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Biomedical subjects

M Dick

Publications and source records attributed to M Dick.

At least 163 records · Page 9Linked to original sources
PubMed1975

Tricuspid atresia: clinical course in 101 patients.

The clinical profile and course of 101 patients with tricuspid atresia seen at the Children's Hospital Medical Center, Boston, were reviewed; the electrocardiograms, hemodynamic data, associated anomalies, complications of the malformation and surgical results were outlined and a definition of anatomic types and radiologic groups formed in order to facilitate therapeutic decisions. Overall survival to 15 years of age was approximately 50 percent. Tricuspid atresia type 1 (normally related great arteries), group A (decreased pulmonary vascularity) was the most frequent category (54 percent); without surgery, these patients had only a 10 percent chance of survival beyond the 1st year of life. Surgical intervention improved chance of survival to 15 years of age to 50 percent. Overall surgical mortality was 23 percent. The Waterston shunt is the procedure of choice in symptomatic small infants with diminished pulmonary flow (group A). Type II patients with increased pulmonary blood flow (group B) would benefit from a pulmonary arterial band. In contrast, patients with group B, type I atresia would rarely need a pulmonary arterial band. Patients with spontaneously changing hemodynamics (group C) usually require a shunt later in life than those in group A, with more favorable operative results. Our experience indicates the continued need of early surgical palliation. New surgical approaches, such as the right atrial-pulmonary arterial anastomosis, may result in a more prolonged survival.

Adolescent↗
PubMed1975

Left ventricular function in tricuspid atresia. Angiographic analysis in 28 patients.

Thirty-one left ventricular (LV) biplane angiograms were performed in 28 patients with tricuspid atresia. Measurements of left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume were obtained by the modified Simpson's rule and systolic ejection fraction (EF) calculated. Left ventricular volumes and ejection fractions were also obtained in 19 control patients with no significant heart disease. The patients with tricuspid atresia were classified according to the appearance of the pulmonary vascularity on initial radiologic examination: Group A, decreased pulmonary vascularity; Group B, increased pulmonary vascularity. In the 13 group A infants who were unoperated, LVEDV was increased and EF mildly diminished. In the group B patients LVEDV was increased and EF normal. In the 12 group A patients with surgical shunts LVEDV was elevated. The five group A patients with long-standing systemic artery to pulmonary artery anastomoses (greater than 10 years) showed the largest LVEDV and the poorest EF. The angiographic data indicate that patients with tricuspid atresia experience significant LV dysfunction as a consequence of longstanding LV volume overload. The early detection of LV dysfunction may be an indication for a right ventricular bypass procedure in these patients.

Adolescent↗
PubMed1975

Repair of tetralogy of Fallot after catheterization-induced complete heart block.

The case of a four-year-old boy with tetralogy of Fallot who developed complete heart block during cardiac catheterization and subsequently underwent surgical repair in the presence of heart block is presented. Return to normal sinus rhythm occurred on the 11th postoperative day, and the manner in which increased atrioventricular conduction appeared was documented with the use of a continuous Holter monitor. Placement of a temporary transvenous pacemaker, systemic heparinization in the preoperative period, and the insertion of a permanent epicardial wire during surgery were performed.

Cardiac Catheterization↗
PubMed1969

Effect of ethanol on magnesium excretion.

The effect of ethanol on magnesium excretion was studied in three normal subjects. It was found that the ingestion of 2 ml ethanol/kg body weight produced a marked immediate increase in urinary magnesium excretion, but there was no significant effect on overall magnesium balance when this amount was taken daily for eight days.

Adult↗
PubMedDate not supplied

Primary preventive health care in children with heart disease.

In order to evaluate the preventive health care practices in children with heart disease, 499 families were surveyed in outpatient settings. Data were collected on 215 children with heart disease and 284 control children without known chronic illness. There was no significant difference between the groups in the type of primary physician utilized or frequency of visits to the primary care physician. Immunizations were incomplete in 32.7% of the children with heart disease compared to only 2.5% in the control group (P less than 0.0001). Among the children over 3 years of age with heart disease, 29% had not received routine dental care within the past year compared with 23.4% in the controls (P = NS). The parents of children with heart disease were found to pay less money out-of-pocket for their child's health care than the parents of control children (P less than 0.0001). The data suggest that important aspects of primary health care were neglected in a large group of children with heart disease and that cost was not a major cause for the inadequate preventive care delivery. An educational program directed at health care professionals and parents is proposed.

Adolescent↗
PubMedDate not supplied

Electrogram patterns associated with successful radiofrequency ablation of accessory pathways in children.

Electrograms observed prior to successful and unsuccessful ablation trials in 33 patients (362 attempts) with manifest pathways and 18 patients (194 attempts) with concealed pathways were compared to identify the electrogram patterns that are associated with successful radiofrequency ablation of accessory atrioventricular connections in young patients (mean age 12.7 years; range 4-22 years). Success was defined as permanent or transient interruption of conduction in the accessory connection. Predictors of success in patients with manifest pathways were local ventricular preexcitation (p &equals 0.0001), left-sidedness (43 or 174) of the accessory connection compared (p &equals 0.04) to right-sidedness (27 of 172), a probable Kent bundle potential (29 of 84 versus 39 of 256; p &equals 0.0001), and short antegrade atrioventricular conduction intervals (53.1 +/- 31.9 ms versus 64.6 +/- 32.0 ms; p &equals 0.02). Predictors of success in patients with concealed pathways were short ventriculoatrial conduction times (103.3 +/- 35.8 ms versus 117.9 +/- 34.8 ms; p &equals 0.01), and left-sided (42 of 125) pathways (p &equals 0.03; versus right-sided, 11 of 60). The presence of a Kent bundle potential was not significant. We conclude that specific electrogram patterns can predict successful ablation of either manifest or concealed accessory pathways. Use of these criteria may reduce the delivery of unnecessary energy to young myocardium.

Adolescent↗
PubMedDate not supplied

Access to the left atrium for delivery of radiofrequency ablation in young patients: retrograde aortic vs transseptal approach.

Reported experience with the transseptal approach to the left atrium for delivery of radiofrequency energy in the young patient is limited. To compare two approaches for radiofrequency ablation (RFA) in the left atrium we reviewed our experience from January 1, 1991, through February 1, 1999, in 154 procedures performed on 136 patients (mean age 12.2 years). The patients were grouped by either the retrograde aortic route (R, n = 30) or the transseptal atrial route (T, n = 106). No significant differences were found in age, weight, height, supraventricular tachycardia cycle length, or electrocardiograph characteristics (manifest vs concealed accessory pathway) between the two approaches. Comparison of the transseptal group to the retrograde aortic group revealed a significant difference in the number of catheters (mean = 4 R vs 3 T, p < 0.0001), total fluoroscopic time (71.3 min R vs 43.0 min T, p = 0.0007), diagnostic fluoroscopic time (40.2 min R vs 16.6 min T, p < 0.0001), ablation fluoroscopic time (44.7 min R vs 25.3 min T, p = 0.019), and procedure time (5.0 hours R vs 4.1 hours T, p < 0.0001). No significant difference was found in success rate, number of radiofrequency applications, or major complication rate. These data suggest that although outcomes and major complication rates are similar for the two groups, the use of fewer catheters and shorter fluoroscopic times warrant consideration of the transseptal atrial approach in young patients.

Adolescent↗
PubMedDate not supplied

Decreased levels of C1q in cerebrospinal fluid of living Alzheimer patients correlate with disease state.

Recent reports that complement proteins comprising the classical pathway are associated with senile plaques suggest that activation of the classical complement cascade in Alzheimer's disease tissue results in bystander cell lysis and may contribute to AD neuropathology. Analysis of cerebrospinal fluid may prove to be a useful means of detecting changes in immunological activity in the brain. We use an enzyme-linked immunosorbent assay to measure levels of C1q, a subunit of the classical complement cascade, in the CSF of patients clinically diagnosed with possible or probable AD. Significantly lower levels of C1q were detected in the CSF of the Alzheimer group as compared to control CSF [AD: mu = 268 ng/ml, SD = 84; non-AD: mu = 340 ng/ml, SD = 76; F(1, 44) = 5.84, p = 0.02]. Diminished performance on global measures of mental status such as the Mini-Mental State Exam (R = 0.45; p = 0.0072) and Blessed's Information, Memory, and Concentration test (R = 0.42; p = 0.0138) showed high correlations with decreased C1q levels. More specific measures of cognitive function, such as word recall (R = 0.42; p = 0.012), word recognition (R = 0.52; p = 0.0017) and delayed recall (R = 0.45; p = 0.0062) memory tasks also correlated strongly with decreased C1q levels.

Adult↗
PubMedDate not supplied

Serum aldosterone concentrations and urine output in oliguric intensive care unit patients receiving low-dose dopamine.

OBJECTIVE: To determine whether the diuretic and natriuretic effects of low-dose dopamine (2.5 micrograms/kg/min) are associated with changes in serum aldosterone concentration. DESIGN: Prospective clinical study. SETTING: Surgical intensive care unit (SICU) of a university hospital. PARTICIPANTS: Oliguric (urine output < 0.5 mL/kg/h) SICU patients. All patients were resuscitated to pulmonary artery occlusion pressure > 10 mm Hg, mean arterial pressure > 65 mm Hg, and cardiac index > 2.5 L/min/m2. Patients with a serum creatinine concentration > 176.8 mumol/L (2.0 mg/dL), those who received diuretics within 12 hours prior to entry into the study, and renal transplant recipients were excluded. MAIN OUTCOME MEASURES: Hourly urine output (mean +/- SD) was recorded 2 hours before and for 6 hours after the initiation of low-dose dopamine. Urine sodium and serum aldosterone concentrations were obtained prior to and 6 hours after the start of low-dose dopamine. RESULTS: Fifteen patients were enrolled in the study. Urine output (mean +/- SD) increased from 0.31 +/- 0.11 mL/kg/h before to 0.80 +/- 0.34 mL/kg/h following low-dose dopamine (p < 0.01). Urine sodium concentrations increased from 46 +/- 32 mmol/L baseline to 72 +/- 53 mmol/L following low-dose dopamine (p < 0.05), and serum aldosterone concentrations decreased from 415.82 +/- 341.48 pmol/L prior to low-dose dopamine infusion to 256.04 +/- 204.17 pmol/L (p < 0.05). Cardiac output, pulmonary artery occlusion pressure, mean arterial pressure, and heart rate did not change. CONCLUSIONS: Low-dose dopamine significantly increases urine output and urine sodium excretion in oliguric, critically ill, surgical patients, and is associated with a decrease in serum aldosterone concentration. The diuretic and natriuretic effects of low-dose dopamine may be, in part, related to a dopamine-mediated inhibition of aldosterone secretion.

Adult↗
PubMedDate not supplied

Job burnout in RN-to-BSN students: relationships to life stress, time commitments, and support for returning to school.

Returning to school is accompanied by changes in role in the work setting and in the home setting, each of which may result in increased stress and conflict and may lead to burnout for RNs. A convenience sample of 54 students enrolled in an RN baccalaureate-completion program were surveyed to explore the relationships among life stress; the multiple time commitments of work, school, and home life; perceived support for returning to school from employer, colleagues, and family; and burnout in the work setting. Pearson's correlations indicated significant negative relationships among burnout and support from family and colleagues, and perceived control of the situation. There were no significant relationships between burnout and life stress or time commitments.

Adult↗