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Biomedical subjects

R M Freedom

Publications and source records attributed to R M Freedom.

At least 127 records · Page 7Linked to original sources
PubMed1993

Pulmonary blood supply by a branch from the distal ascending aorta in pulmonary atresia with ventricular septal defect: differential diagnosis of fifth aortic arch.

A patient with pulmonary atresia and a ventricular septal defect is described in whom an arterial branch from the distal ascending aorta supplied segments of both lungs. The branch is considered to represent a persistent fifth aortic arch. The possible morphogenesis and differential diagnosis of a communication between the ascending aorta and the pulmonary artery in pulmonary atresia with ventricular septal defect are discussed.

Adolescent↗
PubMed1993

Rare types of aortic arch anomalies.

Rare types of aortic arch malformations include isolation of the right or left subclavian arteries in conjunction with a left or right aortic arch respectively. Isolation of the innominate or carotid arteries and an aberrant left innominate artery may exist in association with a right aortic arch. Other anomalies are persistent fifth aortic arch, subclavian artery as the first branch of the aortic arch, pulmonary artery, and ductus arteriosus sling. The angiocardiographic features and embryology of each of these malformations are discussed.

Angiocardiography↗
PubMed1993

Survival analysis of infants under age 18 months presenting with tetralogy of Fallot.

The trend to perform early primary repair of tetralogy of Fallot prompted us to review our experience in the current era with the traditional protocol consisting of palliation during infancy, if required, and repair after infancy. During a 10-year period, 270 infants with tetralogy of Fallot presented aged less than 18 months. Thirteen infants (4.8%) had major noncardiac lesions that precluded definitive care for their congenital heart disease. Twenty infants (7.4%) had major associated cardiac lesions (atrioventricular septal defect or absent pulmonary valve syndrome, or both). Survival in this group was poor, with only 58% +/- 12% reaching the age of 10 years. Four of the seven deaths occurred before intracardiac repair was performed. The remaining 237 infants presented with isolated tetralogy of Fallot. Eight-nine percent +/- 2.3% survived to age 10 years. Sixty percent of these infants required palliation, and survival in these infants did not differ from that in those who never required palliation. However, 19 infants (8%) required palliation in the first month of life. In these children, survival to age 10 years was significantly lower (77%), secondary palliation was frequently required (n = 11), and a transannular patch or conduit at the time of repair (10 of 14 patients) was more likely needed than it was in children who had not undergone a palliative procedure during the neonatal period. The survival in infants with tetralogy of Fallot is unlikely to be different, regardless of whether primary repair or a staged repair is carried out. The quality of survival, including the exercise capability and absence of arrhythmias, must be assessed to determine which protocol is superior.

Abnormalities, Multiple↗
PubMed1993

A case report of double-orifice tricuspid valve.

A heart specimen with double-orifice tricuspid valve is described. The tricuspid valve was divided into the anterior and posterior orifices by a bridge of leaflet tissue. The valve was stenotic because of the arcade deformity of the anterior papillary muscle to which the bridging leaflet tissue had short chordal insertions. The anterior orifice was regurgitant as a result of a deficient septal leaflet. Clinical correlation was obtained by magnetic resonance imaging of the specimen. The functional significance of the malformed valve was assessed by three-dimensional reconstruction of the two-dimensional magnetic resonance images.

Humans↗
PubMed1993

Scimitar syndrome in infancy.

OBJECTIVES: The objectives of this study were to determine the anatomic and physiological factors most responsible for the severe symptoms and poor prognosis of infants with scimitar syndrome. BACKGROUND: Whereas the diagnosis of scimitar syndrome is often made incidentally in older children and adults who undergo chest radiography for diverse reasons, infants in whom the diagnosis is made typically present with severe symptoms and have a poor prognosis. METHODS: The clinical, catheterization and imaging data of 13 consecutive infants with scimitar syndrome who underwent cardiac catheterization in the 1st 6 months of life were reviewed, with emphasis on the pulmonary artery pressure, pulmonary and cardiovascular anatomy, therapeutic interventions and outcome. RESULTS: Twelve of the 13 infants had pulmonary hypertension at the time of diagnosis. Six patients died despite specific treatment. Eleven of 13 infants had associated cardiac malformations and 9 had large systemic arterial collateral channels to the right lung. Seven patients had anomalies involving the left side of the heart, especially varying degrees of hypoplasia of the left heart or aorta, and six of these patients died. Ten patients underwent surgical or transcatheter therapy in the 1st year of life. Systemic arteries to the right lung were ligated in three patients and occluded by transcatheter embolization in four. Balloon angioplasty was carried out in two patients, one with stenosis of the left-sided pulmonary veins and one with stenosis of the anomalous right pulmonary vein. The latter had placement of a balloon-expandable stent. In both patients, pulmonary vein stenosis progressed. Six patients had surgical repair of associated cardiovascular anomalies, and two required repair of extracardiac congenital anomalies. Occlusion of the anomalous systemic arteries was generally associated with clinical improvement, but congestive heart failure and pulmonary hypertension recurred in those patients with associated cardiovascular anomalies, whose condition subsequently responded after correction of the shunt lesions. CONCLUSIONS: The severe symptoms and pulmonary hypertension found in infants with scimitar syndrome have many causes. Anomalous systemic arterial supply, pulmonary vein stenosis and associated cardiovascular anomalies play a significant role, and the ultimate outcome of individual infants depends on the feasibility of treating these anomalies in early infancy.

Abnormalities, Multiple↗
PubMed1993

Regional ventricular wall motion abnormalities in tricuspid atresia after the Fontan procedure.

OBJECTIVES: The purpose of this study was to determine whether wall motion abnormalities are present before or after the Fontan procedure in patients with a univentricular heart of the left ventricular type with an absent right atrioventricular valve connection (tricuspid atresia) and to assess the impact of such abnormalities on ventricular performance and clinical outcome. BACKGROUND: Normal systolic and diastolic ventricular function is critical for a successful Fontan repair. However, there have been no previous studies addressing the relation between regional ventricular function and hemodynamic factors. METHODS: Thirty-seven pediatric patients were studied with biplane ventricular cineangiography. There were 20 male and 17 female patients whose mean age at the time of the Fontan operation was 6.5 +/- 3.5 years (range 2.5 to 15.6). Eighteen patients were studied preoperatively, 25 at > 1 year postoperatively and 6 serially. Wall motion was assessed by a centerline method. Normal ranges for wall motion and other variables were established from 25 normal subjects. RESULTS: Wall motion abnormalities were observed in 2 of 18 patients preoperatively and in 11 of 25 patients postoperatively. Age at operation and ventricular volumes did not differ between postoperative patients who had normal (group I, 14 patients) or abnormal (group II, 11 patients) wall motion. However, ventricular mass and the mass/volume ratio were significantly greater and systolic variables and cardiac index were significantly lower in group II versus group I. Two patients in group I were considered to have a clinically poor outcome (persistent heart failure), and five in group II had heart failure, including one who died late. CONCLUSIONS: These observations suggest that postoperative regional wall motion abnormalities in this setting are not rare, may be related to excessive hypertrophy and may contribute to cardiac dysfunction and a poor clinical outcome.

Adolescent↗
PubMed1993

Influence of ventricular morphology on diastolic filling performance in double-inlet ventricle after the Fontan procedure.

OBJECTIVES: The purpose of this study was to define the influence of dominant chamber morphology on ventricular performance after the Fontan procedure in patients with double-inlet ventricle. BACKGROUND: Previous studies have reported the impact of ventricular morphology on preoperative ventricular performance and surgical outcome. However, the influence on postoperative ventricular performance has not been addressed. METHODS: Twenty-six clinically asymptomatic patients > 1 year after repair (mean age at procedure 6.1 +/- 3.7 years) were evaluated with ventricular cineangiography and radionuclide blood pool studies (18 with a dominant left ventricular morphology [LV group], 8 with a dominant right ventricular morphology [RV group]) and compared with normal control subjects. RESULTS: Ventricular volume, mass and systolic variables were similar between patient groups. In the LV group, however, the mass/volume ratio was significantly elevated compared with values in control subjects (1.11 +/- 0.28, 0.97 +/- 0.19, p < 0.05), whereas this ratio in the RV group (0.90 +/- 0.11) was within the normal range and significantly lower than that in the LV group (p < 0.05). Mean right atrial and pulmonary artery pressures in the RV group were significantly higher than those in the LV group (p < 0.05). Peak filling rates (2.87 +/- 0.70, 2.41 +/- 1.15 and 3.84 +/- 0.51 end-diastolic volume/s [LV and RV groups and control subjects, respectively]) were significantly lower in both groups than in control subjects (p < 0.001), without intergroup difference. CONCLUSIONS: Ventricular filling abnormalities after atrial to pulmonary anastomosis are common regardless of the type of dominant ventricular morphology, and these abnormalities in patients with dominant right ventricular morphology do not coexist with ventricular hypertrophy. Such diastolic abnormalities may be related to either intrinsic myocardial or acquired factors, not to excessive hypertrophy alone. Those differences may become clinically more apparent with longer follow-up and may raise concerns over the long-term course.

Cardiac Catheterization↗
PubMed1993

Outcomes in critically ill neonates with pulmonary stenosis and intact ventricular septum: a multiinstitutional study. Congenital Heart Surgeons Society.

OBJECTIVE: This study attempted to determine the optimal therapeutic interventions by risk-adjusted comparisons of early and intermediate-term outcomes. BACKGROUND: The variety of interventions and the small case load at individual institutions have delayed the generation of reliable information concerning therapy for this condition. METHODS: In this prospective 27-institution study, 101 neonates were consecutively enrolled (between January 1, 1987 and January 1, 1991). Treatment was determined by the physicians. Demographic and morphologic details were tabulated. Dimensions of the pulmonary "anulus" and tricuspid anulus were measured on echocardiograms, and right ventricular cavity size was estimated. Right ventricular-pulmonary trunk pressure gradients were tabulated. Numerous analyses were made. RESULTS: Severe pulmonary valve stenosis and an intact ventricular septum were present in all patients. The right ventricular-pulmonary trunk junction ("anulus") was severely narrowed in 15%. Right ventricular cavity size was severely reduced in 4%. The tricuspid valve was small in 15% of patients; its diameter was poorly correlated with right ventricular cavity size. Eighty-nine percent and 81% of patients survived > or = 1 month and 4 years, respectively, after the initial procedure. Multivariable analysis identified no patient-specific risk factors for death. Only open pulmonary valvotomy without a support technique was uniformly a procedural risk factor; under some circumstances, transannular patching without a shunt was a risk factor. The right ventricular-pulmonary trunk gradient immediately after valvotomy was < 30 mm Hg in 81% of patients and was similar after surgical and balloon valvotomy. In 74% of patients, no intervention was required after the first accomplished intervention. CONCLUSIONS: Marked variation in morphology is uncommon in critical pulmonary stenosis in neonates. Percutaneous balloon valvotomy and certain types of surgical valvotomy are optimal initial procedures. The unusual situation of a small pulmonary "anulus" may initially require a transannular patch and a systemic-pulmonary artery shunt.

Catheterization↗
PubMed1993

Profile of paediatric patients with pulmonary hypertension judged by responsiveness to vasodilators.

OBJECTIVE: To describe the demographic and haemodynamic variables of children presenting with primary pulmonary hypertension or pulmonary hypertension appearing or persisting after surgical correction of congenital heart defects and to assess the acute effect of vasodilator drugs on their pulmonary vascular bed. DESIGN: Retrospective review. SETTING: Paediatric cardiology department and intensive care unit of a large tertiary centre. PATIENTS: Fourteen consecutive patients presenting with primary pulmonary hypertension (group 1) or pulmonary hypertension persisting or appearing late after complete surgical repair (group 2). INTERVENTION: Baseline haemodynamic measurements were taken in room air at rest and repeated in 100% oxygen. With constant monitoring of heart rate and pulmonary and systemic arterial pressures, patients were given serial intravenous, sublingual, or oral incremental doses of vasodilators (mean 4.1 trials per patient). The maximum effect of the drug was charted. MAIN OUTCOME MEASURES: A positive response to acute vasodilator tests was defined as a decrease in mean pulmonary or mean systemic arterial pressure > 15% with the mean pulmonary artery pressure not reaching the systemic level and either no change or an increase in mean systemic arterial pressure. Haemodynamic variables between groups (1 v 2, responders v non-responders, patients experiencing or not experiencing adverse effects to vasodilators) were compared by a two tailed unpaired Student's t test, and their survival curves were compared by the log rank statistic. RESULTS: Groups are small and definitive conclusions are difficult to draw, but the baseline haemodynamic assessments were not significantly different between group 1 and 2 or between responders and non-responders to vasodilators. Patients experiencing adverse effects had a higher pulmonary vascular resistance (p = 0.04) and wedge pressure (p = 0.02) than those without adverse effects. Of the vasodilators used, tolazoline, hydralazine, salbutamol, phentolamine, and phenoxybenzamine were ineffective. A positive response was seen in five of 13 patients given oxygen, in one of eight given prostacyclin, four of 12 given nifedipine, four of eight given diltiazem, one of six given captopril, and two of seven given glyceryl trinitrate. Estimates of survival of the population with primary pulmonary hypertension were 37% at one year and 12% at 2.5 years. Survival was significantly shorter in the non-responders than in the responders (p = 0.005). CONCLUSION: Children with primary pulmonary hypertension present to the cardiologist at a young age (five of eight were younger than 7 years) but with advanced pulmonary vascular disease and have a poor prognosis. 64% of group 1 and group 2 patients had a positive response to acute treatment with at least one vasodilator. Calcium channel blockers were the most effective agents. There was a positive response to drugs despite a negative response to acute treatment with oxygen. The survival of non-responders was shorter than that of the responders.

Adolescent↗
PubMed1993

Familial desminopathy: myopathy with accumulation of desmin-type intermediate filaments.

Two siblings developed cardiomyopathy several years before slowly progressive muscle weakness. Skeletal muscle biopsy specimens showed subsarcolemmal crescents of dark eosinophilic material in both type I and type II fibres. Immunohistochemically the subsarcolemmal material stained positively for the intermediate filament protein desmin and for the heat shock protein ubiquitin but for no other cytoskeletal proteins. Ultrastructurally the subsarcolemmal deposits consisted of aggregates of granular and filamentous material arising from Z-bands. Follow up muscle biopsies six years later showed an increased number of the muscle fibres that contained subsarcolemmal aggregates that stained positively for desmin and ubiquitin. These clinical and pathological features characterise a rare familial myopathy associated with an unusual distribution of desmin intermediate filament proteins in skeletal and probably also cardiac muscle.

Child, Preschool↗
PubMed1993

Experience with the Damus-Kaye-Stansel procedure for children with Taussig-Bing hearts or univentricular hearts with subaortic stenosis.

Anastomosis of the pulmonary artery to the ascending aorta is the essence of a technique for repair of complete transposition proposed by Damus, Kaye, and Stansel. Our Institutional experience with the Damus-Kaye-Stansel procedure (DKS) is limited to 9 children with double-outlet right ventricle and 38 with univentricular heart plus subaortic stenosis. Thirty-eight children (81%) survived the DKS procedure, and there were three late deaths during the mean follow-up of 3.1 years. Five-year survival is 72% (+/- 8%). All six children surviving a DKS and biventricular repair of double-outlet right ventricle have required conduit replacement at a mean interval of 46 months. In the children with univentricular heart, relief of subaortic stenosis with the DKS was successful in all except two. The late function of the semilunar valves is of concern, as 36% of the aortic and 52% of the pulmonary valves have some degree of incompetence.

Aorta↗
PubMed1993

Outcomes in neonatal pulmonary atresia with intact ventricular septum. A multiinstitutional study.

A total of 171 neonates with pulmonary atresia and intact ventricular septum were entered into a prospective multiinstitutional study between January 1, 1987, and January 1, 1991. Treatment was not assigned randomly but was selected by the responsible physicians. The Z-value (standard deviation units) of the diameter of the tricuspid valve was less than -2 in 52% of patients and less than -4 in 26%; it was highly correlated with right ventricular cavity size (which was small in 90% of patients and was severely reduced in 54%). Coronary artery-right ventricular fistulas were present in 45% of patients, and right ventricular dependency was severe in 9%; diameter (Z-value) of the tricuspid valve was negatively correlated (P < 0.0001) with the prevalence of both. Survival was 81% at 1 month after the first intervention and 64% at 4 years; the hazard function (instantaneous risk of death) declined rapidly after the initial procedure but remained appreciable for 24 months. Multivariable analysis showed small diameter of the tricuspid valve, severe right ventricular coronary dependency, birth weight, and the date and type of initial procedure to be risk factors for time-related death. Subsequent procedures were performed in 51% of patients. Among patients undergoing an initial procedure that did not include a systemic-pulmonary artery shunt, only 49% did not receive a shunt in the subsequent 1 month; small size of the tricuspid valve was the only risk factor for receiving the subsequent shunt. Ninety-eight percent of living patients whose initial procedure did not include a transannular patch were free of a subsequently placed transannular patch within 1 month, but only 45% were free of it 3 years later; no risk factors were identified. Eighteen percent of living patients had received a one-ventricle repair within 3 years, and 32% had received a two-ventricle repair; the remainder (50%) had incompletely separated pulmonary and systemic circulations. The only patient-specific risk factor for not receiving a two-ventricle repair was the Z-value of the tricuspid valve.

Heart Septum↗
PubMed1992

Percutaneous pericardial catheter drainage in childhood.

The clinical course of 41 consecutive pediatric patients (mean age 7.6 +/- 5.8 years, weight 27 +/- 22 kg) who underwent percutaneous pericardial drain placement during a 3-year period were reviewed. The most common diagnoses were malignancy (20%), postpericardiotomy syndrome (17%), aseptic pericarditis (12%), and patients recovering from a Fontan type of operation (12%). Indications for drainage included increasing effusion size determined by 2-dimensional echocardiogram (48%), clinical deterioration (33%) and echocardiographic evidence of hemodynamic compromise (12%). Only 3 (7%) patients had clinical evidence of cardiac tamponade. Drainage catheter placement was accomplished percutaneously from the subxiphoid approach. Insertion was successful in all but 1 patient (98%) and successful evacuation of the pericardial space was achieved in 93% of patients. There was 1 death in a critically ill 2-week-old infant and 4 complications, 3 of which occurred in patients aged less than 2 years. Drainage catheters remained in position from 1 to 18 days (mean 3 +/- 3 days) with no late complications. There were 3 instances (7%) of drainage catheter occlusion. These data support the notion that placement of a percutaneous pericardial catheter is safe and effective in providing definitive drainage of the pericardial space in the pediatric age group. Children younger than age 2 years may be at increased risk for complications.

Catheters, Indwelling↗
PubMed1992

Clinical impact of balloon angioplasty for branch pulmonary arterial stenosis.

The clinical impact of percutaneous balloon angioplasty on the management of patients with native or postoperative pulmonary arterial stenosis was reviewed. Seventy-four patients underwent 110 angioplasty procedures. Mean age at dilation was 6.7 +/- 5.3 years (range 0.2 to 18.1), 17 patients were aged less than 1 year, mean follow-up was 37.7 +/- 22.8 months (range 16 to 96), and 34 patients (44%) had follow-up angiography. Pulmonary artery dilation was acutely successful in 53% of patients, 17% had recurrent stenosis, and 5% had complications. The impact on subsequent care was favorably influenced in 26 of 74 patients (35%) with either complete resolution of stenosis (n = 7), optimizing future surgical conditions (n = 14), reduction in right ventricular pressure by greater than 20% (n = 3), or improvement of ipsilateral lung perfusion (n = 2). No patient previously considered inoperable was subsequently considered suitable for surgical repair owing to the intervention. No correlation was found between success and cardiac diagnosis (p = 0.48), site of stenosis (p = 0.78), balloon-vessel ratio (p = 0.42), or whether the stenotic area consisted of native or synthetic material (p = 0.22). No predictive factors for success could be defined, and often there was only a transient clinical impact. Due to the low complication risk and potential for a beneficial result, it still appears prudent to offer angioplasty as an initial therapeutic modality in this setting.

Adolescent↗
PubMed1992

Balloon atrial septostomy under transesophageal echocardiographic guidance.

Balloon atrial septostomy is an established method of palliation for several forms of congenital heart disease. Previously performed under fluoroscopic x-ray control, recent reports have demonstrated the utility of transthoracic echocardiographic monitoring. We report the first application of uniplane transesophageal echocardiography (TEE) (6.7-mm probe) as an alternative imaging modality for control of balloon atrial septostomy on neonates in the intensive care unit.

Catheterization↗