Interaction between digoxin and propafenone in children.
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Adolescent↗
Biomedical subjects
R M Freedom
Publications and source records attributed to R M Freedom.
Echocardiographic analysis of regional left ventricular wall motion in normal children and neonates.
Because comprehensive normal data and the effect of observer variability for echocardiographic evaluation of regional left ventricular wall motion are not available in children or newborns, left ventricular wall motion was assessed by measuring regional area change. The study group comprised 55 infants and children with a normal heart: 15 neonates (greater than 1 week to less than 1 month old), 10 infants (greater than 1 month to less than 1 year old) and 30 children, 10 each in the age group greater than 1 year to less than 5 years, greater than 5 to less than or equal to 10 years and greater than 10 years. A combination of parasternal, apical and subcostal two-dimensional echocardiographic views was applied. After planimetry of an end-systolic and end-diastolic frame, the left ventricle was divided into eight equal segments and the percent area change calculated. Both a fixed reference and a floating system correcting for translation and rotation were applied. Intraobserver variability for percent area change measurements was 2.8 +/- 0.9% and 3.8 +/- 1% for observers 1 and 2, respectively. The mean interobserver difference of regional percent area change was 4.7 +/- 1.8%. Normal values for the eight anatomic segments were established in each echocardiographic imaging plane. The overall results were independent of the type of reference system utilized. The subcostal views yielded different results from their parasternal counterparts, probably because of differing imaging planes. These normal values establish a data base in the pediatric age range that can be used to detect abnormal segments in children at risk for developing regional left ventricular wall motion abnormalities.
Aging↗
Echocardiographic analysis of regional left ventricular wall motion in children after the arterial switch operation for complete transposition of the great arteries.
Regional left ventricular wall motion was assessed by two-dimensional echocardiography in 21 patients with complete transposition of the great arteries at a mean of 2.2 years (range 0.3 to 7) after an arterial switch operation. Fourteen patients had undergone a two-stage and seven patients a primary repair. Twenty patients were found to have echocardiographic images adequate for wall motion analysis. The results of these studies were correlated with thallium-201 myocardial perfusion scans. Left ventricular wall motion was assessed by measuring regional area change in parasternal and apical views. After planimetry of an end-systolic and an end-diastolic frame, the ventricle was divided into eight equal segments and the percent area change was calculated. Both a fixed reference and a floating system correcting for translation and rotation were applied. The measurements in the patient group were compared with normal age-matched values previously obtained in 55 normal infants and children. Wall motion abnormalities, found in seven patients, were located at the apex in three, at the inferior septum and anterolateral wall in one and the inferior, anterolateral and lateral walls in one patient each. All had a myocardial perfusion defect in a corresponding anatomic location. One patient with a small reversible perfusion defect at the basilar septum had normal regional wall motion. The sensitivity of detecting impairment of myocardial perfusion was 0.95. Wall motion abnormalities were found only in patients who had undergone a two-stage repair. Echocardiographic wall motion analysis can be used as a screening method to identify patients with suspected myocardial ischemia after the arterial switch operation.
Child↗
Doppler echocardiographic measurement of pulmonary artery pressure from ductal Doppler velocities in the newborn.
The ductal flow velocities in 37 newborns (group 1: persistent pulmonary hypertension [n = 16], transient tachypnea [n = 3], other [n = 2]; group 2: respiratory distress syndrome [n = 16]) were prospectively evaluated by Doppler ultrasound for the purpose of deriving systolic pulmonary artery pressures. Maximal tricuspid regurgitant Doppler velocity in 21 of these patients was used to validate the pulmonary artery pressures derived from ductal flow velocities. There was a significant linear correlation between tricuspid regurgitant Doppler velocity and pulmonary artery systolic pressure derived from ductal Doppler velocities in patients with unidirectional (pure left to right or pure right to left) ductal shunting (p less than 0.001, r = 0.95, SEE 8) and in those with bidirectional shunting (p less than 0.001, r = 0.95, SEE 4.5). Systolic pulmonary artery pressure in group 1 (67 +/- 13 mm Hg) was significantly higher than that in group 2 (39 +/- 10 mm Hg) (p less than 0.001). In those with bidirectional shunting, duration of right to left shunting less than 60% of systole was found when pulmonary artery pressure was systemic or less, whereas duration greater than or equal to 60% was associated with suprasystemic pulmonary artery pressures. Serial changes in pulmonary artery systolic pressure, reflected by changes in ductal Doppler velocities, correlated with clinical status in persistent pulmonary hypertension of the newborn. Persistently suprasystemic pulmonary artery pressure was associated with death in five group 1 patients. It is concluded that ductal Doppler velocities can be reliably utilized to monitor the course of pulmonary artery systolic pressures in newborns.
Blood Flow Velocity↗
Iliofemoral arterial complications of balloon angioplasty for systemic obstructions in infants and children.
The medical and radiological records of 64 consecutive infants and children who underwent transfemoral balloon dilation of the aorta or aortic valve were reviewed to determine the incidence, nature, and post-treatment outcome of acute iliofemoral complications. Balloon dilation angioplasty or balloon valvotomy was performed with 8F and 9F catheters without an arterial sheath. Patients ranged in age from 5 days to 15.4 years (mean, 6.4 years). Of 64 patients, 29 (45.3%) had an acute iliofemoral complication, including thrombosis (18 of 64), complete disruption (five of 64), incomplete disruption (three of 64), and arterial tear (three of 64). The arterial pathology was confirmed in 23 of 29 patients by one or a combination of surgical exploration and repair (18 of 29), angiography (six of 29), and magnetic resonance imaging (three of 29). Of eight patients, three with arterial disruption had acute hypotension requiring transfusion and immediate surgery; the other five had absent pedal pulses after the procedure. Of these five, three developed bleeding during thrombolytic therapy and underwent surgical exploration, and two were diagnosed by angiography after ineffective thrombolytic therapy. Angiography in three patients with iliac artery avulsion showed tapered occlusion in two and an aneurysm in one. In patients with iliofemoral thrombosis, angiography showed occlusion from the puncture site to the origin of the external iliac artery. Eleven patients (17% of the entire group and 38% of the group with acute iliofemoral complications) had reduced or absent pedal pulses at the time of discharge. A significant correlation was found between increased incidence of iliofemoral thrombosis and disruption (as well as abnormal pedal pulses at hospital discharge) and low patient weight.
Angioplasty, Balloon↗
Coronary angiography of pulmonary atresia, hypoplastic right ventricle, and ventriculocoronary communications.
A retrospective study was undertaken to determine the spectrum of angiographic abnormalities of the coronary arteries in infants and children with pulmonary atresia, hypoplastic right ventricle, and right ventriculocoronary arterial communications. Twenty-nine patients with 67 angiographic examinations were reviewed; findings in seven patients were compared with those at autopsy. Twenty-seven (93%) of 29 patients had caliber abnormalities of the involved coronary arteries, including obstructive lesions in 20 (69%) of 29 and segmental dilatation in 16 (55%) of 29. Nine patients had interruption of the anterior descending artery and one had absent connection between the coronary arteries and the aorta. A single coronary artery was found in four of 29 patients. There was excellent correlation between clinical angiography and autopsy findings in seven patients. This study confirms the ability of high-quality clinical angiography to show significant abnormalities of the coronary arteries in infants and children with pulmonary atresia and ventriculocoronary communications.
Child↗
William Glenn lecture. The cavopulmonary shunt. Evolution of a concept.
A bold and imaginative development, the cavopulmonary anastomosis, appeared to originate in several centers almost simultaneously. After extensive research on right heart bypass, Glenn was the first in North America to perform a successful experimental cavopulmonary shunt, and it became known by his name. In properly selected patients, palliation success was excellent, and mortality rates were low. From 1961 through 1988, we used a cavopulmonary anastomosis for palliation in 139 infants and children. There were eight hospital deaths, and most occurred early in the series. Palliation generally lasted 6-8 years-until the child outgrew the blood supply to the contralateral lung. Palliation could be restored by increased flow to that lung with another shunt. Six otherwise inoperable patients received benefit from the addition of an axillary arteriovenous fistula. Late pulmonary arteriovenous fistulas were identified in 11% of our patients by angiography, but with more sensitive testing, the incidence rate may be as high as 21%. The occurrence of pulmonary arteriovenous fistulas caused general concern and less frequent use of the shunt. Recent application of an end-to-side anastomosis, creating a bidirectional shunt, has restored interest. A major legacy of the cavopulmonary anastomosis was demonstration of the feasibility of partial right heart bypass, which paved the way for the Fontan operation, and it is frequently constructed as part of that operation. Currently, the Glenn shunt is most often used as a temporary or permanent alternative to a Fontan repair if there appears to be significant risk. The risk factors usually encountered include small pulmonary arteries, young age, poor ventricular function, atrioventricular valve incompetence, and myocardial hypertrophy-sometimes alone but often in combination.(ABSTRACT TRUNCATED AT 250 WORDS)
Anastomosis, Surgical↗
Morphological findings contributing to a failed Fontan procedure. Twelve-year experience.
A group of 37 patients (age range, 3 months to 29 years) who died after the modified Fontan procedure (within 2 months), representing 15% of the 245 patients undergoing this procedure from 1976 through 1988, was reviewed to determine the causes of death. The three morphological groups were 1) univentricular atrioventricular connection (n = 19), 2) tricuspid atresia (n = 9), and 3) other complex malformations (n = 9). Subaortic stenosis was present in 15 patients (40%) in this group compared with 31 of 208 early survivors (15%) (p = 0.008). Pulmonary artery banding, identified as a risk factor in our previous experience, was performed in 14 patients, nine of whom had subaortic stenosis. Nine palliative procedures for subaortic stenosis were performed in eight patients--before the Fontan procedure in three patients and concurrently with the Fontan procedure in five patients. Myocardial hypertrophy and signs of acute ischemic injury were common findings at autopsy (n = 25) and were particularly prominent in all patients with univentricular heart of left ventricular morphology associated with subaortic stenosis and previous pulmonary artery banding (n = 7). We conclude that the present majority of deaths occurring after the modified Fontan procedure are myocardial in nature and attributable to advanced myocardial hypertrophy that is potentiated by previous pulmonary artery banding and subaortic stenosis.
Aortic Valve Stenosis↗
Warm induction blood cardioplegia in the infant. A technique to avoid rapid cooling myocardial contracture.
The use of profound hypothermia and total circulatory arrest for repair of heart defects in neonates usually involves a period of systemic and myocardial bypass cooling. Rapid cooling of muscle (skeletal, smooth, and myocardial) can result in contracture through elevation of cytosolic calcium levels. The increased myocardial tone caused by cooling might render the heart more vulnerable to a subsequent period of cardioplegic ischemic arrest. Infants may be more susceptible to contracture because their small body mass allows more rapid myocardial temperature change when prearrest bypass cooling is used. The influence of avoiding rapid myocardial cooling before induced cardioplegic arrest was analyzed in a group of infants weighing less than 6 kg at the time of open cardiac operation. Myocardial ischemic arrest by warm (37 degrees C) induction blood cardioplegia was used in 57 infants and compared with results in 440 infants treated with standard blood cardioplegia. Multivariate logistic regression analysis revealed that patient diagnosis, weight, and age at operation were significant risk factors for operative mortality. The use of warm induction blood cardioplegia had a strongly positive independent effect on survival (p = 0.0003) for any patient weight, age, or diagnostic group. We recommend the avoidance of rapid myocardial cooling on bypass in all patients before induction of cardioplegic ischemic arrest.
Blood↗
Neonatal aortic stenosis. The balloon deflated?
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Aortic Valve Stenosis↗
Angiographic classification of the isolated, persistently patent ductus arteriosus and implications for percutaneous catheter occlusion.
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Angiography↗
Course of tricuspid atresia in the Fontan era.
Tricuspid atresia is an uncommon form of congenital heart disease and long-term survival was rare before the Fontan era. It was thought that the long-term survival of patients with tricuspid atresia would be improved by the introduction of the Fontan procedure and its subsequent modifications. This study reviews the clinical course of 84 patients with tricuspid atresia identified in the first year of life in the Fontan era. Prior palliative operations, their results and their ultimate application for the Fontan procedure were considered. Eleven patients died before surgical intervention and 5 did not undergo catheterization or echocardiographic confirmation before death. Five children underwent the Fontan procedure without prior palliation and 1 child does not require palliation at the present time. Sixty-seven patients (80%) had surgical procedures before evaluation for the suitability of a Fontan operation. Thirty-four patients had a second surgical palliation and 9 patients had a third palliation. The surgical mortalities for the first, second and third palliative surgery were 17.9, 17.6 and 0%, respectively. Thirty-two patients (38%) underwent the Fontan procedure and 2 deaths occurred (6%). An estimate of the probability of surviving for 1 year was 64% (95% confidence limits 54 to 74%) and that of 8 years was 55% (95% confidence limits 44 to 66%).
Blood Vessel Prosthesis↗
A wire technique to cross the congenitally stenotic aortic valve.
We describe a double-catheter "rendezvous" technique that allows the successful placement of a balloon valvotomy catheter retrogradely across a congenitally stenotic aortic valve when traditional single-catheter retrograde methods fail. An important therapeutic procedure that might otherwise be abandoned can be completed with only the additional procedure of a transseptal atrial puncture and a second arterial entry.
Aortic Valve Stenosis↗
Balloon dilatation of the very small patent ductus arteriosus in preparation for transcatheter occlusion.
Balloon dilatation of the very small ductus arteriosus is described, and its application in five patients undergoing catheter occlusion is presented and discussed.
Angioplasty, Balloon↗
Management of subaortic stenosis in the univentricular heart.
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Aortic Valve Stenosis↗
Long-term results in neonates with pulmonary atresia and intact ventricular septum.
Our entire institutional experience with pulmonary atresia and intact ventricular septum (1965 through 1987) included 115 patients, 16 of whom died before surgical intervention. Fifty-six percent of surgical patients (n = 99) had angiographic evidence of right ventricle-coronary arterial connections. The early mortality in the surgical group was 27.2%, and the actuarial survival was 24.7% +/- 6% at 13 years postoperatively. Multivariate analysis indicated that the presence of ventriculocoronary connections (p = 0.037), a decreasing ratio between right ventricular and left ventricular pressure at the initial cardiac catheterization (p = 0.007), and lower weight at operation (p = 0.001) were incremental risk factors for postoperative death; the presence of Ebstein's anomaly was an additional risk factor in the overall experience (including patients not surgically treated) (p = 0.01). Nearly all long-term survivors underwent at least one reoperation, including right ventricular outflow tract reconstruction (n = 39) and thromboexclusion of the right ventricle (n = 9). The presence of severe stenosis or interruption of the proximal left anterior descending coronary artery system was a uniformly lethal risk factor for patients undergoing these procedures (p = 0.0003). We conclude that surgical procedures that successfully decompress the right ventricle will usually result in biventricular circulation in and long-term survival of patients with pulmonary atresia with intact ventricular septum not complicated by Ebstein's anomaly or extensive ventriculocoronary connections. Decompression or thromboexclusion of the right ventricle is contraindicated in patients with ventriculocoronary connections and a right ventricle-dependent coronary circulation.
Coronary Vessel Anomalies↗
Analysis of survival in patients with pulmonary atresia and intact ventricular septum treated surgically.
The epidemiology of 98 children who underwent surgical intervention for pulmonary atresia and intact ventricular septum is presented. Sixty-one (62.2%) of the children died. Survival time from the date of the first operation ranged from 0 to 17.76 years. Analysis of the survivors revealed that an estimate of the probability of surviving for two years is 47% (95% confidence limits of 37%, 57%). An estimate of the median survival time is 1.43 years. In a Cox proportional hazards model, using survival time in days as the outcome variable (n = 73, using complete data), operative weight at first operation (P = 0.0019), right/left ventricular pressure ratio (P = 0.0185), and absence of ventriculo-coronary arterial connections (P = 0.0362) were identified as significant predictors of survival.
Adolescent↗
Tricuspid and pulmonary atresia with coarctation of the aorta: a rare combination possibly explained by persistence of the fifth aortic arch with a systemic-to-pulmonary arterial connection.
A ten-day old baby was found to have tricuspid and pulmonary atresia, and a "ductal-dependent" pulmonary circulation that was prostaglandin-sensitive. An unusual coarctation of the aorta was not recognised until an autopsy was performed, some 11 days after construction of an aortopulmonary shunt. A previously undefined anomaly in this neonate was persistence of the fifth aortic arch with a systemic-to-pulmonary artery connection on the same side as the definitive aorta. The histology of the fifth aortic arch is consistent with the pattern of an arterial duct.
Aorta, Thoracic↗