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.

Constrictive pericarditis in the modern era: evolving clinical spectrum and impact on outcome after pericardiectomy.

BACKGROUND: The clinical spectrum of constrictive pericarditis (CP) has been affected by a change in incidence of etiological factors. We sought to determine the impact of these changes on the outcome of pericardiectomy. METHODS AND RESULTS: The contemporary spectrum of CP in 135 patients (76% male) evaluated at the Mayo Clinic from 1985 to 1995 was compared with that of a historic cohort. Notable trends were an increasing frequency of CP due to cardiac surgery and mediastinal radiation and presentation in older patients (median age, 61 versus 45 years). Perioperative mortality decreased (6% versus 14%, P = 0.011), but late survival was inferior to that of an age- and sex-matched US population (57+/-8% at 10 years). The long-term outcome was predicted independently by 3 variables in stepwise logistic regression analyses: (1) age, (2) NYHA class, and most powerfully, (3) a postradiation cause. Of 90 late survivors in whom functional class could be determined, functional status had improved markedly (2.6+/-0.7 at baseline versus 1.5+/-0.8 at latest follow-up [P<0.0001]), with 83% being free of clinical symptoms. CONCLUSIONS: The evolving profile of CP, with increasingly older patients and those with radiation-induced disease in the past decade, significantly affects postoperative prognosis. Long-term results of pericardiectomy are disappointing for some patient groups, especially those with radiation-induced CP. By contrast, surgery alleviates or improves symptoms in the majority of late survivors.

Spectrum of exercise intolerance in 45 patients with Ebstein's anomaly and observations on exercise tolerance in 11 patients after surgical repair.

To determine the effects of definitive operation for Ebstein's anomaly on rest and exercise cardiorespiratory function, cycle exercise studies were performed on 38 patients with Ebstein's anomaly before definitive operation and on 11 patients after operation. An atrial septal defect was present in 29 of the 38 preoperative patients and in none of the postoperative patients. Seven of the postoperative patients had tricuspid valvuloplasty and four had valve replacement. Exercise tolerance, as defined by maximal oxygen uptake, was significantly greater in patients after operation for Ebstein's anomaly than in the preoperative patients. However, exercise tolerance for preoperative patients without an atrial septal defect was similar to that for postoperative patients. Tricuspid valve repair or replacement appeared to affect favorably cardiac output response to exercise. Rest systemic arterial oxygen saturation increased from 88 to 95% and exercise saturation from 77 to 93% after operation. Rest ventilatory equivalent for oxygen decreased from 48 +/- 13 preoperatively to 37 +/- 6 postoperatively, and exercise ventilatory equivalent for oxygen decreased from 53 +/- 23 preoperatively to 38 +/- 6 postoperatively. Definitive operation (tricuspid valvuloplasty or replacement and atrial septal defect closure) for Ebstein's anomaly results in significant improvement of exercise tolerance, normalization of systemic arterial oxygen saturation and reduction of excess ventilation at rest and during exercise.

The Fontan procedure for pulmonary atresia with intact ventricular septum: operative and late results.

OBJECTIVES: The goals of the study were to evaluate the operative and late mortality associated with the Fontan procedure in patients with pulmonary atresia and an intact ventricular septum and to obtain follow-up information on the current clinical status of surviving patients. BACKGROUND: Between 1979 and October 1, 1995, 40 patients with the anomaly had a nonfenestrated Fontan procedure performed at the Mayo Clinic. Because there are no previously published reports involving a series of this size in which the Fontan approach was used for this condition, a review of patient outcomes was thought to be of value. METHODS: The medical records of the 40 patients were reviewed retrospectively, and 34 were determined to be alive. The status of the survivors as of late 1995 was then ascertained by direct examination, questionnaire or telephone follow-up. RESULTS: There were three operative deaths and three late deaths. The current ages of the 34 survivors ranged from 4 to 30 years (median 13). Thirty-three of the 34 survivors were thought to be in New York Heart Association functional class I or II, and all but three of these patients, of school age or older, were either full-time students or working full time. The three adults who were not employed thought they were capable of working but were not doing so because of socioeconomic reasons. More than half of the patients were not receiving cardiovascular medications. CONCLUSIONS: These overall gratifying early and late results encourage continued application of this operation for appropriately selected patients with this complex congenital cardiovascular anomaly.

The Fontan procedure for tricuspid atresia: early and late results of a 25-year experience with 216 patients.

OBJECTIVES: We assessed the operative and late mortality and the present clinical status of 216 patients with tricuspid atresia who had a nonfenestrated Fontan procedure performed at the Mayo Clinic in the 25-year period 1973 to 1998. BACKGROUND: The Fontan operation eliminates the systemic hypoxemia and ventricular volume overload characteristic of prior forms of palliation. However, it originally did so at the cost of systemic venous and right atrial hypertension, and the long-term effects of this "price" were unknown when the procedure was initially proposed. METHODS: We reviewed the clinical records of the 216 patients retrospectively. These were arbitrarily grouped into early (1973 through 1980), middle (1981 through 1987) and late (1988 through 1997) surgical eras. Patient outcome was also analyzed according to age at surgery. Operative and late mortality rates were determined and present clinical status was ascertained in 167 of 171 surviving patients. RESULTS: Overall survival was 79%. Operative mortality steadily declined and was 2% (one of 58 patients) during the most recent decade. Late survival also continues to improve. Age at operation had no effect on operative mortality, and late mortality was significantly increased only in patients who were operated on at age 18 years or older. Eighty-nine percent of surviving patients are currently in New York Heart Association class I or II. CONCLUSIONS: The initial 25-year experience with the nonfenestrated Fontan procedure for tricuspid atresia has been gratifying, with most survivors now leading lives of good quality into adulthood. These results justify continued application of this procedure for children born with tricuspid atresia.

Partial atrioventricular canal defect: long-term follow-up after initial repair in patients > or = 40 years old.

OBJECTIVES: This study was undertaken to determine the results of repair of partial atrioventricular (AV) canal in patients > or = 40 years old. BACKGROUND: Although postoperative outcomes in younger patients have been well documented, the fate of older patients with repaired partial AV canal is less clear. METHODS: From 1958 to 1990, 31 patients 40 to 71 years old (mean age 51) had repair of partial AV canal. Twenty-three patients had repair of the cleft mitral valve; two had mitral valve replacements; and six needed no mitral valve operation. RESULTS: Early mortality was 6%. One patient was lost to follow-up. Nine of the early survivors are known to have died. There is a small but significant development over the long term of atrial arrhythmias, complete heart block, subaortic stenosis, recurrent mitral regurgitation and, rarely, mitral stenosis. Three of the 28 patients available for follow-up had mitral valve reoperation and subaortic stenosis developed in 2. Nineteen patients were alive in 1991 (mean follow-up 14 years). Seven patients were in New York Heart Association functional class I, eight were in class II, and four were in class III. Fifteen of the 19 patients reported sustained postoperative improvement. CONCLUSIONS: Patients > or = 40 years old can have partial AV canal repair with low risk. Long-term survival is good, with subjective improvement in symptoms. Late complications occur but are uncommon, suggesting that long-term follow-up is warranted.

Surgical repair of uncomplicated atrial septal defect without "routine" preoperative cardiac catheterization.

Whether all patients with atrial septal defect should undergo cardiac catheterization before surgical correction is controversial. Of 152 patients of all ages with surgically documented isolated atrial septal defect (ostium secundum, ostium primum and sinus venosus types) who underwent preoperative two-dimensional echocardiography between January 1978 and December 1983, there were 55 (36%) (group 1) who did not have preoperative cardiac catheterization. These 55 patients are compared with the 97 patients (64%) who did have preoperative catheterization studies (group 2). Group 1 patients were younger (mean age 22 versus 36 years) and did not have clinical evidence of other associated cardiac disorders. Forty-four (80%) of the group 1 patients had typical findings for atrial septal defect on cardiac examination, chest radiograph and electrocardiogram compared with 16 (16%) of group 2 patients (p less than 0.001). The most frequent reasons for cardiac catheterization in group 2 patients were documentation of diagnosis, usually because of atypical clinical findings, and exclusion of associated cardiac abnormalities. Contrast echocardiography, radionuclide shunt studies and Doppler echocardiography were used as additional confirmatory tests in 36 patients (65%). In 19 patients (35%), two-dimensional echocardiography was the only confirmatory test. There were no false positive two-dimensional echocardiographic studies. There were no operative deaths or significant perioperative complications in any of the patients. At a mean follow-up of 28 months (range 6 to 64), there was one late death (3 1/2 years postoperatively) in a 61 year old man with chronic congestive heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Fixed subaortic stenosis in atrioventricular canal defect: a Doppler echocardiographic study.

OBJECTIVES: The objectives of this retrospective study were to describe the Doppler and echocardiographic features of fixed subaortic stenosis in the setting of atrioventricular (AV) canal defect and to document the de novo occurrence of subaortic stenosis and progression of this lesion over time on the basis of sequential echocardiographic studies. BACKGROUND: The coexistence of fixed subaortic and AV canal defect has been sporadically noted, but no single or multicenter experience with this constellation of abnormalities has been previously described. METHODS: All patients with a diagnosis of subaortic stenosis and complete or partial AV canal defect who had one or more Doppler echocardiographic examinations were identified from a computer data bank. Retrospective analysis was performed, including review of patients' charts, operative notes, recorded videotapes and hard copy recordings when available. RESULTS: Twenty-one patients with both subaortic stenosis and AV canal defect were identified over a 13-year period. Fifteen were female and the mean age at diagnosis of subaortic stenosis was 16 years. Fifteen patients had partial AV canal defect with prior repair in 10; 6 patients had complete AV canal defect with prior repair in 4. The mean interval from prior repair to recognition of subaortic stenosis was 6.8 years. In six patients, serial examinations demonstrated the de novo occurrence of subaortic obstruction over a period of 10 to 87 months. In five patients, progression of known subaortic stenosis was documented over a 10- to 59-month period. Surgical resection of subaortic stenosis was performed in 16 patients; the echocardiographic diagnosis was confirmed in 15 of the 16. CONCLUSIONS: In the largest reported echocardiographic series of this lesion complex, it is concluded that subaortic stenosis can occur de novo, is often recognized only after repair of the canal defect and is progressive. Doppler echocardiography is the method of choice for diagnosis and serial follow-up of these patients.

Cardiac arrhythmias in patients with surgical repair of Ebstein's anomaly.

Preoperative, perioperative and postoperative arrhythmias in 52 consecutive patients who underwent operation for Ebstein's anomaly were reviewed. There were 25 male and 27 female patients (mean age 18 years, range 11 months to 64 years). Thirty-four patients had one or more documented arrhythmias preoperatively (18 had paroxysmal supraventricular tachycardia, 10 had paroxysmal atrial fibrillation or flutter, 13 had ventricular arrhythmia and 3 had high grade atrioventricular block). Seven patients without documented arrhythmias had a history typical of tachyarrhythmias. During the perioperative and early postoperative periods, 14 patients had atrial tachyarrhythmias and 8 had ventricular tachycardia or ventricular fibrillation. There were seven deaths between day 1 and 27 months after operation. Five of these deaths were sudden (all in male patients, aged 12 to 34 years), and four of the patients had had perioperative ventricular tachycardia or ventricular fibrillation. One patient was taking one antiarrhythmic agent and another patient was taking two at the time of sudden death. Of the 18 patients with paroxysmal supraventricular tachycardia and 9 patients with paroxysmal atrial fibrillation or flutter preoperatively who were followed up for a mean of 40 and 36 months, respectively, 22 and 33% continued to have symptomatic tachycardia. Of the 11 patients (mean age 9 years) without preoperative documentation or symptoms of arrhythmia, follow-up data were obtained (range 1 to 144 months, mean 31) in 9 patients. None died suddenly or developed symptomatic arrhythmia.

Pulmonary atresia with ventricular septal defect: preoperative and postoperative responses to exercise.

Between April 1982 and June 1984, maximal exercise testing was performed 35 times in 34 consecutive patients with pulmonary atresia and ventricular septal defect (14 studies in patients without repair, 11 studies in patients with partial repair [insertion of a right ventricle to pulmonary artery conduit without ventricular septal defect closure] and 10 studies in patients with complete repair [insertion of a conduit with septal defect closure]). Total work performed, maximal power achieved, exercise time and maximal oxygen uptake were significantly greater in patients after partial or complete repair than in patients without repair. Systemic arterial blood oxygen saturations at rest and during exercise were directly related to the degree of repair. Although heart rate at rest in the three study groups was similar to that in a separate group of normal control subjects, patients in all three study groups had a blunted heart rate response to exercise. The ventilatory equivalent for oxygen was increased both at rest and during exercise for patients without conduit repair and those with a right ventricle to pulmonary artery conduit without ventricular septal defect closure but was similar to that of control subjects in the group with conduit insertion and septal defect closure. This study indicates that patients with pulmonary atresia and ventricular septal defect have decreased exercise tolerance both before and after corrective surgery. Exercise tolerance improves significantly after placement of a conduit from the right ventricle to the pulmonary artery with or without ventricular septal defect closure. Although no further improvement in exercise tolerance occurs with closure of the septal defect, ventilatory function and systemic arterial blood oxygen saturation are improved.

Left ventricular systolic and diastolic function after pericardiectomy in patients with constrictive pericarditis: Doppler echocardiographic findings and correlation with clinical status.

OBJECTIVES: The study assessed changes in left ventricular systolic and diastolic function after pericardiectomy in patients with constrictive pericarditis and correlated postoperative Doppler echocardiographic findings with clinical status. BACKGROUND: Despite the efficacy of pericardiectomy, some patients with constrictive pericarditis fail to improve postoperatively. Data on serial evaluation of systolic and diastolic function after pericardiectomy and its relation to clinical status are not available. METHODS: From 1985 to 1995, a total of 58 patients with constrictive pericarditis underwent pericardiectomy and had at least one follow-up Doppler echocardiographic study with a respirometer: 23 patients had one examination within 3 months postoperatively, 19 had a study within 3 months and another one more than 3 months postoperatively, and 16 had one study more than 3 months postoperatively. RESULTS: In the early postoperative period, diastolic function was normal in 17 patients (40.5%), restrictive in 17 (40.5%), and constrictive in 8 (19%). Among 19 patients who had serial Doppler echocardiography, in 2 patients with restrictive physiology and 5 with constrictive physiology the results had become normal, and 1 patient who had had constrictive physiology had restrictive findings. In late follow-up, left ventricular end-diastolic diameter increased compared with preoperative measurement (p = 0.0009). Diastolic filling pattern at late follow-up was normal in 20 patients (57%), restrictive in 12 (34%) and constrictive in 3 (9%). There was a significant relationship between diastolic filling patterns and symptomatic status (chi2 = 20.9, p < 0.0001). Patients with persistent abnormal diastolic filling on Doppler echocardiography had had symptoms for a longer time preoperatively than did patients with normal diastolic physiology (p = 0.0471). CONCLUSIONS: Diastolic filling characteristics remain abnormal in a substantial number of patients with constrictive pericarditis after pericardiectomy. These abnormalities may resolve gradually but can persist. Diastolic filling abnormalities after pericardiectomy correlate well with clinical symptoms and tend to occur in patients who have had symptoms longer preoperatively. This finding supports the recommendation that pericardiectomy be performed promptly in symptomatic patients with constrictive pericarditis.

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.

Exercise tolerance in patients with Ebstein's anomaly.

OBJECTIVES: The purpose of this study was to identify the determinants of exercise tolerance in patients with Ebstein's anomaly. BACKGROUND: Patients with Ebstein's anomaly of the tricuspid valve may have exercise limitation that improves after surgical repair. METHODS: One hundred seventeen patients performed cycle ergometry for a total of 124 tests (preoperative test in 76 patients, postoperative test in 23, test but no operation in 18, preoperative and postoperative test in 7). Multiple linear regression analysis was used to identify predictors of maximal oxygen uptake, oxygen saturation and heart rate at peak exercise. RESULTS: Age at the time of exercise ranged from 6 to 60 years (median 15). An atrial septal defect was present in 67 patients (88%) preoperatively. Compared with the preoperative group, the postoperative group had significantly higher maximal oxygen uptake (mean [+/- SD] 20.5 +/- 7.4 vs. 25.3 +/- 7.0 ml/kg body weight per min, p = 0.006). Postoperative rest and exercise blood oxygen saturation was higher than that measured preoperatively (p = 0.0001). Six of seven patients tested before and after the operation showed improved exercise tolerance. Preoperatively, major predictors of maximal oxygen uptake were oxygen saturation at rest (p = 0.01) and age (p = 0.0001). Preoperatively, the major predictor of oxygen saturation at peak exercise was rest oxygen saturation (p = 0.0001), and major predictors of peak exercise heart rate were rest heart rate (p = 0.01) and rest oxygen saturation (p = 0.01). In the postoperative group, predictors of maximal oxygen uptake included age at exercise testing, male gender and heart size. CONCLUSIONS: Definitive operation for Ebstein's anomaly results in improved exercise tolerance. Before the operation, rest oxygen saturation is the major predictor of exercise tolerance, oxygen saturation at peak exercise and peak heart rate. Postoperatively, age, gender and heart size influenced maximal oxygen uptake.

Partial anomalous pulmonary venous connection: diagnosis by transesophageal echocardiography.

OBJECTIVE: This study sought to demonstrate that with proper technique, identification of the normal and abnormal pulmonary venous connection can be made with confidence using transesophageal echocardiography (TEE). BACKGROUND: Partial anomalous pulmonary venous connection (PAPVC) is an uncommon congenital anomaly whose diagnosis has classically been made using angiography. METHODS: We performed a retrospective review of all patients of all ages with PAPVC diagnosed at the Mayo Clinic who had undergone TEE because of either right ventricular volume overload or suspected intracardiac shunting by transthoracic echocardiography or intraoperatively. RESULTS: A total of 66 PAPVCs were detected in 43 patients (1.5/patient); in 2 additional patients, TEE suggested, but did not diagnose, PAPVCs. Shortness of breath was the most common presenting symptom (42.2%), followed by heart murmur and supraventricular tachycardia. Right-sided anomalous veins were identified in 35 patients (81.4%), left-sided in 7 (16.3%) and bilateral in 1 (2.3%). There was a single anomalous connecting vein in 23 patients (53.5%), two in 18 (41.9%), three in 1 (2.3%) and four in 1 (2.3%). The connecting site was the superior vena cava (SVC) in 39 veins (59.1%), right atrial-SVC junction in 6 (9.1%), right atrium in 8 (12.1%), inferior vena cava in 1 (1.5%) and the coronary sinus in 2 (3.0%). Ten anomalous left pulmonary veins were connected by a vertical vein to the innominate vein (15.1%). Sinus venosus atrial septal defect (ASD) was the most common associated anomaly in 22 patients (49%), followed by ostium secundum ASD in 6 and patent foramen ovale in 4. Fifteen patients had an intact atrial septum. Thirty-one patients (68.8%) underwent surgical repair. PAPVC was confirmed in all patients, including the two whose TEE results were suggestive of PAPVC. All 49 PAPVCs detected by TEE preoperatively were confirmed at the time of operation. CONCLUSIONS: TEE is highly diagnostic for PAPVC and can obviate angiography. Accurate anatomic diagnosis may influence the need for medical and surgical management. TEE should be performed in patients with right ventricular volume overload when the precordial examination is inconclusive.

Surgical repair of univentricular heart (double inlet left ventricle) with obstructed anterior subaortic outlet chamber.

The results of operation in all patients with univentricular heart and an obstructed anterior subaortic outlet chamber who were operated on utilizing extracorporeal circulation at the Mayo Clinic from 1973 through 1983 were reviewed. Ten of the 18 patients died during the immediate postoperative period and there was one late death. Factors significantly related to operative and immediate postoperative mortality were age at operation, cardiothoracic ratio on X-ray examination, degree of ST depression on electrocardiogram and pressure gradient across the outlet foramen at catheterization. Autopsy in eight cases revealed significant hypertrophy of ventricular myocardium and a small outlet foramen that was considered stenotic relative to either body surface area or aortic root area. The ventricular myocardium showed histologic changes of chronic ischemia that predated the surgical procedure.

Results of the modified Fontan operation for congenital heart lesions in patients without preoperative sinus rhythm.

Preoperative sinus rhythm has been a criterion for the Fontan operation. However, of 297 patients who underwent the Fontan operation between October 1973 and February 1984, 12 (4%) did not have sinus rhythm. The age at operation ranged from 4 to 34 years (median 15). Nine patients had a univentricular heart, two had tricuspid atresia and one had a complex form of transposition. In all 12 patients, 3 to 8 of the 10 proposed criteria for operability were not met. An atrioventricular (AV) conduction abnormality was present in seven patients, six with complete AV block and one with AV dissociation. The patient with complex transposition had complete AV block and atrial fibrillation. Postoperatively, all seven patients continued to have an AV conduction abnormality, and those with complete AV block had a permanent pacemaker implanted. Six of the 12 study patients had atrial flutter or fibrillation refractory to antiarrhythmic medications. Postoperatively, four of the six patients had sinus rhythm. Two of the six patients had complete AV block (including the patient with complex transposition) and both had a permanent pacemaker implanted. Three of the 12 patients died (mortality rate 25%). The nine survivors were followed up for 6 to 55 months; no late deaths occurred. All had marked clinical improvement. This study demonstrates that 1) complete AV block is not a contraindication to the Fontan operation, 2) some patients may not require AV synchrony postoperatively for survival, and 3) postoperative atrial flutter or fibrillation may cease or be easier to control after the Fontan operation.

Functional single ventricle: cardiorespiratory response to exercise.

The cardiorespiratory response to exercise was measured in 27 children with functional single ventricle. All 27 patients had a significant reduction in exercise time, work performed, maximal exercise heart rate, maximal oxygen uptake and systemic arterial blood oxygen saturation. The reduction in exercise performance increased with increasing age of the patients. All patients ventilated excessively at rest and during exercise. This study documented the precise level of exercise intolerance in patients with functional single ventricle. The progressive deterioration in exercise performance with increasing patient age may lend credence to the concept that operation for physiologic correction of functional single ventricle should be considered during or before adolescence.

Hypertrophic obstructive cardiomyopathy: preoperative echocardiographic predictors of outcome after septal myectomy.

OBJECTIVES: The purpose of this study was to determine whether two-dimensional and Doppler echocardiography are predictive of clinical outcome in patients with hypertrophic obstructive cardiomyopathy who undergo septal myectomy. BACKGROUND: Surgical myectomy provides excellent relief of symptoms in most patients with hypertrophic obstructive cardiomyopathy who are severely symptomatic despite medical therapy. There is a subset of patients who will remain symptomatic even after operation. Because comprehensive two-dimensional and Doppler echocardiography can define the range of anatomic and associated pathophysiologic abnormalities, it was hypothesized that preoperative echocardiographic variables may be predictive of clinical outcome after septal myectomy. METHODS: The clinical, electrocardiographic (ECG), echocardiographic and surgical data of 47 adult patients with hypertrophic cardiomyopathy who underwent isolated septal myectomy from 1986 to 1992 were analyzed. Specific symptoms were evaluated both preoperatively and at 1 year postoperatively. Electrocardiography and echocardiography were performed preoperatively and postoperatively. The ECG and echocardiographic variables were analyzed to determine whether any were predictive of residual symptoms 1 year postoperatively. RESULTS: The mean [+/-SD] age of the patients was 47 +/- 15 years. All were New York Heart Association functional class III or IV. Dyspnea was present in all 47 patients and was severe in 70%. Most patients experienced symptomatic improvement at 1 year; dyspnea persisted in 26 patients (55%). The preoperative echocardiographic variables of asymmetric hypertrophy, severe systolic anterior motion of the mitral leaflet(s) and prolonged isovolumetric relaxation time were independent predictors of mild or no residual dyspnea postoperatively. CONCLUSIONS: This initial study shows that the preoperative echocardiographic variables of asymmetric hypertrophy, severe systolic anterior motion of the mitral leaflet(s) and prolonged isovolumetric relaxation time can identify patients who are most likely to benefit from septal myectomy.

Cardiorespiratory response to exercise after modified Fontan operation: determinants of performance.

OBJECTIVES: This study sought to measure the cardiorespiratory responses to exercise and to identify the perioperative determinants of exercise performance in children, adolescents and young adults who underwent the modified Fontan operation. BACKGROUND: Several studies of the cardiorespiratory responses to exercise after the Fontan operation have demonstrated subnormal maximal oxygen uptake and exercise heart rate, but the perioperative variables that ultimately affect exercise responses have not been assessed systematically. METHODS: The study included 59 of the 548 patients who underwent a modified Fontan operation between January 1, 1984 and December 31, 1993 at the Mayo Clinic. Spirometry was performed at rest in all patients before exercise testing. The patients then exercised using a previously calibrated cycle ergometer and a 3-min incremental cycle exercise protocol. Multiple linear regression analysis was used to determine a subset of variables associated with oxygen uptake at peak exercise (VO2max), blood oxygen saturation (O2sat) and heart rate at peak exercise (HRmax). RESULTS: VO2max ranged from 29% to 95% of normal value; O2sat at peak exercise ranged from 77% to 96%; and HRmax ranged from 39.7% to 97.4% of normal value. Multivariate analysis showed that log VO2max/kg2/3 was associated with age at exercise, male gender, body surface area, preoperative confluent pulmonary arteries and rest VO2max/kg2/3. Preoperative left pulmonary artery stenosis, the presence of a classic Glenn anastomosis at exercise and rest O2sat were associated with O2sat at peak exercise. Age, body surface area at exercise, heart rate at rest and diastolic blood pressure were associated with HRmax at exercise. CONCLUSIONS: Subnormal VO2max and HRmax values were demonstrated at peak exercise. Several perioperative variables were associated with VO2max and O2sat at peak exercise. The presence of a classic Glenn anastomosis was associated with decreased O2sat at peak exercise, suggesting intrapulmonary shunting with the classic Glenn anastomosis.

Diagnostic role of Doppler echocardiography in constrictive pericarditis.

OBJECTIVES: This study was conducted to assess the diagnostic role of Doppler echocardiography in constrictive pericarditis. BACKGROUND: It has been observed that patients with constrictive pericarditis have a characteristic Doppler pattern of respiratory variation in ventricular filling and central venous flow velocities. However, the observation was based on a small number of patients with known diagnosis. METHODS: We reviewed the echocardiographic features of 28 patients (21 men and 7 women; mean age +/- SD 55 +/- 15 years) with suspected constrictive pericarditis who underwent exploratory thoracotomy or pericardiectomy. RESULTS: At operation, constrictive pericarditis was diagnosed in 25 patients, restriction in 1 and normal pericardium in 2. Of the 25 patients with constriction, correct preoperative Doppler diagnosis was made in 22 (88%) and Doppler echocardiography showed restriction in 3. In two patients with a normal pericardium, Doppler features were consistent with constriction in one patient and were normal in the other. In the one patient with restriction, Doppler echocardiography showed restriction. In 19 patients with surgically proved constriction, repeat Doppler study after pericardiectomy showed normal findings in 14 and restriction in 5. Twelve of the 14 patients with normalized Doppler findings became asymptomatic, whereas all 5 with restrictive Doppler features remained symptomatic. CONCLUSIONS: Doppler echocardiography performed simultaneously with respiratory recording is highly sensitive for diagnosing constrictive pericarditis, and it appears to predict functional response to pericardiectomy.