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Biomedical subjects

J C Huhta

Publications and source records attributed to J C Huhta.

At least 73 records · Page 4Linked to original sources
PubMed1989

Betamethasone and the human fetal ductus arteriosus.

We used a sensitive Doppler echocardiographic technique to evaluate in utero the effects of betamethasone on the human ductus arteriosus. Transient, mild constriction of the ductus arteriosus 4-5 hours after the first injection of betamethasone occurred in two of 11 trials. The relatively mild and brief effects on the human ductus of betamethasone in usual doses are probably not clinically significant in most instances. Hence, they do not appear to contraindicate the use of glucocorticoids to promote fetal lung maturation.

Betamethasone↗
PubMed1988

Indomethacin in the treatment of premature labor. Effects on the fetal ductus arteriosus.

Indomethacin is a potent agent in the treatment of premature labor, but its use has been limited because of concern about its constrictive effects on the fetal ductus arteriosus. To study these effects we used serial fetal echocardiography in 13 pregnant women in premature labor who received indomethacin according to three different dose schedules, ranging from 100 to 175 mg per day, for a maximum of 72 hours. The gestational ages of the fetuses ranged from 26.5 to 31.0 weeks. The detection of ductal constriction in 7 of the 14 fetuses by echocardiography led to the discontinuation of indomethacin. Three fetuses also had tricuspid regurgitation. There was no statistically significant difference between the mean (+/- SEM) gestational age of the fetuses with ductal constriction and that of those without constriction (29.3 +/- 0.59 and 28.4 +/- 0.52, respectively). There was no relation between serum indomethacin levels in the mothers and ductal constriction. In all seven fetuses affected, ductal constriction had resolved by the time they were restudied 24 hours after the discontinuation of indomethacin. Persistent fetal circulation was not detected in any of the 11 neonates studied after delivery. Indomethacin used to treat premature labor appears to cause transient constriction of the ductus arteriosus in some fetuses, even after short-term use.

Adolescent↗
PubMed1988

Balloon valvuloplasty for pulmonic valve stenosis--two-year follow-up: hemodynamic and Doppler evaluation.

The purpose of this investigation was to evaluate the efficacy, technique, and follow-up results of balloon dilation angioplasty for valvular pulmonary stenosis. Percutaneous dilation was performed on 63 patients with pulmonary stenosis (ages 3 months to 76 years, mean = 4.3 years). In 43 patients, a single balloon was used; in 20 patients two balloons were used simultaneously. The pressure gradient across the pulmonary valve was determined with right ventricular and main pulmonary artery catheters. Pressure gradients simultaneously were estimated by continuous wave Doppler (CWD) during catheterization. The peak systolic ejection gradient was obtained by both techniques both pre- and postangioplasty. There was excellent linear correlation between the simultaneous catheter pressure gradient and the pressure gradient estimated by Doppler (r = 0.99). Follow-up pressure gradient estimations by Doppler echocardiogram were obtained in 30 patients between 6 months and 30 months postcatheterization (mean = 13 months). The mean preangioplasty gradient of 64 mm Hg (range 30-160 mm Hg) was reduced to 22 mm Hg (range 2-31 mm Hg). A significant reduction of transvalvular gradient (52-95%, mean 68%) occurred in each patient. A linear correlation was found between the predilation gradient and the pressure gradient drop (r = 0.92). Mean follow-up gradient by Doppler was 20 mm Hg (range 0-31 mm Hg), and there was no significant difference between these gradients and the postdilation gradient. No important complications were noted. These data confirm that balloon dilation angioplasty for valvular pulmonary stenosis is safe and effective, and suggest that stenosis does not recur.

Adolescent↗
PubMed1988

Continuous wave Doppler cardiac output: use in pediatric patients receiving inotropic support.

Doppler estimates of cardiac output have been shown to correlate closely with invasive measurement of cardiac output in hemodynamically stable adults and children. However, this method has not been validated in hemodynamically unstable pediatric patients. To assess the accuracy of continuous wave Doppler echocardiography in pediatric patients with unstable hemodynamics, we performed 27 simultaneous Doppler and thermodilution comparisons in 12 pediatric patients receiving inotropic support and afterload-reducing agents. Doppler cardiac output was calculated using aortic diameter measured from long-axis two-dimensional echocardiograms at three different sites: the aortic valve anulus, the aortic root at the sinuses of Valsalva, and the ascending aorta. For all measurements, there was a close correlation between Doppler and thermodilution techniques. However the site of measurement of aortic diameter had a significant impact on the strength on the correlation and the variability between Doppler and thermodilution. The best correlation and least variability were obtained using the aortic valve anulus diameter (r = 0.94). On serial determinations, percent change in Doppler stroke volume correlated well with thermodilution stroke volume (r = 0.87) and was useful in detecting both direction and magnitude of change in thermodilution stroke volume. Despite the administration of positive inotropic and afterload-reducing agents, Doppler cardiac output is a useful method for estimating cardiac output in hemodynamically unstable pediatric patients.

Adolescent↗
PubMed1988

Hemodynamic profile of severe pregnancy-induced hypertension.

Cases of severe pregnancy-induced hypertension or eclampsia were studied in forty-five women by catheterization of the right side of the heart to define the presenting hemodynamic profile associated with this disorder. These women could not be easily categorized into one specific hemodynamic pattern. Most patients had high-normal to elevated systemic vascular resistance indices (mean 2726 +/- 120 dynes.sec.cm-5.m2). The mean cardiac index was 4.14 +/- 0.13 L.min-1.m2. The severity of hypertension was largely attributable to a disproportionate rise in the systolic component (mean 193 +/- 3 mm Hg) compared with diastolic blood pressure (mean 110 +/- 3 mm Hg). Women with eclampsia had significantly lower arterial blood pressure and systemic vascular resistance indices when compared with those of the rest of the study group. Analysis of Starling curves indicated that all patients had normal or hyperdynamic left ventricular function. A modest correlation was observed between central venous pressure and pulmonary capillary wedge pressure (r = 0.59). This disparity most likely results from the maintenance of normal to high cardiac output in the presence of an increased left ventricular afterload. The majority of patients with severe pregnancy-induced hypertension do have normal to high cardiac indices and pulmonary capillary wedge pressures accompanied by normal or hyperdynamic left ventricular function. This is true despite the presence of severe hypertension.

Adult↗
PubMed1988

Surgery without angiography for neonates with aortic arch obstruction.

Traditional diagnostic assessment of the neonate and infant with congenital abnormalities of the aorta causing left ventricular outflow tract obstruction has required catheterization and angiography. However, these patients frequently present critically ill and invasive diagnostic procedures may be associated with significant risks. Two-dimensional echocardiography has been used for aiding diagnosis of aortic arch abnormalities, but there has been little information concerning its use as the definitive imaging technique for preoperative assessment. We reviewed neonates who required urgent surgery for congenital obstruction of the aorta. The diagnosis was made using two-dimensional echocardiographic imaging and Doppler techniques for hemodynamic assessment in lieu of catheterization and angiography in all. Anatomic detail provided by the noninvasive approach was both sensitive and specific in guiding surgery in all but one case. We conclude that echocardiography eliminates the need for invasive preoperative diagnostic procedures in selected neonates with congenital aortic arch obstruction.

Aorta, Thoracic↗
PubMed1988

Results of balloon valvuloplasty in typical and dysplastic pulmonary valve stenosis: Doppler echocardiographic follow-up.

To assess the usefulness of balloon valvuloplasty in patients with a dysplastic pulmonary valve, the files of 36 patients (aged 1 day to 18.5 years) who had two-dimensional echocardiography before and continuous wave Doppler echocardiography late after balloon valvuloplasty (balloon diameter greater than or equal to 20% anulus diameter) were reviewed. Results of relief of pulmonary stenosis were graded by catheter gradient in the catheterization laboratory and compared with Doppler echocardiographic findings at follow-up. There were 32 patients with typical pulmonary stenosis and 4 with a dysplastic valve. In the 32 patients with typical pulmonary stenosis, transvalvular gradient changed from a mean of 67 +/- 32 to 20 +/- 20 mm Hg (p less than 0.0001, mean reduction 72.6%). The gradients at follow-up by Doppler echocardiography averaged 20 mm Hg including 15 that increased, 3 that were unchanged and 14 that decreased. Only 3 (9%) of 32 patients had a gradient greater than 25 mm Hg at follow-up and only one gradient was greater than 35 mm Hg. All four patients with a dysplastic valve had a gradient that decreased with valvuloplasty from a mean of 85 +/- 33 to 33 +/- 20 mm Hg (p less than 0.05); gradient reduction in this group ranged from 40 to 85% (mean 57.5%). The gradient at follow-up increased in three of these four patients and decreased in one (the only late gradient less than 25 mm Hg). Late gradient was less than 35 mm Hg in two of the four patients and was reduced by 43 and 57%, respectively, in the other two.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Influence of short-term indomethacin therapy on fetal urine output.

Eight pregnancies ranging from 27-32 weeks' gestation were treated for preterm labor with oral indomethacin. The dosage regimen was 25 mg every four hours in four patients and 25 mg every six hours in the other four patients. The maximum duration of indomethacin therapy was 72 hours. In three patients, fetal ductus arteriosus constriction mandated discontinuation of indomethacin at 24 hours. Sonographic assessment of hourly fetal urine output was performed before therapy, at multiple regular intervals during therapy, and 24 hours after the last dose of indomethacin. A dramatic decline was noted from the mean baseline fetal urine output of 11.2 mL/hour. The mean fetal urine output at five, 12, and 24 hours during therapy was 2.2, 1.8, and 1.8 mL/hour, respectively (P less than .05). Twenty-four hours after completion of indomethacin therapy, the mean fetal urine output was 13.5 mL/hour. Poor correlation (r = 0.14, P less than .05) was noted between maternal serum indomethacin levels and hourly fetal urine output. This significant decline in urine output is consistent with other results in neonatal and adult animals and humans. Furthermore, it implies a role for prostaglandins in controlling urine output during fetal life.

Constriction, Pathologic↗
PubMed1988

Senning repair for transposition of the great arteries without patch augmentation of the septum.

Forty-three consecutive patients with previous balloon atrial septostomy have undergone a Senning type repair of transposition of the great arteries without patch augmentation of the atrial septum. A technique was used that allows expansion of the atrial septum without the use of additional foreign or autogenous materials. The operative (30-day) mortality rate was 4.6% (2/43) with no late deaths. A mean follow-up of 20 months shows that 83% of the patients are in sinus rhythm and none of these patients have clinically detectable caval or pulmonary venous obstruction or baffle leaks. In patients selected for atrial switch, the Senning operation may be performed without patch augmentation of the septum. Performed by the method described herein, the operation provides predictable early and late results with a low prevalence of arrhythmias. Significant venous obstruction has not occurred.

Female↗
PubMed1987

Response of the patent ductus arteriosus to indomethacin treatment.

The purposes of this study were to examine the response of the patent ductus arteriosus (PDA) to indomethacin, using serial two-dimensional and pulsed Doppler echocardiographic studies, and to correlate the response to treatment with serum indomethacin levels. Nineteen preterm infants (gestational age, 26 to 31 weeks [mean, 28 weeks]; weight, 600 to 1680 g [mean, 1060 g]) were treated with indomethacin. Two-dimensional and pulsed Doppler echocardiograms were obtained before administration of indomethacin and daily thereafter until the day after the last dose. Ductal responses to treatment were graded as open, constricted, or closed, and serum indomethacin levels were obtained 24 hours after the last dose. The PDA initially closed in 11 (58%) of 19 infants; however, in four of the 11, PDA reopened and three of four required surgical ligation. In seven (37%) of 19 patients, the PDA initially constricted, but five of seven subsequently reopened and required ligation. In one patient, indomethacin had no effect on the PDA. The mean indomethacin level for the whole group was 622 ng/mL. There was no difference in indomethacin level between the group with initial closure vs those with constriction (580 vs 590 ng/mL), nor between those who eventually required ligation and those who did not. This study demonstrates that the majority of premature infants respond to indomethacin treatment with ductal constriction or closure but that reopening occurs frequently. The initial response does not mean that the ductus will remain constricted or closed, and surgical intervention may still be necessary. A serum indomethacin level of more than 250 ng/mL does not ensure ductal closure.

Drug Evaluation↗
PubMed1987

Pulmonary venous and systemic ventricular inflow obstruction in patients with congenital heart disease: detection by combined two-dimensional and Doppler echocardiography.

Obstruction to pulmonary venous return may be associated with a number of congenital cardiovascular abnormalities occurring both before and after surgery. Hemodynamic assessment by cardiac catheterization is often difficult. A noninvasive method for detection and quantitation of obstruction to systemic ventricular inflow would be clinically useful. Two-dimensionally directed pulsed and continuous wave Doppler echocardiography was performed before cardiac catheterization in 31 patients thought clinically to have possible obstruction to left ventricular inflow or pulmonary venous return. Primary diagnoses included transposition of the great arteries after the Mustard or Senning procedure in nine patients, total anomalous pulmonary venous connection in nine (in two after surgical repair), cor triatriatum in eight (in four after surgical repair), congenital mitral stenosis in four (in one after surgical repair) and mitral atresia in one. Severe obstruction was defined as a mean pressure gradient at catheterization of greater than or equal to 16 mm Hg at any level of the pulmonary venous return or of the systemic ventricular inflow. Severe obstruction was predicted if Doppler examination measured a flow velocity of greater than or equal to 2 m/s across any area of inflow obstruction. At catheterization, 12 patients (39%) had severe obstruction to left ventricular inflow or pulmonary venous return and all obstructions were correctly detected by Doppler echocardiography. The site of pulmonary venous obstruction was localized by two-dimensionally directed pulsed Doppler study. Patients with a lesser degree of obstruction had a lower Doppler velocity, but none had a maximal Doppler velocity of greater than or equal to 2 ms/s.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Surgery without catheterization for congenital heart defects: management of 100 patients.

Little information is available regarding the surgical mortality of children with congenital heart disease who undergo operation on the basis of clinical assessment and echocardiographic diagnosis without cardiac catheterization. If catheterization affects early surgical mortality then perhaps omitting it would improve survival. Early operative mortality of 100 patients managed with echocardiography without preoperative catheterization (Group I) was compared with that of 151 diagnosis-matched control patients who had catheterization (Group II). The catheterization (Group II) and echocardiographic (Group I) groups included patients with the following diagnoses: atrial septal defect (33 and 17 in Group II and Group I, respectively); pulmonary stenosis/pulmonary atresia (33 and 15), aortic stenosis (14 and 3), coarctation of aorta (36 and 29), patent ductus arteriosus (10 and 15) and miscellaneous (25 and 21). Age range was 1 day to 16 years (mean 3.5); 114 (45%) of the 251 patients were less than 1 year of age and 59 (29%) were less than 1 month of age. With one exception, echocardiographic diagnosis was correct when compared with findings at surgery or autopsy, or both. Surgical mortality was 18% in Group I and 9% in Group II; however, multiple logistic regression analysis adjusting for differences in age and preoperative condition showed no significant difference between the two groups with a trend toward lower mortality in Group I (p = 0.075). Echocardiography as the definitive imaging modality in selected patients with congenital heart disease is accurate and is comparable with conventional methods of preoperative diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Umbilical cord hematoma secondary to in utero intravascular transfusion for Rh isoimmunization.

Direct intravascular transfusion of the fetus with Rhesus isoimmunization is becoming more widespread as the procedure of choice in the treatment of this disease. To date no direct complications of this new procedure have been reported. The authors describe a case of cord hematoma with resulting fetal compromise secondary to venipuncture of the umbilical vein. Doppler studies and review of the fetal heart rate tracings pointed toward umbilical artery vasospasm secondary to the cord hematoma as the etiology of the transient fetal bradycardia.

Adult↗
PubMed1987

Detection and quantitation of constriction of the fetal ductus arteriosus by Doppler echocardiography.

Pulmonary hypertension may occur in the fetus in the presence of constriction of the ductus arteriosus. The feasibility of detection and quantitation of fetal ductal constriction by Doppler echocardiography was assessed in an animal preparation in which ductal constriction was created in the fetal lamb with a variable ligature causing varying degrees of fetal pulmonary hypertension (fetal pulmonary arterial systolic pressure 57 to 97 mm Hg and ductal gradient 9 to 42 mm Hg). Comparison of blinded, continuous-wave peak Doppler velocity (V) measurements of the ductal gradient with the modified Bernoulli assumption (gradient = 4V2) compared well with direct catheter measurements of instantaneous peak systolic gradient (r = .99, catheter = 0.95 X Doppler + 0.6), peak-to-peak gradient (r = .97), and mid-diastolic gradient (r = .85). Ductal constriction was characterized by an increase in the peak systolic and diastolic velocities. The normal human fetal ductus arteriosus blood flow velocity pattern was assessed by pulsed Doppler techniques in 25 normal human fetuses after 20 weeks gestation. The peak systolic flow velocity in the ductus arteriosus measured by image-directed pulsed Doppler echocardiography ranged from 50 to 141 cm/sec (mean 80 cm/sec) and increased with gestational age (r = .50). Diastolic velocity in the ductus arteriosus was consistently directed toward the descending aorta and ranged from 6 to 30 cm/sec. The ductal systolic velocities were the highest blood flow velocities in the fetal cardiovascular system. Application of these techniques to fetuses whose mothers were receiving indomethacin for treatment of premature labor at 30 to 31 weeks gestation confirmed this method to be sensitive for detection of fetal ductal constriction, which developed in three fetuses.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Prenatal diagnosis and postnatal management of critical aortic stenosis.

Fetal echocardiography has yet to have an impact on the treatment of congenital heart disease. Critical aortic valve stenosis was diagnosed by echocardiography before birth in a 35 week gestation fetus. The risks to the fetus and mother associated with prolonged rupture of membranes prompted their transport to a hospital with cardiac surgical and high-risk perinatal facilities. Prenatal and postnatal echocardiographic findings agreed regarding the diagnostic criteria for critical aortic stenosis and primary forms of cardiomyopathy were excluded. Results of fetal Doppler examination were consistent with valvular aortic stenosis and excluded mitral regurgitation. Determination of the left ventricular size excluded ventricular hypoplasia. The infant was delivered by cesarean section and underwent successful emergency aortic valvotomy at 12 h of age. Fetal echocardiography, in combination with a multidisciplinary postnatal approach, can be used in the successful treatment of a severe form of congenital heart disease.

Aortic Valve Stenosis↗
PubMed1987

Ultrasound examination of extracardiac chest masses in children. Doppler diagnosis of a vascular etiology.

The purpose of this paper is to describe the use of two-dimensional and Doppler ultrasound techniques in the evaluation of chest masses of unknown etiology. We reviewed the diagnosis of chest masses in 12 children seen over 3 years, all confirmed by surgery or pathology. The masses were vascular in three patients (pseudoaneurysm) and nonvascular in nine. Ultrasound yielded a correct differential diagnosis of the masses. Doppler sampling diagnosed the vascular etiology of the three pseudoaneurysms. We conclude that Doppler techniques can identify the vascular nature of chest masses, and that ultrasonography is valuable in the assessment of chest masses in children.

Child↗