Videometric analysis of regional left ventricular function before and after aortocoronary artery bypass surgery: correlation of peak rate of myocardial wall thickening with late postoperative graft flows.

The peak rate of systolic wall thickening (pdTw/dt) in regions of the left ventricle was determined by biplane roentgen videometry in 60 patients before and a median of 14 mo after aorto-coronary bypass graft surgery. The left ventricular ejection fraction, stroke volume, and end-diastolic volume and pressure did not change significantly after surgery in the presence of patent or occluded grafts (P greater than 0.05). Statistically significant increases occurred in the peak rate of systolic wall thickening regions supplied by patent bypass grafts, and significant decreases occurred in regions with occluded grafts (P less than 0.01). Of 42 preoperatively hypokinetic regions (pdTw/dt greater than 0 less than 5.0 cm/s) supplied by a patent graft, 30 improved by an average of 2.6 cm/s after operation; 18 returned to normal. Failure of 24 hypokinetic regions to improve to normal was associated with myocardial infarction in 11 or with late postoperative graft blood flows of less than 60 ml/min measured by videodensitometry, in 10. All seven preoperatively akinetic (pdTw/dt=0) or dyskinetic (pdTw/dt less than 0) regions did not improve after the operation despite the fact that, in five of the seven, coronary bypass flows were over 60 ml/min. All eight preoperatively hypokinetic regions supplied by coronary artery graft flows of less than or equal 40 ml/min failed to improve to normal after operation. All nine preoperatively hypokinetic regions supplied by coronary artery graft flows of over 60 ml/min improved to normal after surgery. Late postoperative coronary artery bypass graft flows, the functional status of the myocardium, the status and distribution of the native coronary circulation, and decreased regional function elsewhere in the ventricle must all be considered when regional left ventricular function is interpreted.

Coronary artery venous bypass graft aneurysm with symptomatic coronary artery emboli.

A 53 year old man, asymptomatic for 9 years after aorto-right coronary artery venous bypass surgery, developed two prolonged episodes of myocardial ischemia during a 7 month interval. Diagnostic exercise tests subsequent to each episode were normal. Coronary angiography demonstrated marked dilation with filling defects of the venous bypass graft. A large thrombus-filled venous bypass graft aneurysm was excised at surgery. Spontaneous coronary artery embolization related to a venous bypass graft aneurysm has not been described previously, but may become more frequent as survival and follow-up after coronary bypass surgery lengthen.

Aortic and mitral valve incompetence: long-term follow-up (10 to 19 years) of patients treated with the Starr-Edwards prosthesis.

The long-term course (mean 15 years) of 336 patients with valvular incompetence who underwent Starr-Edwards ball valve implantation between 1962 and 1971 was reviewed. Eighteen patients (10%) with aortic valve replacement and 24 (16%) with mitral valve replacement died early postoperatively. Mortality remained high (31%) in the first 3 years after aortic valve replacement; it was highest (13%) in the first year after mitral valve replacement and then approached the normal rate. The most common mode of death was sudden death after aortic and cardiac failure after mitral valve replacement. At follow-up, 76% of survivors had improved symptomatically. Three instances of primary valve malfunction occurred. The probability of freedom from thromboembolism at 15 years postoperatively was 56% for aortic valve replacement and 52% for mitral valve replacement. The Starr-Edwards valve prosthesis is durable over prolonged follow-up period, but thromboembolism remains a persistent problem. Survival may be normal for patients surviving the early postoperative years.

Intracellular calcium transients in human working myocardium as detected with aequorin.

The calcium transients associated with contraction in human working myocardium were recorded by use of the bioluminescent protein, aequorin, a substance that emits light when it combines with calcium ion (Ca++). Small amounts of aequorin were microinjected into superficial cells of human atrial and ventricular muscle obtained from tissue routinely excised and discarded at the time of cardiac surgery. Light output, an index of intracellular Ca++, and isometric tension development were recorded at 37.5 degrees C at 1 to 5 second intervals of stimulation. Light increases much more quickly than tension and decreases toward basal levels by the time that peak tension is reached. The configuration and time course of the aequorin signal in human myocardium and its responses to inotropic interventions are similar to those recorded in lower mammalian species. The calcium transient appears to be dominated by the release and uptake of Ca++ from intracellular stores under all conditions studied. These results indicate that aequorin is a useful tool for studying the effects of drugs and disease states on cardiac excitation-contraction coupling in human beings as well as in lower animals.

Coronary artery disease and its management: influence on survival in patients undergoing aortic valve replacement.

Data from 1,156 patients greater than or equal to 30 years of age who underwent aortic valve replacement alone or with coronary artery bypass grafting from 1967 through 1976 (early series) and 227 similar patients operated on during 1982 and 1983 (late series) were reviewed. In the early series, 414 patients (36%) had preoperative coronary arteriography (group 1): group 1A (n = 224) did not have coronary artery disease, group 1B (n = 78) had coronary artery disease but did not undergo bypass grafting and group 1C (n = 112) had coronary artery disease and underwent bypass grafting. The 742 patients in group 2 did not have preoperative arteriography. Operative mortality rates (30 day) in groups 1A, 1B, 1C and 2 were 4.5, 10.3, 6.3 and 6.3%, respectively (p = NS). The 10 year survival in both groups 1 and 2 was 54%; in groups 1A, 1B and 1C it was 63, 36 and 49%, respectively (1A and 1B, p less than 0.01). In the late series, the 227 patients were divided into similar groups (group 1A, n = 73; 1B, n = 32; 1C, n = 99), and 90% had preoperative coronary arteriography. Operative mortality rates (30 day) for groups 1A, 1B and 1C were 1.4, 9.4 and 4.0%, respectively; that for group 2 (no preoperative arteriography, n = 23) was 4.3%. Definition of coronary anatomy by angiography seems important in most patients greater than or equal to 50 years old who are candidates for aortic valve replacement, and bypass grafting is recommended for those with significant coronary artery disease.

High risk of thromboemboli early after bioprosthetic cardiac valve replacement.

OBJECTIVES: We studied the rate of thromboembolism in patients undergoing bioprosthetic replacement of the aortic or mitral valve, or both, at serial intervals after operation and the effects of anticoagulant or antiplatelet treatment and risk factors. BACKGROUND: Thromboembolism appears to occur early after operation, but the incidence, timing and risk factors for thromboembolism and the role, timing, adequacy, effectiveness, duration and risk of anticoagulation and antiplatelet agents are uncertain. METHODS: The rate of thromboembolism was studied at three time intervals after operation (1 to 10, 11 to 90 and > 90 days) in 816 patients who underwent bioprosthetic replacement of the aortic or mitral valve, or both, at the Mayo Clinic from January 1975 to December 1982. The effect of antithrombotic therapy (warfarin, aspirin or dipyridamole, alone or in combination) was evaluated. RESULTS: Median follow-up of surviving patients was 8.6 years. The rate of thromboembolism (%/year) decreased significantly (p < 0.01) at each time interval after operation (1 to 10, 11 to 90 and > 90 days) for mitral valve replacement (55%, 10% and 2.4%/year, respectively) and over the first time interval for aortic valve replacement (41%, 3.6% and 1.9%/year, respectively). During the first 10 days, 52% to 70% of prothrombin time ratios were low (< 1.5 x control). Patients with mitral valve replacement who received anticoagulation had a lower rate of thromboembolism for the entire follow-up period (2.5%/year with vs. 3.9%/year without anticoagulation, p = 0.05). Of 112 patients with a first thromboembolic episode, permanent disability occurred in 38% and death in 4%. Risk factors for emboli were lack of anticoagulation, mitral valve location, history of thromboembolism and increasing age. Only 10% of aortic, 44% of mitral and 17% of double valve recipients had anticoagulation at the time of an event. Patients with bleeding episodes (2.3%/year) were older and usually underwent anticoagulation. Blood transfusions were required in 60 of 111 patients (1.2%/year), and 13 patients (0.3%/year) died. CONCLUSIONS: Thromboembolic risk was especially high for aortic and mitral valve replacement for 90 days after operation, and overall was increased with lack of anticoagulation, mitral valve location, previous thromboembolism and increasing age. Anticoagulation reduced thromboemboli and appears to be indicated in all patients as early as possible for 3 months and thereafter in those with risk factors, but needs prospective testing.

Permanent pacemaker infections: characterization and management.

From January 1974 to June 1980, a total of 46 patients were treated for infections involving permanent pacing systems. Demographic characteristics, types of infecting organisms, specific clinical features, significance of an infected foreign body and various medical and surgical treatment methods are described. Likely infecting organisms depend on the mode of presentation and the time course of the infection. Optimal treatment for the large majority of patients requires removal of the entire infected pacing system. In a subgroup of patients, a short course of antibiotic therapy followed by one stage surgery involving implantation of a new pacing system and concurrent explanation of the infected pacemaker was used safely with excellent results.

Long-term follow-up of isolated replacement of the aortic or mitral valve with the Starr-Edwards prosthesis.

Review of 1,684 cases of isolated aortic or mitral valve replacement with a Starr-Edwards prosthesis demonstrated that the procedure provides improved life expectancy over that found in the natural history of valvular heart disease. Further improvement in results depends on continued reduction in operative and late mortality and in the incidence of thromboembolism. Advanced preoperative functional class, atrial or ventricular enlargement, a history of prior heart surgery, advanced age at operation and untreated valvular disease were among the factors related to increased early or late mortality. The data suggest that adequate anticoagulation, earlier performance of valve replacement and more complete repair of valvular dysfunction may increase survival rates.

Trial of combined warfarin plus dipyridamole or aspirin therapy in prosthetic heart valve replacement: danger of aspirin compared with dipyridamole.

Despite the use of oral anticoagulation in patients with prosthetic heart valves, persistent thromboembolism over time warrants a search for improved methods of prevention. Thus, patients receiving 1 or more mechanical prosthetic heart valves were randomized to therapy with warfarin plus dipyridamole (400 mg/day) or warfarin plus aspirin (500 mg/day) on the basis of location and type of valve and surgeon, and followed up with a concurrent, nonrandomized control group taking warfarin alone. In 534 patients followed up 1,319 patient-years, excessive bleeding (necessitating blood transfusion or hospitalization) was noted in the warfarin plus aspirin group (23 of 170 [14%], or 6.0/100 patient-years) compared with warfarin plus dipyridamole (7 of 181 [4%], or 1.6/100 patient-years, p less than 0.001), or warfarin alone (9 of 183 [5%], or 1.8/100 patient-years, p less than 0.001). A trend was evident toward a reduction in thromboembolism in the warfarin plus dipyridamole group (2 of 181 [1%], or 0.5/100 patient-years) as compared with warfarin plus aspirin (7 of 170 [4%], or 1.8/100 patient-years), or warfarin alone (6 of 183 [4%], or 1.2/100 patient-years). Adequacy of anticoagulation (based on 12,720 prothrombin time determinations) was similar in all 3 groups with 65% of prothrombin times in the therapeutic range (1.5 less than or equal to prothrombin time/control less than or equal to 2.5), 30% too low, and 5% too high. Warfarin plus aspirin therapy resulted in excessive bleeding and is contraindicated. Longer follow-up study is needed to determine whether further separation of the incidence of thromboembolism can be detected.

Relation of intraoperative or early postoperative transmural myocardial infarction to patency of aortocoronary bypass grafts and to diseased ungrafted coronary arteries.

Serial preoperative and postoperative electrocardiograms and vectorcardiograms were obtained in 500 patients undergoing saphenous vein aortocoronary artery bypass graft surgery. Evidence of transmural myocardial infarction was found early postoperatively in 67 patients (13 percent). Age and sex distributions, number of vessels diseased or vessels grafted, and preoperative and postoperative New York Heart Association functional classification (mean follow-up, 26 months) did not differ in the groups with and without infarction. Increased duration of cardiopulmonary bypass time (more than 120 minutes) was slightly greater in the group with infarction (P smaller than 0.05). Multivariate analysis revealed that 60 percent of patients in the group with infarction were identified by a 1st day serum glutamic oxaloacetic transaminase value greater than 100 U/liter; however, for each such patient identified, there was approximately one false positive result. Use of other values (creatine phosphokinase, cardiopulmonary bypass time and total anoxic rest time) did not improve discrimination. Twenty-five percent of all transmural infarctions occurred within the zone of myocardium supplied by a diseased ungrafted artery. In 32 patients with early evidence of transmural mycardial infarction in a zone of myocardium supplied by a grafted artery, postoperative angiography showed as many with patent as with occluded grafts. Of 154 patients in the group without infarction who had early postoperative graft angiograms, 30 (19 percent) had one graft occluded and yet no evidence of transmural infarction by our criteria. Therefore, early postoperative evidence of transmural myocardial infarction as defined in this study is an unreliable indicator of the status of the graft supplying the zone of infarction.

Echophonocardiographic findings in patients with prosthetic heart valve malfunction.

This report represents a retrospective analysis of preoperative echophonocardiographic studies in 118 patients who had surgery for the repair or replacement of malfunctioning prosthetic valves. A variety of prostheses implanted in the mitral, aortic, and tricuspid positions were assessed. The most frequent prosthetic malfunctions were regurgitation, thrombosis, ball variance, and infective endocarditis. There were echophonocardiographic abnormalities in 71% of the cases. The retrospective diagnosis of prosthetic dysfunction varied according to the type of prosthesis, type of malfunction, and site of implantation of the valve. A high percentage of the prostheses did have echophonocardiographic abnormalities, and consideration of these, in conjunction with clinical data, may help the clinician in the evaluation of prosthetic heart valves.

Temporal changes in the causes of aortic stenosis: a surgical pathologic study of 646 cases.

Among 646 patients with pure aortic stenosis who underwent valve replacement at our institution between 1981 and 1985, the three most frequent causes were calcification of congenitally bicuspid aortic valves (38%), degenerative (senile) calcification of tricuspid aortic valves (33%), and postinflammatory (presumably rheumatic) calcification and fibrosis (24%). Among the 324 patients younger than 70 years of age, calcified bicuspid valves were observed in 50%. In contrast, among 322 patients 70 years of age or older, degenerative calcification accounted for 48% of the stenotic aortic valves. During the 5 years of the study, the relative frequency of postinflammatory disease decreased from 30% to 18%, and that of bicuspid valves decreased from 37% to 33%. In contrast, the relative frequency of degenerative calcification increased from 30% to 46%. Consequently, degenerative (senile) calcification is currently the most common cause of aortic stenosis among patients undergoing valve replacement at our institution. This finding may be related to changes in life expectancy in the general population, alterations in patient referral practices, and an increased willingness of surgeons to operate on older patients. Regardless of cause, the observed temporal changes in etiologic factors for aortic stenosis may indicate a potential source of increasing health-care costs among the elderly population.

Liposarcoma of the pleura.

Pleural liposarcomas are extremely rare; only eight cases have been reported in the literature. Herein we describe a 38-year-old man who had dyspnea on exertion and chest pain. Computed tomography of the chest revealed a large mass in the right pleural cavity. Thoracotomy was performed, and the patient recovered with no complications. Postoperative adjuvant irradiation was successful. In addition to the current case, we review the previously reported cases of pleural liposarcomas and discuss the treatment outcomes.

Left ventricular outflow tract obstruction related to a valve prosthesis: case caused by a low-profile mitral prosthesis.

Mechanical and bioprosthetic mitral prostheses may have many potential complications. In patients with isolated mitral stenosis and a small left ventricular cavity, low-profile prostheses are recommended to avoid myocardial impingement that can result from a high-profile valve and lead to possible left ventricular inflow or outflow obstruction or ventricular arrhythmias. This case report illustrates that left ventricular outflow obstruction may also result from a low-profile mitral valve prosthesis. This obstruction was not diagnosed before cardiac catheterization. Assessment of patients with suspected prosthetic valve dysfunction is difficult and may necessitate cardiac catheterization or even direct surgical inspection for conclusive information.

Intra-aortic balloon assist: initial Mayo Clinic experience and current concepts.

The initial experience with intra-aortic balloon assist (IABA) at the Mayo Clinic has been with 34 desperately ill individuals; 17 survived hospitalization. Hemodynamic improvement associated with institution of IABA can be documented. An unacceptably high complication rate (26%) has resulted in extensive modification in the technique of employing IABA. Concepts of patient selection and applications of IABA have evolved from this initial experience and from a review of the literature and have resulted in less reluctant use of this cardiac-assist modality.

Cardiac papillary fibroelastomas. Two-dimensional echocardiographic recognition.

Papillary fibroelastomas are benign tumors of the heart and are most often incidental findings at cardiac surgery or autopsy. Rarely, symptoms or even sudden death can occur. We report two cases of cardiac papillary tumors diagnosed by two-dimensional echocardiography and successfully excised. One patient was asymptomatic and had a 1-by 1-cm papilloma of the mitral valve. The other patient had intermittent chest pains and diaphoresis associated with a 1.5- by 1-cm aortic valve papilloma.

Thoracoscopic excision of a peripheral corticotropin-secreting pulmonary carcinoid tumor.

Bronchial carcinoid tumors are rare neuroendocrine neoplasms that arise from the Kulchitsky cells of the bronchial epithelium. These tumors can manifest as central carcinoid tumors, pulmonary carcinoid tumorlets, or peripheral carcinoid tumors. Occasionally, the peripheral carcinoid tumors produce corticotropin and result in Cushing's syndrome. Herein we report the first case of Cushing's syndrome associated with a peripheral pulmonary carcinoid tumor that was excised by video-assisted thoracoscopy. After excision, the patient had complete remission. Video-assisted thoracoscopy may be ideal for resecting a peripheral pulmonary carcinoid, especially in patients with debilitation but no evidence of metastasis.

Aorta-coronary artery saphenous vein bypass surgery: clinical and angiographic results.

In a series of 500 consecutive patients undergoing aorta-coronary artery saphenous vein bypass surgery, operative mortality was 2.5% (1% with one-vessel disease, 2% with two-vessel disease, and 3% with three-vessel disease). Transmural myocardial infarction occurred within 30 days after operation in 67 cases (13%) and caused 10 of the 16 deaths in that period. Among 484 patients followed 1 to 58 months (median, 26 months), there have been 20 deaths. Of the 464 survivors, 65% had complete relief of angina, 24% were improved, and 11% were unimproved. In 162 patients who underwent postoperative graft angiography between 1 and 42 months after surgery, a strong positive relationship existed between clinical response and completeness of myocardial revascularization as defined by the presence of a patent graft to all major coronary arteries with greater than 50% stenosis. A similar relationship was found between postoperative multistage treadmill exercise response and completeness of myocardial revascularization. Thus, 82% of patients completely revascularized were asymptomatic at the time of postoperative graft visualization, and 91% had a negative treadmill exercise response.

Survival predictors in coronary artery disease. Medical and surgical comparisons.

Linear discriminant function analysis was used to test the independent prognostic value of nine variables in patients with coronary artery diseaase. For 68 medically treated patients who met the criteria for inclusion in the discriminant function analysis, the most reliable predictor of 2-year survival status was the left ventricular ejection fraction. The prognostic value of the ejection fraction was not improved by the addition of the number of vessels diseased. Comparisons of the survival of 130 medical and 284 surgical patients were made using subsets based on the ejection fraction. When the ejection fraction was greater than or equal to 50%, the probability of 4-year survival was high for both medical (91%) and surgical (96%) groups. When the ejection fraction was less than 25%, the probability of 2-year survival was low in both groups. However, for patients with ejection fraction 25 through 49%, the surgical patients had a better chance (P less than 0.05) for a 3-year survival (89%) than did medical patients (68%). This study emphasizes the prognostic significance of the left ventricular ejection fraction, which should be considered in any comparison of survival in medically and surgically treated patients.

The Marfan syndrome and cardiac surgery.

Of 31 patients with Marfan's syndrome and cardiovascular complications, 25 had ascending aortic aneurysms, five with aortic dissection; 26 had aortic regurgitation, two with aortic stenosis; and eight had mitral regurgitation, five with aortic regurgitation. Surgery included prosthetic aortic valve replacement in 24 patients and aortic valvular bicuspidization in two; 19 had resection of aneurysm with Dacron tube replacement, three had lateral aneurysmorrhaphy, and two had circumferential strip excision with end-to-end anastomosis. Four patients underwent mitral valve replacement. Operative complications occurred in 10 patients. There were nine (29 percent) hospital deaths, but only one death occurred in 12 patients operated upon since 1970. Late complications included prosthetic leak in six patients (23 percent) with reoperation in five; all survived. Five late deaths occurred (16 percent); one was unrelated and one was of unknown cause. Although risk of cardiac surgery remains high, our recent results support an aggressive surgical approach, particularly in patients with advanced or deteriorating cardiovascular complications.