Left Ventricular False Tendons are Associated With Left Ventricular Dilation and Impaired Systolic and Diastolic Function.

BACKGROUND: Left ventricular false tendons (LVFTs) are chord-like structures that traverse the LV cavity and are generally considered to be benign. However, they have been associated with arrhythmias, LV hypertrophy and LV dilation in some small studies. We hypothesize that LVFTs are associated with LV structural and functional changes assessed by echocardiography. METHODS: We retrospectively evaluated echocardiographic and clinical parameters of 126 patients identified as having LVFTs within the past 2 years and compared them to 85 age-matched controls without LVFTs. RESULTS: There were no significant differences in age (52 ± 18 versus 54 ± 18 years, P = 0.37), sex (55% versus 59% men, P = 0.49), race (36% versus 23% white, P = 0.07), systolic blood pressure (131 ± 22 versus 132 ± 23mmHg, P = 0.76) or body mass index (BMI, 31 ± 8 versus 29 ± 10kg/m2, P = 0.07) between controls and patients with LVFTs, respectively. Patients with LVFTs had more prevalent heart failure (43% versus 21%, P = 0.001). Patients with LVFTs had more LV dilation, were 2.5 times more likely to have moderate-to-severe mitral regurgitation, had more severe diastolic dysfunction and reduced LV systolic function (18% lower) compared with controls (all P < 0.05). After adjustment for covariates, basal and middle LVFT locations were associated with reduced LV systolic function (P < 0.01), and middle LVFTs were associated with LV dilation (P < 0.01). CONCLUSIONS: Our findings suggest that LVFTs may not be benign variants, and basal and middle LVFTs may have more deleterious effects. Further prospective studies should be performed to determine their pathophysiological significance and whether they play a causal role in LV dysfunction.

Pulmonary Hypertension Is Associated With a Higher Risk of Heart Failure Hospitalization and Mortality in Patients With Chronic Kidney Disease: The Jackson Heart Study.

BACKGROUND: African Americans develop chronic kidney disease and pulmonary hypertension (PH) at disproportionately high rates. Little is known whether PH heightens the risk of heart failure (HF) admission or mortality among chronic kidney disease patients, including patients with non-end-stage renal disease. METHODS AND RESULTS: We analyzed African Americans participants with chronic kidney disease (estimated glomerular filtration rate <60 mL/min per 1.73 m2 or urine albumin/creatinine >30 mg/g) and available echocardiogram-derived pulmonary artery systolic pressure (PASP) from the Jackson Heart Study (N=408). We used Cox models to assess whether PH (PASP>35 mm Hg) was associated with higher rates of HF hospitalization and mortality. In a secondary, cross-sectional analysis, we examined the relationship between cystatin C (a marker of renal function) and PASP and potential mediators, including BNP (B-type natriuretic peptide) and endothelin-1. In our cohort, the mean age was 63±13 years, 70% were female, 78% had hypertension, and 22% had PH. Eighty-five percent of the participants had an estimated glomerular filtration rate >30 mL/min per 1.73 m2. During follow-up, 13% were hospitalized for HF and 27% died. After adjusting for potential confounders, including BNP, PH was found to be associated with HF hospitalization (hazard ratio, 2.37; 95% confidence interval, 1.15-4.86) and the combined outcome of HF hospitalization or mortality (hazard ratio, 1.84; confidence interval, 1.09-3.10). Log cystatin C was directly associated with PASP (adjusted ß =2.5 [95% confidence interval, 0.8-4.1] per standard deviation change in cystatin C). Mediation analysis showed that BNP and endothelin-1 explained 56% and 40%, respectively, of the indirect effects between cystatin C and PASP. CONCLUSIONS: Among African Americans with chronic kidney disease, PH, which is likely pulmonary venous hypertension, was associated with a higher risk of HF admission and mortality.

Increased Left Ventricular Diastolic Stiffness Is Associated With Heart Failure Symptoms in Aortic Stenosis Patients With Preserved Ejection Fraction.

BACKGROUND: Clinical risk factors associated with heart failure (HF) symptoms in aortic stenosis (AS) patients with preserved ejection fraction (EF) have not been fully identified. We hypothesized that left ventricular (LV) diastolic stiffness is associated with HF symptoms in patients with AS. METHODS AND RESULTS: We retrospectively evaluated 275 patients with at least moderate AS (aortic valve area <1.5 cm2) and preserved EF (≥50%). LV diastolic stiffness was evaluated with the use of echocardiographic parameters, diastolic wall strain (DWS, a measure of LV wall stiffness), and KLV (a marker of LV chamber stiffness). There were 69 patients with HF. Patients with HF were older, were more likely to be African American, had a higher body mass index, and had more hypertension and coronary artery disease (P < .05 for all). Aortic valve area index and mean pressure gradient across the aortic valve were not different between patients with and without HF. Despite similar echocardiographic parameters of AS severity, patients with HF had stiffer LV (DWS 0.21 ± 0.06 vs 0.25 ± 0.06 [P < .01], KLV 0.17 ± 0.11 vs 0.13 ± 0.08 [P < .01]). Logistic regression analyses revealed that after adjusting for age, race, body mass index, history of hypertension, and coronary artery disease, LV diastolic stiffness parameters remained significantly associated with HF symptoms. CONCLUSIONS: LV diastolic stiffness is independently associated with HF in AS patients with preserved EF.

Incidence of primary hypertension in a population-based cohort of HIV-infected compared with non-HIV-infected persons and the effect of combined antiretroviral therapy.

Literature remains scarce on the impact of antiretroviral medications on hypertension in the HIV population. We used the South Carolina Medicaid database linked with the enhanced HIV/AIDS system surveillance database for 1994-2011 to evaluate incident hypertension and the impact of combination antiretroviral therapy (cART) in HIV/AIDS population compared with a propensity- matched non-HIV control group. Multivariable, time-dependent survival analysis suggested no significant difference in incidence of hypertension between the HIV group and the non-HIV control group. However, subgroup analysis suggested that among the HIV-infected group, months of exposure to both non-nucleoside reverse transcriptase inhibitors (adjusted hazard ratio, 1.52; 95% confidence interval, 1.3-1.75) and protease inhibitors (adjusted hazard ratio, 1.26; 95% confidence interval, 1.11-1.44) were associated with an increased risk of incident hypertension after adjusting for traditional demographic and metabolic risk factors. In people with HIV/AIDS, prolonged exposure to both protease inhibitor-based and non-nucleoside reverse transcriptase inhibitor-based cART may increase the risk of incident hypertension.

Clinical correlates and prognostic significance of change in standardized left ventricular mass in a community-based cohort of African Americans.

BACKGROUND: Though left ventricular mass (LVM) predicts cardiovascular events (CVD) and mortality in African Americans, limited data exists on factors contributing to change in LVM and its prognostic significance. We hypothesized that baseline blood pressure (BP) and body mass index (BMI) and change in these variables over time are associated with longitudinal increases in LVM and that such increase is associated with greater incidence of CVD. METHODS AND RESULTS: We investigated the clinical correlates of change in standardized logarithmically transformed-LVM indexed to height2.7 (log-LVMI) and its association with incident CVD in 606 African Americans (mean age 58±6 years, 66% women) who attended serial examinations 8 years apart. Log-LVMI and clinical covariates were standardized within sex to obtain z scores for both visits. Standardized log-LVMI was modeled using linear regression (correlates of change in standardized log-LVMI) and Cox proportional hazards regression (incidence of CVD [defined as coronary heart disease, stroke, heart failure and intermittent claudication]). Baseline clinical correlates (standardized log-LVM, BMI, systolic BP) and change in systolic BP over time were significantly associated with 8-year change in standardized log-LVMI. In prospective analysis, change in standardized LVM was significantly (P=0.0011) associated with incident CVD (hazards ratio per unit standard deviation change log-LVMI 1.51, 95% CI 1.18 to 1.93). CONCLUSIONS: In our community-based sample of African Americans, baseline BMI and BP, and change in BP on follow-up were key determinants of increase in standardized log-LVMI, which in turn carried an adverse prognosis, underscoring the need for greater control of BP and weight in this group.

The predictive value of left atrial size for incident ischemic stroke and all-cause mortality in African Americans: the Atherosclerosis Risk in Communities (ARIC) Study.

BACKGROUND AND PURPOSE: The association between left atrial (LA) size, ischemic stroke, and death has not been well established in African Americans despite their disproportionately higher rates of stroke and cardiovascular mortality compared to non-Hispanic whites. METHODS: For the analysis, participants in the Jackson cohort of the Atherosclerosis Risk in Communities Study were followed from the date of the echocardiogram in cycle three to the date of the first ischemic stroke event (or death) or to December 31, 2004 if no ischemic stroke event (or death) was detected. RESULTS: There were 1886 participants in the study population (mean age 58.9 years, 65% women). Participants in the top quintile of LA diameter indexed to height (LA diameter/height; 2.57 to 3.55 cm/m) were more likely women, hypertensive, diabetic, and obese compared to those not in the top quintile. Over a median follow-up of 9.8 years for ischemic stroke and 9.9 years for all-cause mortality, there were 106 strokes and 242 deaths. In a multivariable model adjusting for traditional clinical risk factors, the top quintile of LA diameter/height was significantly related to ischemic stroke (HR 1.7; 95% CI: 1.1, 2.7) and all-cause mortality (HR 2.0; 95% CI: 1.5, 2.7). After further adjustment for left ventricular (LV) hypertrophy and low LV ejection fraction, the top quintile remained significantly related to all-cause mortality (HR 1.8; 95% CI: 1.3, 2.5). CONCLUSIONS: In this population-based cohort of African Americans, LA size was a predictor of all-cause mortality after adjusting for traditional cardiovascular risk factors, LV hypertrophy, and low LV ejection fraction.

Retinal arteriolar narrowing and left ventricular hypertrophy in African Americans. the Atherosclerosis Risk in Communities (ARIC) study.

BACKGROUND: Whether microvascular disease contributes to the development of left ventricular hypertrophy (LVH) is unclear. We examined the relationship of retinal microvascular signs with LVH in an African-American population. METHODS: A population-based, cross-sectional study of 1,439 middle-aged African-American participants in Jackson, Mississippi. A retinal photograph of one randomly selected eye was obtained and graded for presence of retinal microvascular signs (focal arteriolar narrowing, arterio-venous (AV) nicking, and retinopathy) according to standardized protocols. Retinal vessel diameter was measured from a computer-assisted technique to define generalized arteriolar narrowing. LVH was defined from standardized echocardiography. RESULTS: In age and gender-adjusted models, retinal microvascular signs (except non-diabetic retinopathy) were significantly associated with LVH, with an odds ratio (OR) of 1.64 (95% confidence interval (CI) 1.29-2.09) for generalized arteriolar narrowing, OR 1.82 (95% CI 1.33-2.50) for focal arteriolar narrowing, and OR 1.35 (95% CI 1.02-1.79) for AV nicking. With further adjustment for cardiovascular (serum total cholesterol, fasting glucose, diabetes, diabetes duration, smoking, body mass index (BMI), waist-to-hip ratio, and exercise level) and hypertension-related factors (mean arterial blood pressure (MABP) at the time of retinal photography and antihypertensive medication use), associations were attenuated but remained significant for generalized and focal arteriolar narrowing, with OR 1.35 (95% CI 1.02-1.78) and OR 1.66 (95% CI 1.16-2.38), respectively. CONCLUSIONS: Middle-aged African Americans with generalized and focal retinal arteriolar narrowing were more likely to have LVH. This association was explained only partly by cardiovascular risk factors and hypertension.

Epidemiology of pure valvular regurgitation in the large middle-aged African American cohort of the Atherosclerosis Risk in Communities study.

BACKGROUND: There are limited data on the prevalence and the clinical and echocardiographic correlates of pure valvular regurgitation in African Americans despite the higher rates of cardiovascular disease in this group. PURPOSE: The Jackson, Mississippi, site of the Atherosclerosis Risk in Communities study provides a unique opportunity to study mitral regurgitation (MR), tricuspid regurgitation (TR), and aortic regurgitation (AR) in this population. METHODS: There were 2285 participants who were available for analysis. The prevalence rates of MR, TR, and AR by severity were calculated for participants aged 50 to 59, 60 to 69, and > or = 70 years. Multivariable regression analyses were conducted to determine clinical and echo variables associated with the presence of MR, TR, and AR. RESULTS: Mild or greater MR and TR were present in 14.7% and 17.2% of participants, respectively. Aortic regurgitation was present in 15.6% of participants. In the multivariable regression model, MR was independently associated with age, sex, lower body mass index (BMI), systolic blood pressure, left atrial size, left ventricular (LV) diastolic diameter, and low LV ejection fraction. Tricuspid regurgitation was independently associated with age, sex, lower BMI, high-density lipid, left atrial size, and lower relative wall thickness. Aortic regurgitation was independently associated with age, sex, lower BMI, systolic blood pressure, LV diastolic diameter, LV hypertrophy, and low LV ejection fraction. CONCLUSION: In this middle-aged African Americans cohort, the prevalence of mild to greater MR and TR was similar to that seen in other cohorts; however, AR was more prevalent. Several cardiovascular risk factors and echo parameters were identified as independent correlates of valvular regurgitation.

Echocardiographic left ventricular mass index predicts incident stroke in African Americans: Atherosclerosis Risk in Communities (ARIC) Study.

BACKGROUND AND PURPOSE: Despite theories that link stroke to left ventricular mass, few large, population-based studies have examined the predictive value of echocardiographically derived left ventricular mass index (LVMI) to incident stroke in African Americans. METHODS: Participants in the Jackson cohort of the Atherosclerotic Risk in Communities study have had extensive baseline evaluations, have undergone echocardiography during the third examination (1993-1995), and have been followed up for incident cardiovascular disease including ischemic stroke. RESULTS: The study population consisted of 1792 participants, of whom 639 (35.7%) were men and the mean+/-SD age was 58.8+/-5.7 years. Compared with those without ischemic stroke, those with ischemic stroke had a higher frequency of hypertension (85.6% vs 58.7%) and diabetes (46.9% vs 21.0%). Left ventricular hypertrophy was more prevalent in those with stroke (62.2% vs 38.6%). During a median follow-up of 8.8 years, 98 incident strokes occurred (6.5 per 1000 person-years). LVMI was independently associated with stroke after adjusting for age, sex, hypertension, systolic blood pressure, smoking, diabetes, total to HDL cholesterol ratio, body mass index, and low left ventricular ejection fraction (adjusted hazard ratio per 10 g/m(2.7) increment of LVMI=1.15; 95% CI, 1.02 to 1.28). The relation remained statistically significant after adding left atrial size and mitral annular calcification to the multivariable model. CONCLUSIONS: In this large, population-based African American cohort, we found that echocardiographic LVMI was an independent predictor of incident ischemic stroke even after taking into account traditional clinical risk factors.

Left ventricular architecture and survival in African-Americans free of coronary heart disease (from the Atherosclerosis Risk in Communities [ARIC] study).

Published studies of the prognostic value of left ventricular (LV) hypertrophy and LV geometric pattern in African-Americans were based on referred or hospitalized patients with hypertension or coronary heart disease. All-cause mortality rates and survival associated with LV geometric pattern were determined using echocardiography in a population-based sample of middle-aged and elderly African-American men and women. During the third (1993 to 1995) visit of the ARIC Study, echocardiography was performed at the Jackson, Mississippi, field center on the cohort of 2,445 African-Americans aged 49 to 75 years. M-Mode LV echocardiographic measurements were available for 1,722 persons. Mortality data were available through December 31, 2003. During the follow-up period (median 8.8 years, maximum 10.4), 160 deaths were identified. In men, multivariable-adjusted hazard ratios for all-cause mortality (compared with men with normal LV geometry) were 1.75 (95% confidence interval [CI] 0.71 to 4.33) in those with concentric LV hypertrophy, 0.38 (95% CI 0.08 to 1.88) in those with eccentric LV hypertrophy, and 0.79 (95% CI 0.41 to 1.54) in those with concentric remodeling. In women, multivariable-adjusted hazard ratios for all-cause mortality (compared with women with normal LV geometry) were 1.17 (95% CI 0.48 to 2.84) in those with concentric LV hypertrophy, 1.23 (95% CI 0.46 to 3.28) in those with eccentric LV hypertrophy, and 1.17 (95% CI 0.60 to 2.28) in those with concentric remodeling. In conclusion, in this population-based cohort of middle-aged and elderly African-Americans free of coronary heart disease, adjustment for baseline differences in cardiovascular disease risk factors and LV mass greatly attenuated the strength of the association between LV pattern and all-cause mortality risk in women. In men, an association between concentric LV hypertrophy and mortality risk remained.

Influence of fructose-1,6-diphosphate on endotoxin-induced lung injuries in sheep.

BACKGROUND: Fructose-1,6-diphosphate (FDP) is reported to have a salutary effect in endotoxin shock and sepsis. This investigation describes the effect of FDP on pulmonary and systemic hemodynamics, lung lymph protein clearance, and leukocyte count in sheep infused with Escherichia coli endotoxin. MATERIALS AND METHODS: Anesthetized sheep (n = 18), some of which underwent thoracotomy to cannulate lymphatic nodes, were used in this study. After stabilization, all sheep received E. coli endotoxin, 5 microg/kg i.v. infusion over 30 min. Concomitant with the endotoxin infusion, half of the animals were randomly selected to receive an i.v. bolus of FDP (10%), 50 mg/kg, followed by a continuous infusion of 5 mg.kg(-1).min(-1) for 4 h; the rest were treated in the same manner with glucose (10%) in 0.9% NaCl. RESULTS: Pulmonary artery pressure (PAP) and resistance in the glucose group increased from 20.8 +/- 1.6 to 36.7 +/- 3.2 mmHg (P < 0.007) and from 531 +/- 114 to 1137 +/- 80 dyn.s(-1).cm(-5), respectively (P < 0.005). Despite an increase during endotoxin infusion, these parameters in the FDP group returned to control values. There were no differences in left ventricular pressures, cardiac output, heart rate, and arterial oxygen tension between the groups. In the glucose group, lymph protein clearance was higher (P < 0.01) and blood leukocyte count was lower (P < 0.02). The wet/dry lung weight ratio (g/g) for the glucose group was 5.57 +/- 0.04 and for the FDP-treated group 4.76 +/- 0.06 (P < 0.0005). CONCLUSION: FDP treatment attenuated significantly the characteristic pulmonary hypertension, lung lymph protein clearance, and pulmonary vascular leakage seen in sheep infused with endotoxin.

Diabetes, gender, and left ventricular structure in African-Americans: the atherosclerosis risk in communities study.

BACKGROUND: Cardiovascular risk associated with diabetes may be partially attributed to left ventricular structural abnormalities. However, the relations between left ventricular structure and diabetes have not been extensively studied in African-Americans. METHODS: We studied 514 male and 965 female African-Americans 51 to 70 years old, in whom echocardiographic left ventricular mass measurements were collected for the ARIC Study. In these, we investigated the independent association of diabetes with left ventricular structural abnormalities. RESULTS: Diabetes, hypertension and obesity prevalences were 22%, 57% and 45%, respectively. Unindexed left ventricular mass was higher with diabetes in both men (238.3 +/- 79.4 g vs. 213.7 +/- 58.6 g; p < 0.001) and women (206.4 +/- 61.5 g vs. 176.9 +/- 50.1 g; p < 0.001), respectively. Prevalence of height-indexed left ventricular hypertrophy was higher in women while increased relative wall thickness was similar in men and women. Those with diabetes had higher prevalences of height-indexed left ventricular hypertrophy (52% vs. 32%; p < 0.001), and of increased relative wall thickness (73% vs. 64%; p = 0.002). Gender-adjusted associations of diabetes with left ventricular hypertrophy (OR = 2.29 95% CI:1.79-2.94) were attenuated after multiple adjustments in logistic regression (OR = 1.50 95% CI:1.12-2.00). Diabetes was associated with higher left ventricle diameter (OR = 2.13 95% CI:1.28-3.53) only in men and with higher wall thickness (OR = 1.89 95% CI:1.34-2.66) only in women. Attenuations in diabetes associations were frequently seen after adjustment for obesity indices. CONCLUSION: In African-Americans, diabetes is associated with left ventricular hypertrophy and, with different patterns of left ventricular structural abnormalities between genders. Attenuation seen in adjusted associations suggests that the higher frequency of structural abnormalities seen in diabetes may be due to factors other than hyperglycemia.

Lymphocytic myocarditis presenting as nausea, vomiting, and hepatic dysfunction in the first trimester of pregnancy.

BACKGROUND: Lymphocytic myocarditis, an immune disorder of left ventricular dysfunction with sometimes confounding clinical presentations, occurs rarely during pregnancy. CASE: At 12 weeks gestation, a multigravid patient presented with a 2-month history of nausea and vomiting. Other symptomatology included postprandial epigastric pain, loose stools, and a 10-lb (4.5-kg) weight loss. Laboratory evaluation revealed evidence of hepatic dysfunction with a coagulopathy and an absolute unconjugated hyperbilirubinemia. While undergoing evaluation, the patient deteriorated rapidly and suffered a cardiopulmonary arrest. Autopsy revealed a congested liver and spleen associated with a dilated cardiomyopathy and lymphocytic myocarditis. CONCLUSION: Medically virulent disease processes can mimic the common pregnancy complaint of nausea and vomiting. Intrinsic cardiac disease with secondary hepatic compromise is a rare cause of gastrointestinal symptomatology early in pregnancy.

The prognostic value of the mitral diastolic filling velocity ratio for all-cause mortality and cardiovascular morbidity in African Americans: the Atherosclerotic Risks in Communities (ARIC) study.

BACKGROUND: Although recent data suggest that the mitral diastolic early-to-late (E/A) ratio may be prognostic in selected population-based cohorts, its predictive value for morbidity and mortality in African Americans has not yet been well studied. METHODS: The study population consisted of African American participants from the Jackson cohort of the Atherosclerotic Risks in Community Study. Three subgroups of E/A ratios were defined: E/A <0.7, E/A 0.7-1.5, and E/A >1.5, using the middle group as reference. Cox proportional hazard models were used to assess the association between the E/A ratio and both all-cause mortality and incident cardiovascular disease (CVD). The mean follow-up period was 6.8 +/- 1.3 years. RESULTS: Of the 2211 participants in the study population (mean age 62 years, 65.1% women), 8.2% had an E/A ratio <0.7, 84.7% had an E/A 0.7-1.5, and 7.1% had an E/A >1.5. An E/A >1.5 was independently associated with all-cause mortality (hazard ratio [HR] 2.18, 95% confidence interval [CI] 1.20-4.03) in the multivariable model. An E/A <0.7 was associated with higher all-cause mortality (HR 1.79, 95% CI 1.17-2.73) and incident CVD (HR 1.91, 95% CI 1.29-2.83) compared with a normal E/A in the age and sex adjusted model but was not independently predictive in the multivariable model (P > .05). CONCLUSIONS: In a population-based cohort of middle-aged African Americans, an E/A >1.5 independently predicts all-cause mortality. An E/A >1.5 and an E/A <0.7 were both associated with incident CVD when adjusted for age and sex alone but were not independently predictive in the multivariable analysis.

Burden of valvular heart diseases: a population-based study.

BACKGROUND: Valvular heart diseases are not usually regarded as a major public-health problem. Our aim was to assess their prevalence and effect on overall survival in the general population. METHODS: We pooled population-based studies to obtain data for 11 911 randomly selected adults from the general population who had been assessed prospectively with echocardiography. We also analysed data from a community study of 16 501 adults who had been assessed by clinically indicated echocardiography. FINDINGS: In the general population group, moderate or severe valve disease was identified in 615 adults. There was no difference in the frequency of such diseases between men and women (p=0.90). Prevalence increased with age, from 0.7% (95% CI 0.5-1.0) in 18-44 year olds to 13.3% (11.7-15.0) in the 75 years and older group (p<0.0001). The national prevalence of valve disease, corrected for age and sex distribution from the US 2000 population, is 2.5% (2.2-2.7). In the community group, valve disease was diagnosed in 1505 (1.8% adjusted) adults and frequency increased considerably with age, from 0.3% (0.2-0.3) of the 18-44 year olds to 11.7% (11.0-12.5) of those aged 75 years and older, but was diagnosed less often in women than in men (odds ratio 0.90, 0.81-1.01; p=0.07). The adjusted mortality risk ratio associated with valve disease was 1.36 (1.15-1.62; p=0.0005) in the population and 1.75 (1.61-1.90; p<0.0001) in the community. INTERPRETATION: Moderate or severe valvular diseases are notably common in this population and increase with age. In the community, women are less often diagnosed than are men, which could indicate an important imbalance in view of the associated lower survival. Valve diseases thus represent an important public-health problem.

Osborn (J) wave appearance on the electrocardiogram in relation to potassium transfer and myocardial metabolism during hypothermia.

The genesis of the J wave during hypothermia has been attributed to injury current, delayed ventricular depolarization and early repolarization, tissue anoxia, and acidosis. To our knowledge, no studies have addressed the appearance of the J wave in relation to the myocardial K+ transfer and metabolism during hypothermia. Dogs (n = 9) were progressively cooled, blood samples were taken from the aorta and coronary sinus, and myocardial tissue samples were obtained for adenosine triphosphate (ATP), creatine phosphate (CP), and glycolytic intermediate determination. In every instance, the appearance of the J wave was preceded by a net loss of K+ from the myocardium. In one dog, there was no myocardial K+ loss and the J wave was absent. The J wave appeared when the esophageal temperature was between 27 degrees and 24 degrees C (26.6 +/- 0.73 degrees C). At that temperature, the animals were hypotensive and bradycardic, but arterial oxygen partial pressure, carbon dioxide partial pressure, and pH were within the physiologic range at that temperature. The myocardial ATP and CP from the hypothermic dogs was lower compared with the value obtained from dogs at 37 degrees C (p < .025 and p < .005, respectively). The levels of the glycolytic intermediates, fructose-1,6-diphosphate, dihydroxyacetone phosphate, and pyruvate, were lower and the level of lactate was higher compared with those from the normothermic dogs (not significant; p < .007, p < .02, p < .001, respectively). These findings suggest that the appearance of the J wave on electrocardiography during cooling is a result of depression of the metabolic process concerned with maintenance of the partition of ions across the cell membrane, as evidenced by decreased myocardial energy content and K+ loss during the hypothermic state.

Metabolic syndrome and echocardiographic left ventricular mass in blacks: the Atherosclerosis Risk in Communities (ARIC) Study.

BACKGROUND: The metabolic syndrome has been associated with cardiovascular disease, but few studies have examined its relationship with subclinical measures such as echocardiographic left ventricular (LV) mass. This relationship is likely to be of particular importance in blacks, in whom both the metabolic syndrome and LV hypertrophy are common. METHODS AND RESULTS: Echocardiography, performed at 1 of 4 sites in the Atherosclerosis Risk in Communities (ARIC) Study, was used to assess LV dimensions in 1572 black women and men aged 49 to 75 years in 1993-1996. Participants were categorized by number of metabolic syndrome characteristics (hypertension, dyslipidemia [low HDL cholesterol or high triglycerides], and glucose intolerance). Age-adjusted mean LV mass indexed by height (g/m) increased in a stepwise gradient with increasing number of metabolic syndrome disorders (none, any 1, any 2, all 3) in both women and men (125.1, 143.9, 153.7, 169.3 and 130.5, 148.7, 160.8, 170.2, respectively; P<0.001, tests for trend). Associations were diminished slightly by adjustment for smoking, alcohol intake, and education; additional adjustment for waist circumference resulted in some attenuation, but associations remained statistically significant. Analyses focusing on components of LV mass revealed that posterior wall and interventricular septal thickness, but not LV chamber size, were significantly and independently associated in general with the number of metabolic syndrome disorders. Consistent with these findings, relative wall thickness was also associated with number of disorders. Associations were similar across age and central adiposity. Hypertension had a strong influence on LV mass with additional contributions from dyslipidemia and glucose intolerance; strong synergistic effects of the syndrome beyond its individual components were not observed. CONCLUSIONS: In this cross-sectional population-based study of black women and men, the degree of metabolic syndrome clustering was strongly related to LV mass and its wall thickness components. These associations are consistent with a possible influence of underlying factors such as insulin resistance or other vascular processes on myocardial thickening and not on chamber size.

Left ventricular mass indexed to height and prevalent MRI cerebrovascular disease in an African American cohort: the Atherosclerotic Risk in Communities study.

BACKGROUND AND PURPOSE: Previous studies have demonstrated that echocardiographic left ventricular mass (LVM) is an independent risk factor for stroke in whites. Despite the greater burden of stroke, the echocardiographic predictors of stroke in African Americans remain poorly understood. METHODS: This investigation is a retrospective analysis of prospectively collected data from the Jackson, Miss (all African American), cohort of the Atherosclerotic Risk in the Communities study. Between 1993 and 1995, 2445 participants received an echocardiogram, and a random subset (n=778) received cerebral MRI evaluating presence of infarcts or white matter disease (WMD; >3 on a scale of 0 to 9). Compared with the entire Jackson cohort, the random subset was older, had a lower body mass index (BMI), and a higher systolic blood pressure (SBP). Logistic regression models examined the relations of LVM indexed by height (LVM/height) to MRI findings adjusted for age, gender, BMI, SBP, hypertensive medications, diabetes, total/high-density lipoprotein cholesterol, smoking status, and history of myocardial infarction. RESULTS: The 667 participants (63% women; 62+/-4 years of age) had a high prevalence of hypertension (68%), obesity (46%), echocardiographic left ventricular hypertrophy (49%), MRI stroke (n=133), and WMD (n=92). Adjusted LVM/height was significantly associated with prevalent MRI stroke (odds ratio [OR], 1.3; 95% CI, 1.1 to 1.7; P=0.02) and WMD (OR, 1.5; 95% CI, 1.1 to 1.9; P=0.006; OR expressed per 1 SD LVM/height, 45 g/m). CONCLUSIONS: In this randomized subset of a population-based cohort of African American adults, LVM/height was related to MRI evidence of prevalent cerebrovascular disease. The current study supports the hypothesis that LVM/height is an important risk factor for stroke in multiple ethnicities.