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Biomedical subjects

G Wernovsky

Publications and source records attributed to G Wernovsky.

At least 73 records · Page 4Linked to original sources
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

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

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↗
PubMed1993

A comparison of the perioperative neurologic effects of hypothermic circulatory arrest versus low-flow cardiopulmonary bypass in infant heart surgery.

BACKGROUND: Hypothermic circulatory arrest is a widely used support technique during heart surgery in infants, but its effects on neurologic outcome have been controversial. An alternative method, low-flow cardiopulmonary bypass, maintains continuous cerebral circulation but may increase exposure to known pump-related sources of brain injury, such as embolism or inadequate cerebral perfusion. METHODS: We compared the incidence of perioperative brain injury after deep hypothermia and support consisting predominantly of total circulatory arrest with the incidence after deep hypothermia and support consisting predominantly of low-flow cardiopulmonary bypass in a randomized, single-center trial. The criteria for eligibility included a diagnosis of transposition of the great arteries with an intact ventricular septum or a ventricular septal defect and a planned arterial-switch operation before the age of three months. RESULTS: Of 171 patients with D-transposition of the great arteries, 129 (66 of whom were assigned to circulatory arrest and 63 to low-flow bypass) had an intact ventricular septum, and 42 (21 assigned to circulatory arrest and 21 to low-flow bypass) had a ventricular septal defect. After adjustment for diagnosis, assignment to circulatory arrest as compared with low-flow bypass was associated with a higher risk of clinical seizures (odds ratio, 11.4; 95 percent confidence interval, 1.4 to 93.0), a tendency to a higher risk of ictal activity on continuous electroencephalographic (EEG) monitoring during the first 48 hours after surgery (odds ratio, 2.5; 95 percent confidence interval, 1.0 to 6.4), a longer recovery time to the first reappearance of EEG activity (only in the group with an intact ventricular septum, P < 0.001), and greater release of the brain isoenzyme of creatine kinase in the first 6 hours after surgery (P = 0.046). Analyses comparing durations of circulatory arrest produced results similar to those of analyses comparing treatments. CONCLUSIONS: In heart surgery in infants, a strategy consisting predominantly of circulatory arrest is associated with greater central nervous system perturbation in the early postoperative period than a strategy consisting predominantly of low-flow cardiopulmonary bypass. Assessment of the effect of these findings on later outcomes awaits follow-up of this cohort.

Brain Ischemia↗
PubMed1993

Repair of double aortic arch associated with D-transposition of the great arteries.

D-transposition of the great arteries is infrequently associated with anomalies of the aortic arch. We report a rare case of double aortic arch associated with D-transposition of the great arteries. The diagnosis was made by angiography and transthoracic echocardiography. The patient underwent a successful simultaneous arterial switch operation and division of the vascular ring through a median sternotomy incision.

Aorta, Thoracic↗
PubMed1993

Enlarged bronchial arteries after early repair of transposition of the great arteries.

OBJECTIVES: This study was undertaken to define the incidence of enlarged bronchial arteries after early surgical repair of transposition of the great arteries by the arterial switch operation, and to report the results of catheter-directed therapy in five patients. BACKGROUND: Pathologic and angiographic studies have demonstrated enlarged bronchial arteries in patients with transposition of the great arteries. METHODS: A subjective 4-point scale was used to grade postoperative angiograms performed in 119 patients at our institution between January 1983 and December 1991. Grades 0 and 1 were designated if there was no opacification of the pulmonary arteries or veins, whereas grades 2 and 3 were assigned if there was such opacification. The median age at repair was 8 days (range 1 day to 13 months) and the median age at catheterization was 11.2 months (range 3.6 to 58.5). An intact ventricular septum was present in 84 (71%) of 119 patients. RESULTS: Significantly increased bronchial flow (grade 2 or 3) was present in 55 (46%) of 119 patients. Age at repair, age at catheterization and interval between repair and catheterization were not associated with significantly increased bronchial flow; however, an intact ventricular septum was weakly associated with increased flow (p = 0.04). Coil embolization was performed in five patients with complete occlusion of the vessels and no significant complications. CONCLUSIONS: Abnormally enlarged bronchial arteries are frequently identified at postoperative catheterization despite early repair and may explain continuous murmurs or persistent cardiomegaly in patients with otherwise normal noninvasive findings. When clinically indicated, catheter-directed therapy can be performed with good results.

Bronchial Arteries↗
PubMed1993

Growth of the aortic anastomosis, annulus, and root after the arterial switch procedure performed in infancy.

BACKGROUND: We investigated the size and growth potential of the neoaortic root and aortic anastomosis after the arterial switch operation (ASO) for D-transposition of the great arteries (D-TGA) performed in infants. Circumferential suture lines connecting the great arteries and extensive surgery on the arterial roots to transplant the coronary arteries are essential parts of the ASO. However, little is known about the growth of the aortic anastomosis, the neoaortic root, and the neoaortic annulus after the ASO performed in infancy. METHODS AND RESULTS: Serial echocardiograms on 50 patients with D-TGA who underwent ASO in infancy at our institution were reviewed, and the size of the aortic anastomosis, the neoaortic root, and the neoaortic annulus were compared with similar structures in a group of 312 control subjects. Before surgery, the native pulmonary root (future neoaortic root) was 1.59 SD larger (P < .001) and the native pulmonary annulus (future neoaortic annulus) was 1.4 SD larger (P < .001) in infants with D-TGA than the aortic root and annulus of control patients. At a mean of 22 months (12 months to 6 1/2 years) after surgery, the diameter of the aorta at the anastomosis was 0.45 SD smaller than the ascending aorta of control subjects (P < .001). The neoaortic root was 2.9 SD larger (P < .001) and the neoaortic annulus was 1.6 SD larger (P < .001) than the comparable structures in the control population. Most important, growth of the aortic anastomosis was commensurate with somatic growth, but the dilation of the neoaortic root appeared to be progressive over time. The neoaortic root was significantly more dilated in patients with a history of pulmonary artery banding (P < .001) and in patients with neoaortic regurgitation (P < .001). The presence of a ventricular septal defect was not significantly related to postoperative neoaortic root size. CONCLUSIONS: This study underlies the importance of continued acquisition and examination of the data regarding the long-term outcome of the arterial switch operation performed in infancy.

Anastomosis, Surgical↗
PubMed1993

Diagnosis of intramural coronary artery in transposition of the great arteries using two-dimensional echocardiography.

BACKGROUND: An intramural coronary is an uncommon but potentially significant risk factor for transfer of the coronary arteries as part of the arterial switch operation for transposition of the great arteries. Preoperative diagnosis is advantageous because it helps prevent accidental injury to the intramural coronary artery during transection of the aortic root and excision of the coronary artery ostium from the aorta. Therefore, we investigated the reliability of two-dimensional echocardiography for detecting an intramural coronary artery in infants with d-transposition of the great arteries. METHODS AND RESULTS: All infants with d-transposition of the great arteries who underwent echocardiography and primary surgical repair at this institution between January 1987 and June 1992 were identified by search of the cardiology data base. From this group, all patients diagnosed with an intramural coronary artery were identified by review of the echocardiographic, surgical, and autopsy reports. Among 435 infants with transposition, 29 infants were diagnosed as having an intramural coronary artery. In 27 cases, the diagnosis was confirmed at surgery or autopsy, and there were two false-positive echocardiographic diagnoses (specificity, 99.5%). Twenty of the 27 patients with an intramural coronary artery were correctly diagnosed prospectively by echocardiography (sensitivity, 75%), including 17 of 23 patients with an intramural left coronary artery or left anterior descending coronary artery and 3 of 4 patients with an intramural right coronary artery. Two primary diagnostic criteria were identified: a major coronary artery arising from the contralateral septal sinus, near the usually intercoronary commissure, and a course for this vessel within the posterior aortic wall between the great arteries, creating a "double-border" appearance. Retrospective review using these criteria identified 26 of the 27 intramural arteries with no false-positive diagnoses. CONCLUSIONS: We conclude that coronary echocardiography is a very promising technique for detecting an intramural coronary artery in transposition of the great arteries. Careful prospective application of the identified diagnostic criteria should greatly improve the diagnostic accuracy.

Coronary Vessel Anomalies↗
PubMed1993

Surgical repair of complete atrioventricular canal defects in infancy. Twenty-year trends.

Case histories of 301 patients with complete atrioventricular canal defect presenting to our institution in infancy between January 1972 and January 1992 were reviewed with the purpose of identifying the factors responsible for the observed improvement in perioperative mortality over this time period. A retrospective analysis of hospital records examined 46 patient-related, morphologic, procedure-related, and postoperative variables for associations with perioperative death and reoperation. Operative mortality decreased significantly over the period of the study from 25% before 1976 to 3% after 1987 (p < 0.0001). A number of the 46 variables examined showed trends over time that were similar to that for mortality. Palliative procedures decreased over time. Reoperation for most residual lesions also decreased to the degree that they were essentially eliminated in recent years. The exception to this was reoperation for postoperative left atrioventricular valve regurgitation, which also decreased but remained at 7% in recent years. Both technical and support-related procedural variables showed no trends over time, with the exception of the performance of left atrioventricular valve annuloplasty, which increased over time. Closure of the left-sided cleft was performed in 61% of the patients, with no trend over time. Annuloplasty and cleft closure were not associated with less postoperative left atrioventricular valve regurgitation, fewer reoperations, or lower mortality. Multivariate logistic regression analysis identified only earlier year of operation, the presence of double-orifice left atrioventricular valve, and postoperative residual regurgitation of the left atrioventricular valve as risk factors for death. Experience-related improvements in technical precision achieved over time best account for the reduction in the rate of reoperation for most types of residual lesions and also for the reduction in mortality. The only residual lesion that has not been essentially completely eliminated is left atrioventricular valve regurgitation, with reoperation for this lesion having been reduced in recent years, but not eliminated. Improved understanding of the structural and functional variability of the atrioventricular valve in this lesion may be necessary before postoperative dysfunction of this valve can be completely eliminated.

Child↗
PubMed1993

Early bidirectional cavopulmonary shunt in young infants. Postoperative course and early results.

BACKGROUND: Despite the recent wide applicability of the bidirectional cavopulmonary shunt, there is limited reported experience in performing these shunts in infants 6 months or younger. METHODS AND RESULTS: Before October 1992, 17 consecutive infants aged 4.2 to 6.5 months (median, 6.1 months) underwent bidirectional cavopulmonary shunts. The diagnoses were hypoplastic left heart syndrome (n = 7), single right ventricle (n = 5), and single left ventricle (n = 5). All but 2 patients had prior palliative surgery. The bidirectional cavopulmonary shunt was performed early on an elective basis in 9 patients; the remaining patients had progressive cyanosis (6 patients), severe ventricular failure (1 patient), and coexisting restrictive bulboventricular foramen (1 patient). The median preoperative pulmonary arterial pressure and pulmonary vascular resistance were 15 mm Hg and 2.3 U.m2, respectively. One patient died; the overall hospital survival was 94%. The most common postoperative problem was transient systemic hypertension, observed in 14 (88%) of 16 survivors. Systemic arterial oxygen saturation increased from a median of 75% before surgery to a median of 85% after surgery (P < .05). The median hospital stay was 6 days. There were no late deaths during follow-up (median, 12.4 months). At postoperative cardiac catheterization performed in 9 of 16 survivors, there was no evidence of severe hypoxemia, shunt narrowing, or pulmonary arteriovenous fistulas. Of the 16 survivors, 6 have had a subsequent Fontan operation at a median age of 1.9 years; there were 5 survivors. CONCLUSIONS: Early bidirectional cavopulmonary shunt in young infants has shown encouraging early results and provides improved oxygenation with low morbidity and mortality. We speculate that an early bidirectional cavopulmonary shunt on an elective basis may reduce the deleterious sequelae of chronic hypoxemia, long-term ventricular volume overload, and repeated palliative procedures, thus yielding a more suitable Fontan candidate.

Arteriovenous Shunt, Surgical↗
PubMed1993

Relation of pH strategy and developmental outcome after hypothermic circulatory arrest.

To examine whether pH management during core cooling is a risk factor for adverse developmental outcome, we studied 16 children with transposition of the great arteries and intact ventricular septum who underwent a Senning procedure in infancy (median age 32 days, range 2 to 154 days) between 1983 and 1988. Information was collected retrospectively on many aspects of perfusion, including lowest carbon dioxide tension during core cooling, duration of core cooling, and duration of circulatory arrest. The pH strategy changed from pH-stat to alpha-stat in 1985, resulting in a wide range of pH values and carbon dioxide tension (34 to 76 mm Hg) during the study period. All children had rapid core cooling to a rectal temperature of 19.8 degrees +/- 2.7 degrees C (mean +/- standard deviation) and a tympanic temperature of 16.6 degrees +/- 3.0 degrees C. Development was assessed at median age 48.0 (11 to 79) months with the Bayley Scales (n = 4, children younger than 30 months) or the McCarthy Scales (n = 12, children older than 30 months). The mean core-cooling duration was 14.5 +/- 6.2 minutes, circulatory arrest time was 43.4 +/- 6.6 minutes, and total bypass plus circulatory arrest time was 89.7 +/- 12.7 minutes. Lower carbon dioxide tension (alpha-stat) before onset of circulatory arrest was associated with worse developmental outcome (r = 0.71, p = 0.002). This relationship remained highly significant when we controlled for sociodemographic and intraoperative variables. including core-cooling time, circulatory arrest time, and total elapsed time. Duration of circulatory arrest was not associated with developmental outcome. We conclude that when relatively rapid core cooling is used to achieve hypothermia before circulatory arrest in young infants, a more alkaline pH strategy such as alpha-stat may result in less effective cerebral protection.

Carbon Dioxide↗
PubMed1992

Course in the intensive care unit after 'preparatory' pulmonary artery banding and aortopulmonary shunt placement for transposition of the great arteries with low left ventricular pressure.

BACKGROUND: In patients with transposition of the great arteries with low left ventricular pressure, pulmonary artery banding with aortopulmonary shunt placement has been advocated to "prepare" the left ventricle for systemic work before an arterial switch operation. METHODS AND RESULTS: In 28 patients, this preparatory procedure was performed with one death. A successful arterial switch operation was performed at a median of 7 days later in 24 of 27 survivors; one child had a Senning performed, and two others died. During this interval period, the left ventricular-to-right ventricular pressure ratio increased from 48 +/- 8% to 98 +/- 19%, and left ventricular mass (indexed for body surface area) increased from 46 +/- 17 to 72 +/- 23 g/m2. After the preparatory procedure, the initial postoperative period was frequently characterized by a low-output syndrome of variable length and severity. Prolonged mechanical ventilation, extended inotropic support, and/or a significant metabolic acidosis was present in 21 of 28 patients in the immediate postoperative period. CONCLUSIONS: The low-output syndrome is most likely due to a combination of acute (fixed) right ventricular volume overload from the shunt and acute (transient) left ventricular dysfunction from the pulmonary artery band. This low-output syndrome should be anticipated following the preparatory procedure.

Blood Vessel Prosthesis↗
PubMed1992

Surgical management of late right ventricular failure after Mustard or Senning repair.

BACKGROUND: Information on surgical management and outcome in patients who develop symptomatic right ventricular failure after prior Mustard or Senning operations is limited. METHODS AND RESULTS: From March 1987 to March 1991, 10 patients 3.6-23.5 years old (median, 7.0 years) with transposition of the great arteries and prior Mustard (six patients) or Senning (four patients) repairs (performed at ages 2 months to 5 years; median, 6 months) underwent surgical intervention for symptomatic right ventricular failure. In five of 10 patients, anatomic correction with either an arterial switch operation (three patients) or a pulmonary artery-to-aorta anastomosis and right ventricle-to-pulmonary artery conduit (two patients) was performed. Before anatomic correction in these five patients, four of five patients had a pulmonary artery band to prepare the left ventricle. The interval between preparation and correction ranged from 8 days to 12 months (median, 2 months). One patient died after an arterial switch operation. In the remaining five patients, coexisting left ventricular dysfunction precluded anatomic correction; all five patients survived cardiac transplantation. Survival for the entire group of 10 patients is 90%, and the median postoperative hospital stay was 17 days. During follow-up (12-62 months; median, 27 months), there were no deaths. Neoaortic insufficiency after anatomic correction was common (mild in one patient, moderate in two patients, and severe in one patient who required aortic valve replacement 4 months after surgery). In the transplantation group, one patient developed lymphoma 3 months after transplantation but is currently in remission after reduction of immunosuppression. CONCLUSIONS: In patients who develop late right ventricular failure after Mustard or Senning repair, surgical intervention with either anatomic correction or cardiac transplantation can be done with acceptable morbidity and low mortality. Neoaortic valve insufficiency demands close follow-up after anatomic correction.

Aorta, Thoracic↗