Laurence O. Watkins

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.

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 Quetelets 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.

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.

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)

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.

Coronary heart disease and coronary disease risk factors in black populations in underdeveloped countries: The case for primordial prevention

Coronary heart disease (CHD) is relatively rare in black populations in Africa and is a much less significant cause of morbidity and mortality in black populations in the Caribbean than in U.S. blacks. The incidence of CHD appears to be increasing in segments of some black populations in underdeveloped countries, concurrently with certain patterns of socioeconomic change. Hypertension, hypercholesterolemia, and cigarette smoking are not as common in most of these black populations as in white populations in industrialized countries, although certain affluent groups in African and Caribbean countries have higher levels of some of these risk factors than do the rest of the population. Moreover, the impact on CHD of these risk factors, especially hypertension, appears to be less than is observed in industrialized countries. The absence of mass hyperlipidemia probably accounts for the lower prevalence and incidence of CHD. A policy of primordial prevention of CHD, by control of risk factors and preemptive action to prevent their establishment in the population, has been recommended to Third World governments by a World Health Organization Expert Committee. The need for such a policy, and its applicability in black populations in Africa and the Caribbean, are limited by their socioeconomic situations. Thus for practical purposes, the deteriorating economic situation in the low-income countries (the majority) of sub-Saharan Africa and the Caribbean restricts the possibilities of adverse risk factor changes. In particular, the widespread assumption of the food consumption patterns typical of industrialized countries and the development of mass hyperlipidemia are effectively prevented. In contrast, attempts to foster or maintain desirable food consumption patterns are warranted in middle-income African and Caribbean countries, especially among newly affluent minorities. In all of these territories, primary prevention of hypertension, especially in urban populations, is the ideal approach to the primordial prevention of cardiovascular diseases, of which CHD is a small component.

Classroom use of personal computers in medical education: a practical approach

Classroom lectures in medical schools have traditionally employed a blackboard and slides. We have developed a compact, durable, and relatively lowpriced system for computer‐assisted instruction which introduces audiovisual material in a random‐access manner. When this system was used in the classroom to provide flexible, clinical simulations, it promoted a high level of audience‐instructor interaction and facilitated problem‐based learning. The system has been used successfully in lectures in our medical school, at other medical schools, at community hospitals and at national scientific meetings.

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 < 0.01) and white (r = +0.49; P <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 <0.05) and among women (r = 0.35; P < 0.05 and r = 0.31; P < 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.

Usefulness of computer-assisted instruction for medical education

Although computer-assisted instruction (CAD has been used in many disciplines for more than 3 decades, 1 it has not been widely used in medical education. Several factors may account for this. Main-frame computers and minicomputers, the early types of equipment, were expensive and, in many cases, were available only intermittently for educational purposes. In addition, the medical educator with an interest in CAI had to acquire complex programming skills. The use of several brands of computers and different programming languages prevented lessons from being shared widely among institutions. CAI lessons were often not sufficiently attractive to encourage enthusiastic use by students, because many of these lessons were similar to programmed textbooks, and interaction was often restricted to responding to multiple-choice questions. Few lessons incorporated relevant pictorial or auditory information. Because of these limitations, most students and teachers came to regard CAI as a novelty rather than as a method of instruction suitable for integration into the medical curriculum. The advent of inexpensive microcomputers and reliable random-access audiovisual electronic devices has altered the situation radically. At the Medical College of Georgia, we have developed an authoring system that allows teachers with no knowledge of computer programming to write microcomputer-assisted lessons and use random-access audiovisual devices to present pictorial and auditory information. We have used it to create clinical simulations for teaching problem-solving skills and to develop a competency-based curriculum in electrocardiographic interpretation. In this report, we describe the use of these simulations for promoting problem-based learning and comment on the opportunities offered by computer technology in medical education. The CAI system employs an Apple II series microcomputer or an IBM personal computer. These are interfaced to audiovisual devices. Previously, we have

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.