Search PubMed⌕ Search

Biomedical subjects

J Somerville

Publications and source records attributed to J Somerville.

At least 73 records · Page 4Linked to original sources
PubMed1997

Effects of chronic hypoxemia on chemosensitivity in patients with univentricular heart.

OBJECTIVES: We sought to compare the arterial blood gas chemosensitivity in relation to exercise ventilatory response in patients with univentricular heart and cyanosis and in patients with univentricular heart and Fontan-type circulation without cyanosis. BACKGROUND: Patients with univentricular heart demonstrate excessive ventilation during exercise. Chronic hypoxemia may alter chemoreceptor function, affecting ventilation. METHODS: Cardiopulmonary exercise testing was performed in 10 patients with rest or stress-induced cyanosis (cyanotic group: mean age +/- SE 30.5 +/- 2.3 years; 5 men), 8 patients without cyanosis with Fontan-type circulation (Fontan group: mean age 29.4 +/- 1.5 years; 4 men) and 10 healthy control subjects (normal group: mean age 30.7 +/- 1.9 years; 5 men). Hypoxic and hypercapnic chemosensitivity were assessed by using transient inhalations of pure nitrogen and the rebreathing of 7% CO2 in 93% O2, respectively. RESULTS: Peak O2 consumption was comparable in both patient groups (21.7 +/- 2.5 [cyanotic group] vs. 21.0 +/- 1.9 ml/kg per min [Fontan group]) but was lower than that in the normal group (34.7 +/- 1.9 ml/kg per min). The ventilatory response to exercise, characterized by the regression slope relating minute ventilation to CO2 output, was higher in the cyanotic group (43.4 +/- 4.0) than in the Fontan group (31.4 +/- 3.0, p = 0.02) and the normal group (23.1 +/- 1.1). Hypoxic chemosensitivity was blunted in the cyanotic group compared with that in the Fontan and normal groups (0.148 vs. 0.448 [p = 0.02] vs. 0.311 liter/min per percent arterial O2 saturation, respectively) and did not correlate with the ventilatory response to exercise (r = -0.36, p = 0.29). In contrast, hypercapnic chemosensitivity represented by the slope of the hypercapnic-ventilatory response line was similar in the cyanotic, Fontan and normal groups (1.71 vs. 1.76 vs. 1.70 liter/min per mm Hg, respectively), but the response line had shifted to the left in the cyanotic group (x intercept = 31.9 vs. 39.9 mm Hg [p = 0.026]), compared with 45.2 mm Hg in normal subjects. These findings suggest that in the cyanotic group, ventilation is greater for a given level of arterial CO2 tension and thus may partly explain the increased exercise ventilatory response in this group. CONCLUSIONS: Hypoxic chemosensitivity is blunted in patients with univentricular heart and cyanosis and does not determine the exercise ventilatory response. CO2 elimination appears more important. The blunting of hypoxic chemosensitivity is reversible once chronic hypoxemia is relieved, as evident in the Fontan group.

Adult↗
PubMed1997

Pregnancy in patients with pulmonary autograft valve replacement.

AIM: The purpose of this study is to determine the outcome and complications of pregnancy in women with pulmonary autograft valve replacement for aortic valve disease. METHODS AND RESULTS: The records of all women who had undergone pulmonary autograft valve replacement at the National Heart Hospital (now Royal Brompton Hospital) since 1968 were reviewed. From 1968 to 1993, 27 hospital survivors were female and among eight of them there were 14 pregnancies. All women were in Ability Index 1 at time of pregnancy with normal ventricular function, mild aortic regurgitation (six), mild pulmonary regurgitation (three) and mild pulmonary stenosis (two). None took anticoagulants. There was no maternal death, thromboembolic or haemorrhagic event or evidence of deterioration in valve function during pregnancy. Except for one woman (Ability Index 3) who developed dilated cardiomyopathy without aortic or pulmonary valve disease 6 months after delivery, the women remained in Ability Index 1 after pregnancy. There was no significant progression of aortic regurgitation (mild after seven pregnancies), pulmonary regurgitation (mild after six) or right-sided obstruction (mild after four). Reoperation for right-sided obstruction was carried out in two patients 4 and 7 years after a second pregnancy (9 and 15 years after the pulmonary autograft). CONCLUSION: No valve-related complications occurred during pregnancy and pregnancy appeared to have no effect on the function of the pulmonary valve autograft or the right-sided homograft. The pulmonary autograft is thus an ideal procedure for a young female needing aortic valve replacement.

Adolescent↗
PubMed1997

Dyspnoea and exercise intolerance during cardiopulmonary exercise testing in patients with univentricular heart. The effects of chronic hypoxaemia and Fontan procedure.

BACKGROUND: Patients with univentricular hearts have decreased exercise tolerance and may demonstrate exertional dyspnoea. It is not known if chronic hypoxaemia exacerbates exercise intolerance and contributes to symptomatic limitation. The extent to which surgical correction of a right-to-left shunt by a Fontan-type procedure can increase exercise tolerance by reducing arterial deoxygenation is not well documented. The cardiopulmonary exercise responses and the symptomatic status in two groups of univentricular patients, those who are cyanotic and those who are acyanotic with Fontan-type circulation, were compared. METHODS AND FINDINGS: Cardiopulmonary exercise testing was performed in 10 univentricular patients with rest or stress-induced cyanosis (age 30.5 +/- 2.3 [SE] years; 5 men) who had palliative or no surgery and eight patients (age 29.4 +/- 1.5 years; 4 men) with Fontan-type circulation. Peak oxygen consumption was comparable in both groups of univentricular patients (21.7 +/- 2.5 vs 21.0 +/- 1.9 ml.kg-1.min-1, P = 0.85) but was less than an age-matched group of 10 healthy subjects (34.7 +/- 1.9 ml.kg-1.min-1, P < 0.001 for both). Arterial oxygen saturation was 90.6% at rest in the cyanotic patients compared with 95.1% in the Fontan patients (P < 0.001) and at peak exercise, 66.2% compared with 90.5% (P < 0.001). Using a modified Borg scale (0-10), the symptoms of dyspnoea and fatigue were also assessed during exercise in the patient groups. The Borg scores for dyspnoea in the cyanotic and the corrected univentricular patients were, respectively, as follows: Stage 1: 0.5 vs 1.7; P= 0.04; Stage 2: 1.8 vs 2.3, P = 0.5; Stage 3: 3.0 vs 3.5, P = 0.7; Peak Exercise: 4.9 vs 4.8, P = 0.9. In addition, the Borg scores for fatigue were: Stage 1: 0.4 vs 1.6, P = 0.08; Stage 2: 2.0 vs 2.2, P = 0.9; Stage 3: 3.0 vs 4.3, P = 0.5; Peak Exercise: 4.9 vs 5.4, P = 0.5. The major limiting symptom at peak exercise was dyspnoea in four cyanotic patients compared with one in the Fontan group (Chi-square 0.982, P > 0.10). The arterial oxygen desaturation at peak exercise in the cyanotic patients limited by dyspnoea was not different from those limited by fatigue (67.5 +/- 10.1% vs 66.7 +/- 13.7%, P = 0.92). Exercise tolerance was also not related to the arterial oxygen saturation at peak exercise (r = 0.47, P = 0.17) in these patients. CONCLUSIONS: Despite correction with Fontan-type surgery, the exercise tolerance and symptoms of these univentricular patients remained similar to those who were cyanosed. Cyanotic patients have adjusted to chronic hypoxaemia and it does not appear to determine the exercise tolerance or the genesis of dyspnoea in these patients. Further randomized prospective studies are required to investigate the long-term benefits of Fontan-type procedures in these patients on exercise tolerance, symptoms and prognosis.

Adult↗
PubMed1997

Outcome of pregnancies in patients with complex pulmonary atresia.

OBJECTIVE: To evaluate the outcome of pregnancies in patients with complex pulmonary atresia, comparing those with and without previous radical surgical repair. DESIGN: A retrospective study of all pregnancies in women with complex pulmonary atresia registered on the Grown-up Congenital Heart Unit database between 1977 and 1994. SETTING: Referral centre for adolescents and adults with congenital heart disease. PATIENTS: Forty one pregnancies occurred in 15 patients. They were divided into two groups; group I, 26 pregnancies in nine patients before radical repair (cyanotic); group II, 15 pregnancies in seven women after radical surgical repair. RESULTS: In group I there were three terminations, 13 miscarriages, eight healthy children, and two neonatal deaths. Five children were born prematurely and all had low birthweights. In group II there were two miscarriages, 11 normal children, and two children with congenital heart disease. None was premature and all had normal birthweights. There were major complications in both groups: in group I there were two thromboembolic complications and one episode of heart failure; in group II there was one pulmonary embolism and one arrhythmic complication, five pregnancies in three patients were complicated by left ventricular failure that was persistent in one case and progressive in another, leading to death 13 months after delivery. CONCLUSIONS: Patients with complex pulmonary atresia, with or without surgical repair, who have no or mild symptoms, can have successful pregnancies. Surgical repair decreases fetal complications significantly. In both groups thrombotic disorders and heart failure must be prevented. Patients with residual systemic-pulmonary collaterals after surgical repair are particularly at risk of left ventricular failure.

Abortion, Spontaneous↗
PubMed1997

Management of adults with congenital heart disease: an increasing problem.

A small new population of patients in cardiology, the grown-up (adult) congenital hearts (GUCH), need superspecialist care and expertise, particularly those patients with complex defects previously operated on in childhood or who were not operated on. Arrhythmias are the most common cardiologic reason for admission to the hospital, and atrial flutter is the most frequent disorder of rhythm, usually related to hemodynamic disturbances. The GUCHs need solutions to problems of transition of care, ideally an adolescent area for the younger patients, knowledge of which and when to investigate each anomaly, expertise in cardiac catheterization and interventions, cardiac surgeons experienced in congenital as well as adult disease since one in five admissions are for cardiac surgery, at-risk pregnancy service, counseling on life's problems, and most of all a few dedicated centers with cardiologists and surgeons trained in this subspecialty. The profession needs to achieve optimal care for these precious patients, particularly those with complicated lesions and complex surgery, particularly with the valve replacements. Although small in number and high in expense, GUCH patients should be centralized so expertise and experience can be concentrated despite the need to cross barriers of finance and bureaucracy. Currently, with the exception of a few expert centers, these patients receive suboptimal medical management.

Adolescent↗
PubMed1997

[Quality of life after surgical correction of the aorta coarctation. Retrospective analysis of a group of patients with long-term follow-up].

PURPOSE: To report on the long-term results after operation for coarctation of the aorta. METHODS: One hundred and four patients were studied, divided in four groups (G1, G2, G3 and G4), according to age at operation. Data analysed: reoperation, persistent hypertension, residual lesions, left ventricular function and ability index. RESULTS: Reoperation was frequent, mainly in G1 (60%) and G4 (29%). Resting hypertension occurred predominantly in cases operated on after the 10th year of life: 28% (G3) and 29% (G4). Exercise hypertension was found in cases operated on after the 20th year. Residual lesions were frequent: 97%, 98%, 83% and 65% (G1 to G4). Individual functional limitation was uncommon. The ability index was normal in the great majority of the patients (94%). CONCLUSION: Reoperation is frequent, particularly for recoarctation and aortic stenosis. Rest and/or exercise hypertension is common and related to delayed surgery. Aortic residual lesions are frequent. Physical limitation is uncommon. Postoperative follow-up is essential in order to detect late complications, which, usually, do not limit the individual patient.

Adolescent↗
PubMed1996

Stenting of aortopulmonary collaterals in complex pulmonary atresia.

BACKGROUND: The optimal treatment of patients with complex pulmonary atresia remains controversial. Surgical unifocalization programs are increasing popular but have not previously or currently gained universal acceptance. Furthermore, not all patients are suitable for attempts at biventricular correction. These patients may become increasingly symptomatic and require palliation. METHODS AND RESULTS: We attempted to palliate 12 patients with progressive symptomatic hypoxemia. Each had at least one stenotic but balloon-dilatable collateral supplying at least three lung segments. It was impossible to traverse the stenotic area with the stent in 1 patient, despite two attempts. Twelve stents were thus deployed in 11 patients. There was no effect in 1 patient who had multiple stenoses distal to the stented area. There was excellent palliation in the remainder, arterial oxygen saturation 45% to 79% before stenting (mean, 64 +/- 12%) rising to 67% to 90% (mean, 78 +/- 10%, P < .01) at discharge from hospital. One patient was referred for surgery to secure blood flow to a nearly totally occluded side branch to the right upper lobe traversed by the stent. There was an excellent symptomatic response in the remainder, with an early increase in exercise duration (P < .01). Late arterial desaturation occurred in 2 patients. In 1, there was pulmonary arterial hypertension in the lung segments supplied by the stented vessel. A stenosis had developed within the stent in the other patient, who was noncompliant with anticoagulation therapy. CONCLUSIONS: Stenting of stenotic aortopulmonary collaterals can achieve excellent palliation in the majority of this highly selected subgroup of patients with complex pulmonary atresia.

Adolescent↗
PubMed1996

Should atrial septal defects in adults be closed?

BACKGROUND: By assessing current surgical outcome and symptomatic relief, this study attempts to answer whether atrial septal defects in adults should be closed. METHODS: Thirty-nine adult patients aged 35.2 +/- 13.6 years underwent operation for an atrial septal defect between June 1988 and June 1994. Indications for closure were symptoms (33 patients) or a significant left-to-right atrial shunt (6 patients). Data were obtained from hospital records, and the latest status of the patients was determined by a written questionnaire. RESULTS: There were no deaths. Pulmonary embolism in 1 patient was the only complication observed. The QRS duration on the surface electrocardiogram decreased immediately (p < 0.001), and the cardiothoracic ratio on chest radiographs was significantly lower 3 to 6 months after operation (p < 0.001), both findings reflecting improved hemodynamics. No residual shunts were seen on follow-up (mean follow-up, 3.3 +/- 2.2 years). Twenty-seven (81.8%) of the 33 symptomatic patients improved clinically in terms of exercise performance, atrial arrhythmias, or both. Three (50%) of the 6 previously asymptomatic patients reported improved functional capacity post-operatively. CONCLUSIONS: Today, operation for atrial septal defects in adults can be performed with no mortality and low morbidity and results in symptomatic improvement in the majority of patients. Clinical improvement was seen even in patients who considered themselves asymptomatic preoperatively. We advocate closure of atrial septal defects in adult patients with symptoms or significant atrial shunts.

Adult↗
PubMed1996

Palliative Mustard operation for transposition of the great arteries: late results after 15-20 years.

OBJECTIVE: To assess the clinical, functional state, and complications late (15-20 years) after palliative Mustard operation. DESIGN: Examination and evaluation of all patients presenting in adolescence and adult life after palliative Mustard operation for transposition of the great arteries and pulmonary vascular disease. SETTING: Grown-up Congenital Heart Unit specialised in the care of adolescents and adults with congenital heart disease, designated as having "quaternary" status within a tertiary referral centre for cardiac diseases. PATIENTS AND METHODS: Database searched for patients referred after palliative Mustard for classic transposition of the great arteries. Ten patients aged 18-31 (mean (SD) 25.9 (5.2)) years with a palliative Mustard operation performed at age 1.7-15 (mean (SD) 9 (4.6)) years were fully evaluated by echocardiography, exercise testing, Holter monitoring, and magnetic resonance imaging or radionuclide ventriculography, or both 15-20 years later. RESULTS: One patient died aged 25 years with biventricular failure (ability index 3/4), haemoptysis, and atrial flutter, eight were well (ability index 2), and one disabled (ability index 3). Arterial oxygen saturation at rest was 85-98% (mean (SD) 93.8 (4)%) decreasing to 59-87% (mean 77 (9.5)%) after limited exercise. Symptomatic arrhythmias occurred in four patients, atrial flutter being the most common, and two had sinus node dysfunction. Significant tricuspid regurgitation occurred in four patients. CONCLUSION: Patients with palliative Mustard operation have a low incidence of symptomatic ventricular dysfunction and despite exercise limitation by hypoxia, continue to live active, near normal lives until their thirties.

Adolescent↗
PubMed1996

Salary survey of certified athletic trainers in delaware, new jersey, new york, and pennsylvania.

OBJECTIVE: The objective of this study was to obtain salary information from certified athletic trainers in District Two of the National Athletic Trainers' Association (NATA) for use as a reference guide to assist entry-level and experienced ATCs interested in obtaining athletic training positions in Delaware, New Jersey, New York, and Pennsylvania. DESIGN AND SETTING: Mailed survey, sample of convenience. This study was conducted in the Sports Medicine Department of a children's hospital. SUBJECTS: A survey was sent to all 2,274 certified members of District Two. Of the surveys mailed, 970 (42.7%) were returned. Of the surveys returned, 725 (74.7%) were from full-time athletic trainers, 105 (10.8%) were from part-time athletic trainers, and 140 (14.4%) were unusable. MEASUREMENTS: A survey consisting of 15 questions related to salaries and demographics of the athletic trainers' employment settings. RESULTS: Forty-eight percent of the respondents were employed in the clinic or hospital setting, and almost 48% of those responding possessed a master's degree. The state with the highest response rate was Pennsylvania with 45% of the total. The highest rate of response according to experience was 27% from athletic trainers having 4 to 6 years of experience. According to practice setting, the lowest mean salary was $32,928 +/- $10,098 at the college or university level, and the highest was $59,778 +/- $48,803 at the professional sport level. According to education level, the lowest mean salary was $30,132 +/- $9,584 (bachelor's degree), and the highest was $48,070 +/- $12,973 (PT or ATC). The mean salary by state was lowest in Delaware ($32,330 +/- $12,865) and highest in New Jersey ($36,695 +/- $12,593). The highest mean salary by years of experience was $57,308 +/- $30,723 (25 years or more). CONCLUSIONS: Further comparative studies in this area need to be conducted to recognize current trends with the intent of establishing national or regional standards of salary compensation for certified athletic trainers.

Journal Article↗
PubMed1995

Mechanoelectrical interaction in tetralogy of Fallot. QRS prolongation relates to right ventricular size and predicts malignant ventricular arrhythmias and sudden death.

BACKGROUND: Life-threatening ventricular arrhythmia and sudden death remain serious late complications after tetralogy of Fallot repair. Nevertheless, there remains no clear way of predicting which patients are at risk. METHODS AND RESULTS: The study population included a total of 178 adult survivors (mean follow-up, 21.4 years) of tetralogy of Fallot repair who were currently attending our clinic. Mechano-electrical relations were sought in 41 of the patients (mean follow-up, 23.6 years) who were operated on by one surgeon and who were prospectively studied with a 12-lead ECG, chest radiography, and two-dimensional and Doppler echocardiography. Nine patients (mean follow-up, 17 years) from the total group of 178 were identified as having had sustained ventricular tachycardia (8 with near-miss sudden death), and their ECGs, Holter monitor readings, electrophysiological studies, and chest radiographs were reviewed. The case notes of an additional 4 patients with postoperative sudden cardiac death also were available for review. QRS duration in the 41 patients in whom mechanoelectrical interaction was sought ranged between 90 and 200 milliseconds and correlated with cardiothoracic ratio (CTR) on chest radiography (r = .64, P < .001) and with right ventricular size on echocardiography (r = .43, P < .02). Twenty of the 41 patients had restrictive right ventricular Doppler physiology (reduced ventricular compliance) with mean QRS duration of 129.3 +/- 20 milliseconds and mean CTR of 0.51 +/- 0.03. The remaining 21 patients with no evidence of right ventricular restriction had prolonged QRS duration of 157.5 +/- 13.2 milliseconds (P < .001) and CTR of 0.55 +/- 0.04 (P < .04) compared with the restrictive. In the 9 patients with ventricular tachycardia, the QRS duration ranged from 180 to 230 milliseconds (mean, 198.9 +/- 17.6 milliseconds), and the CTR ranged from 0.54 to 0.9 (mean, 0.67 +/- 0.12) (P < .0001 and P < .01, respectively, compared with patients without life-threatening arrhythmias). All patients with documented sustained ventricular tachycardia and the 4 patients with sudden death had a QRS duration of > or = 180 milliseconds (100% sensitivity). CONCLUSIONS: Chronic right ventricular volume overload after tetralogy of Fallot repair is related to diastolic function and correlated with QRS prolongation. The risk of symptomatic arrhythmia is high when marked right ventricular enlargement and QRS prolongation develop. A QRS duration on the resting ECG of > or = 180 milliseconds is the most sensitive predictor of life-threatening ventricular arrhythmias yet described.

Adult↗
PubMed1995

Pregnancy in patients with congenital heart disease.

Pregnancy and delivery in women with congenital heart disease remain inadvisable for patients at high risk due to the following congenital diseases: (1.) Severe left ventricular outflow tract obstruction (increase of pressure gradient); (2.) Eisenmenger syndrome (increase of right to left shunt with worsening of cyanosis and fetal growth retardation); (3.) Marfan syndrome with enlarged aortic root (risk of aortic dissection). In women suffering from cyanotic congenital heart disease the main risk is fetal complications. These are correlated to oxygen saturation and to the type of maternal disease, particularly if a palliative shunt operation has never been performed. Women with left to right shunt, right outflow tract obstruction or previous correction of the disease can go through pregnancy with low risk of mortality. The complications (mainly heart failure and arrhythmias) can be well managed with medical treatment, and the fetal outcome is similar to that in the general population.

Eisenmenger Complex↗
PubMed1995

Presentation and attrition in complex pulmonary atresia.

OBJECTIVES: This study summarized patterns of presentation and attrition in complex pulmonary atresia. BACKGROUND: Assessment of the potential impact of surgical strategies for managing complex pulmonary atresia requires information about variability in age and physiology at presentation of the condition. METHODS: We performed a retrospective review of age at presentation, referral source, pulmonary artery and collateral anatomy and surgical history of 218 patients from two institutions dealing with congenital heart disease throughout life. RESULTS: Approximately 65% of pulmonary atresia appears in infancy, with 50% of patients severely symptomatic from cyanosis and 25% from heart failure. Compared with those presenting undiagnosed, patients referred secondarily for specialist management tend to be older when first seen, and care must be taken when generalizing about the natural history of the condition from their survival experience. Overall actuarial survival, including the effects of operation, suggests that 60% (95% confidence limits [CL] 43 to 73) of patients presenting in infancy survive to their first birthday, 65% (95% CL 51 to 74) of those alive at 1 year old survive to the age of 10, and 16% (95% CL 5 to 31) of those alive at 10 years old survive to age 35. CONCLUSIONS: Novel surgical approaches have generally been applied beyond infancy in patients selected by their survival through the period of greatest attrition for this disease. Unless successful application in symptomatic infants is demonstrated, we cannot assume that these serial and complicated operations will have a major impact on the outlook of most patients with complex pulmonary atresia.

Actuarial Analysis↗
PubMed1995

Corrected transposition of the great arteries without associated defects in adult patients: clinical profile and follow up.

OBJECTIVE: To assess the clinical course of adult patients with corrected transposition of the great arteries without associated anomalies. DESIGN: All patients with corrected transposition of the great arteries without associated anomalies were reviewed with complete clinical and echocardiographic assessment. The complications were evaluated in each decade. SETTING: Tertiary centre with a specific unit dealing with "grown-up" adolescent and adult congenital heart disease, designated as a quaternary centre and a general hospital with a referral centre for "grown-up" congenital heart disease. PATIENTS: 18 patients (nine male and nine female) aged 16-61 years followed for 1-30 years (mean 10 years). RESULTS: There were no deaths. Six patients had a worsening ability index during follow up. Complications were: (a) complete heart block in seven, three of whom required pacemaker insertion; (b) significant left atrioventricular valve regurgitation in 50%, appearing only in the third decade (12%), with increasing frequency thereafter. Infective endocarditis was responsible for increasing left atrioventricular valve regurgitation in only one patient; (c) supraventricular arrhythmia appeared in the fifth decade, and occurred in all patients over the age of 60 years. One patient aged 61 had recurrent sustained ventricular tachycardia; and (d) congestive heart failure developed only after 50 years in 66%. One patient had severe left atrioventricular valve regurgitation; the function of the systemic ventricle was only moderately reduced in the other three. Three of the nine women had seven uneventful pregnancies. CONCLUSIONS: Patients with corrected transposition of the great arteries without associated defects may remain undiagnosed until adult life. Symptoms occur rarely before the fourth and fifth decades, when rhythm disturbance, left atrioventricular valve regurgitation, and moderately impaired systemic ventricular function cause congestive cardiac failure. The role of pacemaker insertion or surgery for left atrioventricular valve regurgitation needs further assessment.

Adolescent↗