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Biomedical subjects

J C Evans

Publications and source records attributed to J C Evans.

At least 37 records · Page 2Linked to original sources

Thrombosed double inferior vena cava mimicking paraaortic lymphadenopathy.

A case is presented of thrombosis of an anomalous left-sided duplication of the inferior vena cava misinterpreted on CT as lymphadenopathy or other retroperitoneal mass. Recognition of this anomaly is important in reaching the correct diagnosis in such cases. The diagnosis by imaging methods is described as well as their pitfalls.

Aged↗

A national survey of attitudes towards the use of MRI in patients known to have intracranial aneurysm clips.

The objective of this study was to determine the attitudes and practice of neuroradiology centres across the UK regarding the use of MRI in patients known to have intracranial aneurysm clips. A postal survey comprising three questions and a comments section was sent to 35 neuroradiology centres across the UK. There were 32 (91%) respondents to the single questionnaire. 16 (50%) respondents said that they would not consider performing MRI on a patient with an intracranial aneurysm clip. Of the remaining 50%, all said that identification of the clip type and assurance of its safety would be needed prior to scanning the patient. The magnetic strength of the system did not appear to affect the decision regarding whether or not to perform MRI on such patients. There was a variation in attitude towards the use of MRI in such patients between different regions. Neuroradiology centres are equally divided in their attitude and practice about whether it is safe to use MR to image a patient known to have an intracranial aneurysm clip. This is most probably due to the conflicting literature, as well as uncertainty about the identification and ferromagnetic properties of individual clips.

Brain↗

beta-cell genes and diabetes: molecular and clinical characterization of mutations in transcription factors.

beta-Cell transcription factor genes are important in the pathophysiology of the beta-cell, with mutations in hepatocyte nuclear factor (HNF)-1alpha, HNF-4alpha, insulin promoter factor (IPF)-1, HNF-1beta, and NeuroD1/BETA2, all resulting in early-onset type 2 diabetes. We assessed the relative contribution of these genes to early-onset type 2 diabetes using linkage and sequencing analysis in a cohort of 101 families (95% U.K. Caucasian). The relative distribution of the 90 families fitting maturity-onset diabetes of the young (MODY) criteria was 63% HNF-1alpha, 2% HNF-4alpha, 0% IPF-1, 1% HNF-1beta, 0% NeuroD1/ BETA2, and 20% glucokinase. We report the molecular genetic and clinical characteristics of these patients including 29 new families and 8 novel HNF-1alpha gene mutations. Mutations in the transactivation domain are more likely to be protein truncating rather than result in amino acid substitutions, suggesting that a relatively severe disruption of this domain is necessary to result in diabetes. Mutations in the different transcription factors result in clinical heterogeneity. IPF-1 mutations are associated with a higher age at diagnosis (42.7 years) than HNF-1alpha (20.4 years), HNF-1beta (24.2 years), or HNF-4alpha (26.3 years) gene mutations. Subjects with HNF-1beta mutations, in contrast to the other transcription factors, frequently present with renal disease. A comparison of age at diagnosis between subjects with different types and locations of HNF-1alpha mutations did not reveal genotype-phenotype correlations. In conclusion, mutations in transcription factors expressed in the beta-cell are the major cause of MODY, and the phenotype clearly varies with the gene that is mutated. There is little evidence to indicate that different mutations within the same gene have different phenotypes.

Adolescent↗

Association of blood pressure with fibrinolytic potential in the Framingham offspring population.

BACKGROUND: Hypertension is an established risk factor for acute coronary events. Because fibrinolytic and hemostatic factors are also associated with cardiovascular disease, we examined the relations of systolic and diastolic blood pressures (SBP and DBP) to levels of plasminogen activator inhibitor antigen, tissue plasminogen activator antigen, fibrinogen, factor VII, von Willebrand factor, fibrinogen, and plasma viscosity in subjects of the Framingham Offspring Study. METHODS AND RESULTS: We studied 1193 men and 1459 women after the exclusion of subjects with known cardiovascular disease and those receiving anticoagulant or antihypertensive therapy. Linear regression models were used to evaluate SBP and DBP as predictors of fibrinolytic and hemostatic factor levels in separate sex models, with adjustment for age, body mass index, smoking, diabetes, total cholesterol, HDL, triglycerides, alcohol intake, and estrogen use (in women). In both sexes, levels of plasminogen activator inhibitor and tissue plasminogen activator antigen were positively related to SBP and DBP (P<0.001). Plasma viscosity was positively related to SBP (P=0.008) and DBP (P=0.001) in women only. There was no association between SBP or DBP and fibrinogen, factor VII, or von Willebrand factor in either sex. CONCLUSIONS: These data suggest that impaired fibrinolysis may play an important role in the pathogenesis of cardiovascular disease in hypertensive patients.

Adult↗

Confirmation of linkage of Duane's syndrome and refinement of the disease locus to an 8.8-cM interval on chromosome 2q31.

Duane's syndrome is a congenital abnormality of eye movement, which may be inherited as an autosomal dominant trait but usually occurs sporadically. Genetic mapping in a Mexican family has recently identified a locus for Duane's syndrome within a 17.8-cM region of chromosome 2q31. The region was flanked by the microsatellite markers D2S2330 and D2S364. We performed linkage and haplotype analysis in a four-generation UK family with autosomal dominant transmission of Duane's syndrome. Linkage to 2q31 was confirmed with a maximum logarithm of differences (lod) score of 3.3 at theta = 0. The genetic interval was reduced to an 8.8-cM region between markers D2S326 and D2S364 that includes the candidate homeobox D gene cluster.

Chromosome Mapping↗

Is vaginal delivery preferable to elective cesarean delivery in fetuses with a known ventral wall defect?

OBJECTIVE: We sought to test the hypothesis that vaginal delivery compared with elective cesarean delivery results in improved neonatal outcome in fetuses with a known isolated ventral wall defect. STUDY DESIGN: We performed a retrospective chart review. RESULTS: Between 1989 and 1999, we identified 102 infants with a confirmed antenatal diagnosis of an isolated ventral wall defect with either the diagnosis of an omphalocele or gastroschisis. Sixty-six infants were delivered by cesarean and 36 were delivered vaginally. There were no significant demographic differences between the study groups or between the two sites except that one center (Cincinnati) usually delivered these fetuses by cesarean whereas the other (Louisville) usually delivered such fetuses vaginally. Overall, there were a greater number of infants with gastroschisis than omphalocele (gastroschisis, n = 71; omphalocele, n = 31). After we controlled for primary versus staged closure of ventral wall defect and gestational age at delivery; the medians and interquartile ranges for cesarean and vaginal delivery were 39 (25, 63) days versus 42 (26, 75) days, respectively (P =.32), for neonatal length of stay and 13 (9, 18) days versus 13 (9, 26) days, respectively (P =.16), for days to enteral feeding. After we controlled for the size of the defect and the amount of bowel resected, the odds of primary closure given a vaginal delivery was about half that given a cesarean delivery (odds ratio, 0.56; 95% confidence interval, 0.18-1. 69), but this was not statistically significant. There was no statistically significant difference in the rates of neonatal death (2 [3%] vs 2 [6%]; P =.61) and neonatal sepsis (2 [3%] vs 4 [11%]; P =.18) for cesarean versus vaginal delivery. Maternal length of stay after delivery was found to be 1 day less after vaginal delivery [vaginal, 2 (2, 2) days; cesarean, 3 (2, 3) days; P =.0001]. There were 5 instances of maternal complications, and all 5 pregnancies were delivered by cesarean (P =.16). CONCLUSION: Fetuses with an antenatal diagnosis of an isolated ventral wall defect may safely be delivered vaginally, and cesarean delivery should be performed for obstetric indications only.

Adult↗

Antibacterial efficacy of gentamicin encapsulated in pH-sensitive liposomes against an in vivo Salmonella enterica serovar typhimurium intracellular infection model.

Encapsulation of gentamicin in liposomes can be used to achieve intracellular delivery and broaden the clinical utility of this drug. We have previously described a novel, rationally designed, pH-sensitive liposomal carrier for gentamicin that has superior in vitro efficacy against intracellular infections compared to the efficacies of both free gentamicin and non-pH-sensitive liposomal controls. This liposomal carrier demonstrated pH-sensitive fusion that was dependent on the presence of unsaturated phosphatidylethanolamine (PE) and the pH-sensitive lipid N-succinyldioleoyl-PE. The pharmacokinetics and biodistribution of the free and liposomal gentamicin were examined in mice bearing a systemic Salmonella enterica serovar Typhimurium infection. Encapsulation of gentamicin in pH-sensitive liposomes significantly increased the concentrations of the drug in plasma compared to those of free gentamicin. Furthermore, the levels of accumulation of drug in the infected liver and spleen were increased by 153- and 437-fold, respectively, as a result of liposomal encapsulation. The increased accumulation of gentamicin in the liver and spleen effected by liposomal delivery was associated with 10(4)-fold greater antibacterial activity than that associated with free gentamicin in a murine salmonellosis model. These pH-sensitive liposomal antibiotic carriers with enhanced in vitro activity could be used to improve both in vivo intracellular drug delivery and biological activity.

Animals↗

Differential control of systolic and diastolic blood pressure : factors associated with lack of blood pressure control in the community.

Data from the Third National Health and Nutrition Examination Survey, phase 2 (1991 to 1994), indicate that among hypertensive individuals in the United States, 53.6% are treated and only 27.4% are controlled to goal levels. We sought to determine whether poor hypertension control is due to lack of systolic or diastolic blood pressure control, or both. We studied Framingham Heart Study participants examined between 1990 and 1995 and determined rates of control to systolic goal (<140 mm Hg), diastolic goal (<90 mm Hg), or both (systolic <140 and diastolic <90 mm Hg). Of 1959 hypertensive subjects (mean age 66 years, 54% women), 32.7% were controlled to systolic goal, 82.9% were controlled to diastolic goal, and only 29.0% were controlled to both. Among the 1189 subjects who were receiving antihypertensive therapy (60.7% of all hypertensive subjects), 49.0% were controlled to systolic goal, 89.7% were controlled to diastolic goal, and only 47.8% were controlled to both. Thus, poor systolic blood pressure control was overwhelmingly responsible for poor rates of overall control to goal. Covariates associated with lack of systolic control in treated subjects included older age (OR for age 61 to 75 years, 2.43, 95% CI 1.79 to 3.29; OR for age >75 years, 4.34, 95% CI 3.10 to 6.09), left ventricular hypertrophy (OR 1.63, 95% CI 1.04 to 2.54), and obesity (OR for body mass index >/=30 versus <25 kg/m(2), 1.49, 95% CI 1.08 to 2.06). In this community-based sample of middle-aged and older subjects, overall rates of hypertension control were remarkably similar to those in the Third National Health and Nutrition Examination Survey. Poor blood pressure control was overwhelmingly due to lack of systolic control, even among treated subjects. Therefore, clinicians and policymakers should place greater emphasis on the achievement of goal systolic levels in all hypertensive patients, especially those who are older or obese or have target organ damage.

Aged↗

The radiological appearances of tuberous sclerosis.

Tuberous sclerosis is an autosomal dominant disorder often associated with a chromosome 9 abnormality, although up to 60% of cases occur spontaneously. The incidence of the disorder is between 1/100,000 and 1/10,000, and it leads to multiple organ and skeletal abnormalities. The classical triad of epilepsy, mental retardation and adenoma sebaceum defines the syndrome clinically. Other cutaneous associations include shagreen patches, ash leaf-shaped areas of depigmentation, subungual fibromas and café-au-lait spots. This review describes the commoner radiological manifestations of the syndrome, and briefly mentions the rarer associations that have been reported to date.

Echocardiography↗

Extensive soft tissue uptake of 99Tcm methylene diphosphonate in a patient with multiple myeloma.

Bone scintigraphy is not usually performed in multiple myeloma (MM), as marrow deposits characteristically show no tracer uptake. However, metastatic bone disease often mimics MM both clinically and biochemically, resulting in a substantial number of MM patients undergoing bone scintigraphy. Variable appearances in these cases have been reported, ranging from normal to a superscan, the latter a result of massive tracer uptake within bone. Soft tissue uptake has been documented, often when MM is complicated by secondary amyloidosis. This usually results in mainly solid organ uptake of tracer. We report a case of MM where massive soft tissue uptake occurred, primarily within muscles, with very little isotope elsewhere.

Aged↗

Temporal trends in event rates after Q-wave myocardial infarction: the Framingham Heart Study.

BACKGROUND: Short-term (<30 day) mortality after Q-wave myocardial infarction (MI) has declined over the decades, but it is unclear if rates of long-term sequelae after Q-wave MI have improved. METHODS AND RESULTS: In 546 Framingham Heart Study subjects (388 men with a mean age of 60 years; 158 women with a mean age of 69 years) with an initial recognized Q-wave MI from 1950 through 1989, we investigated time trends in risk for coronary heart disease (CHD) death (n=199), all-cause mortality (n=287), reinfarction (n=108), and congestive heart failure (CHF; n=121). With 1950 through 1969 as the reference period, hazards ratios (HRs) for these outcomes were determined for the 1970s and 1980s. Trend analyses across the 3 time periods were performed for each outcome. Compared with the 1950 through 1969 reference period, the HRs for CHD death were lower in subsequent decades (1970 through 1979: HR, 0.69; 95% CI, 0.49 to 0.98; 1980 through 1989: HR, 0.48; 95% CI, 0.33 to 0.72). All-cause mortality also declined (1970 through 1979: HR, 0.70; 95% CI, 0.0.52 to 0.94; 1980 through 1989: HR, 0.59; 95% CI, 0.43 to 0.81). There were no significant temporal changes in the risks for recurrent MI or CHF. CONCLUSIONS: Substantial reductions in risk of CHD death and all-cause mortality occurred over these 4 decades, coincident with improvements in post-MI therapies. The absence of a decline in CHF incidence may be due to improved post-MI survival of individuals with depressed left ventricular systolic function who are at high risk for CHF.

Adult↗

Cross-classification of JNC VI blood pressure stages and risk groups in the Framingham Heart Study.

BACKGROUND: The recently published Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) includes a classification of blood pressure stages and a new risk stratification component. Patients with high-normal blood pressure or hypertension are stratified into risk group A (no associated cardiovascular disease risk factors, no target organ damage or cardiovascular disease); group B (> or =1 associated cardiovascular disease risk factor excluding diabetes, no target organ damage or cardiovascular disease); or group C (diabetes or target organ damage or cardiovascular disease). OBJECTIVE: To examine the prevalence of risk groups and blood pressure stages in a community-based sample. METHODS: We evaluated 4962 subjects from the Framingham Heart Study and Framingham Offspring Study examined between 1990 and 1995. We cross-classified men and women separately according to their JNC VI blood pressure stages and risk groups. RESULTS: In the whole sample, 43.7% had optimal or normal blood pressure and 13.4% had high-normal blood pressure; 12.9% had stage 1 hypertension and 30.0% had stage 2 or greater hypertension or were receiving medication. As blood pressure stage increased, the proportion of subjects in group A decreased, whereas the proportion in group C increased. Among those with high-normal blood pressure or hypertension, only 2.4% (all women) were in risk group A, 59.3% were in group B, and 38.2% were in group C. In the high-normal or hypertensive group, 39.4% qualified for lifestyle modification as the initial intervention according to JNC VI recommendations, whereas 60.6% were eligible for initial drug therapy or were already receiving drug therapy. Nearly one third of high-normal subjects were in risk group C, in which early drug therapy may be needed. Among those in stage 1, only 4.0% were in group A, in which prolonged lifestyle modification is recommended. CONCLUSIONS: These results provide a foundation for estimating the number of individuals with hypertension who fall into different risk groups that require different treatment approaches. With nearly 50 million individuals with hypertension in the United States, there are important implications for clinicians and policymakers if JNC VI recommendations are widely adopted in clinical practice.

Adult↗

Prevalence and clinical outcome of mitral-valve prolapse.

BACKGROUND: Mitral-valve prolapse has been described as a common disease with frequent complications. To determine the prevalence of mitral-valve prolapse in the general population, as diagnosed with the use of current two-dimensional echocardiographic criteria, we examined the echocardiograms of 1845 women and 1646 men (mean [+/-SD] age, 54.7+/-10.0 years) who participated in the fifth examination of the offspring cohort of the Framingham Heart Study. METHODS: Classic mitral-valve prolapse was defined as superior displacement of the mitral leaflets of more than 2 mm during systole and as a maximal leaflet thickness of at least 5 mm during diastasis, and nonclassic prolapse was defined as displacement of more than 2 mm, with a maximal thickness of less than 5 mm. RESULTS: A total of 84 subjects (2.4 percent) had mitral-valve prolapse: 47 (1.3 percent) had classic prolapse, and 37 (1.1 percent) had nonclassic prolapse. Their age and sex distributions were similar to those of the subjects without prolapse. None of the subjects with prolapse had a history of heart failure, one (1.2 percent) had atrial fibrillation, one (1.2 percent) had cerebrovascular disease, and three (3.6 percent) had syncope, as compared with unadjusted prevalences of these findings in the subjects without prolapse of 0.7, 1.7, 1.5, and 3.0 percent, respectively. The frequencies of chest pain, dyspnea, and electrocardiographic abnormalities were similar among subjects with prolapse and those without prolapse. The subjects with prolapse were leaner (P<0.001) and had a greater degree of mitral regurgitation than those without prolapse, but on average the regurgitation was classified as trace or mild. CONCLUSIONS: In a community based sample of the population, the prevalence of mitral-valve prolapse was lower than previously reported. The prevalence of adverse sequelae commonly associated with mitral-valve prolapse in studies of patients referred for that diagnosis was also low.

Adult↗

Heritability of heart rate variability: the Framingham Heart Study.

BACKGROUND: There is evolving evidence that heart rate (HR) is genetically determined. Heart rate variability (HRV) measured by power spectral analysis provides quantitative phenotypic markers of autonomic nervous system activity. Reported determinants of HR and HRV only partially explain their variability in the population. The purpose of this study was to assess the heritability of HR and HRV and estimate the contribution of genetic factors to their variance. METHODS AND RESULTS: Subjects who underwent ambulatory recordings at a routine examination were eligible; subjects with congestive heart failure, coronary artery disease, diabetes mellitus, and those taking cardioactive medications were excluded. We analyzed high-frequency power, low-frequency power, very low-frequency power, total power, low-frequency/high-frequency ratio, and the standard deviation of normal R-R intervals from 2-hour continuous ECG recordings. Heritability analysis was done by studying correlations between siblings (n=682, in 291 sibships, 517 pairs) and between spouse pairs (n=206 pairs) after adjusting for important covariates. Results from separate models were combined to estimate the components of variance attributable to measured covariates, additive genetic effects (heritability), and household effects. After adjusting for covariates, the correlations were consistently higher among siblings (0.21 to 0.26) compared with spouses (0.01 to 0.19). The measured covariates in general accounted for 13% to 40% of the total phenotypic variance, whereas genetic factors accounted for 13% to 23% of the variation among HR and HRV measures. CONCLUSIONS: Heritable factors may explain a substantial proportion of the variance in HR and HRV. These results highlight the contribution of genetic versus environmental factors to autonomic nervous system activity.

Adult↗

Blood pressure response during treadmill testing as a risk factor for new-onset hypertension. The Framingham heart study.

BACKGROUND: Although systolic blood pressure (SBP) response to exercise has been shown to predict subsequent hypertension in small samples of men, this association has not been studied in a large population-based sample of middle-aged men and women. The purpose of this study was to examine, in normotensive subjects, the relations of SBP and diastolic blood pressure (DBP) during the exercise and recovery periods of a graded treadmill test to the risk of developing new-onset hypertension. METHODS AND RESULTS: BP data from exercise testing in 1026 men and 1284 women (mean age, 42+/-10 years; range, 20 to 69 years) from the Framingham Offspring Study who were normotensive at baseline were related to the incidence of hypertension 8 years later. New-onset hypertension, defined as an SBP >/=140 mm Hg or DBP >/=90 mm Hg or the initiation of antihypertensive drug treatment, occurred in 228 men (22%) and 207 women (16%). Exaggerated SBP (Ex-SBP 2) and DBP (Ex-DBP 2) response and delayed recovery of SBP (R-SBP 3) and DBP (R-DBP 3) were defined as an age-adjusted BP greater than the 95th percentile during the second stage of exercise and third minute of recovery, respectively. After multivariable adjustment, Ex-DBP 2 was highly predictive of incident hypertension in both men (OR, 4.16; 95% CI, 2.15, 8.05) and women (OR, 2.17; CI, 1.19, 3.96). R-SBP 3 was predictive of hypertension in men in a multivariable model that included exercise duration and peak exercise BP (OR, 1.92; CI, 1.00, 3.69). Baseline resting SBP (chi2, 23.4 in men and 34.7 in women) and DBP (chi2, 11.3 in men and 13.1 in women) had stronger associations with new-onset hypertension than exercise DBP (chi2, 16.4 in men and 6.1 in women) and recovery SBP (chi2, 6.5 in men and 2.1 in women) responses. CONCLUSIONS: An exaggerated DBP response to exercise was predictive of risk for new-onset hypertension in normotensive men and women. An elevated recovery SBP was predictive of hypertension in men. These findings may reflect subtle pathophysiological features in the preclinical stage of hypertension.

Adult↗

Prevalence and clinical determinants of mitral, tricuspid, and aortic regurgitation (the Framingham Heart Study)

Little information is available on the prevalence and determinants of valvular regurgitation in the general population. This study sought to assess the prevalence and clinical determinants of mitral (MR), tricuspid (TR), and aortic (AR) regurgitation in a population-based cohort. Color Doppler echocardiography was performed in 1,696 men and 1,893 women (aged 54 +/- 10 years) attending a routine examination at the Framingham Study. After excluding technically poor echocardiograms, MR, TR, and AR were qualitatively graded from trace to severe. Multiple logistic regression analysis was used to examine the association of clinical variables with MR and TR (more than or equal to mild severity) and AR (more than or equal to trace severity). MR and TR of more than or equal to mild severity was seen in 19.0% and 14.8% of men and 19.1% and 18.4% of women, respectively, and AR of more than or equal to trace severity in 13.0% of men and 8.5% of women. The clinical determinants of MR were age (odds ratio [OR] 1.3/9.9 years, 95% confidence interval [CI] 1.2 to 1.5), hypertension (OR 1.6; 95% CI 1.2 to 2.0), and body mass index (OR 0.8/4.3 kg/m2; 95% CI 0.7 to 0.9). The determinants of TR were age (OR 1.5/9.9 years; 95% CI 1.3 to 1.7), body mass index (OR 0.7/4.3 kg/m2; 95% CI 0.6 to 0.8), and female gender (OR 1.2; 95% CI 1.0 to 1.6). The determinants of AR were age (OR 2.3/9.9 years; 95% CI 2.0 to 2.7) and male gender (OR 1.6; 95% CI 1.2 to 2.1). A substantial proportion of healthy men and women had detectable valvular regurgitation by color Doppler echocardiography. These data provide population-based estimates for comparison with patients taking anorectic drugs.

Adult↗

Association of left ventricular dilatation and hypertrophy with chronotropic incompetence in the Framingham Heart Study.

BACKGROUND: Chronotropic incompetence and left ventricular (LV) dilatation have both been shown to be markers of an adverse cardiovascular prognosis. Chronotropic incompetence has been described in patients with symptomatic LV dilatation and dysfunction, but the effect of asymptomatic LV dilatation and hypertrophy on exercise heart rate response has not been well characterized. METHODS AND RESULTS: Members of the Framingham Offspring Study underwent M-mode echocardiography and graded exercise testing as part of a routine evaluation. Subjects receiving beta-blockers and digitalis and subjects with preexisting coronary heart disease, heart failure, and baseline ST-segment abnormalities were excluded. Chronotropic incompetence was assessed in 2 ways: (1) failure to achieve an age--predicted target heart rate and (2) a low chronotropic index, a measure of heart rate response that takes into account effects of age, resting heart rate, and physical fitness. Echocardiographic variables studied included LV diastolic and systolic dimensions, LV wall thickness, LV mass, and fractional shortening. There were 1414 men and 1601 women eligible for analyses; failure to reach target heart rate occurred in 20% of men and 23% of women; a low chronotropic index was noted in 14% of men and 12% of women. In unadjusted categorical analyses, an abnormally high LV mass, as defined by exceeding the 90th percentile predicted value of a healthy reference group, was associated with failure to achieve target heart rate in men (31% vs 18%, odds ratio [OR] 2.05, 95% confidence interval [CI] 1.49 to 2.83) and women (34% vs 20%, OR 2.09, 95% CI 1.63 to 2.69). Similarly, an abnormally high LV mass was predictive of a low chronotropic index in men (18% vs 13%, OR 1. 47, 95% CI 1.01 to 2.14) and women (17% vs 10%, OR 1.78, 95% CI 1.29 to 2.45). When considered as a continuous variable, LV diastolic dimension predicted failure to achieve target heart rate in men (ageadjusted OR for 1 SD increase 1.30, 95% CI 1.00 to 1.33) and in women (age-adjusted OR 1.30, 95% CI 1.12 to 1.50). Similarly, LV diastolic dimension predicted low chronotropic index in men (age-adjusted OR 1.22, 95% CI 1.05 to 1.42) and in women (age-adjusted OR 1.18, 95% CI 1.01 to 1.39). After also adjusting for resting blood pressure, physical activity, and other potential confounders, LV mass, when considered as a continuous variable, remained predictive of failure to achieve target heart rate in men (adjusted OR 1.23, 95% CI 1.06 to 1.42) and a low chronotropic index in men (adjusted OR 1.26, 95% CI 1.06 to 1.49). Among women, LV diastolic dimension predicted failure to achieve target heart rate (adjusted OR 1.27, 95% CI 1.12 to 1.45) and low chronotropic index (adjusted OR 1.18, 95% CI 1.01 to 1.39), whereas in men it predicted low chronotropic index (adjusted OR 1.22, 95% CI 1.04 to 1.42). CONCLUSIONS: In this asymptomatic, population-based cohort, chronotropic incompetence was predicted by increased LV mass and cavity size; among men, it was also predicted by depressed systolic function.

Adult↗