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Biomedical subjects

S D Colan

Publications and source records attributed to S D Colan.

At least 73 records · Page 4Linked to original sources
PubMed1995

Status of the left ventricle after arterial switch operation for transposition of the great arteries. Hemodynamic and echocardiographic evaluation.

BACKGROUND: The potential for improved preservation of systemic ventricular function represents an important reason for the increasing popularity of the arterial switch operation. In support of this expectation, prior studies in patients early after arterial switch operation have found normal ventricular contractility and function. This study was conducted to extend those observations to up to 10 years of follow-up and to directly examine the effects of a coexisting ventricular septal defect or short-term preparatory banding of the pulmonary artery before the arterial switch operation. METHODS: Patients operated on from 1983 through 1991 were included. Echocardiographic and catheterization data were collected as part of a prospective evaluation of outcome in all patients who undergo the arterial switch operation at Boston Children's Hospital, with inclusion of data from the most recent catheterization only. Echocardiograms performed at least 6 months after the operation were included, with assessment of both the most recent status as well as serial trends. Whenever possible, echocardiographic evaluation included data necessary to perform analysis of ventricular mechanics including indices of afterload, preload, and contractility. Comparison was made to normal values and between subgroups defined on the basis of an arterial switch operation with or without ventricular septal defect and those who had a rapid two-stage arterial switch operation. RESULTS: Invasive measures of left and right ventricular filling pressures, cardiac index, and pulmonary vascular resistance did not differ among the three groups. Overall, echocardiographic left ventricular end-diastolic dimension, wall thickness, mass, afterload (end-systolic wall stress), function (fractional shortening and rate-corrected velocity of fiber shortening), contractility (stress-velocity and stress-shortening relations), and preload were normal, and none of these variables was different between the groups with and without a ventricular septal defect. Serial evaluation indicated a slight but significant trend toward ventricular dilatation, perhaps related to a relatively high incidence of at least mild aortic regurgitation (30%). In contrast, in the rapid two-stage group the echocardiographic indices of left ventricular function (fractional shortening and velocity of fiber shortening) and contractility (stress-velocity and stress-shortening relations) were found to be mildly but significantly reduced compared with normal subjects and with the other arterial switch operation groups. Over the duration of follow-up encompassed by this study, no tendency toward progressive depression of function was seen. CONCLUSIONS: As the length of observation after the arterial switch operation continues to increase, left ventricular size, mass, functional status, and contractility continues to be normal, with no evidence of time-related deterioration of function. As previously reported, the rapid two-stage arterial switch operation does represent a higher risk for mild impairment of myocardial mechanics.

Aortic Valve Insufficiency↗
PubMed1994

Balloon aortic valvuloplasty in the young adult with congenital aortic stenosis.

Although balloon aortic valvuloplasty (BAV) is effective in the acute management of valvar aortic stenosis (AS), sustained benefit of this technique has been shown to vary in differing age groups. The role of BAV in the young adult with congenital, nondegenerative AS is poorly defined. The catheterization results and follow-up echocardiographic data were reviewed for all patients (n = 18) between the ages of 17 and 40 years (mean 23 +/- 7) undergoing BAV at our institution between March 1986 and January 1992. Peak-to-peak systolic ejection gradient was reduced by 55%, from 85 +/- 29 to 38 +/- 17 mm Hg (p < 0.001). Aortic valve area increased from 0.9 +/- 0.2 to 1.1 +/- 0.3 cm2 (p = 0.003). Results of dilation were inadequate in 2 patients. There were no deaths, myocardial infarction, or embolic events. The 16 "effectively" dilated patients were followed with serial echocardiography for a period of 1 to 82 months, demonstrating persistent gradient relief in most patients (maximal instantaneous gradient at follow-up, 55 +/- 17 vs 79 +/- 22 mm Hg before dilation, p < 0.001). Aortic valve replacements were performed in 5 patients, 2 with unsuccessful initial dilations. At the time of the most recent echocardiogram, 8 of 16 patients remained "incident free," with no subsequent catheterization or surgical interventions, a maximal instantaneous gradient of < or = 55 mm Hg, no more than moderate aortic regurgitation, and preserved ventricular function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Coronary echocardiography in 406 patients with d-loop transposition of the great arteries.

OBJECTIVES: The reliability of two-dimensional echocardiography for determining the proximal coronary artery anatomy in d-loop transposition of the great arteries was investigated in 406 infants who underwent surgical repair at one institution. BACKGROUND: The origin and proximal course of the main coronary arteries can affect the surgical results of the arterial switch operation. Preoperative determination of the coronary artery anatomy appears to be advantageous for the surgeon. METHODS: All infants with d-loop transposition who underwent a two-dimensional echocardiogram and primary surgical repair at our institution between 1987 and 1992 were identified, and the echocardiographic, operative and, when available, autopsy reports were reviewed for coronary artery anatomy, presence of a ventricular septal defect and the spatial relation between the arterial roots. The two-dimensional echocardiographic findings were compared with surgical or autopsy findings. The relation between proximal coronary artery anatomy and 1) a ventricular septal defect, and 2) the spatial orientation of the arterial roots was investigated. Twenty-seven infants diagnosed with an intramural coronary artery were not included because they are the subjects of another report. RESULTS: Excluding intramural coronary artery patterns, 10 different types of coronary artery anatomy were seen in these 406 patients. The coronary arteries were imaged adequately in 387 (95%) of the 406 patients. The coronary artery anatomy was determined correctly by two-dimensional echocardiography in 369 (95.4%) of the 387 patients, with 18 errors in diagnosis. During the most recent 2.5 years, 193 (98.5%) of 196 patients were diagnosed correctly, with three diagnostic errors. Patients with a ventricular septal defect or side-by-side great arteries are more likely to have an unusual coronary pattern. CONCLUSIONS: Echocardiography appears to be highly reliable for determining proximal coronary artery anatomy in d-loop transposition of the great arteries. An unusual coronary artery pattern is more likely in patients with side-by-side great arteries or posterior aorta or a ventricular septal defect, or both.

Child↗
PubMed1994

Effect of young age on coronary adaptations to left ventricular pressure overload hypertrophy in sheep.

OBJECTIVES: This study attempted to determine the effect of young age on changes in coronary conductance and capillary density with left ventricular pressure overload hypertrophy. Mechanisms responsible for age differences in perfusion capacity were examined. BACKGROUND: Hypertension in adults causes alterations in the coronary vasculature, resulting in diminished coronary perfusion capacity and myocardial ischemia. These processes are worsened in adults by advanced age. Young age may provide advantages in coronary adaptation to hypertension. METHODS: Coronary conductance was examined in conscious chronically instrumented 10-week old lambs and adult sheep with progressive ascending aortic stenosis of 6-week's duration and age-matched control sheep by means of the microsphere technique and vasodilators. Capillary density was measured post-mortem. RESULTS: Adult sheep with aortic stenosis had a decrease in left ventricular subendomyocardial capillary density by 17% and maximal coronary conductance with adenosine by 67%. In the nonhypertrophied right ventricle, maximal coronary conductance was depressed by 47%, whereas capillary density was normal, implying an effect of coronary hypertension on resistance vessels. In contrast, lambs with aortic stenosis maintained normal left ventricular capillary density, maximal coronary conductance and coronary reserve and had relatively little impairment of conductance in the right ventricular coronary bed (-15%, p = NS). Similar responses were found with other vasodilators, isoproterenol and chromonar. CONCLUSIONS: Young age confers advantages to coronary adaptation to left ventricular pressure overload, including angiogenesis proportionate to hypertrophy, resulting in normal capillary density and coronary conductance. There is also less hypertension-induced impairment of coronary conductance distinct from the effects of hypertrophy.

Adaptation, Physiological↗
PubMed1994

Myocardial perfusion, function and exercise tolerance after the arterial switch operation.

OBJECTIVES: This study was conducted to determine the prevalence of myocardial perfusion abnormalities at rest and exercise and to assess exercise capacity in children after the arterial switch operation. BACKGROUND: There have been sporadic reports of myocardial ischemia or sudden death in children after the arterial switch operation for transposition of the great arteries, possibly related to inadequate coronary perfusion due to kinking or stenosis of the translocated coronary arteries. METHODS: Myocardial perfusion at rest and peak exercise was assessed using the scintigraphic agent technetium-99m methoxyisobutyl isonitrile (sestamibi). Exercise capacity was determined with a modified Bruce protocol. Ambulatory electrocardiographic (ECG) Holter monitoring was performed. Ventricular function, contractility and wall motion were assessed echocardiographically. RESULTS: Twenty-three children (aged 4.2 to 7.9 years) underwent evaluation. Abnormalities were found on the rest perfusion scans in 22 children (95.6%). The left ventricular myocardium was divided into 13 segments for analysis. Of 299 rest segments, 225 (75.3%) were normal, 11 (3.7%) showed mild defects, 45 (15%) moderate defects and 18 (6%) severe defects at rest. At peak exercise, 237 segments (79.3%) were normal, 24 (8%) showed mild defects, 33 (11%) moderate defects and 5 (1.7%) severe defects. Compared with rest studies, myocardial perfusion grade at exercise was unchanged in 246 segments (82.3%), improved in 42 (14%) and worsened in 11 (3.7%). All patients had normal exercise tolerance without symptoms or ischemic ECG changes. No ventricular tachycardia was seen on Holter monitoring. All patients had a shortening fraction > or = 27%. Left ventricular contractility was normal in 12 children in whom it was assessed. Regional wall motion was normal in 17 children with adequate echocardiographic images for this analysis. CONCLUSIONS: Myocardial perfusion scan abnormalities assessed by technetium-99m sestamibi are common after an arterial switch operation. These abnormalities are of uncertain clinical significance and generally lessen with exercise. The normal exercise tolerance without symptoms or ECG changes suggests that myocardial perfusion is adequate during the physiologic stress of exercise in children up to 8 years after an arterial switch operation.

Child, Preschool↗
PubMed1994

Limitations of fractional shortening as an index of contractility in pediatric patients infected with human immunodeficiency virus.

Left ventricular fractional shortening (FS) is dependent on left ventricular preload and afterload, as well as contractility. Contractility may therefore not be accurately described by FS, especially in infants and children infected with human immunodeficiency virus (HIV), who tend to have abnormal left ventricular preload and afterload. We therefore examined the magnitude and clinical impact of the discrepancy between FS and contractility by assessment of 177 echocardiograms from 76 HIV-infected pediatric patients (median age, 1.9 years). The studies included simultaneous measurements of left ventricular FS, contractility, preload, and afterload. The correlation between contractility and FS was modest (r = 0.70; p < 0.001), and was weaker in children less than 2 years of age (r = 0.52) than in older children (r = 0.84). FS incorrectly predicted contractility in 46% of the studies; 43% with depressed FS (< 28%) had either normal (17/42) or enhanced (1/42) contractility. For 67% of echocardiograms, FS and contractility differed by > 1 SD, and for 36% the difference was > 2 SD. These differences remained after adjustment of FS for age or body surface area. Afterload was abnormal in 42% and preload in 21% of all echocardiograms. High preload predicted that FS would overestimate contractility (p = 0.002); high afterload predicted that FS would underestimate contractility (p < 0.001). The discrepancy between FS and contractility was larger among children who were younger, had more advanced HIV disease, or were not sedated during echocardiography. One third of children with congestive symptoms had normal contractility and depressed FS; the discrepancy was primarily due to loading conditions. We conclude that the high incidence of abnormal loading conditions in HIV-infected infants and children limits the usefulness of load-dependent FS for assessing contractility. Measurements of loading conditions and load-independent indexes, which more directly reflect contractility, allow a more accurate determination of myocardial status and may lead to better clinical management.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Gamma-globulin treatment of acute myocarditis in the pediatric population.

BACKGROUND: Myocardial damage in myocarditis is mediated, in part, by immunological mechanisms. High-dose intravenous gamma-globulin (IVIG) is an immunomodulatory agent that is beneficial in myocarditis secondary to Kawasaki disease, as well as in murine myocarditis. Since 1990, the routine management of presumed acute myocarditis at Children's Hospital, Boston, and Children's Hospital, Los Angeles, has included administration of high-dose IVIG. METHODS AND RESULTS: We treated 21 consecutive children presenting with presumed acute myocarditis with IVIG, 2 g/kg, over 24 hours, in addition to anticongestive therapies. A comparison group comprised 25 recent historical control patients meeting identical eligibility criteria but not receiving IVIG therapy. Left ventricular function was assessed during five time intervals: 0 to 7 days, 1 to 3 weeks, 3 weeks to 3 months, 3 to 6 months, and 6 to 12 months. At presentation, the IVIG and non-IVIG groups had comparable left ventricular enlargement and poor fractional shortening. Compared with the non-IVIG group, those treated with IVIG had a smaller mean adjusted left ventricular end-diastolic dimension and higher fractional shortening in the periods from 3 to 6 months (P = .008 and P = .033, respectively) and 6 to 12 months (P = .072 and P = .029, respectively). When adjusting for age, biopsy status, intravenous inotropic agents, and angiotensin-converting enzyme inhibitors, patients treated with IVIG were more likely to achieve normal left ventricular function during the first year after presentation (P = .03). By 1 year after presentation, the probability of survival tended to be higher among IVIG-treated patients (.84 versus .60, P = .069). We observed no adverse effects of IVIG administration. CONCLUSIONS: These data suggest that use of high-dose IVIG for treatment of acute myocarditis is associated with improved recovery of left ventricular function and with a tendency to better survival during the first year after presentation.

Acute Disease↗
PubMed1994

Rapid two-stage arterial switch operation. Evaluation of left ventricular systolic mechanics late after an acute pressure overload stimulus in infancy.

BACKGROUND: Banding of the pulmonary artery to induce left ventricular (LV) hypertrophy followed by arterial switch operation (ASO) within 2 weeks has been performed when a primary ASO was considered high risk because of inadequate LV hypertrophy. METHODS AND RESULTS: Potential adverse myocardial effects of the two-stage procedure were examined by comparing outcome in 18 patients after a rapid two-stage ASO with 33 patients after a primary ASO. Regional wall motion was assessed. Echocardiographic and noninvasive pressure data were combined to obtain LV dimension, wall thickness, mass, fractional shortening, rate-corrected mean velocity of shortening, and end-systolic wall stress. Afterload-adjusted velocity of shortening was obtained as a load-independent index of contractility. In the two-stage ASO group, the magnitude and rate of hypertrophy after pulmonary artery banding were measured serially. No wall motion abnormalities were seen in either group. Systolic dysfunction due to higher afterload and lower contractility was observed in the two-stage ASO group. Contractility below the limits of normal was seen in 25% of two-stage ASO compared with 3% of primary ASO; however, symptomatic or progressive LV dysfunction was not observed. There was a significant inverse relation between the peak rate of hypertrophy immediately after banding and contractility at late exam. Lower ejection fraction before and early after pulmonary artery banding correlated with depressed contractility on late examination. CONCLUSIONS: Myocardial contractility is lower after the two-stage ASO than after a primary repair. Severe or progressive dysfunction was not seen. A very high peak rate of hypertrophy and severe LV dysfunction after banding predict a greater reduction in late contractility.

Acute Disease↗
PubMed1994

Rapid two-stage arterial switch operation. Acquisition of left ventricular mass after pulmonary artery banding in infants with transposition of the great arteries.

BACKGROUND: Banding of the pulmonary artery (PAB) in preparation for arterial switch operation (ASO) in patients with transposition of the great arteries (TGA) represents a unique model of acute left ventricular pressure overload in humans. METHODS AND RESULTS: To establish the rate, magnitude, and determinants of left ventricular hypertrophy and the acute effect on ventricular function, serial bidimensional echocardiographic evaluations were performed on 26 patients with TGA after PAB. Mass, volume, and ejection fraction of the left ventricle were measured. Cardiac catheterization data before PAB and again before ASO were reviewed. The mean interval between the PAB and ASO was 9 +/- 4 days. The left ventricular to right ventricular pressure ratio before PAB was 0.5 and increased to 1.0 before ASO. The mean percentage increase in left ventricular mass from PAB to ASO was 96%, 95% of which was achieved in the first 7 days. The average rate of left ventricular hypertrophy for the entire period was 0.06 g/h and was 0.19 g/h during the interval from PAB to attainment of maximum left ventricular mass. The most rapid rate of hypertrophy was seen by day 2, with an exponential fall in the growth rate thereafter approaching zero by day 7. Ejection fraction was significantly reduced at 12 hours after PAB, but mean values returned to pre-PAB levels by 3.5 days after banding. The absolute rate of left ventricular hypertrophy correlated directly with body surface area but not to other hemodynamic variables. CONCLUSIONS: Doubling of left ventricular mass can be achieved in 1 week after PAB. Function falls acutely due to afterload excess and/or depressed contractility but recovers rapidly as compensatory hypertrophy occurs.

Echocardiography↗
PubMed1994

Infantile dilated cardiomyopathy. Relation of outcome to left ventricular mechanics, hemodynamics, and histology at the time of presentation.

BACKGROUND: For patients with acute dilated cardiomyopathy, definition of prognosis and of clinical features predictive of outcome is particularly important due to the availability of cardiac transplantation and other innovative treatment strategies. METHODS AND RESULTS: We reviewed our experience with 24 children under 2 years of age with dilated congestive cardiomyopathy to determine outcome and potential predictive variables. Clinical, serological, ECG, echocardiographic, hemodynamic, and histological findings were analyzed. Idiopathic cardiomyopathy or myocarditis constituted 29% of the patients presenting with congestive heart failure without structural heart disease. Among these patients, 45% recovered completely, 25% survived with persistent left ventricular dysfunction, and 30% died. All except one of the deaths occurred during the first 2 months after presentation. Poorer outcome and higher mortality were associated with a more severely depressed left ventricular ejection fraction and/or a more spherical left ventricular shape at presentation. Histological evidence of myocardial inflammation was a favorable prognostic indicator, whereas histological evidence of endocardial fibroelastosis was associated with a poor outcome. During the recovery phase, diastolic volume fell rapidly. Ventricular mass was elevated from the earliest observations and fell more slowly, with persistent elevation of the mass-to-volume ratio up to 2 years. Function and contractility improved over the first several months in most patients who recovered, although in occasional patients continued improvement was seen for as long as 2 years after presentation. CONCLUSIONS: Histological and echocardiographic features can be used to identify patients at particularly high risk for death. To have any impact on outcome, decisions about cardiac transplantation must be reached rapidly, since almost all deaths occurred within the first 2 months after presentation. Recovery of function is often rapid, but continued improvement may be seen for as long as 2 years.

Cardiomyopathy, Dilated↗
PubMed1994

Monitoring for anthracycline cardiotoxicity.

OBJECTIVE: To review the basis for recommendations of the Cardiology Committee of the Children's Cancer Study Group, published in Pediatrics, for serial cardiac monitoring of cancer patients during anthracycline therapy and reduction of therapy should cardiac studies show abnormalities. DESIGN: Because the effects of overall morbidity and mortality should be considered when a recommendation is made to withhold potentially lifesaving chemotherapy based on abnormal cardiac findings of patients without clinical evidence of cardiac dysfunction, supporting studies referenced in the published recommendations were reviewed. Specifically, studies were evaluated to determine whether a reduction in anthracycline dose, as a result of abnormal cardiac findings by monitoring, reduced cardiac morbidity and related mortality compared with a prospectively followed control population without dose modification. In addition, the effects of cardiac monitoring and subsequent anthracycline dose modification on oncologic morbidity and mortality were reviewed in these studies. Finally, the contributions of the cardiac and oncologic effects of dose modification were examined to determine the effect of this change in therapy on overall morbidity and mortality. RESULTS: None of the studies cited in developing these recommendations prospectively determined, with controls, the effects of cardiac monitoring and anthracycline dose modification on cardiac, oncologic, or overall morbidity and mortality. Therefore, none of the studies cited in support of cardiac monitoring and subsequent dose reduction demonstrated the efficacy of such an approach. In the absence of such data, concerns are raised as to whether such a monitoring program with subsequent dose modification might do more harm than good. In addition, none of the methods of screening for anthracycline cardiotoxicity has been shown to be adequately predictive of early or late cardiac outcomes. Finally, adoption of these recommendations would inhibit the investigation of the efficacy of the proposed plan. CONCLUSION: Given the absence of supportive data and the potential to do harm, no recommendation for dose modification based on abnormal cardiac findings in patients without clinical evidence of cardiotoxicity can be endorsed, including those of the Cardiology Committee of the Children's Cancer Study Group. When clinical evidence of cardiotoxicity is present, anthracycline dose modification is recommended. A prospective controlled study to determine the effects of dose modification based on cardiac test results is indicated.

Antibiotics, Antineoplastic↗
PubMed1993

Conal anatomy in 119 patients with d-loop transposition of the great arteries and ventricular septal defect: an echocardiographic and pathologic study.

OBJECTIVES: We sought to study the range of conal morphology in transposition of the great arteries with ventricular septal defect and their embryologic and surgical implications. BACKGROUND: Conal anatomy in transposition of the great arteries and ventricular septal defect is variable and might affect surgical repair. METHODS: Conal anatomy was explored using two-dimensional echocardiography in 119 patients with transposition of the great arteries and a large ventricular septal defect who presented between 1984 and 1991. The influence of conal anatomy on surgical technique was determined by review of the operative reports. Specimens of transposition of the great arteries with unusual conal anatomy were selected from the Cardiac Registry for comparison with the echocardiograms. RESULTS: One hundred five patients (88.2%) had subaortic conus only with no subpulmonary conus (Group 1). Subarterial conus was present bilaterally in eight patients (6.7%) (Group 2). Four patients (3.4%) had only subpulmonary conus with no (or minimal) subaortic conus (Group 3). Among these four patients, the aorta was posterior to the pulmonary artery in one patient, side by side relative to the pulmonary artery in two patients and slightly anterior in the fourth patient. Subarterial conus was absent bilaterally in two patients (1.7%) (Group 4); the aorta was slightly posterior in one and side by side with the pulmonary artery in the other. CONCLUSIONS: This variability of conal anatomy in transposition of the great arteries with ventricular septal defect implies four mechanisms by which transposition can occur. The conal anatomy appeared to affect surgical repair in Groups 1 and 2 insofar as it influenced ventricular outflow tract obstruction. In Groups 3 and 4, an arterial switch operation was performed in four of the six patients. The posterior location of the aorta obviated the need for the Lecompte maneuver in two of these four patients. In the remaining two cases in Groups 3 and 4, the condition was repaired by directing the left ventricular outflow across the ventricular septal defect to the aorta using a patch, with or without placement of a conduit from the right ventricle to the pulmonary artery.

Abnormalities, Multiple↗
PubMed1993

Multipolar endocardial mapping of the right atrium during cardiac catheterization: description of a new technique.

OBJECTIVES: Using a new mapping system that allows the simultaneous acquisition of data from 25 right atrial bipolar electrodes during cardiac catheterization, we mapped normal sinus rhythm and atrial reentrant tachycardia in 24 sheep (20 to 49 kg) and 7 pigs (25 to 35 kg). BACKGROUND: Rapid, high resolution mapping during cardiac catheterization may shorten ablation procedures and permit ablation of otherwise refractory arrhythmias. METHODS: A flexible, elliptic, basket-shaped recording catheter has five spokes, each with 10 electrodes arranged as 5 bipolar pairs. Catheter shape, electrode spacing and introduction technique were modified in response to the results of experiments in the first 23 animals. In the most recent eight animals, retraction of a string attached to the distal tip distended the basket, providing safe tissue contact. Filtered (30 to 250 Hz) bipolar recordings from all 25 electrode pairs, as well as a surface electrocardiogram, were recorded and digitized at 1,000 Hz using custom software. An activation map was digitally constructed and superimposed on anteroposterior and lateral fluoroscopic catheter images. Bipolar recordings were made in normal sinus rhythm (31 animals), with adequate signals recorded from > 95% of electrode pairs. Rapid burst pacing and intentional right atrial air embolus (30 to 50 ml) induced sustained atrial reentrant tachycardia in five animals, which was also adequately recorded. RESULTS: Catheter positioning and complete atrial mapping required < 10 min after venous access in the most recent eight experiments. The catheter was left in position for up to 4 h. Postmortem evaluation revealed minor superficial abrasion of the venae cavae or right atrial endocardium in six animals and moderate abrasion in two. No other damage was observed. CONCLUSIONS: This new system may ultimately assist in mapping simple or complex atrial arrhythmias during cardiac catheterization.

Animals↗
PubMed1993

Echocardiographic predictors of left ventricular outflow tract obstruction after repair of interrupted aortic arch.

OBJECTIVES: This study was designed to identify preoperative echocardiographic predictors of left ventricular outflow tract obstruction after repair of interrupted aortic arch and ventricular septal defect closure. BACKGROUND: Left ventricular outflow tract obstruction becomes apparent in nearly 50% of patients after repair of interrupted aortic arch and ventricular septal defect closure but is seldom recognized preoperatively. METHODS: We analyzed the preoperative echocardiograms of all patients with interrupted aortic arch who had postoperative echocardiographic or catheterization data available. Thirty-seven infants (aged 1 day to 10 months, median 5 days) were included. Off-line measurements were performed on hard copies of selected images. The cross-sectional area (indexed to body surface area) and diameters (indexed to the square root of body surface area) of the left ventricular outflow tract; ascending and descending aorta; ventricular septal defect; and mitral, aortic and pulmonary valves were compared with outcome by using analysis of variance. Outcome was classified according to development of postoperative left ventricular outflow tract Doppler gradient (Group 1 < or = 20 mm Hg, Group 2 > 20 mm Hg). RESULTS: The cross-sectional area of the left ventricular outflow tract was significantly smaller in patients who did than in those who did not develop subaortic obstruction ([mean +/- SD] 0.64 +/- 0.25 vs. 1.7 +/- 1.01 cm2/m2, p < 0.004). Left ventricular outflow tract and aortic valve diameters and aortic valve area were not predictive of postoperative left ventricular outflow tract obstruction. Incidence of postoperative left ventricular outflow tract obstruction was lower (p < 0.03) in interrupted aortic arch type A (0 of 6) than in type B (15 of 31). The incidence of aberrant right subclavian artery was lower (p < 0.02) in Group 1 (6 of 22) than in Group 2 (10 of 15). CONCLUSIONS: The preoperatively measured cross-sectional area of the left ventricular outflow tract is significantly smaller in patients with interrupted aortic arch who develop subaortic obstruction postoperatively, with a left ventricular outflow tract area < or = 0.7 cm2/m2 being a sensitive predictor. Aortic arch anatomy (i.e., type of interrupted aortic arch and presence of aberrant right subclavian artery) is also predictive of postoperative left ventricular outflow tract obstruction, possibly by influencing the volume of blood flow across the left ventricular outflow tract. These data should enable preoperative identification of infants who may require surgical relief of subaortic stenosis.

Aorta, Thoracic↗
PubMed1993

Individual pulmonary vein size and survival in infants with totally anomalous pulmonary venous connection.

OBJECTIVES: We investigated whether mortality in totally anomalous pulmonary venous connection could be predicted from preoperative individual pulmonary vein size. BACKGROUND: Some infants with this anomaly die with or without surgical repair because of stenosis of individual pulmonary veins. METHODS: Individual pulmonary vein, vertical vein and pulmonary venous confluence diameters were retrospectively measured from preoperative echocardiograms in 32 infants with totally anomalous pulmonary venous connection presenting to Children's Hospital, Boston over a 4 1/2-year period. Data on body surface area, other cardiac anomalies, presence of initial pulmonary venous obstruction and early surgery and outcome were also recorded. RESULTS: Of 32 patients, 6 (18.8%) died before hospital discharge, and 8 (25.0%) died subsequently. Six (75.0%) of the eight patients who died late had individual pulmonary vein stenosis at sites remote from the surgical anastomosis to the left atrium. The remaining 18 patients (56.3%) are alive at a mean follow-up period of 9.7 months. A Cox proportional hazards model revealed that small sum of individual pulmonary vein diameters (p = 0.0004), small confluence size (p = 0.02) and presence of heterotaxy syndrome (p = 0.008) were each significant univariate predictors of survival. Multivariate analysis showed that small pulmonary vein sum was a strong predictor of survival (p = 0.008), independent of the presence of heterotaxy syndrome. An analysis stratified by the presence of heterotaxy syndrome showed that the predictive effect of small pulmonary vein sum on survival was strongest in patients without heterotaxy syndrome. CONCLUSIONS: These data show that individual pulmonary vein size at diagnosis is a strong, independent predictor of survival in patients with totally anomalous pulmonary venous connection. In patients with this anomaly and small individual pulmonary veins, the anomaly may not be correctable by surgical creation of an anastomosis between the pulmonary venous confluence and the left atrium.

Echocardiography↗
PubMed1993

Reliability of Doppler color flow mapping in the identification and localization of multiple ventricular septal defects.

The purpose of this study was to compare Doppler color flow mapping with angiography and surgical observation for detection of multiple ventricular septal defects (VSDs). Only patients with elevated pulmonary ventricular pressure were included. Among 137 patients with VSDs, 38 multiple defects were identified in 25 patients echocardiographically, 34 multiple defects in 24 patients angiographically, and 21 multiple defects in 17 patients surgically. Using surgical observation as the reference standard, the sensitivity of echocardiography for identifying patients with multiple VSDs was 17 of 17 (100%) and for angiography 15 of 17 (88%). The sensitivity of echocardiography for identifying all multiple VSDs seen at operation was 19 of 21 (90%) and of angiography was also 19 of 21 (90%). In many patients, use of both techniques may no longer be necessary.

Angiography↗