Biparietal diameter measurements: is there an optimal level for these?
Explore the source record for details and available documents.
Brain↗
Biomedical subjects
R M Whitlock
Publications and source records attributed to R M Whitlock.
Inheritance of hypertrophic cardiomyopathy: a cross sectional and M mode echocardiographic study of 50 families.
To determine the mode of inheritance of hypertrophic cardiomyopathy 193 first degree relatives (parents, siblings, and offspring) of 50 patients with hypertrophic cardiomyopathy were assessed by clinical examination, electrocardiography, M mode and cross sectional echocardiography, and necropsy when available. Thirty nine (20%) first degree relatives had hypertrophic cardiomyopathy--37% of parents, 25% of siblings, and 8% of offspring. Eight (23%) of 35 affected relatives diagnosed by echocardiography had normal clinical and electrocardiographic findings. In the total study group 43% of the male population and 30% of the female population were affected. This difference is statistically significant. In 28/50 families there was familial occurrence of hypertrophic cardiomyopathy. Familial occurrence was demonstrated in 17 of 18 families in which five or more family members were assessed. In 15 families the pattern of inheritance was consistent with an autosomal dominant trait; in the other 13 the affected members were identified in a single generation and the pattern of inheritance could not be determined.
Adolescent↗
Long-term follow-up of patients with the antibiotic-sterilized aortic homograft valve inserted freehand in the aortic position.
A series of 252 isolated aortic homograft valves in 248 patients have been followed for 9 to 16.5 years (mean 10.8). The valves were sterilized in antibiotic solution and stored in a nutrient medium at 4 degrees C and were nonvital. There were 15 in-hospital deaths (6%) and a mortality of 2.7% in patients undergoing an elective first operation. Actuarial survival with the study valve in situ was 57% at 10 years and 38% at 14 years. Only 8.4% of the patients died late from homograft valve failure, chiefly because of failure to refer patients with endocarditis for reoperation or because reoperation was refused in elderly, frail subjects. Incompetence was the sole cause of valve failure and was due either to valve wear or endocarditis. Significant incompetence required reoperation. On actuarial analysis, freedom from significant incompetence for the entire group was 95% at 5 years, 78% at 10 years, and 42% at 14 years. Factors increasing the risk of significant incompetence due to valve wear on multivariate analysis were increasing donor valve age (greater than or equal to 55 years), recipient age (less than 15 years), and an aortic root diameter over 30 mm. Analysis of the patient group that excluded each of these variables (low-risk group), which comprised 61% of the study population, indicated freedom from significant incompetence due to valve wear of 98% at 5 years, 94% at 9 years, and 56% at 13 years.
Actuarial Analysis↗
Left ventricular end-systolic volume as the major determinant of survival after recovery from myocardial infarction.
Impairment of left ventricular function is the major predictor of mortality after acute myocardial infarction, but it is not known whether this is best described by ejection fraction or by end-systolic or end-diastolic volume. We measured volumes, ejection fractions, and severity of coronary arterial occlusions and stenoses in 605 male patients under 60 years of age at 1 to 2 months after a first (n = 443) or recurrent (n = 162) myocardial infarction and followed these patients for a mean of 78 months for survivors (range 15 to 165 months). There were 101 cardiac deaths, 71 (70%) of which were sudden (instantaneous or found dead). Multivariate analysis with log rank testing and the Cox proportional hazards model showed that end-systolic volume (chi 2 = 82.9) had greater predictive value for survival than end-diastolic volume (chi 2 = 59.0) or ejection fraction (chi 2 = 46.6), whereas stepwise analysis showed that once the relationship between survival and end-systolic volume had been fitted, there was no additional significant predictive information in either end-diastolic volume or ejection fraction. Severity of coronary occlusions and stenoses showed additional prediction of only borderline significance (p = .04 in one analysis), but continued cigarette smoking did remain an independent risk factor after stepwise analysis. For a subset of patients (n = 200) who had taken part in a randomized trial of coronary artery surgery after recovery from infarction, surgical "intention to treat" showed no predictive value.(ABSTRACT TRUNCATED AT 250 WORDS)
Blood Volume↗
Multivariate analysis of the long-term results of coronary artery bypass grafting performed during 1976 and 1977.
The results of 492 consecutive coronary artery bypass grafting operations performed for angina in the 2-year period from 1976 to 1977 were evaluated 77 months after surgery. Follow-up was complete in 99%. In 80% of patients angina severity was New York Heart Association functional classes III or IV. An ejection fraction of less than 50% and left ventricular end-diastolic pressure of more than 15 mm Hg were each present in one-third of patients. Thirteen patients (2.6%) died in hospital and 70 (14%) died later during the follow-up period. Twenty-six reoperations were performed for recurrent angina (5.3%). Angina was initially relieved by operation in 97% of patients, but only 57% were alive and free of angina 6 years after their operation. Despite this, 91% of patients at last follow-up were in functional class I or II and 94% thought their symptoms were better than preoperatively. The mean postoperative time of onset of angina, estimated independently by family physicians and patients, was 33 months. The significant preoperative predictors of late death were a low left ventricular ejection fraction, previous myocardial infarction, prior cardiac surgery, increased cardiothoracic ratio and the number of coronary arteries with significant narrowing.
Adult↗
Long-term tolerance of amiodarone treatment for cardiac arrhythmias.
For the 5-year period 1979 to 1983, 242 patients were followed up who had received amiodarone treatment, 156 for supraventricular tachycardia (SVT) and 86 for ventricular arrhythmias. Five patients were lost to follow-up overseas; the rest were followed to cessation of therapy, death or recent review for a mean of 24 +/- 15 months. Male/female incidence was 1.8:1 and mean age was 58 years (range 4 to 88). Half the group had impaired left ventricular function. Adverse effects were recorded in 59% of the patients and led to drug withdrawal in 26% of the total group. In contrast, unsuccessful treatment was the cause of drug withdrawal in only 5% of the patients, although an additional 25% stopped taking the drug for various reasons. Actuarial survival for the whole group, and subgroups with SVT and ventricular tachycardia/fibrillation were 66%, 74% and 52%, respectively, at 50 months. For the whole group, the actuarial probability of being alive and continuing with amiodarone therapy was only 19% at 50 months. Thus, although amiodarone was effective, few patients tolerated the drug on a long-term basis. Although amiodarone remains a valuable treatment for patients with ventricular tachycardia, its long-term effectiveness for patients with SVT is less certain.
Adolescent↗
Prognosis after recovery from first acute myocardial infarction: determinants of reinfarction and sudden death.
Factors associated with total cardiac mortality, sudden cardiac death and reinfarction were studied in 325 male survivors aged younger than 60 years of age (mean 50) of a first myocardial infarction (MI). All patients had undergone exercise testing and cineangiocardiography 4 weeks after MI, 24% underwent coronary artery surgery and 30% received beta-blocking therapy. Patients were followed 1 to 6 years (mean 3.5). Total cardiac mortality was best predicted by the left ventricular (LV) ejection fraction (EF) and by a coronary prognostic index. In contrast, neither the severity of coronary arterial lesions measured with a scoring system nor the results of the exercise test gave significant prediction of mortality. Of the 2 major late sequelae of MI, reinfarction could not be predicted by any clinical or cineangiocardiographic variable. However, sudden death not associated with reinfarction was significantly more common (p less than 0.001) when EF was less than or equal to 40% than when it was greater than 40%. Comparison of patients with an EF less than or equal to 40% who did or did not die suddenly showed that LV dilation (high volumes at ventriculography) was an added risk factor, but the extent of coronary occlusions and stenoses was not. It is concluded that, at least for groups of patients treated with standard modern methods after MI, the main determinant of medium-term survival is the extent of LV damage. The state of the coronary arteries and the presence of ischemic myocardium during exercise are only of secondary importance for survival.
Adrenergic beta-Antagonists↗
Results after repair of coarctation of the aorta beyond infancy: a 10 to 28 year follow-up with particular reference to late systemic hypertension.
The late outcome in 160 patients aged 1 to 54 years who had surgical repair of coarctation of the aorta was examined 10 to 28 years postoperatively. Twenty years postoperatively the probability of survival of patients discharged from the hospital aged 1 to 19 years at operation was a little less than that of the general population (95% versus 97%). The discrepancy between patients and the general population was more marked in those aged 20 to 39 years and was grossly different when surgical repair was undertaken beyond age 40. There were 19 late deaths (12%), 79% due to cardiovascular disease. Thirteen patients had a poor result because of recoarctation (11 patients) or the development of complications at the site of repair (2 patients). Most patients were hypertensive before operation. The frequency of hypertension decreased markedly in the first few postoperative years. Blood pressure was normal in most patients 5 to 10 years after operation, but when followed up for longer periods the proportion of patients with hypertension increased. Hypertension was more common in patients operated on after 20 years of age than in those aged 5 to 19 years at operation (p = 0.007). The likelihood of being alive without complications and with a normal blood pressure was 69% at 10 years, 55% at 15 years, and 20% at 25 years postoperatively.
Adolescent↗
Late follow-up of the Braunwald-Cutter valve.
A retrospective review has been made of 234 patients who received 239 Braunwald-Cutter valves (109 aortic, 130 mitral). For the aortic valve, the thromboembolic rate was very high (10.3 per 100 patient-years). This was associated with severe strut cloth wear in 94.5% of valves and with long strands of fibrin attached to the worn cloth in 58% of valves studied at reoperation or postmortem examination. The aortic poppet showed a mean decrease in volume of 4%, and poppet escape was recognized in 4 patients. The actuarial incidence of poppet escape was less than that predicted in earlier reports. There was a 4% incidence of stenosis of the valve. The hospital mortality associated with removal of the aortic Braunwald-Cutter valve and replacement with another device was 4%. Performance of the mitral Braunwald-Cutter valve appears satisfactory to date (mean follow-up, 42 months). Its electric removal is not recommended.
Actuarial Analysis↗
Renal cysts in a cow with anorexia, hypocalcemia and abdominal pain.
A ten-year-old Holstein cow developed anorexia, fever, and recumbency 2 weeks before calving. She was hypocalcemic with concurrent mild pneumonia and mastitis. Due to evidence of impending abortion, parturition was induced and the cow developed metritis. Despite post partum improvement of pneumonia, mastitis and metritis, the cow remained anorexic and had signs of abdominal pain. An exploratory lapartomy via the left flank revealed a greatly enlarged right kidney. On examination through the right flank, 2 large simple renal cysts were found and a nephrectomy was performed. Postoperatively, the cow's appetite gradually improved and she made an apparent clinical recovery.
Abdomen↗
The maximal expiratory flow/volume curve in 197 healthy New Zealanders: a comparison with recent American standards.
Maximal expiratory flow/volume curves were recorded from 155 healthy, non-smoking Europeans aged seven to 71 yr and 42 Polynesian children aged nine to 11 yr. Forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), FEV1/FVC, peak expiratory flow (PEF) and flow at 50 and 25% of FVC (V50 and V25) were compared with the predictions made from the equations of Schoenberg, Beck and Bouhuys, describing healthy people in Connecticut, USA. In general the equations described our subjects well; the small but significant discrepancies may reflect either technical factors or possibly a true difference in populations.
Adolescent↗
Coronary surgery after recurrent myocardial infarction: progress of a trial comparing surgical with nonsurgical management for asymptomatic patients with advanced coronary disease.
A randomized trial of surgical vs nonsurgical management was carried out in men 60 years of age or younger who had recovered from a recurrent myocardial infarction. Of 205 patients considered, 100 had few or no symptoms and had coronary vessels favorable for bypass grafting; these patients fulfilled the trial conditions and were randomized (50 surgical and 50 nonsurgical). In 41 patients (elective nonsurgical group), randomization was not considered justifiable because of relatively unfavorable coronary anatomy or severe left ventricular dysfunction. Nineteen patients had elective surgery because of disabling angina despite full medical treatment or because of significant left main coronary stenosis. In 45 patients, coronary angiography was not undertaken because of medical contraindications or reluctance of the patient to enter the study. Actuarial survival curves (mean follow-up 4.5 years) show an annual mortality rate of 3-4% per year for all investigated patients, and no advantage for the randomized surgical over the randomized nonsurgical group. The results suggest that in the absence of disabling angina or left main coronary artery stenosis, coronary artery surgery need not be advised for survivors of recurrent infarctions who have severe coronary artery disease. Moreover, the prognosis for the group of patients not treated surgically appears to be better than has been previously described.
Adult↗
Plasma timolol levels and systolic time intervals.
The beta-blocking potency of timolol was compared with that of propranolol under steady-state conditions in eight healthy subjects. The effects on systolic time intervals in healthy subjects and patients (n = 6) with coronary artery disease were evaluated in relation to varying timolol dose schedules and plasma concentrations. The beta-blocking potency was assessed by the inhibition of exercise-induced tachycardia. Timolol was eight times as potent as propranolol. There was wide between-patient variation (2.6 to 13.8) in timolol plasma concentration, and correlation between dose and peak (r = 0.61, p < 0.01) or nadir (r = 0.5 p < 0.01). There was a relatively weak correlation between timolol plasma concentration and degree of beta-blockade (r = 0.45, p < 0.05) and a linear correlation with dose (r = 0.98, p < 0.001). In healthy subjects timolol and propranolol had variable effects on systolic time intervals but in patients with coronary artery disease equipotent doses prolonged the preejection period, isovolumetric contraction time, and the ratio of the preejection period over the left ventricular ejection time. In patients as well as in normal subjects, the data indicated considerable beta-blocking effects for both drugs at the end of a 12-hourly dosing schedule, suggesting that twice-daily timolol and propranolol may be clinically practical.
Adult↗
Systolic time intervals and ankle reflex time in patients with minimal serum TSH elevation: response to triiodothyronine therapy.
Explore the source record for details and available documents.
Achilles Tendon↗
Developmental progress after cardiac surgery in infancy using hypothermia and circulatory arrest.
Seventy-two of 76 long-term survivors who had surgical repair of congenital heart lesions at 11 days to 26 months of age using profound hypothermia and circulatory arrest underwent psychometric testing (Stanford-Binet) late postoperatively. The mean IQ of the 72 patients was 92.9 +r16.5 (SD). Stanford-Binet scores bore no relationship to the duration of circulatory arrest or other aspects of surgical technique. Scores were significantly lower in those who had a low birth weight for gestational age, important neurologic problems preoperatively or were in the lower socioeconomic classes. An "ideal" control group of 69 children randomly selected from patients satisfying certain criteria based on birth and neonatal characteristics had a mean IQ of 106.2 +r11.6. Twenty-five patients who had surgical treatment of cogenital heart disease met the criteria for the control group except for their heart lesions. Their mean IQ was 101.4 +r15.0(NS). We could not demonstrate any significant deleterious effect that could be attributed to the surgical methods. Rather, the postoperative IQ scores reflected characteristics related to individual patients.
Cardiac Surgical Procedures↗
Sulphinpyrazone (Anturan) after myocardial infarction.
Explore the source record for details and available documents.
Clinical Trials as Topic↗
Transit-time analysis of the forced expiratory spirogram during clinical remission in juvenile asthma.
The mean transit time (MTT), coefficient of variation (CoV), and index of skewness (IoS) of transit times of the forced expiratory flow/time curve have been compared with maximal mid-expiratory flow (MMEF), flow at 75, 50, and 25% of vital capacity (V75, V50, and V25), and the ratio of forced expiratory volume in 1 second (FEV1) to vital capacity (VC) in 51 asthmatic children judged on clinical grounds to be in remission. In 19 children all eight indices were normal. Of the remaining 32, MTT was normal in 5, V50 in 11, V75 in 12, and FEV1/VC and MMEF in 13 each. MTT was significantly more sensitive in detecting abnormality when other indices were normal, and abnormalities in MTT were of significantly greater magnitude when present. In 12 patients with at least one abnormal index given salbutamol aerosol, MTT was not more sensitive than MMEF, V25, FEV1/VC, or V50 in detecting change.
Adolescent↗
Transit-time analysis of the forced spirogram in healthy children and adults.
Mean transit time (MTT), coefficient of variation (COV), and index of skewness (IOS) of transit times were measured, with the more conventional derivatives of the forced expiratory spirogram, in 178 healthy people aged 6-71 yr breathing air, and in 18 healthy adults breathing 20% oxygen in helium (O2He) in addition. Breathing O2He very significantly altered MTT and all derivatives with dimensions of flow or time, but altered COV and IOS very little. Between 6 and 30 yr mean MTT, after adjustment for expired volume, remained constant and then increased to 71 yr. Mean COV and IOS increased from 6 to 71 yr, though with an apparent change in rate during the early teens. The results suggest that whereas the resistance of large airways falls in proportion to growth of the lungs, small-airway resistance becomes less uniform during both childhood and adult life.
Adolescent↗