Serum digoxin levels in neonates under 1500 grams.
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Digoxin↗
Biomedical subjects
G G Sandor
Publications and source records attributed to G G Sandor.
The ECG in aortic stenosis. Value of TAVF and QV6.
Fifty patients with a mean age of 9.2 years (range, 1.2 to 17.5 years) had cardiac catheterization performed under standardized conditions plus a scalar ECG the previous day. Twenty different direct measurements and 25 derived measurements from the ECG were correlated with the resting peak systolic gradient across the aortic valve. Some of the best correlations were with the measured TAVF, TV6, QV6, and the sum of SV1 + RV6 with r values between .33 and .59. Another group of different patients with isolated aortic stenosis were studied with measurements of the important ECG segments. The r value of this "test" series was similar to that of the original group, so the groups were pooled. The best three-term regression equation involved TAVF, QV6, and the sum (SV1 + RV6), with r = .636. A scoring system was also devised to predict severity. If the TAVF is 0.1 mV or less or the TV6 is 0.3 mV or less or if there is no Q in V6, the gradient may be high. In our series, the ECG estimation of resting peak systolic gradient across the aortic valve in aortic stenosis was enhanced by the inclusion of TAVF and QV6 in the regression equation, as well as SV1 + RV6.
Adolescent↗
Determination of left ventricular diastolic chamber stiffness and myocardial stiffness in patients with congenital heart disease.
Left ventricular diastolic indexes were derived in 13 patients aged 5 to 21 years. Three had a normal heart, three had lesions causing volume overload and seven had coarctation of the aorta, including one whose main lesion was severe endocardial fibroelastosis. At cardiac catheterization simultaneous high fidelity pressure (P) and left ventricular volume (V) measurements were obtained and several points in one diastolic cycle taken. With use of a monoexponential formula (P = aebv) for P versus V, dP/dv and the operant chamber stiffness b were obtained. Similarly, with use of sigma = alpha e beta epsilon, d sigma/d epsilon, elastic stiffness (E) and the muscle stiffness constant KE were obtained. Values for b were 0.0273 +/- 0.0065 in normal subjects, 0.017 +/- 0.0043 in those with volume overload, 0.0369 +/- 0.0173 in those with coarctation (without endocardial fibroelastosis) and 0.0192 in the child with endocardial fibroelastosis. The plot of P versus V for coarctation was to the left and steeper than normal and the patients with volume overload had a flattened rightward curve, whereas the curve for those with endocardial fibroelastosis was extremely rightward. The stress-radii curves of the normal subjects and those with coarctation were similar whereas the curves for patients with volume overload and endocardial fibroelastosis were rightward of normal. The value for KE was 8.92 +/- 0.87 for the normal subjects, 8.26 +/- 0.75 for those with volume overload, 9.2 +/- 2.5 for those with coarctation and 22.75 for those with endocardial fibroelastosis. Thus, the pressure-loaded ventricle is stiffer than the normal, which in turn, is stiffer than the volume-loaded ventricle. This response, due to hypertrophy, appears to be appropriate in that diastolic stress was normalized and muscle stiffness was not increased except in the patient with endocardial fibroelastosis.
Adolescent↗
Serum digoxin levels in neonates whose weights are less than 1,500 grams.
Digoxin was given to 29 infants in congestive heart failure and weighing less than 1,500 gm. All the infants were considered to have an isolated patent ductus arteriosus and were recovering from the respiratory distress syndrome. Forty-eight serum digoxin levels were measured after 4 or more days on twice daily parenteral maintenance therapy and a significant correlation obtained between the dose and resultant serum level (P less than .001). A total parenteral maintenance dose of 5 micrograms/kg produced a serum level of 2.4 ng/ml (+/- 1.2 ng). This is a much lower dose regime than in frequently recommended and underscores the need for caution in digitalizing small premature infants.
Digoxin↗
Reliability of systolic time intervals in diagnosis of transposition of great arteries in newborn.
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Diagnosis, Differential↗
Intrinsic defects in the fetal alcohol syndrome: studies on 76 cases from British Columbia and the Yukon Territory.
Children diagnosed as FAS using standard criteria of maternal alcoholism, poor growth, delayed development and characteristic facial appearance underwent an investigative protocol involving skeletal x-ray surveys, cardiac assessments and intravenous pyelograms (IVP). Significant skeletal findings included cervical spine fusion in 20 of 46 children (43%), x-ray confirmation of microcephaly in 26/49 (53%) and abnormal thoracic cage development in 13/48 (27%). Thirty-nine of 54 children (72%) demonstrated a characteristic tapering of the shaft and occasional associated prominence of the tuft of the distal phalanges Bone age was delayed 2 standard deviations or greater in 14 of 51 children (27%). Cardiac lesions were found in 31 of 76 (41%) and a further 12 (16%) had functional murmurs. Lesions were ventricular septal defect 20 (26%), Tetralogy of Fallot 4 (5.1%), plus a variety of less frequent abnormalities. IVP's were limited to 19 random cases with 5 (26%) showing alterations from the normal. Cervical spine abnormalities of FAS as compared to the Klippel-Feil Syndrome are dissimilar and probably represent a different entity. Hand and lateral cervical spine x-ray studies are felt to be a useful adjunct to the diagnosis and management of the fetal alcohol syndrome.
Abnormalities, Drug-Induced↗
Noninvasive assessment of left ventricular function related to serum digoxin levels in neonates.
Eighteen neonates in heart failure were investigated to assess whether high or low serum digoxin levels had differing effects on left ventricular function as determined by systolic time intervals obtained by echocardiography. Nine patients had digoxin levels of 1.99 +/- 0.35 ng/ml (group 1). Nine others had levels of 3.62 +/- 0.95 ng/ml (group 2). Systolic time intervals were obtained by echocardiography before and at 5 days after digoxin and correlated with serum levels. The heart rate, preejection period (PEP), left ventricular ejection time (LVET), electromechanical systole (QS2) and the PEP/LVET ratio were measured. LVET and electromechanical systole were indexed. These measurements were analyzed and the two groups were compared using Student's t test. The clinical improvement in both groups was similar and no difference in ECG changes were noted. Therapy with digoxin produced changes in heart rate and systolic time intervals in both groups. Both showed significant shortening of electromechanical systole index; group 1 significantly shortened the LVET index and PEP/LVET ratio, whereas group 2 significantly shortened the PEP. Statistical analysis comparing the two groups showed no difference between them. Digoxin produces measurable changes in the indices of left ventricular function. The magnitude of these changes suggests no therapeutic advantage to the higher levels.
Digoxin↗
Long-term follow-up of patients after valvotomy for congenital valvular aortic stenosis in children: a clinical and actuarial follow-up.
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Adolescent↗
Role of transesophageal echocardiography in the management of aortic-left ventricular tunnel.
A 10-year-old patient has been followed for 10 years after repair of an aortic-left ventricular tunnel (ALVT) for residual aortic regurgitation and significant recurrent leak through the ALVT. Transesophageal echocardiography (TEE) was done prior to surgery and intraoperatively to (1) clarify the precise anatomy of the ALVT, (2) evaluate the degree of aortic regurgitation, and (3) assess the repair. Delineation of the anatomy of the ALVT and assessment of the residual aortic insufficiency helped with the intraoperative decision-making. We describe the TEE findings of a residual ALVT in this patient and discuss the role of TEE in managing the lesion.
Aorta↗
Double-blind placebo-controlled trial of corticosteroids in children with postpericardiotomy syndrome.
The objective of this study was to assess the efficacy of corticosteroids in hastening the recovery of children with postpericardiotomy syndrome, using a randomized double-blind placebo-controlled trial in a tertiary care referral center for pediatric cardiology and cardiac surgery. Twenty-one children, 6 months of age or older (mean age 3.9 years) with postpericardiotomy syndrome following open or closed heart surgery were administered either prednisone 2 mg/kg/day reducing to zero over 14 days (n = 12) or placebo (n = 9). Progress was monitored by daily clinical assessment and alternate day cross-sectional echocardiograms. The primary measures of efficacy were the number of patients in remission at 72 h and at 1 week. No difference in remission rates were found at 72 h, but at 1 week significantly more children treated with prednisone were in remission (placebo 3/9; prednisone 10/12, p = 0.03). A trend to faster resolution of all symptoms and signs was seen in the prednisone-treated group but this was not associated with earlier hospital discharge. Enlargement of pericardial effusion was seen in two children treated with steroids. No complications of treatment were encountered. Prednisone hastens the recovery of children with postopericardiotomy syndrome. Pericardial effusions may increase in size despite the use of corticosteroids.
Adolescent↗
Clinical and echocardiographic evidence suggesting afterload reduction as a mechanism of action of tolazoline in neonatal hypoxemia.
The effect of tolazoline was assessed in 29 hypoxic neonates. Tolazoline was given in a bolus starting at 1 mg/kg and repeated or infused for 5-134 hours. A "good clinical response," defined as a rise in PaO2 of more than 20 mm Hg, was obtained in 23 (79%), 20 of this group were weaned from the respirator, and three died. Six infants did not respond initially and four died. Failure to respond to tolazoline or to be weaned from the ventilator was usually associated with severe additional pathology. Urine output (greater than 1 ml/kg/h) was adequate in most neonates during therapy. In those with preexisting oliguria (less than 1 ml/kg/h), output improved during therapy. Blood pressure monitoring showed a fall in blood pressure in 19 patients during tolazoline administration, but true hypotension only occurred in four; in seven there was no fall and in three there was a rise in blood pressure. Echocardiography was performed prior to therapy in 19 patients and repeated in 12 patients after 24 h. Additional "tracking" was performed at 10 min, 1 h, and 4 h in seven patients. Prior to therapy, right ventricular dysfunction was demonstrated by abnormal right ventricular systolic time intervals (RVSTIs) in 17 of the patients tested. A rapid improvement was evident during therapy especially with "tracking." Left ventricular dysfunction, assessed by left ventricular systolic time intervals (LVSTIs), ejection fraction (EF), shortening fraction (SF), and velocity of circumferential fiber shortening (VCF), was also evident prior to therapy and improved, though more gradually than the RVSTIs.(ABSTRACT TRUNCATED AT 250 WORDS)
Blood Pressure↗
Balloon angioplasty of right ventricular outflow tract conduits.
Palliation of complex congenital heart disease, requiring reconstruction of the right ventricular outflow tract (RVOT), is standard practice. Survival of the homograft is a limiting factor. We examined the role of balloon angioplasty (BAP) in prolonging conduit life. Twelve patients underwent 15 BAP procedures between February 1989 and October 1997. The median age at conduit insertion was 28 months with detection of a significant echo gradient 42 months later. Calcification of homografts, with attendant obstruction and valve dysfunction, was present in all patients. BAP was performed within 1 month of echocardiography and reduced the gradient from a median of 57 to 38 mmHg (p < 0.0005). Echocardiographic follow-up showed persistent gradients (median 68 mmHg) and 11/12 patients went on to conduit replacement after BAP. Only one patient had replacement deferred as a result of BAP. Complications requiring intervention occurred in 20% of the procedures and included bleeding and an unusual balloon fracture. Although BAP can reduce the pressure gradient across the RVOT conduit, the effect is transient and the delay of surgery is not due to improved hemodynamic function. Approximately 10% of cases will benefit from BAP alone, but given the high rate of complications, we do not recommend this procedure as a means of prolonging conduit life.
Adolescent↗
Coil occlusion of the patent ductus arteriosus: lessons learned.
PURPOSE: To review the clinical outcomes of catheter-directed coil occlusion (coil occlusion) of persistently patent ductus arteriosus (PDA) at a pediatric tertiary care hospital. METHODS: A retrospective review of all patients referred to the Cardiac Catheterization Laboratory for coil occlusion at our institution was performed. Twenty-one consecutive patients (12 female) underwent coil occlusion and follow-up between May 1995 and December 1997. We undertook PDA occlusion if: (a) the PDA narrowed to less than 4 mm on echocardiogram and (b) the minimum body weight was approximately 10 kg. Standard right and retrograde left heart catheterization was performed, followed by coil occlusion. Color-flow mapping (CFM) was used intra-procedurally to confirm occlusion of the PDA with a follow-up study several weeks later. RESULTS: The median age and weight of the patients were 33 months and 13.2 kg, respectively. Fourteen patients received one coil, with six requiring a second coil and one requiring multiple coils. Initial follow-up was at a median of 2.4 months. At latest follow-up, 2 patients still have persistent flow at the ductal level. The coils were deployed without complication or embolization. CONCLUSIONS: A review of our first 21 cases demonstrated three important lessons: (1) the maximum diameter of the PDA suitable for coil occlusion is approximately 3 mm; (2) CFM must show complete obliteration of flow in the catheterization lab in order to ensure occlusion of the PDA at follow-up; and (3) the Jackson detachable system allows for precise placement of the coil, often within another coil.
Adolescent↗
Short- and long-term variability of echocardiographic stress-velocity indexes of cardiac function in a pediatric population.
This study determined the short- and long-term variability of stress-velocity relationships at end systole and peak systole. A prospective study during the short term (0 to 15 and 0 to 30 minutes) and long term (0 to 1 and 0 to 12 months) was performed calculating variability by the limits of agreement method. The study was performed in a tertiary-care pediatric echocardiographic laboratory. Twenty-five normal children underwent repeat testing as described. Standard blood pressure, carotid pulse tracing, and M-echocardiography of the left ventricle was performed at the intervals described. The rate-corrected mean velocity of fiber shortening (MVCFC), echocardiographic stress at end systole (SES), and echocardiographic stress at peak systole (SPS) were calculated for all recordings. The slopes of MVCFC-SES and MVCFC-SPS were determined by regression and plotted. With these slopes, the second and third stress values were normalized to the first stress value for the short and long term. The differences in normalized MVCFC and MVCFC (delta MVCFC) for 15 to 0 minutes, 30 to 0 months, 1 to 0 month, and 12 to 1 month were obtained for both SES and SPS, and 95% limits of agreement were estimated. The mean delta MVCFC for SES and SPS for the short and long term were not different from 0 or each other, indicating no bias. The 95% limits of agreement of delta MVCFCs (i.e., variability for SES at 15 to 0 minutes, 30 to 0 minutes, 1 to 0 month, and 12 to 0 month) were +/- 0.18, +/- 0.24, +/- 0.34, and +/- 0.27, respectively, and for SPS +/- 0.18, +/- 0.24, +/- 0.33, and +/- 0.28. Variability showed an increasing trend with time but was significant only from 15 to 0 minutes and 1 to 0 month (p = 0.006). This study has established short- and long-term variability in the stress-velocity relationship that is essential for monitoring acute and chronic changes in ventricular contractility in an individual patient.
Adolescent↗
Effectiveness of primary level antenatal screening for severe congenital heart disease: a population-based assessment.
The four-chamber view of the fetal heart has been advocated as an effective antenatal screen for severe forms of congenital heart disease (CHD). To evaluate the sensitivity of this test at a primary care level, a retrospective review was undertaken for the period 1988 to 1992 of ultrasonograms of fetuses referred for fetal echocardiography, mothers of neonates referred for cardiac assessment, and perinatal deaths attributed to CHD. The study centers serve a population base of 3.5 million persons. Sixty-nine cases of severe forms of CHD were reviewed. The diagnoses were chosen because all show abnormal findings on four-chamber view: 38 hypoplastic left heart syndrome, 13 pulmonary atresia with intact ventricular septum, and 17 variants of univentricular heart. The cases involved a total of 94 scans. These were reviewed by diagnosis and stratified by gestational age and year of scanning. No diagnosis was made at a gestational age younger than 16 weeks. From 16 weeks to term, overall sensitivity was 40% (32/80 scans); sensitivity improved with advanced gestational age (34% to 48% at 16 to 24 and > 24 weeks' gestation, respectively). There was no longitudinal evidence of a learning curve. Reasons for this low sensitivity are related to unfamiliarity with CHD, low incidence in small populations, and inadequate evaluation of the fetal heart. These problems can be resolved with continued training and direction from a major center.
Adult↗