascularization Group I: Digoxin prophylaxis (n = /37) No.
Atrial fibrillation* Atrial flutter" Paroxysmal atrial tachycardia* Total supraventricular* Ventricular tachycardia Ventricular fibrillation VPD necessitating treatment (R on T, multifocal, coupling, or frequency > six/minute) Total ventricular
I
Group II: No digoxin (n = 270)
I
%
No.
2 I 0
1.5 0.7
16 17 8
5.9 6.3 3.0
3
2.2
41
15.2
I 7
0.8 5.0
2 4 15
0.7 1.1 5.6
8
5.8
21
7.8
0
%
Legend: VPD, Ventricular premature depolarization. *p < 0.01 by Fisher's exact test (other differences not significant).
Table IV. Death and infarction rates in 407 patients undergoing myocardial revascularization Group I: Digoxin prophylaxis (n = /37) No.
Perioperative myocardial infarction Hospital death
I
Group II: No digoxin (n = 270)
I
%
No.
0.7
2
0.7
0.7
3
1.1
%
herein is theoretically preferable to acute preoperative digitalization and appears to be clinically safe and effective in SVT prophylaxis. REFERENCES Johnson LW, Dickstein RA, Fruehan CT, et al: Prophylactic digitalization for coronary artery bypass surgery. Circulation 53:819, 1976 2 Tyras DH, Stothert JC Jr, Kaiser GC, Barner HB, Codd JE, Willman VL: Supraventricular tachyarrhythmias after myocardial revascularization. A randomized trial of prophylactic digitalization. J THORAC CARDIOVASC SURG 77:310, 1979 3 Cheanvechai C, Effler DB, Groves LK, et al: Triple bypass graft for the treatment of severe triple coronary vessel disease. Ann Thorac Surg 17:545, 1974 4 Wisoff BG, Harstein ML, Aintablian A, Hamby RI: Risk of coronary surgery. J THORAC CARDIOVASC SURG 69:669, 1975
The Journal of
422
Csicsko, Schatzlein, King
Thoracic and Cardiovascular Surgery
5 Burman SO: The prophylactic use of digitalis before thoracotomy. Ann Thorac Surg 14:359, 1972 6 Kirsh MM, Rotman H, Behrendt DM, et al: Complications of pulmonary resection. Ann Thorac Surg 20:215, 1975 7 Shields TW, Ujiki GT: Digitalization for prevention of arrhythmias following pulmonary surgery. Surg Gynecol Obstet 126:743, 1968 8 Wheat MW, Burford TH: Digitalis in surgery. Extension of classical indications. J THORAC CARDIOVASC SURG 41:162, 1961 9 Selzer A, Kelly 11: Action of digitalis upon the nofailing heart. A critical review. Prog Cardiovasc Dis 7:273, 1964 10 Smith TW: Digitalis glycosides. N Engl J Med 288:719, 1973 II Chamberlain DA: The influence of cardiopulmonary bypass on plasma digoxin concentrations, Symposium on Digitalis, 0 Storsteon, ed., Oslo, 1973, Glydendal Norsk Forlag 12 Morrison J, Killip T: Serum digitalis and arrhythmia in patients undergoing cardiopulmonary bypass. Circulation 47:341, 1973 13 Porter GA, Kloster FE, Herr RJ, et al: Relationship be-
14 15
16
17
18
19
tween alterations in renal hemodynamics during cardiopulmonary bypass and postoperative renal function. Circulation 34: 1005, 1966 Mason DT, Zelis R, Lee G, et al: Current concepts and treatment of digitalis toxicity. Am J CardioI27:546, 1971 Rodman T, Pastor BH: The hemodynamic effect of digitalis in normal and diseased heart. Am J Heart 65:564, 1963 Krasula RW, Hastreiter AR, Levitsky S, et al: Serum, atrial, and urinary digoxin levels during cardiopulmonary bypass in children. Circulation 49: 1047, 1974 Selzer A, Kelly 11, Gerbode F, et al: Case against routine use of digitalis in patients undergoing cardiac surgery. JAMA 195:141,1966 Waldo AL, MacLean WAH, Cooper TB, Kouchoukos NT, Karp RB: Use of temporarily placed epicardial atrial wire electrodes for the diagnosis and treatment of cardiac arrhythmias following open-heart surgery. J THORAC CARDIOVASC SURG 76:500, 1978 Selzer A, Walter RM: Adequacy of preoperative digitalis therapy in controlling ventricular rate in postoperative atrial fibrillation. Circulation 34: 119, 1966
Immediate postoperative digitalization in the prophylaxis of supraventricular arrhythmias following coronary artery bypass Regimens of acute preoperative digitalization have been evaluated previously in the prophylaxis of supraventricular tachycardias (SVT) following coronary artery bypass operations, with equivocal results. This study assesses the effectiveness of immediate postoperative digitalization on the incidence of arrhythmias in 407 consecutive patients recovering from myocardial revascularization, In 137 patients treated by our regimen, which begins digitalization within 4 hours postoperatively, the incidence of supraventricular tachyarrhythmias was 2%, while the corresponding figure for 270 untreated patients was 15%. Digitalization reduced the incidence of supraventricular arrhythmias significantly (p < 0.01), whereas death, ventricular ectopy, and infarction rates were similar in the two groups. The few patients who did have supraventricular arrhythmias while receiving prophylactic digoxin were no more easily treated than patients in the undigitalized group. The timing of administration of digoxin for SVT prophylaxis may be more important than previously recognized. Immediate postoperative digitalization, theoretically preferable to preoperative regimens, is a safe, effective way to reduce the incidence of supraventricular arrhythmias following myocardial revascularization .
John F. Csicsko, M.D.,* Michael H. Schatzlein, M.D.,* and Robert D. King, M.D., Indianapolis, Ind.
Supraventricular tachyarrhythmias frequently complicate the early postoperative course of patients undergoing myocardial revascularization. Attempts to lower the incidence of supraventricular tachycardias (S VT) in these patients by acute preoperative digitalization have had mixed results, 1,2 and the controversy regarding the risk/benefit ratio of prophylactic digitalis in this setting continues. This study was undertaken to assess the effect of immediate postoperative digitalization (begun within the first 4 hours) on the incidence of SVT in patients undergoing coronary artery operations. Patients and methods The study included 407 consecutive patients undergoing elective coronary artery bypass without concomiFrom the Section of Cardiothoracic Surgery, Department of Surgery, Indiana University Medical Center, Indianapolis, Ind. 46202. Received for publication May 2, 1980. Accepted for publication Aug. 4, 1980. Address for reprints: Robert D. King, M. D., Professor of Surgery, Department of Surgery, Indiana University Medical Center, 1100 West Michigan 51., Indianapolis, Ind. 46202. *Present address: The Duemling Clinic, 2828 Fairfield Ave., Fort Wayne, Ind. 46807.
tant procedures (valve replacement, ventricular aneurysmectomy, or others) at the Indiana University Hospital. No patient had a history of treatment for any arrhythmia. Propranolol was discontinued at least I week preoperatively in those patients who had been receiving it, and patients who were receiving digitalis or antiarrhythmic drugs preoperatively were excluded from the study. All patients underwent myocardial revascularization employing cardiopulmonary bypass with topical hypothermia, moderate systemic hypothermia, and intermittent aortic cross-clamping with left ventricular decompression. The study was conducted prior to our adoption of hyperkalemic cold blood cardioplegia. Anesthesia was obtained with oxygen, nitrous oxide, and morphine. Group I patients (n = 137) received 0.5 mg of digoxin intravenously within 4 hours postoperatively, an additional 0.5 mg in divided doses intravenously over the next 12 hours, and 0.25 mg intravenously or by mouth each day for the next 5 weeks. Intravenous potassium chloride was given if necessary to correct the serum potassium level to at least 4.0 mEq/L prior to administration of digoxin. Group II patients (n = 270) received digoxin only as treatment for specific digitalis-
0022-5223/811030419+04$00.4010 © 1981 The C. V. Mosby Co.
419
The Journal of
420
Csicsko, Schatzlein, King
Thoracic and Cardiovascular Surgery
Table I. Population characteristics in 407 patients undergoing myocardial revascularization Group I: Digoxin prophylaxis (n = /37) No.
I
56.2 122 15 41 0
Mean age (yr) Male Female Previous myocardial infarction Prior treatment for supraventricular arrhythmia Prior treatment for ventricular arrhythmia Grafts/patient
Group 1/: No digoxin (n = 270) No.
%
89 II
30
I
55.4 237 33 75 0
0
0
2.4
2.4
%
88 12 28
Results
Table II. Preoperative electrocardiographic findings in 407 patients undergoing myocardial revascularization Group I: Digoxin prophylaxis (n = /37) No. Anterior ischemia Inferior ischemia Anterior infarction, old Inferior infarction, old Right bundle branch block Left bundle branch block Intraventricular conduction delay Sinus arrhythmia Atrial premature depolarization, occasional Ventricular premature depolarizaion, unifocal, occasional * Junctional premature depolarization, occasional First-degree atrioventricular block Pre-excitation, type A
I
Group 1/: No digoxin (n = 270)
%
No.
I
0.7
0 4 37 2 2 4
27 I.5
8 3 13 62
2.9
1.5 2.9
I
3 I 2
%
3.0 I.I 4.8 23 I.I 0.4 0.7 0.4 0.4
0 I
0.7
12
8.8
4
0.7
o
0.7
2
0
referred by one group of cardiologists and were operated upon by the one group of surgeons. Preoperative electrocardiographic findings were comparable between groups and are detailed in Table II. All patients underwent continuous electrocardiographic monitoring for at least 72 hours on units with automatic printout for tachyarrhythmias or bradyarrhythmias. Standard twelve-lead electrocardiograms were obtained preoperatively, daily for 3 days postoperatively, and on the day prior to discharge from the hospital. Following transfer from the intensive care unit and cessation of continuous monitoring, cardiograms and rhythm strips were obtained whenever the pulse became irregular or was recorded to be outside the range of 60 to 120 beats/min.
1.5
0.7 0.4
.p < 0.05 by Fisher's exact test (other differences not significant).
responsive arrhythmias. No patient in either group received propranolol during the period of this study. Group assignment was random, but not formally randomized. However, there were no significant differences between the groups on retrospective analysis of age, sex, history of previous myocardial infarction, or number of vessels bypassed (Table I). All patients were
The arrhythmias observed are presented in Table Ill. The incidence of SVT was 2% in patients receiving prophylactic digoxin (Group I) and 15% in those (Group II) who did not receive the drug (p < 0.01). There was no significant difference in the incidence of ventricular arrhythmia (6% in Group I and 8% in Group II), even though occasional unifocal ventricular premature depolarizations had been noted more frequently on the preoperative tracings of patients who ultimately received digoxin (Table II). Arrhythmias suggesting digitalis toxicity (bidirectional tachycardia, Mobitz I atrioventricular block, paroxysmal atrial tachycardia with block) were not observed in any patient. Perioperative infarction rates (as determined by the development of new Q waves in association with enzyme criteria) and death rates were similar in the two groups (Table IV).
Discussion Supraventricular tachycardias (S VT) complicate the postoperative course of 10% to 15% of patients undergoing myocardial revascularization.v 4 In view of the known beneficial effects of preoperative prophylactic digitalization on the incidence of S VT in patients undergoing general thoracic surgical procedures.v " and because digitalis is the drug of choice in the treatment of S VT, 9, 10 it was inevitable that this mode of therapy would be tried in an effort to reduce the incidence of this complication of coronary operations. Johnson and associates I noted a pronounced reduction in the incidence of S VT in a group of patients given digitalis prior to coronary artery bypass. On the other hand, several factors weigh against routine prophylactic digitalization immediately before cardiac operations. At least two studies have shown considerable variations in digoxin blood levels associated with cardiopulmonary bypass,": 12 and bypass-
Volume 81 Number 3 March,1981
related alterations in renal function have also been documented.'" The effects of cold potassium cardioplegia on myocardial digoxin levels have yet to be explored. Mason and colleagues H suggested increased myocardial sensitivity to the toxic effects of digitalis during bypass and the first 24 hours thereafter. Losses of potassium tend to occur as a result of the diuresis accompanying hemodilution perfusion, 11 and such losses may potentiate digitalis toxicity. H. 15 Krasula and associates 16 showed that acute digitalization leads to high myocardial concentrations of digoxin, which might potentiate irritability during intraoperative manipulation. Selzer and co-workers'? have made the point that the possibility of digitalis toxicity does not confuse the differential diagnosis of arrhythmia in the patient who has received no digitalis. Finally, Tyras and associates" recently reported a prospective study of acute preoperative digitalization of coronary bypass patients in which they found a significant increase in the incidence of SVT in the treated group. We felt that many of the objections to prophylactic digitalization could be overcome by deferring the administration of digitalis until the immediate postoperative period, beginning as soon as the patient's condition has stabilized off bypass and the serum potassium has been shown to be normal. This has provided excellent SVT prophylaxis, and toxicity has not been a problem. Although digitalis toxicity has been shown to cause virtually any and all arrhythmias, 10 our patients did not have problems in which the decision as to whether to withhold digitalis or give more of the drug was a difficult one. Routine use of temporary atrial pacing wires for recording the atrial electrogram, as described by Waldo and associates.!" has increased diagnostic accuracy for supraventricular versus ventricular arrhythmias, and all of the troublesome supraventricular arrhythmias in our series were associated with a rapid ventricular response indicating the need for more digitalis. While some authors" 6. 19 have reported greater ease of control of S VT which did develop in patients given digitalis prophylactically, this was not the case in our patients. Atrial arrhythmias were rare in patients receiving digitalis, but when they did occur they necessitated repeated additional doses of digoxin, quinidine, and/or cardioversion. Conversely, ventricular arrhythmias in our patients, whether given digitalis or not, responded readily to lidocaine. In conclusion, we feel that the conflicting data regarding the efficacy of digoxin prophylaxis in coronary bypass patients may be related at least in part to the timing of the digitalization. Immediate postoperati ve treatment with digoxin in the dosage schedules outlined
Supraventricular arrhythmias after coronary bypass
42 1
Table III. Postoperative arrhythmias in 407 patients undergoing myocardial revascularization Group I: Digoxin prophylaxis (n = /37) No.
Atrial fibrillation* Atrial flutter" Paroxysmal atrial tachycardia* Total supraventricular* Ventricular tachycardia Ventricular fibrillation VPD necessitating treatment (R on T, multifocal, coupling, or frequency > six/minute) Total ventricular
I
Group II: No digoxin (n = 270)
I
%
No.
2 I 0
1.5 0.7
16 17 8
5.9 6.3 3.0
3
2.2
41
15.2
I 7
0.8 5.0
2 4 15
0.7 1.1 5.6
8
5.8
21
7.8
0
%
Legend: VPD, Ventricular premature depolarization. *p < 0.01 by Fisher's exact test (other differences not significant).
Table IV. Death and infarction rates in 407 patients undergoing myocardial revascularization Group I: Digoxin prophylaxis (n = /37) No.
Perioperative myocardial infarction Hospital death
I
Group II: No digoxin (n = 270)
I
%
No.
0.7
2
0.7
0.7
3
1.1
%
herein is theoretically preferable to acute preoperative digitalization and appears to be clinically safe and effective in SVT prophylaxis. REFERENCES Johnson LW, Dickstein RA, Fruehan CT, et al: Prophylactic digitalization for coronary artery bypass surgery. Circulation 53:819, 1976 2 Tyras DH, Stothert JC Jr, Kaiser GC, Barner HB, Codd JE, Willman VL: Supraventricular tachyarrhythmias after myocardial revascularization. A randomized trial of prophylactic digitalization. J THORAC CARDIOVASC SURG 77:310, 1979 3 Cheanvechai C, Effler DB, Groves LK, et al: Triple bypass graft for the treatment of severe triple coronary vessel disease. Ann Thorac Surg 17:545, 1974 4 Wisoff BG, Harstein ML, Aintablian A, Hamby RI: Risk of coronary surgery. J THORAC CARDIOVASC SURG 69:669, 1975
The Journal of
422
Csicsko, Schatzlein, King
Thoracic and Cardiovascular Surgery
5 Burman SO: The prophylactic use of digitalis before thoracotomy. Ann Thorac Surg 14:359, 1972 6 Kirsh MM, Rotman H, Behrendt DM, et al: Complications of pulmonary resection. Ann Thorac Surg 20:215, 1975 7 Shields TW, Ujiki GT: Digitalization for prevention of arrhythmias following pulmonary surgery. Surg Gynecol Obstet 126:743, 1968 8 Wheat MW, Burford TH: Digitalis in surgery. Extension of classical indications. J THORAC CARDIOVASC SURG 41:162, 1961 9 Selzer A, Kelly 11: Action of digitalis upon the nofailing heart. A critical review. Prog Cardiovasc Dis 7:273, 1964 10 Smith TW: Digitalis glycosides. N Engl J Med 288:719, 1973 II Chamberlain DA: The influence of cardiopulmonary bypass on plasma digoxin concentrations, Symposium on Digitalis, 0 Storsteon, ed., Oslo, 1973, Glydendal Norsk Forlag 12 Morrison J, Killip T: Serum digitalis and arrhythmia in patients undergoing cardiopulmonary bypass. Circulation 47:341, 1973 13 Porter GA, Kloster FE, Herr RJ, et al: Relationship be-
14 15
16
17
18
19
tween alterations in renal hemodynamics during cardiopulmonary bypass and postoperative renal function. Circulation 34: 1005, 1966 Mason DT, Zelis R, Lee G, et al: Current concepts and treatment of digitalis toxicity. Am J CardioI27:546, 1971 Rodman T, Pastor BH: The hemodynamic effect of digitalis in normal and diseased heart. Am J Heart 65:564, 1963 Krasula RW, Hastreiter AR, Levitsky S, et al: Serum, atrial, and urinary digoxin levels during cardiopulmonary bypass in children. Circulation 49: 1047, 1974 Selzer A, Kelly 11, Gerbode F, et al: Case against routine use of digitalis in patients undergoing cardiac surgery. JAMA 195:141,1966 Waldo AL, MacLean WAH, Cooper TB, Kouchoukos NT, Karp RB: Use of temporarily placed epicardial atrial wire electrodes for the diagnosis and treatment of cardiac arrhythmias following open-heart surgery. J THORAC CARDIOVASC SURG 76:500, 1978 Selzer A, Walter RM: Adequacy of preoperative digitalis therapy in controlling ventricular rate in postoperative atrial fibrillation. Circulation 34: 119, 1966