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Biomedical subjects

G Wernovsky

Publications and source records attributed to G Wernovsky.

87 records · Page 5Linked to original sources

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↗

Corrected transposition in situs inversus. Biventricular repair of associated cardiac anomalies.

Corrected transposition of the great arteries (C-TGA) in situs inversus [I,D,D] is a rare variant of C-TGA (5-8% of the cases). Few anatomic and surgical data on this anomaly have been published. Between 1974 and 1990, 13 such patients (mean age, 12.7 +/- 8.6 yr) underwent repair of associated cardiac anomalies, including ventricular septal defect (VSD) and pulmonary outflow tract obstruction (POTO) in all 13 patients and atrial septal defect (ASD) in 11. Systemic venous anomalies were present in four. Nine patients also had dextrocardia. Patches to close the VSD were placed on the right side of the ventricular septum (through a right [systemic] ventriculotomy) in two patients and on the left side of the ventricular septum in the other 11 via a left ventriculotomy in one or a morphological right (left-sided) atriotomy in 10. The POTO was relieved directly in five patients and bypassed by a left ventricle-pulmonary artery conduit in the other eight. There was one early death due to cerebral hemorrhage. Two patients required a pacemaker for permanent heart block. Other rhythm disturbances included transient heart block in three patients and late atrial fibrillation in one. All the survivors are asymptomatic as late as 15.5 years after the repair. One patient had conduit revision 10.5 years after the initial operation, two had residual POTO of greater than 40 mm Hg, and none had residual VSD. In conclusion, patients with [I,D,D] C-TGA present with a relatively uniform subset of anatomic lesions, including predominantly ASD, VSD, and POTO.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Vessel Prosthesis↗

Cognitive development of children following early repair of transposition of the great arteries using deep hypothermic circulatory arrest.

Twenty-eight children who underwent corrective cardiac surgery in early infancy had developmental evaluations to explore whether cardiopulmonary bypass perfusion variables are associated with later cognitive function. All had transposition of the great arteries repaired by the arterial switch operation using deep hypothermic circulatory arrest. The mean duration of deep hypothermic circulatory arrest was 64 +/- 10 minutes (mean +/- SD). Median age at repair was 4 days (range 1 to 125 days). Tests of development were administered at age 7 to 53 months: Bayley Scales for children younger than 30 months of age (n = 18) and McCarthy Scales for older children (n = 10). Overall cognitive development score was 101.2 +/- 11.1. Duration of deep hypothermic circulatory arrest was not associated with performance. However, for core cooling periods of less than 20 minutes' duration, shorter cooling periods were associated with lower scores (r = .85, n = 11, P less than .001). These data suggest that patients undergoing relatively long periods of deep hypothermic circulatory arrest may require some minimum time of cardiopulmonary bypass cooling to avoid central nervous system injury.

Child Development↗

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↗

Coronary artery pattern and outcome of arterial switch operation for transposition of the great arteries.

A successful outcome of an arterial switch operation (ASO) for dextro-transposition of the great arteries (D-TGA) depends in large part on the transfer of the coronary arteries to the neoaorta without distortion or narrowing. However, the origins and distribution of the coronary arteries are quite variable in D-TGA; therefore, the entire experience with ASO at the Children's Hospital in Boston was reviewed. From 1983 through November 1989, 314 patients underwent surgery for D-TGA with the intent to perform an ASO. An ASO was actually performed in 290 patients, and 20 patients died, with 12 deaths (4.2%) clearly related to problems with the coronary arteries (CA deaths). The ASO was aborted to a Senning operation in 24 patients (7.6%), primarily due to coronary anatomy. Eight coronary patterns were identified and related to the outcome of the ASO. In 182 patients with the "usual" coronary pattern for D-TGA (i.e., anterior descending and circumflex arteries from the left sinus and right coronary artery from the right sinus), five CA deaths occurred, and two patients had Senning operations. Sixty-seven patients had right coronary and circumflex arteries from the right sinus and anterior descending arteries from the left sinus. Three CA deaths occurred, and one patient had a Senning operation. Single right coronary artery was found in 14; 12 had ASOs with three CA deaths (25%); and two had Senning operations. One late death was due to diffuse narrowing of the single right coronary artery. Single left coronary artery occurred in 11 patients, and seven had ASO with no early but one late "sudden" death, whereas four had Senning operations.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗

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↗

Transposition of the great arteries: the arterial switch operation.

Primary arterial switch operation in neonates for repair of transposition of the great arteries with an intact ventricular septum or with a ventricular septal defect has become the operation of choice in our institution. By now, the surgical risk has been decreased to approximately 2 per cent. Early in our experience, postoperative supravalvar pulmonary stenosis was the only late hemodynamic complication of significance. Postoperative left ventricular function, including echocardiographic indices of left ventricular function, including echocardiographic indices of left ventricular systolic and diastolic function, have been within normal range in all patients. Almost all patients are in sinus rhythm as late as 6 years of the operation. It is our contention that primary arterial switch operation in infants with transposition of the great arteries results in improved left ventricular performance; the potential hazard of late coronary insufficiency and of aortic valve dysfunction requires continued monitoring of these patients.

Aorta, Thoracic↗

Comparison of technetium-99m MIBI and thallium-201 chloride myocardial scintigraphy in infants.

Myocardial perfusion scintigraphy was performed with both 201Tl and a new six coordinate monocationic isonitrile complex of 99mTc, [99mTc]2-methoxyisobutylisonitrile (MIBI), on 11 infants who had undergone the arterial switch procedure for transposition of the great arteries. Unlike 201Tl which can show rapid and variable rates of washout from myocardium, 73% of the initial first-pass activity of the isonitrile complex in the myocardium remains 1 hr after intravenous administration. The images obtained with [99mTc]MIBI required a shorter recording time, entailed less radiation exposure to the patient, and were qualitatively at least as good as those obtained with 201Tl. No infant had perfusion abnormalities. The potential applications of the isonitrile complexes for myocardial perfusion scintigraphy in children are discussed.

Female↗

Rapid, two-stage arterial switch for transposition of the great arteries and intact ventricular septum beyond the neonatal period.

Optimal management of dextrotransposition of the great arteries with intact ventricular septum is currently an arterial switch procedure performed in the first 2 weeks of life. However, a subgroup of patients presents for surgery beyond this time for reasons of sickness, size, or late referral. Experience with 11 such patients (mean age at first-stage procedure, 4.5 months) has revealed that the left ventricle can be prepared by a surprisingly short interval period (median, 9 days) between a first-stage preparatory operation (pulmonary artery band with or without a shunt) and a subsequent second-stage arterial switch procedure. Serial two-dimensional echocardiography showed that left ventricular mass increased by a mean of 85% during this short interval. Mean left ventricular-right ventricular-pressure ratio as measured by cardiac catheterization increased from 0.5 +/- 0.08 a median of 7 days before the first stage to 1.04 +/- 0.29 a median of 7 days after the first stage. One patient underwent a Senning procedure because of an intramural left coronary artery. The other 10 patients underwent an arterial switch, with no early deaths. Median hospitalization after the arterial switch was 8 days. There has been one late death at 5 months. No patient has been detected to have abnormal ventricular function, although trivial to mild aortic regurgitation has been commonly observed with color flow mapping. These results have encouraged us to offer a two-stage arterial switch procedure to appropriate infants with an interval period of approximately 1 week. Both stages can be performed at one hospitalization, with important psychosocial, logistic, and financial advantages.

Cardiac Catheterization↗

Midterm results after the arterial switch operation for transposition of the great arteries with intact ventricular septum: clinical, hemodynamic, echocardiographic, and electrophysiologic data.

Although the short-term results of atrial level repair of transposition of the great arteries (TGA) are satisfactory, longer follow-up has disclosed a significant incidence of systemic right ventricular dysfunction and rhythm disturbances. The arterial switch operation (ASO) may represent a major improvement by restoring the left ventricle as the systemic ventricle and avoiding extensive atrial surgery. We have prospectively evaluated 49 consecutive survivors of ASO for TGA with intact ventricular septum (IVS) by clinical examination, echocardiography, cardiac catheterization, ambulatory electrocardiographic monitoring, and invasive electrophysiologic studies. The mean length of follow-up has been 29 +/- 14 (SD) months after surgery. All children are currently asymptomatic and on no medications. Severe supravalvular pulmonary stenosis (greater than 60 mm Hg) was present in five children, all of whom have undergone reoperation. No patient has severe supravalvular aortic obstruction. Mild degrees of supravalvular pulmonary or aortic obstruction have not progressed. Seven children (14%) have trivial or mild aortic regurgitation. Two children have proximal occlusion of the left anterior descending coronary artery with adequate retrograde collateral perfusion. One child had an electrocardiographic pattern of inferior myocardial infarction without evidence of ventricular dysfunction. Systemic (left) ventricular function is normal as measured by end-diastolic pressure (mean 7 +/- 6 mm Hg), ejection fraction (mean 68 +/- 6%), end-diastolic volume (mean 101 +/- 22% of predicted normal), and cardiac index (mean 4.7 +/- 1.3 liters/min/m2). Only one patient has sinus node dysfunction. There have been no late deaths. These early results are encouraging. We conclude that the arterial switch operation is currently the procedure of choice for neonates with TGA and IVS.

Cardiac Catheterization↗

Myocardial performance after arterial switch operation for transposition of the great arteries with intact ventricular septum.

Left ventricular dimensions, wall thickness, wall stress, and indexes of afterload, preload, contractility, and early diastolic function, as well as regional wall motion, were determined by echocardiographic methods in patients with transposition of the great vessels after arterial switch operation and in age-matched normal controls. In patients evaluated early after surgery, body surface area-adjusted left ventricular dimensions were smaller, and wall thickness was increased compared with controls. Ventricular performance (fractional shortening) was normal in most patients but was abnormally low in 10%. Nevertheless, contractility was normal or augmented in all subjects, with a mean value higher than the control group. The reduction in systolic function was related to altered loading conditions with a combination of reduced afterload and preload combined with augmented contractility. These altered myocardial mechanics appeared to be secondary to routine therapy with digitalis and diuretics. Diastolic function was also normal with differences in the rate of peak filling and rate of wall thinning entirely attributable to differences in ventricular size and function, and normalized indexes of diastolic function were not different between patients and controls. Patients evaluated late after repair were found to have normal regional wall motion with no evidence to suggest regional dysfunction as might be seen with regional ischemia. Ventricular size, wall thickness, systolic function, afterload, preload, contractility, and early diastolic function were indistinguishable from control values. Indexes of diastolic function demonstrated the same relation to age, body surface area, and ventricular size and function in both patients and controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗

L-phenylalanine mustard-dianhydrogalactitol and hyponatremia.

The incidence of hyponatremia in 34 patients following administration of high-dose L-phenylalanine mustard (L-PAM) and dianhydrogalactitol (DAG) was determined. Two consecutive daily levels of 133 mEq/l or less were observed in 12 patients. These episodes coincided with the advent of diarrhea about 10-12 days after drug administration. The hyponatremia was not due to the syndrome of inappropriate antidiuretic hormone secretion.

Diagnosis, Differential↗

The incidence of arrhythmias in a pediatric cardiac intensive care unit.

A pediatric cardiac intensive care unit (CICU) manages critically ill children and adults with congenital or acquired heart disease. These patients are at increased risk for arrhythmias. The purpose of this study was to prospectively evaluate the incidence of arrhythmias in a pediatric CICU patient population. All patients admitted to the CICU at the Cardiac Center at The Children's Hospital of Philadelphia between December 1, 1997, and November 30, 1998, were evaluated prospectively from CICU admission to hospital discharge via full disclosure telemetry reviewed every 24 hours. Arrhythmias reviewed included nonsustained and sustained ventricular tachycardia (VT), nonsustained and sustained supraventricular tachycardia (SVT), atrial flutter and fibrillation, junctional ectopic tachycardia, and complete heart block. We reviewed 789 admissions consisting of 629 patients (age range, 1 day-45.5 years; median, 8.1 months). Hospital stay ranged from 1 to 155 days (total of 8116 patient days). Surgical interventions (n = 602) included 482 utilizing cardiopulmonary bypass. During the study period, there were 44 deaths [44/629 patients (7.0%)], none of which were directly attributable to a primary arrhythmia. The operative mortality was 5.1%. Overall, 29.0% of admissions had one or more arrhythmias the most common arrhythmia was nonsustained VT (18.0% of admissions), followed by nonsustained SVT (12.9% of admissions). Patients admitted to a pediatric CICU have a high incidence of arrhythmias, most likely associated with their underlying pathophysiology and to the breadth of medical and surgical interventions conducted.

Adolescent↗

Utility of intraoperative transesophageal echocardiography in the assessment of residual cardiac defects.

To investigate the accuracy of immediate postbypass transesophageal echocardiography in the assessment of residual cardiac defects, we compared intraoperative transesophageal echocardiograms with intra/postoperative data in 86 patients, aged 4 days to 30.7 years (median = 1.4 years), at risk for a total of 174 postoperative lesions: right (n = 55) or left (n = 26) ventricular outflow tract obstruction, ventricular septal defect (n = 65), aortic (n = 12) or mitral regurgitation (n = 8), or mitral stenosis (n = 8). Accuracy of intraoperative transesophageal echocardiography was evaluated based on comparison with (1) immediate post-bypass left (n = 4) or right (n = 9) ventricular outflow tract pressure gradients by pullback in the operating room, (2) direct surgical inspection of residual ventricular septal defects (n = 3), (3) pulmonary artery oxygen saturation (n = 49), (4) right ventricular outflow tract pullback gradient (n = 24), and (5) transthoracic echocardiogram (n = 51) performed within 40 days of surgery. The results indicate that intraoperative transesophageal echocardiography agreed with intra/postoperative data in 87% of patients at risk for right ventricular outflow tract obstruction, 96% at risk for left ventricular outflow tract obstruction, 97% at risk for ventricular septal defect, and 100% at risk for aortic regurgitation, mitral regurgitation, or mitral stenosis. Significant residual lesions led to immediate surgical revision in 11 cases: 3 ventricular septal defects, 6 right and 2 left ventricular outflow tract obstructions. Of these, intraoperative transesophageal echocardiography confirmed and quantified suspected residual lesions in 7 and identified unsuspected lesions in 4 cases. Immediate postbypass transesophageal echocardiography proved reliable for assessing residual ventricular septal defect, mitral stenosis, and mitral or aortic regurgitation. Although accurate for assessment of the left and right ventricular outflow tracts in most patients, transesophageal echocardiography may not reliably reflect the severity of obstruction in all cases.

Adolescent↗