Recent data suggest that echocardiographic left ventricular (LV) hypertrophy is associated with increased cardiovascular morbidity and mortality. Based upon application of sex-specific echocardiographic criteria for LV hypertrophy, the clinical characteristics of 863 subjects with and 4097 subjects without LV hypertrophy are examined. Subjects with LV hypertrophy are older, more obese, have higher blood pressure, and are more likely to have pre-existing coronary artery disease. In addition subjects with LV hypertrophy have a higher prevalence of reduced echocardiographic fractional shortening. We conclude that subjects with echocardiographic LV hypertrophy are at high risk for cardiovascular disease complications by virtue of their clinical profile. Additional investigation of the benefits of therapeutic interventions directed toward the prevention or regression of LV hypertrophy is warranted.

Numerous electrocardiographic criteria, which are largely dependent on fixed voltage thresholds, have been proposed for the diagnosis of left ventricular hypertrophy (LVH). Electrocardiographic criteria for LVH were examined in 4,684 subjects of the Framingham Heart Study who underwent echocardiographic study for LVH. Echocardiographic LVH was detected in 290 men (14.2%) and 465 women (17.6%). Electrocardiographic features of LVH were present in 2.9% of men (60/2,042) and 1.5% of women (39/2,642). The overall sensitivity of the electrocardiographic diagnosis of LVH was 6.9%, whereas specificity was 98.8%. Sensitivity of the electrocardiogram (ECG) for LVH was marginally lower in women than in men (5.6% vs. 9.0%, p = 0.075). Obesity was inversely associated with sensitivity (p less than 0.05, both sexes combined, sex-adjusted). Smoking was also inversely related to sensitivity (p = 0.001, both sexes combined, sex-adjusted). In contrast, sensitivity of the ECG increased with age (p less than 0.001, both sexes combined, sex-adjusted). These findings suggest that electrocardiographic detection of LVH can be improved by incorporating information about noncardiac factors that impact on electrocardiographic sensitivity for LVH, presumably by attenuating QRS voltage. New strategies that take into consideration sex, age, smoking status, and obesity might improve the sensitivity of the ECG without diminishing specificity.

To the Editor.— In the July 7 issue Dr Palumbo 1 editorializes on the cost for screening and treatment of cholesterol levels in the entire population. Careful observers of the letters sections of several journals will have noted a thin stream of protests from various parts of the country, over the last several years, regarding the numbing costs of the great cholesterol public health initiative, if applied as recommended by the National Cholesterol Education Program. It seems that at last some of those considerations have come to the attention of mainstream academia. I only regret that such considerations have followed, rather than preceded, the publication of the National Cholesterol Education Program, which may produce the largest collection of malpractice litigation ever seen in this country if the courts come to agree that failure to apply the explicit algorithms and recommendations constitutes negligence. The fact that the program contains a disclaimer

Recently published guidelines from the National Cholesterol Education Program were applied to 792 men and 853 women aged 30 to 69 years who participated in Framingham Offspring examination 3 from 1983 to 1987. Using nationally recommended algorithms, cholesterol levels are desirable in 50% of men and women, borderline in 12% of men and 30% of women, and elevated in 35% of men and 19% of women. Assuming that diet reduces low-density lipoprotein cholesterol levels 20%, 10%, or 5%, rates of lipid medication use are projected as 2%, 5%, or 10%, respectively. Applying 6-year estimates of coronary risk derived from the original Framingham cohort to their offspring, the nationally recommended algorithm lacks specificity in women younger than 40 years and in both men and women older than 60 years. This study suggests that effective diet probably will be the cornerstone of current guidelines, and individuals aged 40 to 60 years might benefit most.

The prevalence of and risk factors associated with echocardiographically determined left ventricular hypertrophy were examined in 4976 participants in the Framingham Heart Study (age, 17 to 90 years). Left ventricular hypertrophy was detected in 356 men (16%) and 513 women (19%). Prevalence increases dramatically with age (P less than 0.001), with 33% of men and 49% of women age 70 or older affected. A significant association between blood pressure and left ventricular hypertrophy is present and occurs at levels of systolic pressure below 140 mm Hg (age adjusted, P less than 0.001). There is a ninefold (women) to tenfold (men) increase from leanest to most obese group (age adjusted, P less than 0.001). In multivariate analysis, age, blood pressure, obesity, valve disease, and myocardial infarction are independently associated in both sexes. We conclude that left ventricular hypertrophy is a common echocardiographic finding for which several risk factors can be identified. These findings support weight reduction and blood pressure control for prevention or regression of this condition.

The associations between 6 echocardtographic measurements and ventricular arrhythmias on 1-hour ambulatory electrocardiograms were evaluated in 3,348 subjects of the Framingham Heart Study who were free of symptomatic coronary artery disease, congestive heart failure and valvular heart disease and were not receiving diuretic drugs or other blood pressure or cardiac medications. Age-adjusted estimates of association between echocardiographic measurements of left ventricular (LV) structure and function and complex or frequent (Lown grade 2 or greater) ventricular arrhythmia were computed using logistic regression. In this bivariate model only LV internal diameter (systolic and diastolic) and fractional shortening were associated with arrhythmia in both sexes (p <0.01). When all variables were entered into a multivariate model, only age and systolic LV internal diameter remained independently associated with arrhythmia (p <0.001). Thus, LV chamber size and function are important predictors of risk for ventricular arrhythmia. Systolic LV internal diameter, which reflects both functional and structural information, is the only measurement independently predictive of arrhythmia risk in persons free of apparent heart disease.