Biomedical subjects

J Rychik

Publications and source records attributed to J Rychik.

At least 37 records · Page 2Linked to original sources

PubMed1999

Caval contribution to flow in the branch pulmonary arteries of Fontan patients with a novel application of magnetic resonance presaturation pulse.

BACKGROUND: A complete understanding of fluid mechanics in Fontan physiology includes knowledge of the caval contributions to right (RPA) and left (LPA) pulmonary arterial blood flow, total systemic venous return, and relative blood flow to each lung. METHODS AND RESULTS: Ten Fontan patients underwent cine MRI. Three cine scans of the pulmonary arteries were performed: (1) no presaturation pulse, (2) a presaturation pulse labeling inferior vena cava (IVC) blood (signal void), and (3) a presaturation pulse labeling superior vena cava (SVC) blood. The relative signal decrease is proportional to the amount of blood originating from the labeled vena cava. This method was validated in a phantom. Whereas 60+/-6% of SVC blood flowed into the RPA, 67+/-12% of IVC blood flowed toward the LPA. Of the blood in the LPA and RPA, 48+/-14% and 31+/-17%, respectively, came from the IVC. IVC blood contributed 40+/-16% to total systemic venous return. The distributions of blood to each lung were nearly equal (RPA/LPA blood=0.94+/-11). CONCLUSIONS: In Fontan patients with total cavopulmonary connection, SVC blood is directed toward the RPA and IVC blood is directed toward the LPA. Although the right lung volume is larger than the left, an equal amount of blood flow went to both lungs. LPA blood is composed of equal amounts of IVC and SVC blood because IVC contribution to total systemic venous return is smaller than that of the SVC. This technique and these findings can help to evaluate design changes of the systemic venous pathway to improve Fontan hemodynamics.

Blood Flow Velocity↗

PubMed1999

Usefulness of intraoperative transesophageal echocardiography in predicting the degree of mitral regurgitation secondary to atrioventricular defect in children.

The objectives of this study were to determine the validity of the grade of mitral regurgitation (MR) as imaged by intraoperative transesophageal echocardiography (TEE) in predicting the grade of MR at follow-up. Intraoperative TEE and corresponding follow-up transthoracic studies were retrospectively reviewed and the regurgitant jet area to left atrial area ratio was used to quantify the MR. Patient records were reviewed to identify factors contributing to the development of a certain grade of MR. Intraoperative TEE was useful in detecting severe MR that required further repair at the same time. However, discrepancy in the grade of MR at follow-up was noted in 47% of patients (21 of 47) and unchanged grade of MR was found only in 53% of patients (26 of 47). Blood pressures were significantly lower and heart rates higher intraoperatively. Initial preoperative grade of MR and type of atrioventricular canal defect did not predispose for a particular grade of MR at follow-up. The grade of MR by intraoperative TEE does not predict the grade of MR at follow-up as imaged by transthoracic echocardiography.

Adolescent↗

PubMed1999

Outcome after repair of tetralogy of Fallot with absent pulmonary valve.

BACKGROUND: Tetralogy of Fallot with absent pulmonary valve (TOF/APV) is associated with pulmonary artery dilatation and airway compression. METHODS: Since January 1, 1984, 28 patients with TOF/ APV have undergone complete repair (median age 11 days, range 1 day to 16 years). RESULTS: Thirteen patients were ventilated for respiratory failure preoperatively and extracorporeal membrane oxygenation was used in 3. Twenty-six patients underwent pulmonary artery plication (11 anterior, 15 anterior/ posterior). The right ventricular outflow tract (RVOT) was reconstructed with a patch (19), valved conduit (5), or monocusp valve (4). Early mortality was 21.4% (6/28), with 1 late death. All early deaths occurred in infants intubated preoperatively. Survival was 77% (95% confidence limit [CL] 56%, 89%) at 1 year and 72% (95% CL 50%, 86%) at 10 years. After surgery, 3 patients underwent reoperation for persistent respiratory symptoms, which resolved after repeat plication and placement of a valved conduit. Freedom from death or reoperation was 68% (95% CL 46%, 83%) at 1 year and 52% (95% CL 29%, 71%) at 10 years. In a multivariable analysis, only preoperative intubation was associated with a worse outcome (p = 0.04). CONCLUSIONS: Long-term outcome for patients with TOF/APV who survive the initial repair is good. Repeat plication and pulmonary valve implantation may improve outcome in patients with persistent airway compression.

Adolescent↗

PubMed1999

Long-term outcome of infants with single ventricle and total anomalous pulmonary venous connection.

BACKGROUND AND METHODS: Between January 1, 1984, and December 1, 1997, 73 infants with functional single ventricle and total anomalous pulmonary venous connection were admitted to our institution. A retrospective review was undertaken to determine factors influencing survival. RESULTS: Heterotaxy syndrome was present in 52 patients and hypoplastic left heart syndrome in 14. Obstructed total anomalous pulmonary venous connection was present in 21 patients. The pulmonary venous connection was supracardiac in 32 patients, cardiac in 21 patients, infracardiac in 13, and mixed in 7. Twelve patients died before the operation. The remaining 61 patients underwent surgery at a median age of 5 days (range 1 day-2. 5 years). Overall survival was 45% at 6 months of age, 37% at 1 year, and 19% at 5 years. Survival for patients undergoing surgery was 54% at 6 months of age, 44% at 1 year, and 23% at 5 years. By univariate analysis with the Cox proportional hazards model, younger age at the time of the initial operation and repair of total anomalous pulmonary venous connection were predictors of mortality. Lung tissue from 14 patients was available for histologic examination. The pulmonary veins were dilated and wall thickness was increased. Increased muscularization of the arteries was seen in 11 patients. CONCLUSIONS: The long-term prognosis for children undergoing staged reconstructive operations for single ventricle and total anomalous pulmonary venous connection is poor. Early mortality is high and late death is a continuing risk. Development of the pulmonary vasculature, especially the pulmonary veins, is abnormal, even in children without clinical evidence of pulmonary venous obstruction.

Cardiac Surgical Procedures↗

PubMed1999

The hypoplastic left heart syndrome with intact atrial septum: atrial morphology, pulmonary vascular histopathology and outcome.

OBJECTIVES: The purpose of this study was to investigate the outcome in infants with hypoplastic left heart syndrome and intact atrial septum and to evaluate the relationship of atrial morphology, left atrial decompression pathway and lung histopathology to outcome. BACKGROUND: In the hypoplastic left heart syndrome, severe restriction at the atrial level results in marked systemic hypoxemia after birth. Infants with intact atrial septum may be at high risk for mortality after Norwood operation. METHODS: Of 316 infants with hypoplastic left heart syndrome seen at our center over a 6.5-year period, 18 (5.7%) had intact atrial septum. Medical records and echocardiograms were reviewed. RESULTS: On echocardiography, three types of intact atrial septal morphology were identified: 1) large left atrium, thick prominent septum secondary with thin septum primary adherent (type A, n = 12); 2) small left atrium with thick, muscular atrial septum (type B, n = 4), and 3) giant left atrium, thin atrial septum with severe mitral regurgitation (type C, n = 2). Seven infants had left atrial decompression pathways that were severely obstructed (3/12 type A, 4/4 type B). Norwood operation was performed in 17 infants; one underwent emergency balloon atrial septostomy and died. Of six early survivors, all with type A atrial morphology and unobstructed decompression pathway, three died after subsequent cavopulmonary surgery. Lung histopathology revealed severely dilated lymphatics and "arterialization" of the pulmonary veins in those with the severest degree of obstruction to left atrial egress (type B atrial morphology). CONCLUSIONS: Despite aggressive intervention, outcome for infants born with hypoplastic left heart syndrome and intact atrial septum is poor. Maldevelopment of the pulmonary vasculature contributes to the high mortality seen. Atrial morphology can be used as a marker for the severity of pulmonary vascular disease.

Heart Atria↗

PubMed1999

Changes in oxygenation with inhaled nitric oxide in severe bronchopulmonary dysplasia.

BACKGROUND: Severe bronchopulmonary dysplasia (BPD), which is associated with high mortality and morbidity, is thought to be the result of mechanical, inflammatory, and oxidant injury to the immature lung, and includes the development of pulmonary hypertension with vascular remodeling. METHODS: A phase II pilot study was conducted to determine the effect of inhaled nitric oxide (iNO) on oxygenation in severe BPD. This was an open-labeled, noncontrolled trial to evaluate safety and determine appropriate dosing for a future randomized controlled trial. Infants were eligible for enrollment if they were >/=4 weeks of age and ventilator dependent with a mean airway pressure of >/=10 cm H2O and an FIO2 of >/=0.45. Study infants received iNO (20 ppm) for 72 hours, and FIO2 was adjusted to maintain oxygen saturations of >92%. Infants who had a >/=15% reduction in FIO2 after 72 hours received prolonged treatment with low-dose iNO, weaning by 20% every 3 days as tolerated. FINDINGS: Sixteen preterm infants (23-29 weeks of gestation), age 1 to 7 months, were enrolled. Eleven of 16 infants had a significant increase in PaO2 after 1 hour of iNO (median change, 24 mm Hg; range, -15 to 59 mm Hg; P <.01), but there was no significant change in PaCO2. After 72 hours of iNO, 11 infants had >/=15% reduction in FIO2, and 7 of the 11 had >/=35% reduction (P <. 01). Among the 11 infants who responded to iNO after 72 hours, 10 had a sustained improvement in oxygenation throughout their course of treatment (duration, 8-90 days), and ventilator support could also be decreased. No adverse effects from iNO (increased methemoglobin, bleeding, or increased plasma 3-nitrotyrosine) were observed. Four of the 11 infants (36%) who responded to iNO ultimately weaned off mechanical ventilation and 4 died, whereas all the infants who failed to respond to iNO either died or continue to require mechanical ventilation. INTERPRETATION: We conclude that the use of low-dose iNO may improve oxygenation in some infants with severe BPD, allowing decreased FIO2 and ventilator support without evidence of adverse effects. Randomized clinical trials of low-dose iNO for BPD are warranted.

Administration, Inhalation↗

PubMed1998

Mechanics of the single left ventricle: a study in ventricular-ventricular interaction II.

BACKGROUND: Left ventricular (LV) effects on right ventricular (RV) function are well known. Less is understood about the effect of the RV on systemic LV mechanics. To determine this interaction, we compared systemic LVs with and without an RV mechanically coupled to them. METHODS AND RESULTS: MR myocardial tagging was used to examine 18 subjects with systemic LVs: 10 with functional single LVs (SLV) and 8 normal subjects (NL). Tracking the systolic motion of the intersecting stripes were used to determine regional twist and radial motion. Finite strain analysis was applied to derive principal strains at the atrioventricular valve (AVV) and apical short-axis levels and in 4 anatomic wall regions. Similar E1 (circumferential shortening) strain and heterogeneity of strain were noted between SLV and NL except in the septal wall. At the septal wall, NL displayed greater absolute strain (AVV=-0.16+/-0.02, apex=-0.17+/-0.02) and less heterogeneity of strain than SLV (AVV= -0.12+/-0.02, apex=-0.13+/-0.02). Similar E2 (wall thickening) strain and heterogeneity of strain were also noted between SLV and NL except again at the septal wall. At the septal wall, SLV displayed greater absolute E2 strain (AVV=0.17+/-0.08, apex=0.19+/-0.09) and less heterogeneity of strain than NL (AVV=0.07+/-0.07, apex=0.05+/-0.05). SLV twisted significantly less counterclockwise than NL in 6 of 8 wall regions and actually twisted clockwise at the AVV lateral wall. Although there was no significant difference between groups in radial wall motion, the septal and inferior walls of SLV demonstrated significantly less radial motion compared with other SLV walls. CONCLUSIONS: A major influence of the RV on systemic LV strain and radial motion occurs in the septal wall, whereas absence of the RV causes marked differences in LV twist. These findings may yield clues to the long-term functioning of the SLV and be useful in determining strategies for RV augmentation of LV function.

Adolescent↗

PubMed1998

Can echocardiography predict the presence or absence of endocardial fibroelastosis in infants <1 year of age with left ventricular outflow obstruction?

This study assesses the use of echocardiography in detecting endocardial fibroelastosis in 32 infants with obstructive left-sided lesions. The data demonstrate that neither endocardial echo-brightness nor geometric variables of the left ventricle allow for accurate prediction of the presence of endocardial fibroelastosis.

Echocardiography, Doppler↗

PubMed1998

Acute changes in preload, afterload, and systolic function after superior cavopulmonary connection.

BACKGROUND: Superior cavopulmonary connection reduces the volume work of the single ventricle. METHODS: To determine the effects of superior cavopulmonary connection on preload, wall stress (or afterload), and systolic ventricular function, we studied 9 patients before and after operation, and at hospital discharge. Using echocardiography, preload was estimated by the ventricular end-diastolic area, and wall stress was calculated at end-systole and peak-systole. Ventricular function was represented by rate-corrected velocity of circumferential fiber shortening and fractional area change divided by rate-corrected ejection time. RESULTS: End-diastolic area and wall stress decreased postoperatively. Ventricular wall thickness increased with a concomitant decrease in cavity area. There was no change in mean blood pressure or heart rate or in rate-corrected velocity of circumferential fiber shortening or fractional area change divided by rate-corrected ejection time. These findings persisted at hospital discharge. CONCLUSIONS: In single ventricles, superior cavopulmonary correction results in an immediate decrease in preload and afterload. The decrease in afterload results primarily from alterations in ventricular geometry. Although no improvement in systolic function was noted, diminished work related to the reduction in loading conditions may have beneficial long-term effects on preserving myocardial performance.

Anastomosis, Surgical↗

PubMed1998

Outcome after operations for pulmonary atresia with intact ventricular septum.

OBJECTIVE: Pulmonary atresia with intact ventricular septum is an anatomically heterogeneous anomaly with a variety of surgical strategies possible. We sought to compare the outcome of patients with a single ventricle approach to those with a biventricular repair and to compare outcome of patients with coronary abnormalities to those with normal coronary arteries. METHODS: A retrospective review of our surgical database revealed 67 patients with pulmonary atresia with intact ventricular septum operated on between 1981 and 1998. Patients were categorized on the basis of initial surgical strategy: strategy A, aortopulmonary shunt alone (n = 31); strategy B, right ventricular recruitment (n = 32); strategy C, heart transplantation (n = 4). Tricuspid valve size (Z-score) and coronary anatomy were determined. Right ventricular-coronary artery dependency was noted in 8 patients. RESULTS: Overall actuarial survivals at 1, 5, and 8 years were 82%, 76%, and 76%. Mortality was highest in infancy (10 of 16 deaths). Outcome was equivalent for all 3 strategies. There was no difference in tricuspid valve size between survivors and nonsurvivors (mean Z-score -2.0 (2.5) vs -2.0 (1.9), P =.83). There was no difference in survival based on severity of coronary abnormality. Only one third of patients had a successful biventricular repair, and the tricuspid valve was significantly larger in these than in patients who had Fontan operation (mean Z-score -0.53 [1.6], range -3.5 to 1, versus mean Z-score -3.03 [2.7], range -5.5 to 0, P =.002). CONCLUSIONS: Surgical outcome for patients born with pulmonary atresia with intact ventricular septum is satisfactory. The strategies of biventricular repair, single ventricle palliation, and heart transplantation allow for equal outcome among all anatomic subtypes.

Coronary Angiography↗

PubMed1998

Growth characteristics of the aortic arch after the Norwood operation.

OBJECTIVES: We sought to characterize the growth of the reconstructed aortic arch after the Norwood operation (NO). BACKGROUND: The first stage of surgical palliation of hypoplastic left heart syndrome (HLHS), the NO, includes augmentation of the aortic arch with homograft. Growth characteristics of the reconstructed aortic arch, which is comprised of both native aortic tissue and homograft, have not been characterized. METHODS: Retrospectively, we examined the serial echocardiograms of 50 patients with HLHS who underwent NO to determine the diameter of the reconstructed transverse arch. Measurements were taken immediately after NO and at two other points (1 to 11 years of age). In addition, the autopsy specimens of 10 other patients with HLHS who underwent NO were examined to determine the contribution of native aortic tissue to the overall size of the reconstructed arch at the time of death (12 to 34 months). RESULTS: The diameter of the transverse aorta increased after NO in all subjects. Its rate of growth paralleled that seen in the normal population, though the reconstructed arch had a significantly larger diameter throughout childhood. Examination of autopsy specimens demonstrated a mean increase in circumference of the native aortic tissue of 0.67 cm (p value <0.01), whereas there was no significant change in homograft circumference. CONCLUSIONS: After reconstruction of the aortic arch in HLHS, the diameter of the arch continues to increase throughout childhood, and this increase is due to growth of the native aortic tissue.

Aorta, Thoracic↗

PubMed1997

Comparison of patterns of pulmonary venous blood flow in the functional single ventricle heart after operative aortopulmonary shunt versus superior cavopulmonary shunt.

In this study we investigated the patterns of pulmonary venous flow in children with functional single ventricles to obtain a better understanding of the determinants of transpulmonary blood flow. Sixty-eight patients with functional single ventricles and aortopulmonary shunt (n = 34, group I), or superior cavopulmonary connection (n = 34, group II) underwent transesophageal Doppler echocardiographic assessment of flow in the left upper pulmonary vein before undergoing the next stage of surgery. Twelve patients from group II also underwent simultaneous evaluation of superior vena caval flow. Biphasic forward pulmonary venous flow was noted in 62 patients in sinus rhythm (S wave in systole, D wave in diastole); in 6 patients with junctional rhythm, significant early systolic reversal of flow was present. Both the S- and D-wave velocity-time integrals (VTI) were greater in group I than in group II (S(VTI) 9.9 +/- 4.2 vs 8.0 +/- 2.6, p = 0.02; D(VTI) 8.0 +/- 3.5 vs 4.2 +/- 2.6, p <0.001). In both groups, pulmonary venous flow was predominantly systolic; however, the proportion of flow during ventricular systole was significantly greater in group II than in group I (S(VTI)/D(VTI) group II: 2.4 +/- 1.5; group I 1.4 +/- 0.5, p = 0.001; percent systolic fraction of pulmonary venous flow group II = 67%, group I = 56%, p <0.001). Analysis of superior vena caval flow in group II revealed a single predominant wave with onset at early systole and peak in late systole at a mean of 150 ms after the pulmonary venous S-wave peak. Our data suggest that ventricular systole (i.e., atrial relaxation, atrioventricular valve descent) asserts great influence on transpulmonary blood flow in the functional single ventricle.

Echocardiography, Doppler↗

PubMed1997

Late surgical fenestration for complications after the Fontan operation.

BACKGROUND: Significant morbidity after Fontan operation results in either takedown, heart transplantation, or death. Initial creation of a fenestration results in less morbidity and mortality; however, the role of late creation of a fenestration in aiding patients manifesting morbidity after an initial nonfenestrated Fontan operation is unclear. METHODS AND RESULTS: We reviewed our experience with late creation of a surgical fenestration in 9 patients (5.2 +/- 3.1 years old) exhibiting chronic effusions (n = 4) or protein-losing enteropathy (PLE) (n = 5) after lateral tunnel-type Fontan operation. Patients with effusions had creation via coronary punch of two or three 3-mm defects; patients with PLE had creation of a large, 5-mm defect. One child with effusions and multisystem organ failure before fenestration died 7 weeks after surgery secondary to low cardiac output; the other 3 had resolution of effusions within 4 to 6 weeks. Of the 5 with PLE, 3 had normalization of serum proteins and resolution of symptoms at 2 to 6 weeks. The 2 failures had arterial saturations > 89% after surgery. Follow-up was from 25 to 30 months. Spontaneous closure of defects occurred in all 3 with effusions. No return of symptoms was noted in 2; however, the third reaccumulated effusions and has undergone refenestration with a large defect. All 3 patients with PLE have remained asymptomatic with patency of the fenestration (4 to 5 mm on echocardiography) and arterial saturation < or = 85% for > 2 years. CONCLUSIONS: Late surgical creation of fenestration results in resolution of morbidity after Fontan operation. Improvement is related to the degree of right-to-left shunt created.

Cardiac Catheterization↗

PubMed1997

Pulmonary AV malformations after superior cavopulmonary connection: resolution after inclusion of hepatic veins in the pulmonary circulation.

BACKGROUND: A high incidence of pulmonary arteriovenous malformations (PAVMs) has been reported in patients who have polysplenia and congenital heart disease after superior cavopulmonary anastomosis. Interruption of hepatic venous return to the pulmonary circulation is believed to potentiate the development of PAVMs. Surgical inclusion of hepatic flow in the pulmonary circulation may result in their resolution. METHODS: We reviewed 3 patients with congenital heart disease and polysplenia in whom PAVMs developed and who had subsequent hepatic vein inclusion in the pulmonary circulation. RESULTS: Patients underwent superior cavopulmonary connection at a median age of 8 months. The PAVMs were diagnosed at a median duration of 8 months after operation (arterial saturation <75% in room air). Hepatic venous flow was included in the pulmonary circulation at operation. Resolution of PAVMs occurred at a median duration of 7 months after operation (arterial saturation >90% in room air). CONCLUSIONS: Surgical inclusion of hepatic venous blood in the pulmonary circulation results in the resolution of PAVMs. Electively associating the hepatic veins with the pulmonary vasculature may prevent the development of PAVMs in patients who are at risk.

Arteriovenous Malformations↗

PubMed1997

Effect of surgical reconstruction on flow profiles in the aorta using magnetic resonance blood tagging.

BACKGROUND: The aorta that has undergone an aorta-pulmonary artery anastomosis may not exhibit the same velocity profile as the nonreconstructed aorta, whose velocity profile is thought to be uniform across the vessel diameter (plug flow). This may have an impact on fluid dynamics and will alter Doppler flow calculations. Our objective was to determine the impact of surgical reconstruction on the velocity and flow profiles of the reconstructed ascending and descending aorta. METHODS: Using a magnetic resonance imaging tagging technique that labels flowing blood (bolus tagging), we studied 22 patients (mean age, 8.6 +/- 4.7 years) who had had a Fontan procedure. A cine sequence labeled the blood and acquired the image after 20 ms in the middle of the ascending aorta and behind the left atrium in the descending aorta. The repetition time was 50 ms. RESULTS: The reconstructed ascending aorta displayed a velocity profile skewed anteriorly, whereas in the nonreconstructed aorta, the velocity profile was flat. Reconstructed aortas also displayed flows that were higher anteriorly, took a longer time to reach maximum velocity, and were less like "plug" flow than the nonreconstructed aorta. The descending aorta, regardless of whether aortic reconstruction was present, displayed velocity profiles (at various phases of systole) skewed posteriorly. CONCLUSIONS: The reconstructed aorta displays disturbed flow, and the velocities across the ascending aortic diameter are more varied than those in aortas without reconstruction and are skewed anteriorly. The descending aortic velocity profile in children is skewed posteriorly, regardless of whether aortic reconstruction is present. This information may help design and build a "better" aortic reconstruction.

Adolescent↗

PubMed1997

The nature of flow in the systemic venous pathway measured by magnetic resonance blood tagging in patients having the Fontan operation.

OBJECTIVES: Our objectives were twofold: (1) to determine cardiac and respiratory dependency of systemic venous pathway flow of patients having the Fontan operation with a total cavopulmonary connection and (2) to describe the velocity profile. Systemic venous pathway flow is hypothesized to be mostly respiratory dependent, to be laminar, and to have a smooth velocity profile. METHODS: Twenty-two patients having the Fontan operation (aged 8.6 +/- 4.7 years) underwent magnetic resonance blood tagging (bolus tagging). Systemic venous pathway spin-echo images parallel to the blood flow were used as a localizer. A saturation pulse labeled the blood, and a cine image was acquired at the inferior and superior venae cavae and midportion of the baffle in the systemic venous pathway, triggered to the electrocardiogram and gated to both end-expiration and end-inspiration. Repetition time was 50 msec. RESULTS: Flow in the systemic venous pathway was laminar throughout its course and was found to be phasic to both cardiac and respiratory cycles. Approximately 70% of flow was cardiac dependent, and the rest was respiratory. Highest flow occurred near end-systole and early diastole and in inspiration. Lowest flow occurred in diastasis. Velocity was highest and flow least "pluglike" in the mid-baffle area during cardiac or respiratory imaging (45 +/- 17 and 32 +/- 11 cm/sec, respectively). CONCLUSION: A substantial amount of pulmonary blood flow in patients who have undergone a total cavopulmonary connection type of Fontan operation has a cardiac component. Furthermore, we confirm that this flow is laminar but nonuniform across the systemic venous pathway. Highest flows occurred near end-systole and early diastole, as well as in inspiration, and the lowest flow occurred in diastasis. This information may help in designing the systemic venous pathway and optimizing medical management.

Blood Flow Velocity↗

PubMed1997

Effect of volume unloading surgery on coronary flow dynamics in patients with aortic atresia.

OBJECTIVES: The objectives of this study were to define physiologic effects on and a clinical correlate to coronary blood flow during volume unloading surgery in patients with aortic atresia. METHODS: Twenty-two patients with aortic atresia (group I, 13 patients with stage I reconstruction undergoing hemi-Fontan operation; group II, 9 patients with hemi-Fontan undergoing Fontan operation) underwent perioperative transesophageal echocardiography. Doppler spectral patterns, peak velocity, velocity time integral, and blood flow in the native ascending aorta were measured. Preoperative hemodynamics and postoperative clinical data were analyzed. Significance was defined as p < 0.05. RESULTS: Higher values of coronary blood flow (982.9 +/- 321.7 vs 548.6 +/- 333.8 ml/min per square meter), velocity time integral (20.7 +/- 5.6 vs 12.6 +/- 4.0 cm), and peak velocity (96.1 +/- 21.4 vs 51.0 +/- 18.2 cm/sec) were found before operation in group I than after operation and in group II at both times. Flow changed from predominately systolic in preoperative group I to both systolic and diastolic after operation and in group II. Before operation in groups I and II, a number of hemodynamic parameters such as superior vena cava oxygen saturation correlated with coronary blood flow dynamics. After operation in group II, urine output (r = 0.86) and central venous pressure (r = -0.85) correlated with coronary blood flow dynamics. CONCLUSION: Coronary blood flow parameters were higher in group I as a result of the increased energy needs required to pump to two circulations. No changes were found in group II. A number of coronary blood flow parameters correlated with preoperative hemodynamics and postoperative clinical data. These parameters appear to be useful in assessing the performance status of the myocardium after the Fontan operation, consistent with the notion that myocardial perfusion relates directly to ventricular function.

Aorta↗

PubMed1997

Tetralogy of Fallot with absent pulmonary valve: echocardiographic morphometric features of the right-sided structures and their relationship to presentation and outcome.

Respiratory symptoms in tetralogy of Fallot with absent pulmonary valve are believed to be due to bronchial compression secondary to dilated pulmonary arteries; however, not all patients are born compromised. Echocardiographic morphometry of the right-sided structures was investigated to determine the possible relationship between anatomy and clinical presentation. Twenty-five patients were identified, and 15 had preoperative echocardiograms. Patients were divided into two groups: those with respiratory distress (group I, n = 9) and those without (group II, n = 6). No difference was noted in branch pulmonary artery diameters between groups; however, the pulmonary valve/ aortic valve ratio, reflecting the dimension of the narrowest pathway from the right ventricle, was larger in group I (0.74 +/- 0.15 versus 0.60 +/- 0.07, p < 0.05). Pulmonary valve diameter correlated with main and right pulmonary artery diameters. We conclude that patients with tetralogy of Fallot with absent pulmonary valve and respiratory compromise have a greater pulmonary valve/aortic valve ratio but do not have greater dilatation of proximal branch pulmonary arteries. This suggests that the pathophysiology is not due solely to compression of the bronchi but is also related to the blood flow dynamics in the pulmonary vessels.

Adolescent↗