Innominate artery aneurysm with thrombus: detection by two-dimensional echocardiography.

A 51 year old man with an innominate artery aneurysm presented with claudication and ischemia of the right forearm and hand. Two-dimensional echocardiography visualized the saccular aneurysm and a pedunculated mobile thrombus within it that were not seen during aortic arch angiography. Two-dimensional echocardiography, shown to be useful in identifying intracardiac masses and aortic aneurysms, may be important in selecting patients with increased risk of embolization.

Diastolic blood pressure as a determinant of Doppler left ventricular filling indexes in normotensive adolescents.

Alterations in left ventricular filling can occur with aging and in patients with hypertension, ischemic heart disease, congestive and hypertrophic cardiomyopathy and congenital heart disease. This study examines the effects of blood pressure on left ventricular diastolic filling indexes measured by Doppler ultrasound technique in 47 young normotensive adolescents (mean age 13 years). Left ventricular filling was assessed by Doppler peak early and late diastolic transmitral flow velocities, early and late diastolic flow velocity integrals and early diastolic deceleration. Systolic blood pressure did not correlate with any of the Doppler filling indexes, although it was related to echocardiographic left ventricular mass (r = 0.44, p less than 0.005). Diastolic blood pressure did not correlate with left ventricular mass; however, it was inversely related to peak early diastolic flow velocity (r = -0.44, p less than 0.005), early diastolic flow velocity integral (r = -0.40, p less than 0.01) and early diastolic deceleration (r = -0.32, p less than 0.05). The ratio of late to early peak filling (A/E) was directly related to diastolic blood pressure (r = 0.48, p less than 0.001). Examination of electrocardiograms showed that there was a stronger correlation between A/E ratio and diastolic blood pressure (r = 0.63) in 22 subjects with bimodal P waves in lead V1 than in subjects with unimodal P waves (r = 0.45).(ABSTRACT TRUNCATED AT 250 WORDS)

Predictive value of systolic and diastolic function for incident congestive heart failure in the elderly: the cardiovascular health study.

OBJECTIVES: We sought to assess the ability of echocardiographic indices of systolic and diastolic function to predict incident congestive heart failure (CHF). BACKGROUND: Noninvasive indices of subclinical systolic and/or diastolic dysfunction that can be used to identify patients in a transition phase between normal cardiac function and clinical CHF would be valuable. Though midwall shortening and Doppler mitral inflow patterns are seemingly well suited to predict subsequent CHF, the predictive value of these indices has not been investigated. METHODS: We studied 2,671 participants in the Cardiovascular Health Study who were free of coronary heart disease, CHF or atrial fibrillation. Clinical and quantitative echocardiographic data were obtained in all participants. RESULTS: At a mean follow-up of 5.2 years (range 0 to 6 years), 170 participants (6.4% of the cohort) developed CHF. Although 96% of these participants had normal or borderline ejection fraction (EF) at baseline, only 57% had normal or borderline EF at the time of hospitalization. In multivariate modeling, fractional shortening at the endocardium (relative risk [RR] 1.85 per 10-unit decrease, confidence interval [CI] 1.27 to 2.39), fractional shortening at the midwall (RR 1.29 per five-unit decrease, 95% CI 1.11-1.51) and peak Doppler peak E (RR 1.15 for each 0.1 M/s increment; CI 1.02 to 1.21) independently predicted incident CHF. Both high and low Doppler E/A ratios were predictive of incident CHF. CONCLUSIONS: Roughly half the occurrences of CHF in this population are associated with normal or borderline EF. Echocardiographic findings suggestive of subclinical contractile dysfunction and diastolic filling abnormalities are both predictive of subsequent CHF. The standard (FSendo) and refined (FSmw) parameters of systolic function performed similarly in this regard, though subjects with left ventricular hypertrophy and depressed FSmw are at particularly high risk for subsequent CHF.

Calculation of volume flow rate by the proximal isovelocity surface area method: simplified approach using color Doppler zero baseline shift.

OBJECTIVES: The goal of this study was to develop an accurate, simplified proximal isovelocity surface area (PISA) method for calculating volume flow rate using lower blue-red interface velocity produced by a color Doppler zero baseline shift technique. BACKGROUND: The Doppler color proximal isovelocity surface area method has been shown to be accurate for calculating the volume flow rate (Q) across a narrowed orifice by the formula Q = PISA x Blue-red interface velocity. A hemispheric model is generally used to calculate proximal isovelocity surface area (PISA = 2 pi a2, where a = the radius corresponding to the blue-red interface velocity). Although a hemispheric model is simple, requiring measurement of one radius, it may underestimate the actual volume flow rate because, in the general case, the shape of a proximal isovelocity surface area is hemielliptic. Although a hemielliptic model is generally more accurate for calculating proximal isovelocity surface area, it is more complex, requiring measurement of two orthogonal radii. METHODS: Sixteen in vitro constant flow model studies were performed using planar circular orifices (diameter range 6 to 16 mm). The blue-red interface velocity was changed from 3 to 54 cm/s using color Doppler zero baseline shift. RESULTS: 1) With decreasing blue-red interface velocity, the size of the proximal isovelocity surface area was increased, and its shape changed from hemielliptic to hemispheric. 2) With the blue-red interface velocity in the range 11 to 15 cm/s, the proximal isovelocity surface area became nearly hemispheric; however, it was difficult to determine the blue-red interface radius at a blue-red interface velocity < 10 cm/s because of interface fluctuations. 3) Calculated volume flow rate using the hemispheric proximal isovelocity surface area model with a single radius was relatively accurate at a blue-red interface velocity of 11 to 15 cm/s (mean percent difference from actual volume flow rate was -3.6%). CONCLUSIONS: Because the shape of the proximal isovelocity surface area is nearly hemispheric at a blue-red interface velocity of 11 to 15 cm/s, volume flow rate can be accurately calculated in this proximal isovelocity surface area interface velocity range (produced by zero baseline shift) by measuring a single-interface radius. This approach should be clinically useful for calculating the volume flow rate across stenotic and regurgitant valves and across shunt defects.

Left ventricular filling in hypertrophic cardiomyopathy: a pulsed Doppler echocardiographic study.

Abnormal left ventricular diastolic properties have been described in patients with hypertrophic cardiomyopathy. To evaluate the diastolic filling characteristics of the left ventricle in patients with this disease, pulsed Doppler echocardiography was used to study mitral flow velocity in 17 patients with hypertrophic cardiomyopathy (11 with and 6 without systolic anterior motion of the mitral valve) and 16 age-matched normal subjects. There were no statistically significant differences between patients with hypertrophic cardiomyopathy with and without systolic anterior motion with regard to ventricular septal thickness, left ventricular posterior wall thickness, left ventricular internal dimensions or the extent of hypertrophy evaluated by two-dimensional echocardiography. Mitral regurgitation was detected by Doppler echocardiography in all 11 patients with and in 2 (33%) of the 6 patients without systolic anterior motion of the mitral valve. Early and late diastolic peak flow velocity, the ratio of late to early diastolic peak flow velocity and deceleration of early diastolic flow were measured from Doppler mitral flow velocity recordings. There were no statistically significant differences in these four indexes between the patients with systolic anterior motion and normal subjects. In contrast, the patients with hypertrophic cardiomyopathy without systolic anterior motion showed lower early diastolic peak flow velocity, higher ratio of late to early diastolic peak flow velocity and lower deceleration of early diastolic flow compared with the patients with systolic anterior motion and normal subjects, suggesting impaired left ventricular diastolic filling.(ABSTRACT TRUNCATED AT 250 WORDS)

Doppler flow velocity mapping in an in vitro model of the normal pulmonary artery.

Pulsed Doppler pulmonary artery velocity measurements are useful in evaluating a number of cardiac conditions including pulmonary hypertension, pulmonary stenosis and insufficiency, intracardiac shunts and other congenital abnormalities. However, variations in sample location relative to the arterial wall and valve have been thought to affect pulmonary artery velocity and acceleration measurements clinically. Therefore, pulsed Doppler and color flow mapping were performed in a pulsatile flow apparatus connected to a glass or Plexiglas model of the main pulmonary artery and its bifurcation, which contained a Hancock 29 mm pericardial tissue valve (5.35 cm2 orifice). Doppler sample volumes were placed at four sites: 1) at the pulmonary valve leaflet tips, centrally; 2) 2 cm distal to the leaflet tips, centrally; 3) 2 cm distal but laterally near the pulmonary artery wall; and 4) at the pulmonary artery bifurcation, centrally. Doppler peak flow velocity and acceleration time were measured. There was no difference between sites 1 and 2 in peak flow velocity or acceleration time. At site 3, peak flow velocity and acceleration time were both less than at site 1 (mean +/- SD, 85 +/- 44 versus 105 +/- 39 cm/s, p less than 0.005, and 162 +/- 65 versus 188 +/- 46 ms, p less than 0.03, respectively). Moreover, the pulmonary artery velocity contour at site 3 exhibited increased spectral dispersion and notching and increased variance on the color spectrum. At site 4, peak flow velocity was less than at site 1 (85 +/- 31 versus 105 +/- 39 cm/s, p less than 0.005), whereas pulmonary artery acceleration time was not significantly different. In this model, Doppler pulmonary artery flow velocity was best recorded within 2 cm of the valve and in the center of the vessel. Similar studies should be performed in the human pulmonary artery to standardize the recording technique and sample sites for Doppler measurements of velocity and acceleration.

Doppler color flow "proximal isovelocity surface area" method for estimating volume flow rate: effects of orifice shape and machine factors.

Previously described Doppler color flow mapping methods for estimating the severity of valvular regurgitation have focused on the distal jet. In this study, a newer Doppler color flow technique, focusing on the flow proximal to an orifice, was used. This method identifies a proximal isovelocity surface area (PISA) by displaying an aliasing interface. Volume flow rate (cm3/s) can be calculated as PISA (cm2) x aliasing velocity (cm/s). For planar circular orifices, a hemi-elliptic model accurately approximated the shape of PISA. Clinically, however, orifice shapes may be noncircular. In vitro flow experiments (n = 226) using orifices of various shapes (ellipse, square, triangle, star, rectangle) were performed. Volume flow rate calculated using a hemi-elliptic model for PISA was accurate, with average percent differences from actual flow rate = +4.3% for a square, -4.2% for a triangle, -4.7% for a star, -4.5% for an ellipse and -2.8% for a rectangle. However, average percent differences for calculated volume flow rates using a hemispheric model for PISA shape ranged from -11.6% (square) to -34.8% (rectangle). In addition, to evaluate whether PISA is influenced by machine factors, in vitro studies (n = 83) were performed.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of association of recreational cocaine and alcohol use with left ventricular mass in young adults. The Coronary Artery Risk Development in Young Adults (CARDIA) study.

OBJECTIVES: This study examined the associations of left ventricular mass with self-reported cocaine and alcohol use prevalent in the young adult population. BACKGROUND: Increased left ventricular mass has been associated with long-term use of cocaine and alcohol; however, few of the published studies have been population based. METHODS: Data from 3,446 black and white participants (mean age 29.9 years) in the Coronary Artery Risk Development in Young Adults (CARDIA) study were used to examine the associations between echocardiographically measured left ventricular mass obtained from 1990 to 1991 and self-reported cocaine and alcohol use. Categories of cocaine use were those who denied ever using cocaine (n = 2,122), experimental users who admitted to cocaine use only 1 to 10 times in their lifetime (n = 755) and recurrent users who admitted to cocaine use > 10 times in their lifetime (n = 568). For alcohol consumption, categories were abstainers who consistently denied any alcohol consumption in the year before each of the three CARDIA examinations (n = 275), occasional users who admitted consuming alcohol less than once a week or not at all during the year before the third examination (n = 1,322), moderate users who consumed 1 to 209 ml of alcohol/week during the year before the third examination (n = 1,524) and heavy users who consumed > or = 210 ml of alcohol/week during the year before the third examination (n = 323). Estimated power to detect a 10% difference in left ventricular mass between groups was > 80%. RESULTS: For white women, left ventricular mass was significantly higher among those who reported 1 to 10 lifetime uses of cocaine than in never-users (128.5 g [SE 2.0] vs. 122.7 g [SE 1.4], p = 0.002). There were no other significant differences in left ventricular mass among categories of cocaine or alcohol use in unadjusted analyses or among analyses controlling for age, body mass index, alcohol or cocaine use, physical activity, cigarette smoking status and systolic blood pressure. CONCLUSIONS: At the levels of consumption reported, neither cocaine nor alcohol use was associated with left ventricular mass in this cohort of healthy young adults.

Cardiac function in smokers and nonsmokers: the CARDIA study. The Coronary Artery Risk Development in Young Adults Study.

OBJECTIVES: This study assessed clinical and echocardiographic measures of cardiac function at rest in smokers and nonsmokers to determine the associations of cigarette smoking with various measures of left and right ventricular performance. BACKGROUND: Whereas the immediate cardiovascular effects of cigarette smoking have been well described, the long-term effects in an otherwise healthy cohort have not. Of particular interest were associations with heart rate, left ventricular end-systolic stress and left ventricular mass because higher levels of these measures would suggest increased myocardial oxygen consumption. METHODS: In year 5 of the Coronary Artery Risk Development in Young Adults (CARDIA) study, 3,366 smokers and nonsmokers (ex-smokers were excluded) underwent echocardiography as well as assessment of heart rate, anthropometric measurements and blood pressure. Participants ranged in age from 23 to 35 years and were equally distributed by race and gender. Echocardiographic measures included pulsed Doppler pulmonary artery acceleration time (a decrease suggests increased pulmonary artery pressure), left ventricular mass, left ventricular end-systolic stress and left ventricular fractional shortening. RESULTS: All comparisons were between smokers and nonsmokers. Heart rate at rest was significantly higher in smokers by 1.5 to 5 beats/min in all race/gender groups except black men. In men who smoked, pulmonary artery acceleration time was significantly lower by 4 to 8 ms. Except for black male smokers, there was a trend toward increased left ventricular mass (3 to 8 g) in all race/gender groups, significant in black women. Left ventricular end-systolic stress was significantly higher in women who smoked (4 to 6 dynes/cm2). There were no differences for systolic blood pressure or left ventricular fractional shortening. CONCLUSION: In an assessment of cardiovascular function at rest in young adults, quantifiable differences between smokers and nonsmokers that predict increased rest myocardial oxygen consumption in smokers were found. Some of these differences were gender specific.

Submaximal exercise testing after stabilization of unstable angina pectoris.

To determine the prognostic value of exercise testing in patients with unstable angina pectoris, 125 hospitalized patients were prospectively evaluated soon after stabilization of their pain. Exercise testing was performed after exclusion of acute myocardial infarction and a pain-free period of at least 3 days (mean +/- SD 3.9 +/- 1.4). No complications were noted during or immediately after exercise testing. A positive test (angina or greater than or equal to 1 mm ST segment depression, or both) was noted in 60 patients (48%). During a 1 year follow-up period, 52 (87%) of these 60 patients had an unfavorable outcome (American Heart Association class III or IV angina, recurrent unstable angina, coronary artery bypass surgery, acute myocardial infarction or cardiac death) compared with 19 (29%) of the 65 patients with a negative test (p less than 0.001). The sensitivity and specificity of exercise testing in predicting outcome were 73 and 85%, respectively. The predictive value of a positive test was 87% and that of a negative test was 71%. Angina by itself during the exercise test was a reliable predictor of severe angina (class III or IV angina) at follow-up (sensitivity 92%, specificity 89%, positive predictive value 83% and negative predictive value 95%; p less than 0.001). The findings were not significantly affected by beta-adrenergic blocking agents or digitalis in the study sample. Thus, in patients with unstable angina which has been stabilized, the results of early submaximal exercise testing may be useful in predicting outcome in the first year after hospital discharge. Patients with a positive test result should be considered for further diagnostic studies.

Superiority of two-dimensional measurement of aortic vessel diameter in Doppler echocardiographic estimates of left ventricular stroke volume.

Attempts to measure left ventricular stroke volume utilizing the Doppler aortic flow method have found varying correlations between invasive thermodilution and non-invasive Doppler methods. Because stroke volume is the product of the Doppler flow velocity integral (that is, the area under the flow velocity curve) and the cross-sectional area of the vessel through which blood flows, both variables are potential sources of error. Previous studies have shown that the Doppler flow velocity integral can be measured with acceptable reproducibility in the ascending aorta. Consequently, in this study an attempt was made to determine empirically the optimal method for measuring aortic diameter and area. The diameter of the ascending aorta was measured utilizing four M-mode and seven two-dimensional echocardiographic conventions. Doppler aortic flow velocity patterns were recorded with a 2.25 MHz M-mode echocardiographic transducer from the suprasternal notch by mapping the ascending aorta until aortic peak flow velocity was recorded. In 19 adult patients undergoing cardiac catheterization for clinical indications, Doppler stroke volume estimates utilizing the various echocardiographic conventions for measuring aortic root diameter and area were compared with simultaneous measurements of stroke volume by the thermodilution technique. The best correlation (r = 0.87) with thermodilution stroke volume was obtained by estimating aortic area from the two-dimensional parasternal long-axis images with the aortic dimension measured distal to the aortic sinuses from the inner to inner wall. The data were related by the equation: Thermodilution stroke volume = (0.73) X (two-dimensional Doppler stroke volume) + 17 cc.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical factors associated with calcific aortic valve disease. Cardiovascular Health Study.

OBJECTIVES: The aim of this study was to determine the prevalence of aortic sclerosis and stenosis in the elderly and to identify clinical factors associated with degenerative aortic valve disease. BACKGROUND: Several lines of evidence suggest that degenerative aortic valve disease is not an inevitable consequence of aging and may be associated with specific clinical factors. METHODS: In 5,201 subjects > or = 65 years of age enrolled in the Cardiovascular Health Study, the relation between aortic sclerosis or stenosis identified on echocardiography and clinical risk factors for atherosclerosis was evaluated by using stepwise logistic regression analysis. RESULTS: Aortic valve sclerosis was present in 26% and aortic valve stenosis in 2% of the entire study cohort; in subjects > or = 75 years of age, sclerosis was present in 37% and stenosis in 2.6%. Independent clinical factors associated with degenerative aortic valve disease included age (twofold increased risk for each 10-year increase in age), male gender (twofold excess risk), present smoking (35% increase in risk) and a history of hypertension (20% increase in risk). Other significant factors included height and high lipoprotein(a) and low density lipoprotein cholesterol levels. CONCLUSIONS: Clinical factors associated with aortic sclerosis and stenosis can be identified and are similar to risk factors for atherosclerosis.

Cardiac arrhythmias on 24-h ambulatory electrocardiography in older women and men: the Cardiovascular Health Study.

OBJECTIVES: This study describes the prevalence and correlates of cardiac arrhythmias in older persons. BACKGROUND: Cardiac arrhythmias are frequent in selected samples of elderly persons, but their prevalence and association with cardiovascular disease and its risk factors have not been examined in a large population-based sample. METHODS: In 1,372 participants in the Cardiovascular Health Study, a population-based study of cardiovascular disease risk factors, 24-h ambulatory electrocardiography was performed. RESULTS: Serious arrhythmias, such as sustained ventricular tachycardia and complete atrioventricular block, were uncommon, but brief episodes of ventricular tachycardia (> or = 3 consecutive ventricular depolarizations) were detected in 4.3% of women and 10.3% of men. Ventricular arrhythmias as a group (excluding ectopic beats < 15/h) were more common in men than in women but were not significantly associated with age. The same patterns were true for bradycardia/conduction blocks. Supraventricular arrhythmias as a group (excluding ectopic beats < 15/h), in contrast, did not differ by gender but were strongly associated with increased age. Multivariate analyses showed associations with arrhythmias to differ by gender, with only one association (increased age and supraventricular arrhythmias) present in both women and men. Ventricular arrhythmias, particularly in men, were associated with a higher prevalence of cardiovascular disease and its risk factors and with subclinical disease, as measured by increased left ventricular mass and impaired left ventricular function. CONCLUSIONS: Arrhythmias are common in the elderly, and their association with cardiovascular disease differs by gender. Although risk related to arrhythmias can only be determined by prospective study, such studies should have adequate power to examine potential gender differences in associations.

Predictors of congestive heart failure in the elderly: the Cardiovascular Health Study.

OBJECTIVES: We sought to characterize the predictors of incident congestive heart failure (CHF), as determined by central adjudication, in a community-based elderly population. BACKGROUND: The elderly constitute a growing proportion of patients admitted to the hospital with CHF, and CHF is a leading source of morbidity and mortality in this group. Elderly patients differ from younger individuals diagnosed with CHF in terms of biologic characteristics. METHODS: We analyzed data from the Cardiovascular Health Study, a prospective population-based study of 5,888 elderly people >65 years old (average 73 +/- 5, range 65 to 100) at four locations. Multiple laboratory measures of cardiovascular structure and function, blood chemistries and functional assessments were obtained. RESULTS: During an average follow-up of 5.5 years (median 6.3), 597 participants developed incident CHF (rate 19.3/1,000 person-years). The incidence of CHF increased progressively across age groups and was greater in men than in women. On multivariate analysis, other independent predictors included prevalent coronary heart disease, stroke or transient ischemic attack at baseline, diabetes, systolic blood pressure (BP), forced expiratory volume 1 s, creatinine >1.4 mg/dl, C-reactive protein, ankle-arm index <0.9, atrial fibrillation, electrocardiographic (ECG) left ventricular (LV) mass, ECG ST-T segment abnormality, internal carotid artery wall thickness and decreased LV systolic function. Population-attributable risk, determined from predictors of risk and prevalence, was relatively high for prevalent coronary heart disease (13.1%), systolic BP > or =140 mm Hg (12.8%) and a high level of C-reactive protein (9.7%), but was low for subnormal LV function (4.1%) and atrial fibrillation (2.2%). CONCLUSIONS: The incidence of CHF is high in the elderly and is related mainly to age, gender, clinical and subclinical coronary heart disease, systolic BP and inflammation. Despite the high relative risk of subnormal systolic LV function and atrial fibrillation, the actual population risk of these for CHF is small because of their relatively low prevalence in community-dwelling elderly people.

ECG manifestations of myocardial ischemia.

Exercise ECG is widely used for the diagnosis of ischemic heart disease. The most common ECG sign of myocardial ischemia is flat or down-sloping ST-segment depression of 1.0 mm or greater. This report draws attention to other much less common, but possibly equally important, ECG manifestations of myocardial ischemia. Serial ECGs obtained during the treadmill stress test of a 40-year-old man with angiographically proven coronary artery disease exhibited virtually all known ECG signs of ischemia, namely, ST-segment depression, ST-segment elevation and alternans, intraventricular conduction abnormalities, and U-wave inversion.

Pseudodysrhythmias in ambulatory ECG monitoring.

Artifacts mimicking a variety of dysrhythmias occur relatively frequently in ambulatory ECG (Holter) monitoring records. Proper interpretation is imperative if serious therapeutic errors are to be avoided. Two-channel recording systems may facilitate recognition of some, but not all, of these artifacts. Pseudodysrhythmias may mimic paroxysmal supraventricular tachycardia and atrial fibrillation, atrial dissociation, extrasystoles, and sinus pauses. There are several causes of pseudodysrhythmias. Failure to recognize these patterns may result in serious errors in patient management.

Myocardial infarction and coronary ectasia in idiopathipc mitral valve prolapse syndrome.

Angina pectoris and myocardial infarction occurred in two patients with idiopathic mitral valve prolapse in the absence of atherosclerotic coronary artery disease. Instead, both patients showed the presence of coronary artery ectasia on cineangiography. The anatomic localization of ectasia corresponded with segmental derangement of left ventricular wall motion. Repeated thromboemboli from ectatic vessels and/or locally liberated platelet metabolites were considered the probable mechanism of these symptoms.

Echocardiographic practice in a large metropolitan area.

A survey performed concerning echocardiography in a metropolitan area. Of 110 hospitals in the area, 62 reported having echocardiographic facilities. Echocardiographic physicians and/or technicians from 41 of these hospitals responded to questionnaires designed to determine the following: (1) educational background and credentials of technicians, (2) average salaries of technicians, (3) role of the physician and technician in the performance and reporting of echocardiograms, (4) volume, cost, and method of storage of echocardiograms, and (5) number and type of echocardiographic units in use. Our data suggest various trends, including a lack of formal training among technicians, the prevalence of cardiologists-internists as directors of echocardiographic facilities, the performance of echocardiograms by cardiology fellows in only 46% of institutions with cardiology training programs, and the widespread projected availability of cross-sectional echocardiographic capability within the next two years.

Osteoarthritis in cynomolgus macaques. III: Effects of age, gender, and subchondral bone thickness on the severity of disease.

Knee joints from cynomolgus monkeys of both genders and a wide range of ages were examined to characterize further the natural history of osteoarthritis (OA) in these animals. The objectives of this study were to characterize better the subchondral bone changes previously noted in this disease, to determine whether the severity of OA in these animals is affected by age or weight, and to determine whether males and females are affected similarly. As had been seen in previous studies, the medial tibial plateau was the most severely affected site. The thickness of the subchondral plate in the medial tibial plateau increased with increasing severity of articular cartilage lesions in both males and females; however, in monkeys with subchondral plate thicknesses less than 400 microns, articular cartilage lesions were essentially absent. Subchondral plate thickness increased with increasing weight in both genders, but females had a higher subchondral plate thickness than males for a given body weight. There was no correlation between bone volume in the proximal tibial epiphysis and articular cartilage lesions of OA. The prevalence and severity of OA in the medial tibial plateau increased with increasing age, but were not affected by gender or weight. Although there was no correlation between articular cartilage lesions and body mass index or weight, the waist/hip circumference ratio and severity of articular cartilage lesions were correlated in the female monkeys. This work provides evidence that thickening of the subchondral bone plate may be more important than the volume of epiphyseal/metaphyseal cancellous bone in determining the biomechanical stresses in the joint and in influencing the development of articular cartilage lesions.

Effect of age, sex, and body surface area on echocardiographic left ventricular wall mass in normal subjects.

M-mode echocardiography was used to estimate left ventricular wall mass in 136 older normal subjects (Group I: 78 men and 58 women, ages 20 to 97 years) and 105 younger normal subjects (Group II: 52 male and 53 female subjects, ages 1 day to 23 years). Echocardiographic left ventricular mass (in grams) was estimated from the following formula: left ventricular mass = 1.05 ([ left ventricular internal diastolic dimension + ventricular septal thickness (diastole) + posterior wall thickness (diastole)] - [left ventricular internal diastolic dimension]). In both groups, female subjects had a slightly smaller left ventricular mass than male subjects (mean difference 7.2% in Group I, p less than 0.05, and 3.6% in Group II, p = 0.05) for any given age and body surface area. Left ventricular mass varied linearly with body surface area and increased as a function of age. In group I subjects, echocardiographic left ventricular mass (in grams) could be estimated by the general formula: left ventricular mass = 124 (body surface area) + A +/- C, where A is the age-dependent intercept; +/- C encompasses a 95% prediction interval for normal values, which is assumed to be nearly constant (+/- 58 g); and body surface area is expressed in square meters. In the Group II (younger) subjects, with age not considered, left ventricular mass (in grams) could be estimated from the following formula: left ventricular mass = 115 (body surface area) -11 +/- C, where +/- C = +/- 32% and this 95% prediction interval varies as a percentage of the mean.(ABSTRACT TRUNCATED AT 250 WORDS)