Reference Ranges and Regional Patterns of Left Ventricular Strain and Strain Rate Using Two-Dimensional Speckle-Tracking Echocardiography in a Healthy Middle-Aged Black and White Population: The CARDIA Study.

BACKGROUND: Strain and strain rate are sensitive markers of left ventricular (LV) myocardial function. The aim of this study was to assess reference ranges and regional patterns of LV strain and strain rate using two-dimensional speckle-tracking echocardiography in a large population of black and white subjects. METHODS: This study involved a retrospective review of prospectively collected images in 557 participants in the Coronary Artery Risk Development in Young Adults study who remained healthy at the year 25 examination. LV deformation parameters were measured in apical four-chamber, apical two-chamber, and parasternal short-axis views in 509, 391, and 521 subjects, respectively. RESULTS: Patients' mean age was 49.6 ± 3.6 years, 61.6% were women, and 69.5% were white. White women showed the highest LV systolic and diastolic deformation values, reflected by a more negative reference range for apical four-chamber longitudinal strain (-16.4%; 95% prediction interval [PI], -20.8% to -12.0%) and a higher positive reference range for early diastolic strain rate (0.93 1/sec; 95% PI, 0.41 to 1.46 1/sec), respectively. The lowest LV systolic and diastolic deformation values were found in black men, with apical four-chamber longitudinal strain (14.7%; 95% PI, -19.1% to -10.3%) and early diastolic strain rate (0.79 1/sec; 95% PI, 0.42 to 1.16 1/sec). Absolute strain increased from the epicardium toward the endocardium. A base-to-apex gradient of longitudinal strain toward the apex was exhibited in inferior and inferoseptal regions and, in contrast, in the opposite direction in anterior and anterolateral walls. Sex had the strongest influence on LV deformation variability. CONCLUSIONS: Strain and strain rate reference values were sex and race related. White women showed the highest reference ranges for LV deformation, while the lowest values were found in black men. Significant layer- and level-specific patterns in regional LV deformation were identified.

Air Pollution, Cardiovascular Outcomes, and Social Disadvantage: The Multi-ethnic Study of Atherosclerosis.

BACKGROUND: Social factors may enhance health effects of air pollution, yet empirical support is inconsistent. The interaction of social and environmental factors may only be evident with long-term exposures and outcomes that reflect long-term disease development. METHODS: We used cardiac magnetic resonance imaging data from the Multi-Ethnic Study of Atherosclerosis to assess left-ventricular mass index (LVMI) and left-ventricular ejection fraction (LVEF). We assigned residential concentrations of fine particulate matter (PM2.5), oxides of nitrogen, and nitrogen dioxide in the year 2000 to each participant in 2000 using prediction models. We examined modifying roles of four measures of adversity: race/ethnicity, racial/ethnic residential segregation, and socioeconomic status and psychosocial adversity as composite indices on the association between air pollution and LVMI or LVEF. RESULTS: Compared with whites, blacks showed a stronger adjusted association between air pollution and LVMI. For example, for each 5 µg/m greater PM2.5 level, whites showed a 1.0 g/m greater LVMI (95% confidence interval = -1.3, 3.1), while blacks showed an additional 4.0 g/m greater LVMI (95% confidence interval = 0.3, 8.2). Results were similar for oxides of nitrogen and nitrogen dioxide with regard to black race and LVMI. However, we found no evidence of a modifying role of other social factors or ethnic groups. Furthermore, we found no evidence of a modifying role for any social factors or racial/ethnic groups on the association between air pollution and LVEF. CONCLUSIONS: Our results suggest that racial group membership may modify the association between air pollution and cardiovascular disease.

Metabolic syndrome, strain, and reduced myocardial function: multi-ethnic study of atherosclerosis.

BACKGROUND: Subclinical cardiovascular disease is prevalent in patients with Metabolic Syndrome (MetSyn). Left ventricular (LV) circumferential strain (εCC) and longitudinal strain (εLL), assessed by Speckle Tracking Echocardiography (STE), are indices of systolic function: shortening is indicated by negative strain, and thus, the more negative the strain, the better the LV systolic function. They have been used to demonstrate subclinical ventricular dysfunction in several clinical disorders. OBJECTIVE: We hypothesized that MetSyn is associated with impaired myocardial function, as assessed by STE. METHODS: We analyzed Multi-Ethnic Study of Atherosclerosis (MESA) participants who underwent STE and were evaluated for all MetSyn components. RESULTS: Among the 133 participants included [women: 63%; age: 65 ± 9 years (mean ± SD)], the prevalence of MetSyn was 31% (41/133). Individuals with MetSyn had lower εCC and lower εLL than those without MetSyn (-16.3% ± 3.5% vs. -18.4% ± 3.7%, p < 0.01; and -12.1% ± 2.5% vs. -13.9% ± 2.3%, p < 0.01, respectively). The LV ejection fraction (LVEF) was similar in both groups (p = 0.09). In multivariate analysis, MetSyn was associated with less circumferential myocardial shortening as indicated by less negative εCC (B = 2.1%, 95%CI:0.6 3.5, p < 0.01) even after adjusting for age, ethnicity, LV mass, and LVEF). Likewise, presence of MetSyn (B = 1.3%, 95%CI:0.3 2.2, p < 0.01) and LV mass (B = 0.02%, 95% CI: 0.01-0.03, p = 0.02) were significantly associated with less longitudinal myocardial shortening as indicated by less negative εLL after adjustment for ethnicity, LVEF, and creatinine. CONCLUSION: Left ventricular εCC and εLL, markers of subclinical cardiovascular disease, are impaired in asymptomatic individuals with MetSyn and no history of myocardial infarction, heart failure, and/or LVEF < 50%.

Síndrome Metabólica, Strain e Redução da Função Miocárdica: Multi-Ethnic Study of Atherosclerosis / Metabolic Syndrome, Strain, and Reduced Myocardial Function: Multi-Ethnic Study of Atherosclerosis

Fundamento: A doença cardiovascular subclínica é prevalente em pacientes com síndrome metabólica (SM). O strain circunferencial (εCC) e o strain longitudinal (εLL) do ventriculo esquerdo (VE), avaliados pelo ecocardiograma com speckle tracking (STE), são índices de função sistólica: o encurtamento das fibras circunferenciais e longitudinais do VE é indicado por um valor negativo do strain. Portanto, quanto mais negativo o strain, melhor a função sistólica do VE. O εCC e o εLL têm sido usados para demonstrar disfunção ventricular subclínica em vários distúrbios clínicos. Objetivo: Levantamos a hipótese de que a SM está associada com comprometimento da função miocárdica, quando avaliada pelo STE. Métodos: Este estudo analisou participantes do Multi-Ethnic Study of Atherosclerosis (MESA) que realizaram o STE e foram avaliados para todos os componentes da SM. Resultados: Entre os 133 participantes incluídos (mulheres: 63%; idade: 65 ± 9 anos), a prevalência de SM foi de 31% (41/133). Indivíduos com SM apresentaram valores menores do εCC e do εLL que aqueles sem SM (-16,3% ± 3,5% vs. -18,4% ± 3,7%, p < 0,01; e -12,1% ± 2,5% vs. -13,9% ± 2,3%, p < 0,01, respectivamente). A fração de ejeção do VE (FEVE) foi semelhante nos dois grupos (p = 0,09). Na análise multivariada, a SM associou-se a um valor mais baixo do strain circunferencial (B = 2,1%, IC 95%: 0,6-3,5; p < 0,01), mesmo após ajuste para idade, etnia, massa VE e FEVE. De maneira semelhante, a presença de SM (B = 1,3%, IC 95%: 0,3-2,2; p < 0,01) e a massa do VE (B = 0,02%, IC 95%: 0,01 0,03; p = 0,02) associaram-se a um valor menor do strain longitudinal após ajuste para etnia, FEVE e creatinina. Conclusão: O εCC ...

Background: Subclinical cardiovascular disease is prevalent in patients with Metabolic Syndrome (MetSyn). Left ventricular (LV) circumferential strain (εCC) and longitudinal strain (εLL), assessed by Speckle Tracking Echocardiography (STE), are indices of systolic function: shortening is indicated by negative strain, and thus, the more negative the strain, the better the LV systolic function. They have been used to demonstrate subclinical ventricular dysfunction in several clinical disorders. Objective: We hypothesized that MetSyn is associated with impaired myocardial function, as assessed by STE. Methods: We analyzed Multi-Ethnic Study of Atherosclerosis (MESA) participants who underwent STE and were evaluated for all MetSyn components. Results: Among the 133 participants included [women: 63%; age: 65 ± 9 years (mean ± SD)], the prevalence of MetSyn was 31% (41/133). Individuals with MetSyn had lower εCC and lower εLL than those without MetSyn (-16.3% ± 3.5% vs. -18.4% ± 3.7%, p < 0.01; and -12.1% ± 2.5% vs. -13.9% ± 2.3%, p < 0.01, respectively). The LV ejection fraction (LVEF) was similar in both groups (p = 0.09). In multivariate analysis, MetSyn was associated with less circumferential myocardial shortening as indicated by less negative εCC (B = 2.1%, 95%CI:0.6 3.5, p < 0.01) even after adjusting for age, ethnicity, LV mass, and LVEF). Likewise, presence of MetSyn (B = 1.3%, 95%CI:0.3 2.2, p < 0.01) and LV mass (B = 0.02%, 95% CI: 0.01-0.03, p = 0.02) were significantly associated with less longitudinal myocardial shortening as indicated by less negative εLL after adjustment for ethnicity, LVEF, and creatinine. Conclusion: Left ventricular εCC and εLL, markers of subclinical cardiovascular disease, are impaired in asymptomatic individuals with MetSyn and no history of myocardial infarction, heart failure, and/or LVEF < 50%. .

Thiamine deficiency and cardiac dysfunction in Cambodian infants.

OBJECTIVES: To compare blood thiamine concentrations, echocardiography findings, and plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in infants with clinically diagnosed beriberi and healthy matched controls, and to evaluate changes after thiamine treatment. STUDY DESIGN: Sixty-two Cambodian infants (20 cases and 42 controls), aged 2-47 weeks, were enrolled in this prospective study. Echocardiography and phlebotomy were performed at baseline and after thiamine treatment. RESULTS: Both cases and controls were thiamine-deficient, with median blood thiamine diphosphate (TDP) concentrations of 47.6 and 55.1 nmol/L, respectively (P = .23). All subjects had normal left ventricular ejection fraction. The median NT-proBNP concentration in cases (340 pg/mL [40.1 pmol/L]) was higher than previously reported normal ranges, but not statistically significantly different from that in controls (175 pg/mL [20.7 pmol/L]) (P = .10), and was not correlated with TDP concentration (P = .13). Two cases with the lowest baseline TDP concentrations (24 and 21 nmol/L) had right ventricular enlargement and elevated NT-proBNP levels that improved dramatically by 48 hours after thiamine administration. CONCLUSION: Only a minority of thiamine-deficient Cambodian infants demonstrate abnormal echocardiography findings. Thiamine deficiency produces echocardiographic evidence of right ventricular dysfunction, but this evidence is not apparent until deficiency is severe. NT-proBNP concentrations are mildly elevated in sick infants with normal echocardiography findings, indicating possible physiological changes not yet associated with echocardiographic abnormalities.

Left-ventricular function and autonomic cardiac adaptations after short-term inpatient cardiac rehabilitation: a prospective clinical trial.

OBJECTIVE: Cardiac rehabilitation is associated with cardiac autonomic and physiological benefits. However, it is unclear whether baseline left ventricular function (LVF) impacts on training-induced cardiac autonomic adaptations. The aim of this study was to assess the cardiac autonomic adaptations in patients with varying left ventricular function profiles undergoing coronary artery bypass grafting and cardiac rehabilitation. DESIGN: Assessor-blinded prospective trial. PATIENTS: Forty-four patients undergoing coronary artery bypass grafting, divided into normal LVFN (≥ 55%, n = 23) or reduced LVFR (35-54%, n = 21) were evaluated. METHOD: Cardiac autonomic function was evaluated by heart rate variability indexes obtained both pre- and post-cardiac rehabilitation. All patients participated in a short-term (approximately 5 days) supervised inpatient physiotherapy program. RESULTS: There were differences in heart rate variability indexes, correlation dimension and SD2 according to time and group (e.g. interaction time (effect of cardiac rehabilitation) vs group (LVFN vs LVFR), p = 0.04). Simple main effects analysis showed that the LVFR group benefited to a greater degree from cardiac rehabilitation compared with the LVFN group. Heart rate variability indexes increased significantly in the former group compared with the latter. CONCLUSION: Among post-coronary artery bypass grafting patients engaged in short-term inpatient rehabilitation, those with reduced left ventricular function are most likely to have better cardiac autonomic adaptations to exercise-based rehabilitation.

Comparison of Afro-Caribbean patients presenting in heart failure with normal versus poor left ventricular systolic function.

Data suggest that heart failure (HF) in Afro-Caribbean patients may be more often associated with preserved left ventricular (LV) systolic function, LV hypertrophy, and probable LV diastolic dysfunction than in other populations. Echocardiographic results on all patients referred for HF in a contemporary Afro-Caribbean population were reviewed, comparing findings in patients with and without preserved LV systolic function with. Echocardiographic findings included left atrial dimension, LV systolic and diastolic dimensions, ventricular septal and posterior wall thicknesses, right ventricular dimension, valve abnormality, or pericardial effusion. LV shortening fraction and ejection fraction were calculated. Age, gender, and presence of atrial fibrillation were recorded. Results from patients with preserved LV systolic function (LV shortening fraction >0.27) were compared with those with poor LV systolic function. There were 505 patients with HF with adequate studies; mean age +/- SD was 64 +/- 15 years, 46% were men, 17% had atrial fibrillation, and 285 of 505 (57%) had preserved LV systolic function. Those with preserved LV systolic function were no different in age (64 +/- 15 vs 64 +/- 14 years, p = 0.98) but were less likely to be men (40% vs 54%, p <0.01). They were less likely to have a dilated left atrium (61% vs 81%, p <0.001) or increased LV diastolic dimension (8% vs 63%, p <0.001). They were more likely to have increased ventricular septal or posterior wall hypertrophy (84% vs 66%, p <0.001) or other abnormal findings, including an abnormal valve, right ventricular enlargement, increased septal to posterior wall thickness ratio, or pericardial effusion (25% vs 6%, p <0.001). The presence of atrial fibrillation was no different (14% vs 20%, p = 0.10). In conclusion, most Afro-Caribbean patients with HF have preserved LV systolic function with high rates of LV hypertrophy, septal hypertrophy, and other echocardiographic abnormalities.