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Biomedical subjects

R E Ringel

Publications and source records attributed to R E Ringel.

At least 19 recordsLinked to original sources
PubMed1996

Intermediate results of the extracardiac Fontan procedure.

BACKGROUND: Fourteen children (ages 2 to 14 years) and 1 adult (32 years) have undergone a modification of the Fontan procedure in which an extracardiac lateral tunnel or conduit is used in combination with staged or simultaneous bidirectional Glenn shunt(s). METHODS: Extracardiac lateral tunnels (n = 9) were constructed using a polytetrafluoroethylene patch (n = 7), pericardial patch (n = 1), or in situ pericardial flap (n = 1). Extracardiac lateral conduits (n = 6) were constructed using nonvalved homografts (n = 2) or polytetrafluoroethylene tube grafts (n = 4). Fenestrations were created in 4 patients (2 each in extracardiac lateral tunnel and extracardiac lateral conduit patients). Aortic cross-clamping was completely avoided in 12/15 patients (aortic cross-clamping in 2 patients for atrial septal defect enlargement and 1 for Damus-Kaye-Stansel procedure). RESULTS: There have been no operative deaths. Prolonged postoperative chest tube drainage (> 2 weeks) has been rare (n = 1). At follow-up (range, 6 to 54 months; mean, 27.5 months), all patients are in New York Heart Association class I or II and remain in normal sinus rhythm. Late protein-losing enteropathy was seen in 1 patient and was successfully treated by percutaneous creation of a stented fenestration from the extracardiac tunnel to the systemic atrium. Late catheterizations reveal unobstructed extracardiac lateral tunnel function and low pulmonary pressures (range, 11 to 13 mm Hg). Advantages of the extracardiac Fontan include (1) avoidance of aortic cross-clamping in most patients, (2) the hemodynamic benefits of total cavopulmonary connection, (3) avoidance of atriotomy and intraatrial suture lines, (4) preservation of sinus rhythm and no arrhythmias at 2 year follow-up, (5) drainage of the coronary sinus to low pressure atrium, (6) allowance for early/late fenestrations, (7) prevention of baffle leaks and intraatrial obstruction, and (8) allowance for growth (tunnel procedures only). CONCLUSIONS: We recommend this extracardiac procedure for all suitable patients undergoing surgical conversion to the Fontan circulation.

Adolescent↗
PubMed1995

Pulmonary vein stenosis.

Pulmonary vein stenosis (PVS) is a rare disorder. Accurate diagnosis often requires anatomical examination. We report four children with pulmonary vein stenosis. Autopsy showed bilateral lesions in two patients who were thought clinically to have unilateral disease. A diagnosis of PVS was made at autopsy in the third case. Intimal and medial fibromuscular proliferation was noted in extrapulmonary and intrapulmonary veins. Some of the fibromuscular proliferation were eccentric, resembling organized thrombi. In one case a focal organizing thrombus was found in a clinically unobstructed but anatomically narrowed veno-atrial junction. In another case injection of contrast medium into the stenotic pulmonary vein (PV) showed anastomosis between PV and bronchial vessels as well as small pulmonary arteries. Bilateral hypertensive arteriopathy was observed in unilateral and bilateral PVS. Our histological finding of intrapulmonary venous lesions in the lobes in which PVS was not detected clinically suggests that during surgical correction of unilateral PVS multiple biopsies of the opposite lung may help to evaluate possible bilateral disease. Our study also suggests that thrombosis in a stenotic pulmonary vein may further compromise the lumen and contribute to the progression of pulmonary vein obstruction. The possible pathogenesis of bilateral pulmonary hypertensive arteriopathy in unilateral PVS also is discussed.

Biopsy↗
PubMed1993

The extracardiac total cavopulmonary connection for definitive conversion to the Fontan circulation: summary of early experience and results.

Between July 1991 and March 1993, five children (ages 2 to 6 years) with complex congenital heart disease have undergone a new operation for conversion to the Fontan circulation. This procedure combines a bidirectional Glenn shunt with an extracardiac lateral tunnel (ELT) to carry systemic venous return to the pulmonary arteries (PAs). The ELT was constructed so that the circumference consists of Gore-Tex (2/3) and lateral epicardial atrial wall (1/3). The ELT can be performed with all varieties of single ventricle physiology, as in our patients with tricuspid atresia (n = 3), dextrocardia (n = 1), and situs inversus with levocardia (n = 1). PA reconstruction was required in four patients. At follow-up from 1 to 20 months, all patients are in New York Heart Association Class I and in normal sinus rhythm. Postoperative catheterization has revealed low PA pressures (< or = 12 +/- 1 mmHg) and angiography has shown excellent ELT function with brisk flow into the PAs bilaterally. All patients maintain an O2 saturation > 94% on room air. The advantages of this new extracardiac modification of Fontan's operation are: (1) aortic cross-clamping is not usually required; (2) incorporation of lateral atrial wall in ELT allows for growth while permitting construction of a fenestration or adjustable atrial septal defect in high risk patients; (3) absence of atriotomy and intraatrial suture lines may decrease late risk of arrhythmias; (4) early or late baffle leaks cannot occur; (5) intraatrial obstruction from the baffle cannot occur; (6) coronary sinus remains in low pressure atrium; and (7) hydrodynamic benefits of the total cavopulmonary connection are preserved. We recommend this procedure for patients undergoing surgical conversion to the Fontan circulation.

Anastomosis, Surgical↗
PubMed1993

Cardiovascular reflex abnormalities in children and adolescents with diabetes mellitus.

OBJECTIVE: To assess the usefulness of specific cardiovascular reflex tests in childhood and to estimate the prevalence of cardiovascular reflex abnormalities among children with IDDM. In adults, abnormal cardiovascular reflexes are a frequent complication of diabetes, associated with increased morbidity and mortality. RESEARCH DESIGN AND METHODS: We measured heart-rate responses to deep breathing and standing in ambulatory children with and without IDDM between 6-19 yr of age. A subgroup of the IDDM patients was retested after 1 yr. RESULTS: We found the best techniques for detecting cardiovascular reflex abnormality in children were as follows: to record heart-rate responses to deep breathing either as the change in heart rate corrected for inspiratory heart rate or as the ratio of R-R intervals during expiration and inspiration; and to use the Maximum-minimum ratio for heart-rate responses to standing. HR-DBc was lower in diabetic than nondiabetic children (28.6 +/- 9.2% [n = 248] vs. 33.6 +/- 6.8% [n = 60]; P < 0.0005). Similarly, E:I was lower in children with IDDM than control subjects (1.42 +/- 0.19 [n = 248] vs. 1.52 +/- 0.15 [n = 60]; P < 0.0005). In the IDDM group, 21% of the children had abnormal HR-DBc or E:I responses. HR-STND M/m was lower in children with IDDM than control subjects (1.28 +/- 0.20 [n = 167] vs. 1.38 +/- 0.22 [n = 45]; P < 0.014). Among children with IDDM, 11.4% had abnormal HR-STND M/m responses. Overall, 29% of IDDM children tested abnormal in either HR-DBc or HR-STND M/m; 3% were abnormal in both tests. We found no correlation of HbA1c levels (n = 74) or duration of diabetes with either HR-DB, expiration to inspiration (n = 248), or HR-STND M/m (n = 167). In patients who were reevaluated after 1 yr we found a high correlation of the first and repeat HR-DBc tests (r = 0.47, n = 75, P < 0.0001), E:I (r = 0.53, n = 75, P < 0.0001), and HR-STND M/m (r = .49, n = 37, P < 0.002), but no evidence of an increased number of children with cardiovascular reflex abnormality. CONCLUSIONS: With easily performed HR-DB and HR-STND tests, we detected cardiovascular reflex abnormality in 29% of children with IDDM. We found no correlation of changes in HR-DB and HR-STND with HbA1c or duration of diabetes. These tests provide an objective clinical measurement to monitor autonomic neuropathy in children with diabetes.

Adolescent↗
PubMed1992

Extracardiac total cavopulmonary connection.

We report the case of a 6-year-old child who underwent definitive conversion to the Fontan circulation using a newly conceived operative technique. This new procedure allows the operation to be performed as a totally extracardiac operation and is based on the hydrodynamic principles of the total cavopulmonary connection.

Anastomosis, Surgical↗
PubMed1988

Intrapericardial triamcinolone hexacetonide in the treatment of intractable uremic pericarditis in a child.

Uremic pericarditis in children on chronic hemodialysis represents a difficult management problem, necessitating vigorous medical therapy and often surgical drainage of the pericardial effusion. Standard therapeutic approaches have met with limited success. The successful use of intrapericardial triamcinolone in a 10-year anephric boy on chronic dialysis is reported and accompanied by a description of the technique applied and literature review.

Cardiac Catheterization↗
PubMed1987

Red blood cell Na+,K+-ATPase in men with newly diagnosed or previously treated essential hypertension.

Alterations of cellular function of Na+,K+-adenosine triphosphatase (ATPase; Na+-K+ pump) have been implicated in the pathophysiology of essential hypertension. Therefore, this aspect of red blood cell (RBC) Na metabolism was studied in black men with newly diagnosed, untreated essential hypertension (NEH) and a normotensive control group. RBC Na content, Na+-K+ pump number (ouabain binding sites), and pump activity were measured. No statistically significant differences were found between the two groups for any of these three parameters. However, a group of previously treated essential hypertensive subjects (PEH) who had been withdrawn from therapy in the preceding 6 weeks were also studied. This group differed significantly from the NEH subjects in regard to all RBC Na+-K+ pump parameters. Their RBC Na content (10.27 +/- 3.23 vs 7.77 +/- 2.52 mmol Na/LRBC; p = 0.006) was higher, and their Na+-K+ pump activity (166 +/- 50 vs 221 +/- 87 nmol inorganic phosphate/mg membrane protein/hr; p = 0.03) and Na+-K+ pump number (213 +/- 40 vs 284 +/- 85 binding sites/RBC; p = 0.001) were lower compared with those in NEH subjects. Although the PEH subjects were older and somewhat less hypertensive than their NEH counterparts, these factors were not found to influence the Na+-K+ pump parameters. These results indicate that chronic diuretic therapy of patients with essential hypertension is associated with a reduced number of RBC Na+-K+ pumps. Since RBCs are not considered target cells for diuretics, the effects of these drugs on RBC electrolyte metabolism may occur at the time of erythropoiesis by the production of RBCs with fewer Na+-K+ pumps.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Detection of cardiac dysrhythmias by continuous electrocardiographic recording in children undergoing cardiac surgery.

The incidence of dysrhythmias was studied using 24-hour ambulatory electrocardiographic monitoring in 65 consecutive cases of children undergoing cardiac surgery. Recordings were made prior to surgery and in the early (1-10 days) and late (3-12 months) post operative periods. Prior to surgery, 25% of the patients displayed supraventricular dysrhythmias (SVD) and 39% ventricular dysrhythmias (VD). Immediately following surgery a dramatic increase in incidence occurred in both SVD and VD. On late follow-up the frequency of ectopy decreased but not to pre-operative levels. Standard 12-lead ECG was much less sensitive than Holter monitoring, detecting less than 25% of all dysrhythmias. Assessment of preoperative rhythm status is necessary to properly interpret postoperative dysrhythmias. Twenty-four hour ambulatory ECG recording is essential for the detection and evaluation of dysrhythmias in children undergoing cardiac surgery.

Adolescent↗
PubMed1984

Cardiologic perspectives of chest pain in childhood: a referral problem? To whom?

Discussed are the diagnostic and therapeutic issues of cardiac disease in the pediatric age group that have the potential to result in ischemic ventricular dysfunction. The discussion then turns to the nontraumatic thoracic, gastrointestinal, and psychogenic disturbances that are likely to produce symptoms of chest pain. In this context, the question of when to refer, when to reassure, when to begin a diagnostic evaluation, and when to institute longitudinal follow-up are addressed.

Arrhythmias, Cardiac↗
PubMed1984

Echocardiographic evidence of left ventricular bands in infants and children.

M-mode and two-dimensional echocardiographic studies were carried out on 100 consecutive neonates, infants and children to evaluate the incidence of left ventricular chordae or bands. These fibromuscular structures were noted in 61 subjects and were seen to traverse both the long and short axes of the left ventricle. Although a single left ventricular band was usually noted, several subjects had multiple bands. These bands were seen in normal subjects and in patients with a wide variety of congenital cardiac lesions. Distortion of left ventricular geometry was noted in one subject. Identification of these linear echoes is essential to allow differentiation of left ventricular bands from true anatomic left ventricular outflow tract obstruction or septal thickening.

Adolescent↗
PubMed1983

Myocarditis as a complication of infantile Chlamydia trachomatis pneumonitis.

The case is presented of an infant with chlamydia pneumonitis who developed clinical and electrocardiographic signs of myocarditis. No significant antiviral antibodies developed. Elevated antichlamydial IgG titers were demonstrated during the initial phase. These declined during convalescence. This report provides further evidence associating C. trachomatis with infectious myocarditis.

Chlamydia Infections↗
PubMed1983

Structural failure of a Starr-Edwards aortic track valve.

Structural failure of a Model 2400 Starr-Edwards aortic track valve occurred suddenly, 4 years after implantation. At operation, the valve cage was removed from the descending aorta. Examination of the excised prosthesis disclosed minimal cloth wear and no evidence of infective growth; however, three struts were fractured above their insertion into the valve ring. To our knowledge, this type of valve malfunction has not been previously noted.

Journal Article↗