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Revascularization after acute myocardial infarction
MEDICAL-SURGICAL Isolated Right Atrial Tamponade Surgery: Role of Echocardiography and Management
CONSIDERATIONS potassium chloride infusion. Otherwise there were no significant differences in regard to incidence of heart block, temporary epicardial pacing, myocardial infarction, or atria1 fibrillation between the two groups. Conclusions: Conversion of postischemic ventricular fibrillation with potassium chloride administered through the arterial line from the heartlung machine is an effective, gentle, and convenient method. No side effects were noted.
After Open Heart in Diagnosis
H.E. Saner, J.D. Olson, I.F. Goldenberg, RW. Asinger. Kantonrrpital, Olten, Switierland. Cardiology I995;86:464 -72.
Ten patients with isolated right atria1 tamponade complicating open heart surgery were identified over a 3.5-year period at three institutions. Clinical manifestations varied but were typically those of decreased perfusion with elevated central venous pressure. Hemodynamically these patients had systemic hypotension and tachycardia with elevated central venous pressure but without elevation of pulmonary artery or pulmonary artery wedge pressures. The correct diagnosis in each case was established by echocardiography; 7 via the transthoracic and 3 via the transesophageal approach. The typical echocardiographic feature was an extrinsic extracardisc mass compressing the atrium. Doppler findings included high flow velocities through the right atria, and color flow demonstrated narrow color jets through compressed, slit-like right atria. Surgical exploration confirmed these findings in each case. We conclude that the combination of clinical awareness and appropriate hemodynamic evaluation can alert the physician to the possibility of isolated right atria1 hematoma causing decreased perfusion and/or shock following open heart surgery. Echocardiography using either the transthoracic or transesophageal approach can establish the diagnosis and lead to timely surgical intervention.
Conversion of Postischemic Ventricular With lntraaortic Infusion of Potassium
Coronary Artery Bypass Failure of lntracoronary
Background: Ventricular fibrillation after declamping of the aorta after cardioplegic arrest is commonly managed by direct-current countershock. However, in coronary artery bypass grafting, placement of the electrodes can cause mechanical damage to the grafts and anastomoses, and the surgical procedure must be interrupted. As an alternative, intraaortic infusion of potassium chloride through the arterial line from the heart-lung machine was investigated. Methods: In a series of 100 patients with postischemic ventricular fibrillation (group P), 20 mmol of potassium chloride (plus 10 mmol later if necessary) was added to the oxygenator reservoir and perfused through the arterial line into the proximal aorta. The results were compared with those in a matched control group of 100 patients primarily treated with direct-current countershock (group DC). Results: In group P, the ventricular fibrillation was effectively converted to a supraventricular rhythm m 82% of the patients. The remaining 18 patients required significantly (p < 0.005) fewer electric shocks than the patients in group DC. Serum K+ levels were slightly elevated for a short period after the JOURNAL
After
Background: Intracoronary stents are being used to treat acute and threatened closure after percutaneous transluminal coronary angioplasty and to prevent restenosis. Methods: The outcomes of 68 patients having coronary artery bypass grafting after stent placement were reviewed. The mean age was 60.5 t 9.7 years, and 71% were male. Thirty-seven percent had hypertension, 13% had diabetes, 62% had class III or IV angina, 60% had multivessel disease, and 40% had sustained a prior myocardial infarction. Fifty-three patients underwent emergency operation, 22 with hemodynamic collapse immediately after percutaneous transluminal coronary angioplasty, and 7 others required urgent revascularization within 24 hours of angioplasty. Seventeen underwent coronary artery bypass grafting for acme closure of the stented vessel several days after the angioplasty procedure. Results: There was no correlation between urgency of the procedure, previous infarction, or previous coronary artery bypass grafting with successful procedure. The in-hospital mortality was 4.4%, 21% had a Q-wave myocardial infarction, and 1.5% sustained a stroke. Ejection fraction was the only correlate of long-term mortality. Conclusions: Coronary artery injury for which stents are placed for acute or threatened occlusion or to prevent restenosis but then fail, thus necessitating coronar>i artery bypass grafting, can be treated successfully. Although the rate of Q-wave myocardial infarction is substantial and related to the initial ischemic insult, the long-term survival and event rates are excellent with prompt surgical revascularization.
Fibrillation Chloride
CLIRRENT
in Patients
J.M. Craver, A.G. Justis W.S. Weintraub, Y. Shen. RA. Guyton, J.P. GOD E.L Jones. Emory Clinic Inc., Atlanta, GA Ann Thorac Surg 1995;60:60-6.
E. Ovrum, G. Tangen, E.A. Holen. H.-AL Ringdal, R Istad. Oslo Heart Center, Oslo, Norway. Ann Thorac Surg I995;60:156-9.
KC
Grafting Stenting
Revascularization After Acute Myocardial Infarction LL Crerwell, M.J. Moulton, J.L (ox, Il. Rosenbloom. Division of Cardiothoradc Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO. Ann Thotac Surg 1995;60:19-26.
Background: The optimal timing for coronary artery bypass grafting (CABG) after acute myocardial infarction (MI) remains controversial. Methods: We examined our experience retrospectively in 3,942 patients who underwent CABG between 1986 and 1993, including 2,296 patients after REVIEW
45
January/February
1996
MEDICAL-SURGICAL
CONSIDERATIONS
acute MI. Results: The operative mortality associated with increasing time intervals between MI and CABG were 9.1%, 8.3%, 5.2%, 6.5%, and 2.9%, for less than 6 hours, 6 hours to 2 days, 2 to 14 days, 2 to 6 weeks, and more than 6 weeks, respectively. In comparison, the operative mortality was 2.5% for patients with no history of acute MI. The incidence of permanent stroke and perioperative MI were greater and the length of postoperative hospitalization was longer for patients undergoing CABG early after MI. For patients undergoing operation electively, however, the operative mortality associated with increasing time intervals between MI and CABG were less, at O.O%, 3.6%, 2.1%, 6.4%, and 2.1% for less than 6 hours, 6 hours to 2 days, 2 to 14 days, 2 to 6 weeks, and more than 6 weeks, respectively. For patients undergoing CABG within 14 days of MI, the operative mortality was 5.3% for those receiving an intraaortic balloon pump preoperatively for postinfarction angina, but 11.8% for those who underwent urgent/emergent operation without intraaortic balloon pump support. Conclusions: Elective CABG can be accomplished with acceptable morbidity and mortality early after acute MI if an elective operation is possible. In addition, the intraaortic balloon pump should be used aggressively in patients with postinfarction angina to allow for elective rather than urgent/emergent operation.
unchanged compared with preoperative studies among patients with leaflet flail (jet diameter 1.04 f 0.26 vs 1.10 f 0.28 cm, area 9.8 t 4.5 vs 10.1 f- 5.2 cm’ on preoperative studies), although jet size decreased significantly in patients with functional MR (jet diameter 0.79 + 0.33 vs 1.10 -+ 0.29 cm [p < O.OOl], area 5.7 t 3.5 vs 10.0 ? 3.8 cm2 [p < O.OOl] on preoperative studies). These findings were not accounted for by variation in heart rate, blood pressure, echocardiographic instrumentation, or Doppler Nyquist limit, General anesthesia is associated with decrease in regurgitation severity in patients with functional MR. Decisions regarding surgical intervention for functional MR should be made before induction of general anesthesia.
Percutaneous Transluminal Coronary Failures in Patients With Multivessel There an Increased Risk?
N. Wang, S.R Gundry, G. Van Arrdell, A.J. Bazzouk, A.C. Hill, M. Sjolander, KA. Cavazos, J.M. Brewer, E.E. Vyhmeirter, LL Bailey, 1.L Grover, A. El Gamel, W. DembitsQ. Division of Cardiothoracic Surgery, Department of Surgety, Loma Linda University Medical Center, loma Linda, CA. J lhorac Cardiovax Surg 1995;110:214-23.
In recent years, there has been a nationwide trend toward performing percutaneous transluminal coronary angioplasty in patients with multivessel coronary artery disease. The clinical course of 57 consecutive patients who required emergency first-time coronary artery bypass grafting operations were reviewed to assess for difference in outcome between the 28 patients (49%) with single-vessel disease and the 29 patients (5 1%) with multivessel disease. The two groups were similar in preoperative characteristics except for a higher proportion of chronic obstructive pulmonary disease in the patients with multivessel disease (p = 0.03). Twice as many patients with multivessel disease were in shock (single-vessel disease = 4 [14%], multivessel disease = 8 [28%], p = not significant) en route to the operating room and significantly more patients with multivessel disease required ongoing cardiopulmonary resuscitation (single-vessel disease = 0 [O%], multivessel disease = 5 [ 17%], p = 0.03). Significantly more coronary artery bypass grafts were placed in the patients with multivessel disease (single-vessel disease = 1.5 -+ 0.6, multivessel disease = 2.9 + 0.7, p < O.Ol>, which required longer aortic clamping time (p = 0.02) and cardiopulmonary bypass time (p < 0.01). There were seven postoperative deaths; all but one occurred in patients with multivessel disease (single-vessel disease = 1 [4%], multivessel disease = 6 [21%1, p = 0.05). According to multivariate analysis, incremental risk factors of mortality were preoperative shock (p < O.Ol), urgent or emergency percutaneous transluminal coronary angioplasty (p = 0.06), and multivessel disease (p = 0.12). Despite a similar incidence of myocardial infarction (single-vessel dis-
Accuracy of lntraoperative Echocardiography Functional Mitral
Transesophageal for Estimating the Severity Regurgitation
of
D.S. Bach, G.M. Deeb, S.F. Boiling. University of Michigan, Ann Arbor, MI. Am ) Cardiol 1995;76:508-12.
Although intraoperative transesophageal echocardiography (TEE) is used to guide mitral valve reconstructive procedures, the effects of hemodynamic alterations accompanying general anesthesia on mitral regurgitation (MR) are unknown. This study was performed to evaluate the effect of general anesthesia on MR jet size using TEE with color Doppler imaging patients undergoing mitral valve surgery, Matched preoperative TEES performed with the patient under intravenous conscious sedation, and intraoperative studies performed with the patient under general anesthesia were retrospectively reviewed in 46 patients undergoing mitral valve surgery. Patients were divided into groups based on etiology of MR, including 2 1 patients with myxomatous degeneration and leaflet flail, 19 patients with structurally normal leaflets and functional regurgitation due to abnormal leaflet coaptation, and 6 patients with rheumatic mitral disease. On both preoperative and intraoperative studies, regurgitation was quantified using maximal jet area and jet diameter at the vena contracta on color flow Doppler. Patients with leaflet flail and patients with functional MR had similar measures of regurgitation severity on preoperative imaging. On intraoperative imaging, regurgitant jet size was ACC CURRENT
JOURNAL
Angioplasty Disease: Is
REVIEW
46
January/Februar),
1996
CONSIDERATIONS potassium chloride infusion. Otherwise there were no significant differences in regard to incidence of heart block, temporary epicardial pacing, myocardial infarction, or atria1 fibrillation between the two groups. Conclusions: Conversion of postischemic ventricular fibrillation with potassium chloride administered through the arterial line from the heartlung machine is an effective, gentle, and convenient method. No side effects were noted.
After Open Heart in Diagnosis
H.E. Saner, J.D. Olson, I.F. Goldenberg, RW. Asinger. Kantonrrpital, Olten, Switierland. Cardiology I995;86:464 -72.
Ten patients with isolated right atria1 tamponade complicating open heart surgery were identified over a 3.5-year period at three institutions. Clinical manifestations varied but were typically those of decreased perfusion with elevated central venous pressure. Hemodynamically these patients had systemic hypotension and tachycardia with elevated central venous pressure but without elevation of pulmonary artery or pulmonary artery wedge pressures. The correct diagnosis in each case was established by echocardiography; 7 via the transthoracic and 3 via the transesophageal approach. The typical echocardiographic feature was an extrinsic extracardisc mass compressing the atrium. Doppler findings included high flow velocities through the right atria, and color flow demonstrated narrow color jets through compressed, slit-like right atria. Surgical exploration confirmed these findings in each case. We conclude that the combination of clinical awareness and appropriate hemodynamic evaluation can alert the physician to the possibility of isolated right atria1 hematoma causing decreased perfusion and/or shock following open heart surgery. Echocardiography using either the transthoracic or transesophageal approach can establish the diagnosis and lead to timely surgical intervention.
Conversion of Postischemic Ventricular With lntraaortic Infusion of Potassium
Coronary Artery Bypass Failure of lntracoronary
Background: Ventricular fibrillation after declamping of the aorta after cardioplegic arrest is commonly managed by direct-current countershock. However, in coronary artery bypass grafting, placement of the electrodes can cause mechanical damage to the grafts and anastomoses, and the surgical procedure must be interrupted. As an alternative, intraaortic infusion of potassium chloride through the arterial line from the heart-lung machine was investigated. Methods: In a series of 100 patients with postischemic ventricular fibrillation (group P), 20 mmol of potassium chloride (plus 10 mmol later if necessary) was added to the oxygenator reservoir and perfused through the arterial line into the proximal aorta. The results were compared with those in a matched control group of 100 patients primarily treated with direct-current countershock (group DC). Results: In group P, the ventricular fibrillation was effectively converted to a supraventricular rhythm m 82% of the patients. The remaining 18 patients required significantly (p < 0.005) fewer electric shocks than the patients in group DC. Serum K+ levels were slightly elevated for a short period after the JOURNAL
After
Background: Intracoronary stents are being used to treat acute and threatened closure after percutaneous transluminal coronary angioplasty and to prevent restenosis. Methods: The outcomes of 68 patients having coronary artery bypass grafting after stent placement were reviewed. The mean age was 60.5 t 9.7 years, and 71% were male. Thirty-seven percent had hypertension, 13% had diabetes, 62% had class III or IV angina, 60% had multivessel disease, and 40% had sustained a prior myocardial infarction. Fifty-three patients underwent emergency operation, 22 with hemodynamic collapse immediately after percutaneous transluminal coronary angioplasty, and 7 others required urgent revascularization within 24 hours of angioplasty. Seventeen underwent coronary artery bypass grafting for acme closure of the stented vessel several days after the angioplasty procedure. Results: There was no correlation between urgency of the procedure, previous infarction, or previous coronary artery bypass grafting with successful procedure. The in-hospital mortality was 4.4%, 21% had a Q-wave myocardial infarction, and 1.5% sustained a stroke. Ejection fraction was the only correlate of long-term mortality. Conclusions: Coronary artery injury for which stents are placed for acute or threatened occlusion or to prevent restenosis but then fail, thus necessitating coronar>i artery bypass grafting, can be treated successfully. Although the rate of Q-wave myocardial infarction is substantial and related to the initial ischemic insult, the long-term survival and event rates are excellent with prompt surgical revascularization.
Fibrillation Chloride
CLIRRENT
in Patients
J.M. Craver, A.G. Justis W.S. Weintraub, Y. Shen. RA. Guyton, J.P. GOD E.L Jones. Emory Clinic Inc., Atlanta, GA Ann Thorac Surg 1995;60:60-6.
E. Ovrum, G. Tangen, E.A. Holen. H.-AL Ringdal, R Istad. Oslo Heart Center, Oslo, Norway. Ann Thorac Surg I995;60:156-9.
KC
Grafting Stenting
Revascularization After Acute Myocardial Infarction LL Crerwell, M.J. Moulton, J.L (ox, Il. Rosenbloom. Division of Cardiothoradc Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO. Ann Thotac Surg 1995;60:19-26.
Background: The optimal timing for coronary artery bypass grafting (CABG) after acute myocardial infarction (MI) remains controversial. Methods: We examined our experience retrospectively in 3,942 patients who underwent CABG between 1986 and 1993, including 2,296 patients after REVIEW
45
January/February
1996
MEDICAL-SURGICAL
CONSIDERATIONS
acute MI. Results: The operative mortality associated with increasing time intervals between MI and CABG were 9.1%, 8.3%, 5.2%, 6.5%, and 2.9%, for less than 6 hours, 6 hours to 2 days, 2 to 14 days, 2 to 6 weeks, and more than 6 weeks, respectively. In comparison, the operative mortality was 2.5% for patients with no history of acute MI. The incidence of permanent stroke and perioperative MI were greater and the length of postoperative hospitalization was longer for patients undergoing CABG early after MI. For patients undergoing operation electively, however, the operative mortality associated with increasing time intervals between MI and CABG were less, at O.O%, 3.6%, 2.1%, 6.4%, and 2.1% for less than 6 hours, 6 hours to 2 days, 2 to 14 days, 2 to 6 weeks, and more than 6 weeks, respectively. For patients undergoing CABG within 14 days of MI, the operative mortality was 5.3% for those receiving an intraaortic balloon pump preoperatively for postinfarction angina, but 11.8% for those who underwent urgent/emergent operation without intraaortic balloon pump support. Conclusions: Elective CABG can be accomplished with acceptable morbidity and mortality early after acute MI if an elective operation is possible. In addition, the intraaortic balloon pump should be used aggressively in patients with postinfarction angina to allow for elective rather than urgent/emergent operation.
unchanged compared with preoperative studies among patients with leaflet flail (jet diameter 1.04 f 0.26 vs 1.10 f 0.28 cm, area 9.8 t 4.5 vs 10.1 f- 5.2 cm’ on preoperative studies), although jet size decreased significantly in patients with functional MR (jet diameter 0.79 + 0.33 vs 1.10 -+ 0.29 cm [p < O.OOl], area 5.7 t 3.5 vs 10.0 ? 3.8 cm2 [p < O.OOl] on preoperative studies). These findings were not accounted for by variation in heart rate, blood pressure, echocardiographic instrumentation, or Doppler Nyquist limit, General anesthesia is associated with decrease in regurgitation severity in patients with functional MR. Decisions regarding surgical intervention for functional MR should be made before induction of general anesthesia.
Percutaneous Transluminal Coronary Failures in Patients With Multivessel There an Increased Risk?
N. Wang, S.R Gundry, G. Van Arrdell, A.J. Bazzouk, A.C. Hill, M. Sjolander, KA. Cavazos, J.M. Brewer, E.E. Vyhmeirter, LL Bailey, 1.L Grover, A. El Gamel, W. DembitsQ. Division of Cardiothoracic Surgery, Department of Surgety, Loma Linda University Medical Center, loma Linda, CA. J lhorac Cardiovax Surg 1995;110:214-23.
In recent years, there has been a nationwide trend toward performing percutaneous transluminal coronary angioplasty in patients with multivessel coronary artery disease. The clinical course of 57 consecutive patients who required emergency first-time coronary artery bypass grafting operations were reviewed to assess for difference in outcome between the 28 patients (49%) with single-vessel disease and the 29 patients (5 1%) with multivessel disease. The two groups were similar in preoperative characteristics except for a higher proportion of chronic obstructive pulmonary disease in the patients with multivessel disease (p = 0.03). Twice as many patients with multivessel disease were in shock (single-vessel disease = 4 [14%], multivessel disease = 8 [28%], p = not significant) en route to the operating room and significantly more patients with multivessel disease required ongoing cardiopulmonary resuscitation (single-vessel disease = 0 [O%], multivessel disease = 5 [ 17%], p = 0.03). Significantly more coronary artery bypass grafts were placed in the patients with multivessel disease (single-vessel disease = 1.5 -+ 0.6, multivessel disease = 2.9 + 0.7, p < O.Ol>, which required longer aortic clamping time (p = 0.02) and cardiopulmonary bypass time (p < 0.01). There were seven postoperative deaths; all but one occurred in patients with multivessel disease (single-vessel disease = 1 [4%], multivessel disease = 6 [21%1, p = 0.05). According to multivariate analysis, incremental risk factors of mortality were preoperative shock (p < O.Ol), urgent or emergency percutaneous transluminal coronary angioplasty (p = 0.06), and multivessel disease (p = 0.12). Despite a similar incidence of myocardial infarction (single-vessel dis-
Accuracy of lntraoperative Echocardiography Functional Mitral
Transesophageal for Estimating the Severity Regurgitation
of
D.S. Bach, G.M. Deeb, S.F. Boiling. University of Michigan, Ann Arbor, MI. Am ) Cardiol 1995;76:508-12.
Although intraoperative transesophageal echocardiography (TEE) is used to guide mitral valve reconstructive procedures, the effects of hemodynamic alterations accompanying general anesthesia on mitral regurgitation (MR) are unknown. This study was performed to evaluate the effect of general anesthesia on MR jet size using TEE with color Doppler imaging patients undergoing mitral valve surgery, Matched preoperative TEES performed with the patient under intravenous conscious sedation, and intraoperative studies performed with the patient under general anesthesia were retrospectively reviewed in 46 patients undergoing mitral valve surgery. Patients were divided into groups based on etiology of MR, including 2 1 patients with myxomatous degeneration and leaflet flail, 19 patients with structurally normal leaflets and functional regurgitation due to abnormal leaflet coaptation, and 6 patients with rheumatic mitral disease. On both preoperative and intraoperative studies, regurgitation was quantified using maximal jet area and jet diameter at the vena contracta on color flow Doppler. Patients with leaflet flail and patients with functional MR had similar measures of regurgitation severity on preoperative imaging. On intraoperative imaging, regurgitant jet size was ACC CURRENT
JOURNAL
Angioplasty Disease: Is
REVIEW
46
January/Februar),
1996