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Biomedical subjects

L O Watkins

Publications and source records attributed to L O Watkins.

At least 19 recordsLinked to original sources

Efficacy and tolerability of lovastatin in 459 African-Americans with hypercholesterolemia.

A paucity of substantive data from clinical drug trials is available specifically evaluating the effects of therapy for hypercholesterolemia in African-Americans, even though a substantial number are candidates for medical advice and intervention for high blood cholesterol. The efficacy and safety of lovastatin in 459 African-Americans with hypercholesterolemia were studied in the Expanded Clinical Evaluation of Lovastatin study, a multicenter, double-blind, diet- and placebo-controlled trial. This trial involved 8,245 patients who were randomly assigned, regardless of race, to receive placebo or lovastatin at doses of 20 mg once daily, 40 mg once daily, 20 mg twice daily, or 40 mg twice daily for 48 weeks. Among African-Americans, lovastatin produced sustained, dose-related (p <0.001) decreases in low-density lipoprotein cholesterol (20% to 38%), total cholesterol (14% to 28%), and triglycerides (8% to 15%). From 75% to 96% of African-Americans treated with lovastatin achieved the National Cholesterol Education Program goal of low-density lipoprotien cholesterol <160 mg/di, and from 33% to 71% achieved the goal <130 mg/di. The safety profile of lovastotin in African-Americans was generally favorable. A relatively high incidence of creatine kinase levels greater than the upper limit of normal was observed in African-Americans during the study, i.e., 63% in the placebo group and similar levels in lovastatin treatment groups. Lovastatin is highly effective and generally well tolerated as therapy for primary hypercholesterolemia in African-Americans.

Black or African American↗

Mexiletine versus quinidine as first-line antiarrhythmia therapy: results from consecutive trials.

The efficacy of mexiletine and quinidine in controlling ventricular couplets (VC) and ventricular tachycardia (VT) was compared in 156 trials (78 for each drug) in 114 consecutive patients. Forty-two patients received both drugs, whereas 36 patients were given mexiletine, and 36 patients received quinidine only. During acute drug testing, mexiletine was more effective than quinidine in controlling VC and VT (54 vs. 32 patients, respectively, P less than .001) and resulted in fewer proarrhythmic events (4 vs. 13, respectively, P less than .05). Mean duration of follow-up for mexiletine (27 +/- 14 mo) and quinidine (21 +/- 14 mo) did not differ. Long-term success was more frequent with mexiletine administration than quinidine administration (33/47 vs. 10/30 patients, respectively, P less than .01). The incidence of sudden death during follow-up with the two drugs did not differ overall, but more patients with ejection fraction greater than or equal to 40% died suddenly while taking quinidine than while receiving mexiletine (4/17 vs. 0/24, P less than .02). Mexiletine is as effective as quinidine for treating VC and VT and appears to be less proarrhythmic. It should be considered as an initial choice in the management of VC and VT.

Aged↗

Cardiomyopathy in blacks.

The intent in this chapter has been to bring to general awareness the fact that myocardial dysfunction represents a significant proportion of cardiovascular disease affecting blacks; in particular, dilated cardiomyopathy is a new frontier in cardiology, which demands an aggressive approach. At present, the prognosis is not good in the majority of cases; despite the best medical therapy, most of those with cardiomyopathy are doomed to death within a few years after the onset of congestive heart failure. Many of these are young African-American men in the prime of their lives. Cardiac transplantation offers some hope from this desperate situation, but donor shortages as well as restrictive criteria for prospective recipients and socioeconomic constraints, which may deny many blacks the opportunity to receive a transplant, make this option less than ideal.

Black People↗

A mechanism for the development of fixed primary (essential) hypertension: insights from population-based studies using echocardiography.

Two recent observations based on echocardiographic studies in large population-based studies may have far-reaching implications: The concentric form of left ventricular hypertrophy emerges prominently in white Framingham (MA) men aged 40-49 years, and ten years later in white Framingham women. This parallels the pattern of emergence of fixed primary hypertension in white Framingham adults. Normotensive black teenage boys in Bogalusa have an echocardiographic profile that parallels more closely the profile of middle-aged white Framingham men and women than white teenage boys and girls. As noted, the former echocardiographic profiles are strongly associated with fixed primary hypertension in older adults and may be the harbingers of the premature development of fixed primary hypertension in the young black boys. These findings fit into a chain of observations that: (1) give new insight into the mechanism for premature development of primary hypertension and that should ultimately lead to closing the loop needed to characterize the cause of such hypertension: (2) may ultimately help to explain the excess of premature cardiovascular, renal, and cerebrovascular morbidity and mortality in the U.S. black population compared with the white population; and (3) may lead to new, more effective strategies for reducing such excess morbidity and mortality.

Adolescent↗

Electrocardiographic abnormalities and mortality among middle-aged black men and white men of Evans County, Georgia.

The distribution of electrocardiographic (ECG) abnormalities and the relationship between ECG abnormalities and mortality after 20 years of follow-up were examined among 40-64-year-old black men and white men enrolled in the Evans County Heart Study. Major or minor ECG abnormalities, as defined in the Pooling Project, were present at entry for 53% of blacks (164 of 308) and 31% of whites (159 of 511). For both races, the presence of ECG abnormalities was directly related to age, blood pressure, and Quetelet's index at baseline. After adjustment for these and other risk factors, major ECG abnormalities were similarly predictive of all-cause mortality for blacks [rate ratio (RR) = 1.7 (1.1.2.8)] and whites [RR = 2.2 (1.4, 3.4)]. Associations of similar magnitude were observed in relationship to deaths from all cardiovascular diseases and deaths from coronary heart disease. These results are consistent with the hypothesis that ECG abnormalities convey risk for blacks as well as whites.

Adult↗

Computer-aided learning: experiences, perspectives and promises.

Despite the recent strong interest in computer-aided learning, very few high quality programs are available. This article describes an authoring system that was designed to help faculty at medical schools develop a library of effective computer-based lessons. Features of the system include ease of authoring and the ability to incorporate natural language input by the learner, model complex situations, keep track of 100 performance variables and employ interactive laser video disk technology. The authors describe the experience that has been gained in the development and implementation of computer-aided learning at a medical school, and reflect on its future applications and value.

Computer Simulation↗

Racial differences in high-density lipoprotein cholesterol and coronary heart disease incidence in the usual-care group of the Multiple Risk Factor Intervention Trial.

To test the hypothesis that higher levels of high-density lipoprotein cholesterol (HDL-C) in black men than in white men may offer the former greater protection against coronary heart disease (CAD), the relation between HDL-C and 7-year incidence of CAD was examined in the 5,792 white men and in the 465 black men assigned to the usual-care group of the Multiple Risk Factor Intervention Trial. CAD events included nonfatal myocardial infarction diagnosed on the basis of serial electrocardiographic change or medical record review, and fatal CAD events including sudden CAD deaths, deaths attributed to myocardial infarction or congestive heart failure caused by CAD, and deaths associated with coronary artery bypass surgery. At baseline, mean diastolic blood pressure and prevalence of cigarette smoking were significantly higher in black men, but the reverse was true for serum cholesterol (246 vs 254 mg/dl, p less than 0.01). Mean HDL-C was higher in black men than in white men (49.3 vs 41.6 mg/dl, p less than 0.01), but low-density lipoprotein cholesterol (LDL-C) levels were similar (159 vs 160 mg/dl). An inverse association between HDL-C and socioeconomic status was observed in black men, whereas a direct association was observed in white men. During follow-up, small reductions occurred in HDL-C and LDL-C in both groups. No black men died of stroke; 16 black and 404 white men sustained CAD events (5.1 vs 10.4/1,000 person-years of risk). The black-white relative risk was 0.49 (p = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Hostility, coronary heart disease (CHD) incidence, and total mortality: lack of association in a 25-year follow-up study of 478 physicians.

Higher levels of hostility, assessed by a Minnesota Multiphasic Personality Inventory (MMPI) scale (Ho), have been associated with the incidence of coronary disease and mortality from coronary disease and other causes in two prospective studies. In this study we examined the relationship between hostility and health status 25 years later in 478 physicians who completed the MMPI at the time of their medical-school admission interview. In contrast to earlier studies, higher Ho scores were not predictive of coronary disease incidence or total mortality. The implications of this finding for current research on the hostility component of the Type A behavior pattern are discussed.

Coronary Disease↗

The association of lipoprotein cholesterol with vitamin A.

Several studies have linked total serum cholesterol concentrations below 200 mg/dl with increased cancer risk, especially among men. Cancer risk appears to be associated primarily with low concentrations of total cholesterol and of low-density lipoprotein cholesterol but not of high-density lipoprotein cholesterol (HDL). It has been suggested that low concentrations of total cholesterol are associated with increased cancer risk indirectly by virtue of their association with low concentrations of carotene and/or retinol. The relationship between serum carotene and cholesterol in a biracial group of 146 first-year college students was investigated. White men and women had similar carotene concentrations. Blacks had higher serum carotene concentrations than whites. There was a significant relationship between carotene concentrations and total cholesterol, which was most evident in men, both black (r = +0.72; P less than 0.01) and white (r = +0.49; P less than 0.01). The correlations for the women were significant, but of lower magnitude than for the men. Significant carotene-HDL relationships were observed among black men (r = 0.31; P less than 0.05) and among women (r = 0.35; P less than 0.05 and r = 0.31; P less than 0.05, black and white, respectively). Furthermore, the women also demonstrated a significant carotene-HDL2 association. The results are consistent with the hypothesis that the association between low serum cholesterol concentrations and cancer may be the result of a relationship between lipoprotein cholesterol concentrations and vitamin A metabolism.

Adolescent↗

Preventing cardiovascular disease in blacks, a perspective.

The bitter history of blacks in the United States has made their health problems more severe than the majority white sector. This reality requires special strategies, nowhere more imperative than in prevention endeavors. This article examines these theses in relation to the massive problem off hypertension in the black population.

Black or African American↗

Potentially lethal arrhythmias and their management in hypertrophic cardiomyopathy.

The prevalence of potentially lethal arrhythmias (PLA) in groups of patients with hypertrophic cardiomyopathy has been assessed, but the rate at which they develop (their incidence) during long-term follow-up has not been reported. Therefore, conduction system disease (CSD) (sick sinus syndrome and His-ventricular disease), ventricular couplets and ventricular tachycardia (VT) detected by routine electrocardiograms, periodic 24-hour Holter monitoring and periodic exercise stress testing were studied in 50 patients treated with large doses of beta-adrenergic blocking drugs who were followed for 2 to 14 years (mean 5.9). Sixteen PLAs detected at the beginning of observation were excluded from actuarial analysis for new PLAs . Twenty-one patients had 24 new PLAs (7 with CSD, 1 patient with sustained supraventricular tachycardia, 6 with ventricular couplets and 10 with VT); only 43% of these PLAs were heralded by new symptoms. In 6 patients, the arrhythmia caused symptoms and was identified by a routine electrocardiogram. The 3 patients with His-ventricular disease presented with syncope and required electrophysiologic confirmation of this diagnosis. In only 1 patient was a PLA (ventricular couplets) detected only by exercise testing. All other ventricular arrhythmias were detected by Holter monitoring. The incidence of CSD in 47 patients free of this condition at entry was 5% at 5 years and 33% at 10 years. The incidence of ventricular couplets or VT in 39 patients free of these at entry was 26% at 5 years and 75% at 10 years, and the incidence of VT only was 18% at 5 years and 40% at 10 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Bedside evaluation in cardiac emergencies. Criteria for rapid diagnosis.

Because timely diagnosis and treatment are essential in cardiac emergencies, every physician who provides primary critical care should master the art of cardiovascular examination. In particular, this requires patience and skill at auscultation, as subtle differences in murmurs, for example, often differentiate two conditions. With a tentative diagnosis, the physician can then choose only the necessary confirmatory tests.

Acute Disease↗

Epidemiology of coronary heart disease in black populations: methodologic proposals.

The Working Conference on Coronary Heart Disease in Black Populations should define an agenda for research to determine (1) the degree to which the persistent socioeconomic differences between U.S. blacks and whites are important environmental determinants of differing risk factor distributions and (2) whether these differences have a differential impact on the natural history of coronary disease in these groups. In addition, research should be directed toward the resolution of existing controversies and to the testing of hypotheses suggested by earlier work. In the definition of this agenda, attention must be paid to the methodologic problems identified in this article. The resolution of the controversies and the testing of hypotheses suggested by ethnic comparisons are of intrinsic scientific importance for ischemic heart disease research and is likely to yield insights of value in diminishing the heart disease burden in all segments of the population.

Adult↗