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Biomedical subjects

S D Colan

Publications and source records attributed to S D Colan.

At least 109 records · Page 6Linked to original sources

Late potentials and their relation to ventricular function in human immunodeficiency virus infection.

Signal-averaged electrocardiograms were performed in 225 patients with serologic evidence of human immunodeficiency virus infection as part of a prospective longitudinal study of patients with HIV-associated heart disease and 12 seronegative control subjects. The duration of signal-averaged QRS vector, root-mean-square voltage of the terminal 40 ms of the vector magnitude and the duration of the low-amplitude (less than 40 microV) signal were determined during serial visits at 4-month intervals. One or more of these variables was abnormal on initial visit in 59 of patients (26%); QRS duration was greater than 114 ms in 9 patients (4%), root-mean-square voltage less than 20 microV in 55 patients (24%) and low-amplitude signal duration greater than 39 ms in 43 (19%). In contrast, none of the seronegative control subjects had any abnormal variables (p less than 0.03). During follow-up (mean 10 +/- 8 months), 26 patients with initially normal studies developed abnormal variables and 24 with abnormal signal-averaged electrocardiograms reverted to normal. Left ventricular contractility was assessed by echocardiography using the rate-corrected velocity of fiber shortening-end-diastolic wall stress relation. Late potentials were not related to contractile abnormalities. Clinical arrhythmias were rare and did not appear more frequent among patients with late potentials. Thus, late potentials were both common and evanescent in patients infected with human immunodeficiency virus.

Adult↗

A single intravenous infusion of gamma globulin as compared with four infusions in the treatment of acute Kawasaki syndrome.

BACKGROUND: Treatment of acute Kawasaki syndrome with a four-day course of intravenous gamma globulin, together with aspirin, has been demonstrated to be safe and effective in preventing coronary-artery lesions and reducing systemic inflammation. We hypothesized that therapy with a single, very high dose of gamma globulin would be at least as effective as the standard regimen. METHODS: We conducted a multicenter, randomized, controlled trial involving 549 children with acute Kawasaki syndrome. The children were assigned to receive gamma globulin either as a single infusion of 2 g per kilogram of body weight over 10 hours or as daily infusions of 400 mg per kilogram for four consecutive days. Both treatment groups received aspirin (100 mg per kilogram per day through the 14th day of illness, then 3 to 5 mg per kilogram per day). RESULTS: The relative prevalence of coronary abnormalities, adjusted for age and sex, among patients treated with the four-day regimen, as compared with those treated with the single-infusion regimen, was 1.94 (95 percent confidence limits, 1.01 and 3.71) two weeks after enrollment and 1.84 (95 percent confidence limits, 0.89 and 3.82) seven weeks after enrollment. Children treated with the single-infusion regimen had lower mean temperatures while hospitalized (day 2, P less than 0.001; day 3, P = 0.004), as well as a shorter mean duration of fever (P = 0.028). Furthermore, in the single-infusion group the laboratory indexes of acute inflammation moved more rapidly toward normal, including the adjusted serum albumin level (P = 0.004), alpha 1-antitrypsin level (P = 0.007), and C-reactive protein level (P = 0.017). Lower IgG levels on day 4 were associated with a higher prevalence of coronary lesions (P = 0.005) and with a greater degree of systemic inflammation. The two groups had a similar incidence of adverse effects (including new or worsening congestive heart failure in nine children), which occurred in 2.7 percent of the children overall. All the adverse effects were transient. CONCLUSIONS: In children with acute Kawasaki disease, a single large dose of intravenous gamma globulin is more effective than the conventional regimen of four smaller daily doses and is equally safe.

Acute Disease↗

Late cardiac effects of doxorubicin therapy for acute lymphoblastic leukemia in childhood.

BACKGROUND: Cardiotoxicity is a recognized complication of doxorubicin therapy, but the long-term effects of doxorubicin are not well documented. We therefore assessed the cardiac status of 115 children who had been treated for acute lymphoblastic leukemia with doxorubicin 1 to 15 years earlier in whom the disease was in continuous remission. METHODS: Eighteen patients received one dose of doxorubicin (45 mg per square meter of body-surface area), and 97 received multiple doses totaling 228 to 550 mg per square meter (median, 360). The median interval between the end of treatment and the cardiac evaluation was 6.4 years. Our evaluation consisted of a history, 24-hour ambulatory electrocardiographic recording, exercise testing, and echocardiography. RESULTS: Fifty-seven percent of the patients had abnormalities of left ventricular afterload (measured as end-systolic wall stress) or contractility (measured as the stress-velocity index). The cumulative dose of doxorubicin was the most significant predictor of abnormal cardiac function (P less than 0.002). Seventeen percent of patients who received one dose of doxorubicin had slightly elevated age-adjusted afterload, and none had decreased contractility. In contrast, 65 percent of patients who received at least 228 mg of doxorubicin per square meter had increased afterload (59 percent of patients), decreased contractility (23 percent), or both. Increased afterload was due to reduced ventricular wall thickness, not to hypertension or ventricular dilatation. In multivariate analyses restricted to patients who received at least 228 mg of doxorubicin per square meter, the only significant predictive factors were a higher cumulative dose (P = 0.01), which predicted decreased contractility, and an age of less than four years at treatment (P = 0.003), which predicted increased afterload. Afterload increased progressively in 24 of 34 patients evaluated serially (71 percent). Reported symptoms correlated poorly with indexes of exercise tolerance or ventricular function. Eleven patients had congestive heart failure within one year of treatment with doxorubicin; five of them had recurrent heart failure 3.7 to 10.3 years after completing doxorubicin treatment, and two required heart transplantation. No patient had late heart failure as a new event. CONCLUSIONS: Doxorubicin therapy in childhood impairs myocardial growth in a dose-related fashion and results in a progressive increase in left ventricular afterload sometimes accompanied by reduced contractility. We hypothesize that the loss of myocytes during doxorubicin therapy in childhood might result in inadequate left ventricular mass and clinically important heart disease in later years.

Child↗

Two-dimensional echocardiography in the pre- and postoperative management of totally anomalous pulmonary venous connection.

The records of 23 infants who underwent surgical repair of isolated totally anomalous pulmonary venous connection were reviewed to assess the accuracy of pre- and postoperative echocardiographic diagnoses. Preoperative echocardiographic diagnoses were accurate in 22 of 23 patients, including the sites of connection of the individual pulmonary veins. Cardiac catheterization in 13 patients confirmed the echocardiographic findings. Analysis of multiple pre- and postoperative variables revealed no statistically significant difference between the infants with and without catheterization, although there was a tendency toward a higher mortality rate in the catheterized group. Postoperative echocardiographic examination revealed obstruction to pulmonary venous return in 7 of 19 patients. Catheterization confirmed the echocardiographic findings, localizing the obstruction in one patient. The size of the venoatrial anastomosis was measured on postoperative echocardiograms performed on 14 patients. The cross-sectional area of the anastomosis was less than 0.3 cm2/m2 of body surface area in the four patients with obstruction of the anastomosis, and greater than 0.95 cm2/m2 in all long-term survivors examined. Two-dimensional echocardiography with pulsed Doppler examination and Doppler color flow mapping is an excellent means of diagnosing totally anomalous pulmonary venous connection. The connections of the individual pulmonary veins can be identified in nearly all cases. Surgical repair can usually be undertaken on the basis of echocardiographic diagnosis alone. Echocardiography also provides an extremely accurate method of evaluating surgical repair and of identifying and localizing postoperative obstruction to pulmonary venous return.

Cardiac Catheterization↗

Double-inlet single left ventricle: echocardiographic anatomy with emphasis on the morphology of the atrioventricular valves and ventricular septal defect.

The echocardiographic anatomy of double-inlet single left ventricle was studied in 57 patients, aged 1 day to 27 years (mean 6 years); the variables examined included morphology, size and function of the atrioventricular (AV) valves and ventricular septal defect and their relation to pulmonary stenosis, aortic stenosis and aortic arch obstruction. The visceroatrial situs was solitus and the heart was in the left side of the chest in all 57 patients. A d-loop ventricle was present in 21 patients and an l-loop ventricle in 36. The great arteries were normally related (Holmes heart) in 8 patients and transposed in 49. In all hearts, the right AV valve was anterior to the left AV valve. In 53 patients, the tricuspid valve (right valve in d-loop and left valve in l-loop) was closer to and had attachments on the septum. The tricuspid valve straddled the outflow chamber in eight patients. No significant difference was noted in the mean AV valve diameter when comparing mitral and tricuspid valves within the same group or between the groups with a d- or l-loop ventricle. The right AV valve diameter had a significant direct correlation with the aortic valve diameter and the size of the ventricular septal defect regardless of ventricular loop. Both AV valves were functionally normal in 34 patients. Among patients with AV valve dysfunction, the tricuspid valve tended to be stenotic in patients with an l-loop ventricle and regurgitant in patients with a d-loop ventricle. Mitral valve dysfunction was uncommon. The ventricular septal defect (46 patients) was separated from the semilunar valves in 24 patients (muscular defect) and adjacent to the anterior semilunar valve as a result of hypoplasia or malalignment, or both, of the infundibular septum (subaortic defect) in 19 patients. Multiple defects were present in three patients. The defect was unrestrictive in 26 patients, restrictive in 23 and could not be evaluated in 8. Pulmonary artery banding had been performed in 8 of the 26 patients with an unrestrictive defect and in 10 of the 23 patients with a restrictive defect. Only 4 of 19 subaortic defects compared with 16 of 24 muscular defects were restrictive. The size of the defect was significantly correlated with the measured pressure gradient. Among patients with transposition, only 2 of 13 with pulmonary stenosis had a restrictive ventricular septal defect compared with 15 of 30 without pulmonary stenosis. In patients with transposition, the defect size was significantly smaller when coarctation was present.

Child↗

Predictors of survival in neonates with critical aortic stenosis.

BACKGROUND: Failure of infants with critical aortic stenosis to survive after adequate valvotomy despite a left ventricular size that appears to be adequate indicates that additional preoperative anatomic features may contribute to mortality. METHODS AND RESULTS: Discriminant analysis was used to determine which of several echocardiographically measured left heart structures were independent predictors of survival after valvotomy for neonatal critical aortic stenosis. It was possible to predict outcome after classic valvotomy (two-ventricle-type repair) with 95% accuracy based on mitral valve area, long-axis dimension of the left ventricle relative to the long-axis dimension of the heart, diameter of the aortic root, and body surface area. Left ventricular volume was not a major determinant in this study, in part because patients who had initial valvotomy had been preselected in favor of an adequately sized left ventricle. Patients with multiple small left ventricular structures were found to have significantly improved survival after initial Norwood operation. In contrast, balloon valvotomy with subsequent Norwood procedure was usually unsuccessful. CONCLUSIONS: The adverse effects of small inflow, outflow, and/or cavity size of the left ventricle are cumulative. The accuracy of prediction of outcome based only on preoperative anatomy indicates that adequacy of valvotomy is not generally a limiting factor for survival in this group of patients. It is possible to identify subjects whose chance of survival is better after a Norwood procedure rather than valvotomy, even if left ventricular volume is not critically small.

Aortic Valve Stenosis↗

Myocardial angiogenesis and coronary perfusion in left ventricular pressure-overload hypertrophy in the young lamb. Evidence for inhibition with chronic protamine administration.

In contrast to young growing animals, pressure-overload hypertrophy in adults is frequently associated with diminished myocardial capillary density and maximal coronary flow per gram. To determine the role of angiogenesis in maintaining perfusion capacity in the hypertrophying heart, the angiogenesis inhibitor protamine sulfate was administered to young lambs during the development of left ventricular (LV) pressure-overload hypertrophy. Baseline and maximum (adenosine) myocardial perfusion was measured in four groups of chronically instrumented 10-week-old lambs subjected to 1) ascending aortic bands since the age of 4 weeks (LVH group, n = 10), 2) sham operation at the age of 4 weeks (SHAM group, n = 8), 3) aortic bands and twice daily injections of protamine since the age of 4 weeks (LVH + P group, n = 9), 4) sham operation and injection of protamine (SHAM + P group, n = 8). Capillary density was measured postmortem. Peak LV pressure and the LV/body weight ratio were similarly increased in LVH and LVH + P compared with sham-operated lambs (p less than 0.001). In LVH lambs, LV capillary number increased by 32% compared with sham-operated lambs (p less than 0.05), and capillary density, coronary flow reserve, and minimal coronary resistance remained normal. In contrast, LVH + P lambs had no significant increase over SHAM lambs in LV capillaries and total maximum coronary flow. The LVH + P lambs had lower LV subendomyocardial capillary density and higher minimal coronary resistance per gram (p less than 0.05 versus LVH lambs). Right ventricular capillary density and minimal resistance were similar in all groups. These findings support the hypotheses that myocardial angiogenesis with pressure-overload hypertrophy is important in maintaining maximal LV coronary flow in the young and that impairment of angiogenesis results in diminished coronary flow capacity.

Age Factors↗

Function of the anatomic pulmonary valve in the systemic circulation.

The anatomic pulmonary valve, which has thin leaflets with little elastic tissue in the normal heart, must function as the neoaortic valve after arterial switch operation (ASO) for transposition of the great arteries, palliative surgery for hypoplastic left heart syndrome (HLHS), and pulmonary artery-to-aortic (P-A) anastomosis for complex heart disease with subaortic obstruction. The long-term function of this valve under these circumstances is not known. To investigate the function of this valve in the systemic circulation, the follow-up echocardiograms, catheterization data, and angiograms were reviewed for 189 patients at our institution after an ASO (n = 112), palliative surgery for HLHS (n = 45), or P-A anastomosis (n = 32). In addition, the effect on valve function of preoperative anatomy, prior placement of a pulmonary artery band (PAB), and length of follow-up was examined. Neoaortic regurgitation was present in 41% of patients after an ASO (mean +/- SD) follow-up (20 +/- 20; range, 2.2-80.5 months), 60% of patients after an HLHS repair (21 +/- 15; range, 3.7-62.4 months) and 50% after a P-A anastomosis (27 +/- 21; range, 2.6-89.4 months). Only eight patients had more than trivial/mild regurgitation. No neoaortic stenosis was observed. Minor preoperative valve abnormalities did not influence postoperative valve function. Prior PAB placement significantly increased the likelihood of postoperative neoaortic regurgitation after a two-stage ASO but not after a P-A anastomosis. In the ASO group, patients with an intact ventricular septum had a significantly higher prevalence of neoaortic regurgitation than those with a ventricular septal defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗

Cardiotoxicity during treatment of severe childhood asthma.

We prospectively evaluated 20 patient admissions for severe exacerbation of childhood asthma at The Children's Hospital, Boston, to detect evidence of cardiotoxicity. Evidence of cardiotoxicity was found in all six patient admissions for which isoproterenol infusion was utilized. This included marked elevation of serum creatine phosphokinase isoenzyme (CPK-MB) levels and electrocardiogram abnormalities consistent with transient myocardial ischemia. Peak serum CPK-MB levels were significantly lower and electrocardiogram abnormalities were significantly less frequent during 14 patient admissions for which isoproterenol infusion was not utilized. Risk factors associated with cardiotoxicity included tachycardia, hypercapnia, acidosis, and intravenous isoproterenol therapy. We conclude that cardiotoxicity is not infrequent during therapy for severe exacerbations of childhood asthma. Electrocardiograms and measurement of serum CPK-MB levels are sensitive, useful, and readily obtained indicators of cardiotoxicity. Abnormalities of these studies may detect cardiotoxicity prior to the occurrence of more blatant or catastrophic manifestations of cardiotoxicity. We therefore recommend serial monitoring of serum CPK-MB levels and electrocardiograms for all children requiring an admission to the intensive care unit for management of severe asthmatic exacerbation.

Adolescent↗

Results of the arterial switch operation in patients with transposition of the great arteries and abnormalities of the mitral valve or left ventricular outflow tract.

Between January 1983 and October 1989, 290 patients underwent an arterial switch operation for transposition of the great arteries; 30 (10.3%) of the patients had abnormalities of the left ventricular outflow tract or mitral valve, or both. These abnormalities included isolated pulmonary valve stenosis (n = 9), septal (dynamic) subpulmonary stenosis (n = 5), anatomic (fixed) subpulmonary stenosis (n = 7), abnormal mitral chordae attachments (n = 2) or a combination of abnormalities (n = 7). There were two early deaths, one of which was due to previously unrecognized mitral stenosis and a subpulmonary (neo-aortic) membrane and one late death due to presumed coronary obstruction. Of the nine patients with pulmonary valve abnormalities due to either a bicommissural (n = 5) or a thickened tricommissural (n = 4) valve, only one underwent valvotomy. Peak systolic ejection gradients in these nine patients measured preoperatively ranged from 0 to 50 mm Hg. At follow-up study 5 to 30 months postoperatively, the neo-aortic valve gradient was less than or equal to 15 mm Hg in all patients; three patients had mild neo-aortic regurgitation. Preoperative gradients may overestimate the degree of obstruction because of the increased pulmonary blood flow present in transposition. No patient with "dynamic" subpulmonary obstruction before the arterial switch operation had a surgical procedure performed on the left ventricular outflow tract; none had evidence of subaortic obstruction after the arterial switch.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Multiple↗

Cardiovascular manifestations of human immunodeficiency virus infection in infants and children.

Thirty-one pediatric patients with human immunodeficiency virus infection were prospectively evaluated using 2-dimensional and M-mode echocardiography, Doppler cardiography, electrocardiography and Holter monitoring. Left ventricular shape, wall motion and valve morphology were evaluated with 2-dimensional echocardiography. Valve function was assessed using Doppler cardiography. Left ventricular performance was evaluated with shortening fraction, afterload with end-systolic wall stress and contractility with the end-systolic wall stress and rate-corrected velocity of shortening relation. Although left ventricular performance, afterload and contractility varied widely, 2 patterns of left ventricular function abnormalities were noted. Hyperdynamic left ventricular performance, generally with enhanced contractility and reduced afterload, was the most common echocardiographic finding (63%). Diminished contractility was noted in 8 patients (26%), including 4 patients with symptomatic dilated cardiomyopathy. Serial echocardiographic evaluation revealed changes from the original level (elevated, normal or depressed) of left ventricular function, afterload or contractility in 89%. Pericardial effusion without tamponade was seen in 8 patients (26%). Mononuclear pericarditis, myocarditis and inflammation of the intracardiac conduction tissue as well as peripheral nerve were seen in autopsy specimens, yet histologic or culture evidence of myocardial infection with opportunistic organisms was lacking. High grade atrial (1 patient) and ventricular (3 patients) ectopy, as well as second-degree atrioventricular block, were observed. Cardiac abnormalities, detectable by noninvasive methods but often clinically inapparent, appear to be common in children with human immunodeficiency virus infection and may cause symptoms or even death.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗

Recognition of abnormal connections of coronary arteries with the use of Doppler color flow mapping.

Anomalous connection of a coronary artery to a ventricle or pulmonary artery causes shunting of blood from the coronary circuit and may produce myocardial ischemia. Such a coronary anomaly may occur in isolation or with other defects. Doppler color flow mapping and two-dimensional echocardiography were used to diagnose anomalous coronary connections in 13 patients, 1 day to 7 years of age, over a 1 year period. The diagnoses were anomalous origin of the left coronary artery from the pulmonary trunk in five patients, a coronary artery to left ventricle fistula or coronary artery to pulmonary artery fistula in four patients with other complex defects, right ventricular sinusoids in two patients with pulmonary atresia and intact ventricular septum and an isolated coronary artery fistula in two patients. In all cases, the abnormal coronary connection was recognized on the basis of an abnormal, continuous or to and fro flow pattern in the fistula and its connections as demonstrated by scanning in multiple views with Doppler color flow mapping. The low spatial resolution of Doppler color flow mapping limits the anatomic detail available; nonetheless, it is a significant advance in the noninvasive diagnosis of abnormal coronary connections.

Arterio-Arterial Fistula↗

Left ventricular contractility and function in Kawasaki syndrome. Effect of intravenous gamma-globulin.

To investigate the effect of Kawasaki syndrome on myocardial function, as well as the influence of high-dose intravenous gamma-globulin therapy on resolution of functional abnormalities, we studied 98 patients with Kawasaki syndrome during five time intervals from onset of illness: 1) 10 days or less, 2) 11-31 days, 3) 1-3 months, 4) 3-12 months, and 5) 1-3 years. Normal controls included 48 children under age 8 years, without known cardiovascular disease. Using two-dimensional directed M-mode echocardiograms, we obtained chamber dimensions, fractional shortening, rate-corrected velocity of shortening (Vcfc) adjusted for end-systolic wall stress, and early diastolic function parameters that included adjusted peak rates of left ventricular dimension change, wall thinning, and their respective timing. Left ventricular systolic and diastolic dimensions were larger (both p less than 0.01) in patients than in normal subjects in period 1. Stress-adjusted Vcfc was much lower in patients in the 3 months after disease onset; by period 5, contractility was comparable in patients and normal subjects. Adjusted indexes of early diastolic function did not differ significantly between patients and normal subjects. To investigate the effect of gamma-globulin, we analyzed data on 47 patients prospectively randomized to therapy with aspirin alone (n = 19, 40%) or to aspirin plus gamma-globulin, 400 mg/kg/day for 4 consecutive days (n = 28, 60%). In period 1, before treatment, the two groups had mean fractional shortening and stress-adjusted Vcfc comparable to each other but much lower than those of normal subjects (p less than or equal to 0.001). Patients treated with aspirin alone continued to have diminished fractional shortening and Vcfc compared with normal subjects in periods 2, 3, and 4 (all p less than or equal to 0.05). In contrast, fractional shortening and Vcfc in gamma-globulin-treated patients in these periods were comparable to those of normal subjects. By period 5, no difference was detected in systolic function or contractility between either treatment group and normal subjects. We conclude that early abnormalities of left ventricular contractility and myocardial function, as assessed by echocardiography, generally resolve by 1-3 years after disease onset and that recovery is accelerated by administration of IVGG in the acute phase.

Aspirin↗

Results of the arterial switch operation for transposition of the great arteries with ventricular septal defect. Surgical considerations and midterm follow-up data.

Between January 1983 and December 1987, 62 patients underwent an arterial switch operation for transposition of the great arteries with ventricular septal defect or double outlet right or left ventricle. There were three hospital deaths (4.8%), and no deaths occurred in neonates (less than 1 month of age, n = 18). There were three late deaths, one due to coronary obstruction and two due to pulmonary vascular obstructive disease. One child has been lost to follow-up. We have prospectively evaluated the remaining 55 survivors by clinical evaluation, echocardiography, cardiac catheterization, ambulatory electrocardiographic monitoring, and limited electrophysiologic studies. The mean length of follow-up has been 27 +/- 16 months since surgery. One child has required reoperation for a residual ventricular septal defect; no child has undergone reoperation for supravalvar pulmonary or aortic stenosis. Aortic regurgitation was identified in 12 children (22%), which was mild in 11 and moderate in one. One child has asymptomatic occlusion of the left main coronary artery, one child has a tiny right coronary artery-to-pulmonary artery fistula, and one child has abnormal left ventricular wall motion according to follow-up angiography. No other abnormalities of systemic (left) ventricular function have been identified at late follow-up. In addition to the two late deaths due to pulmonary vascular obstructive disease, three children, all of whom were repaired at more than 6 months of age, have elevated pulmonary vascular resistance. Notable postoperative arrhythmias include complete heart block in four patients and nonsustained supraventricular or ventricular tachycardia early after surgery in eight patients (all resolved without medication at later follow-up). Only two patients have evidence of sinus node dysfunction and have not required treatment. The low hospital mortality and encouraging early follow-up data represent a significant improvement over atrial level repairs, supporting the arterial switch operation as the procedure of choice for children who have transposition of the great arteries with ventricular septal defect or double outlet ventricle. Because of the potential for the development of early pulmonary vascular obstructive disease in these patients, repair is recommended within the first 2 months of life.

Coronary Vessels↗

Effect of isolated right ventricular outflow obstruction on left ventricular function in infants.

Resting left ventricular (LV) function was evaluated in 29 infants with isolated right ventricular (RV) outflow obstruction. Age-corrected cardiac index was significantly inversely correlated with the degree of obstruction (r = 0.59, p = 0.0001). Right ventricular hypertension resulted in septal displacement and altered LV geometry. The magnitude of RV outflow obstruction related closely to the degree of LV distortion. Septal displacement toward the LV free wall was associated with lower values for cardiac index, indexed LV end-diastolic volume, ejection fraction, ratio of early to atrial LV diastolic inflow and with a higher RV ejection fraction. The LV end-diastolic volume index and the ratio of early to atrial LV diastolic inflow correlated with the degree of obstruction and amount of septal displacement. Four infants evaluated during the development of supravalvar pulmonary stenosis demonstrated decreasing cardiac index during development of obstruction and significant increase in cardiac index after surgical relief. These findings indicate that significant RV outflow obstruction in infants is associated with a reversible alteration in LV function related to abnormal LV geometry and impaired LV diastolic filling.

Cardiac Output↗

Are routine preoperative cardiac catheterization and angiography necessary before repair of ostium primum atrial septal defect?

Two-dimensional and Doppler echocardiography were compared with cardiac catheterization and angiography in the preoperative evaluation of ostium primum atrial septal defect. Preoperative echocardiographic examinations as well as operative reports of all patients (33 patients aged 2 months to 23 years at surgery) with ostium primum atrial septal defect or transitional atrioventricular (AV) canal defect having had echocardiography and surgical repair at The Children's Hospital, Boston from July 1983 to January 1986 were retrospectively reviewed. Original cardiac catheterization and angiographic reports also were reviewed. Preoperative echocardiography resulted in no false positive or false negative primary diagnoses when compared with the diagnoses obtained at preoperative angiography or surgery. Doppler assessment of mitral regurgitation correlated well with angiographic (93% agreement) and intraoperative (85% agreement) assessments of mitral regurgitation to within two diagnostic categories on the six level scoring system used. There was reasonably good agreement between the two-dimensional echocardiographic estimate of right ventricular systolic pressure and that measured at catheterization when expressed as percent of the simultaneous left ventricular pressure. Seven of nine ventricular septal defects observed intraoperatively were noted on preoperative echocardiography; five of these defects were detected on preoperative angiography. A variety of other surgically confirmed associated cardiovascular defects were observed by both preoperative techniques. However, echocardiography appeared to be superior to angiography for evaluation of AV valve morphology and papillary muscle architecture. This study implies that in children with typical clinical and two-dimensional echocardiographic and Doppler findings for ostium primum atrial septal defect or transitional AV canal defect, routine preoperative cardiac catheterization and angiography are unnecessary.

Adolescent↗

Noninvasive estimation of the left ventricular pressure waveform throughout ejection in young patients with aortic stenosis.

Validation of a totally noninvasive method for estimating instantaneous left ventricular pressure and constructing a pressure waveform throughout ejection in patients with aortic stenosis is reported. In 20 patients (aged 8.75 +/- 10 years) with congenital aortic stenosis (measured peak left ventricular pressure 120 to 260 mm Hg; transvalvular gradient 18 to 165 mm Hg), transaortic valve continuous wave Doppler ultrasound, indirect carotid pulse tracing, peripheral blood pressure and measured left ventricular pressure were recorded simultaneously at cardiac catheterization. Data were entered into a microcomputer using a digitizing tablet and the instantaneous Doppler gradient was calculated and added to instantaneous aortic pressure, derived from the time-corrected and calibrated carotid pulse tracing, to estimate instantaneous left ventricular pressure. Estimated left ventricular pressure waveforms reproduced measured left ventricular pressure closely. The mean error at peak left ventricular pressure was 0.2 +/- 4.8 mm Hg (r = 0.98, p = 0.001). The average error throughout ejection was 0.9 +/- 5.1 mm Hg. The error of estimated pressure was not related to age or the severity of aortic stenosis. The Doppler peak instantaneous gradient was observed to correlate closely (r = 0.97, p = 0.001) with peak to peak gradient. With this technique, the left ventricular pressure waveform throughout ejection can be accurately estimated noninvasively in patients with aortic stenosis. This methodology enables determination of mean, total and instantaneous systolic left ventricular pressure.

Adolescent↗