Gender differences in diastolic function among youth

Impact of Sex and Obesity on Echocardiographic Parameters in Children and Adolescents

Subclinical alterations in left ventricular structure and function are detectable in adolescents with hypertension or obesity. However, data on early echocardiographic abnormalities in seemingly healthy children are lacking. Sex differences in cardiac structure and function have been previously reported, but sex-specific reference values are not available. Specifically, the potential interaction of sex and overweight has not been addressed at all. Anthropometric data, blood pressure and exercise tests were obtained in 356 healthy children. Echocardiographic parameters comprised peak early (E) and late (A) mitral inflow Doppler velocities, E/A ratio, tissue Doppler peak velocities of early (e') and late diastolic (a') excursion of mitral/septal annulus and isovolumetric relaxation time (IVRT). Left ventricular mass index (LVMI) and LVMI z-score were calculated. Interaction terms between BMI and sex and stratification by sex were used for analysis. We provide values for echocardiographic parameters for children of two age groups separated by BMI. Overweight/obese children had a significant higher LVMI, lower E/A ratio, higher E/e' ratios and a longer IVRT. For a given BMI in the upper ranges we demonstrated a higher LVMI in girls than in boys, the IVRT extended significantly more in girls than in boys with increasing BMI. There are sex differences in structural and functional echocardiographic parameters in children and adolescents. Our data not only confirms the importance of overweight and obesity, but demonstrates important interactions between sex and overweight. The greater susceptibility of overweight girls toward echocardiographic changes associated with potential long-term functional impairment needs further exploration and follow-up.Trial registration number DRKS00012371; Date 18.08.2017.

From pediatrics to geriatrics: Mechanisms of heart failure across the life-course

Heart failure (HF) is a significant public health problem and a disease with high 5-year mortality. Although age is the primary risk factor for development of HF, it is a disease which impacts patients of all ages. Historically, HF has been studied as a one-size fits all strategy- with the majority of both clinical and basic science investigations employing adult male subjects or adult male pre-clinical animal models. We postulate that inclusion of biological variables in HF studies is necessary to improve our understanding of mechanisms of HF and improve outcomes. In this review, we will discuss age-specific differences in HF patients, particularly focusing on the pediatric and geriatric age groups. In addition, we will also discuss the biological variable of sex. Characterizing and understanding the mechanistic differences in these distinct HF populations can provide insights that will benefit and personalize therapeutic interventions. Further, we propose that future investigations into the cellular mechanisms involved in the developing and juvenile heart may provide valuable insights for targets that would be beneficial in aging patients.

Abnormal Central Pulsatile Hemodynamics in Adolescents With Obesity: Higher Aortic Forward Pressure Wave Amplitude Is Independently Associated With Greater Left Ventricular Mass

We hypothesized that increased aortic forward pressure wave amplitude (Pf), which is determined by characteristic impedance (Zc) in the proximal aorta, is the primary hemodynamic determinant of obesity-associated higher left ventricular (LV) mass in adolescents. Aortic pulsatile hemodynamics were measured noninvasively in 60 healthy adolescents (age 14-19 years; 42% male; 50% black) by sequential recordings of pulse waveforms via tonometry, brachial blood pressure, and pulsed Doppler and diameter of the LV outflow tract using 2-dimensional echocardiography. Adolescents who were overweight/obese (n=23; age 16.0±0.3 years; body mass index ≥85th percentile) had higher LV mass index, brachial and carotid systolic blood pressure and pulse pressure, normalized Zc and Pf compared with adolescents with healthy weight (n=37; 16.7±0.3 years; body mass index <85th percentile, all P<0.01). In contrast, there was no difference in mean or diastolic blood pressure, carotid-femoral pulse wave velocity, carotid augmentation index, or aortic backward wave amplitude (all P>0.05). Stepwise multiple linear regression analysis that included age, sex, race, normalized Zc, and brachial systolic blood pressure revealed that body mass index (B±SE; 0.49±0.20, P=0.02, R2=0.26), aortic Pf (0.22±0.07; P<0.02, R2 change=0.11), and cardiac output (2.82±1.02, P<0.01; R2 change=0.08) were significant correlates of LV mass index (total R2=0.44, P<0.01). These findings suggest that higher aortic Pf is a major hemodynamic determinant of increased LV mass in adolescents with elevated adiposity. Improper matching between aortic diameter and pulsatile flow during early systole potentially contributes to the early development of LV hypertrophy in childhood obesity.

Brain natriuretic hormone predicts stress-induced alterations in diastolic function

BACKGROUND

Mental stress (MS) reduces diastolic function (DF) and may lead to congestive heart failure with preserved systolic function. Whether brain natriuretic hormone (brain natriuretic peptide [BNP]) mediates the relationship of MS with DF is unknown.

METHODS

One hundred sixty individuals aged 30 to 50 years underwent 2-hour protocol of 40-minute rest, videogame stressor and recovery. Hemodynamics, pro-BNP samples and DF indices were obtained throughout the protocol. Separate regression analyses were conducted using rest and stress E/A, E' and E/E' as dependent variables. Predictor variables were entered into the stepwise regression models in a hierarchical fashion. At the first level, age, sex, race, height, body mass index, pro-BNP and left ventricular mass (LVM) were permitted to enter the models. The second level consisted of systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR). The final level contained cross-product terms of race by SBP, DBP and HR.

RESULTS

E/A ratio was lower during stress compared to rest and recovery (P < 0.01). Resting E/A ratio was predicted by a regression model of age (-0.31), pro-BNP (0.16), HR (-0.40) and DBP (-0.23) with an R² = 0.33. Stress E/A ratio was predicted by age (-0.24), pro-BNP (0.08), HR (-0.38) and SBP (-0.21) with total R² = 0.22. Resting E' model consisted of age (-0.22), pro-BNP (0.26), DBP (-0.27) and LVM (-0.15) with an R² = 0.29. Stress E' was predicted by age (-0.18), pro-BNP (0.35) and LVM (-0.18) with an R² = 0.18. Resting E/E' was predicted by race (0.17, B > W) and DBP (0.24) with an R² = 0.10. Stress E/E' consisted of pro-BNP (-0.36), height (-0.26) and HR (-0.21) with an R² = 0.15.

CONCLUSIONS

pro-BNP predicts both resting and stress DF, suggesting that lower BNP during MS may be a marker of diastolic dysfunction in apparently healthy individuals.

Early diastolic functional abnormalities in normotensive offspring of Nigerian hypertensives

Background

Some studies have suggested that diastolic dysfunction precedes the clinical manifestation of hypertension. Whether changes in cardiac structure and function predate the clinical manifestation of hypertension later in life is now being investigated. The aim of this study was to assess the differences in cardiac structure and function between the offspring of hypertensive and normotensive parents.

Methods

Eighty normotensive offspring of hypertensive parents (OHyp) (41 females and 39 males) and 62 normotensive offspring of normotensive parents (ONorm) (31 males and 31 females) were recruited for echocardiography.

Results

The mean age was 25.0 (5.31) and 24.3 (3.60) years in the OHyp and ONorm participants, respectively (p = 0.369). Other baseline parameters were comparable between the two groups. Septal wall thickness in systole was higher in the OHyp than the ONorm subjects [1.3 (0.35) vs 1.1 (0.25), p = 0.0173]. Indexed left ventricular mass [28.1 (7.33) vs 27.5 (7.23), p = 0.631] and relative wall thickness [(0.3 (0.10) vs 0.3 (0.90), p = 0.280] were similar in the two groups. The offspring of hypertensives had lower deceleration time [149.9 (38.89) vs 169.0 (50.08) ms, p = 0.012], prolonged duration of pulmonary A reverse flow [113.5 (70.69) vs 81.7 (38.31) ms, p = 0.024], increased myocardial isovolumic relaxation time [173.4 (47.98) vs 156.1 (46.74) ms, p = 0.033] and a lower myocardial Em [0.2 (0.05) vs 0.3 (1.38), p = 0.037] and myocardial Em/Am ratio [1.6 (0.01) vs 2.1 (0.01), p = 0.019] than the offspring of normotensives.

Conclusion

This study showed that offspring of OHyp subjects had early diastolic functional abnormalities when compared with offspring of ONorm participants. Longitudinal studies are needed to determine the implications of this finding in this African population.

Impact of gender on left ventricle function in postmenopausal women and age-matched men: analysis of echocardiographic parameters in healthy participants and patients with coronary artery disease

OBJECTIVE

Our aim was to evaluate the impact of gender on the diastolic function of the left ventricle in healthy men and women and in patients with coronary artery disease (CAD) without systolic impairment.

METHODS

We examined 67 healthy participants (34 men with a mean age of 51 +/- 13 y and ejection fraction [EF] of 62% +/- 3% and 33 women with a mean age of 53 +/- 11 y and EF of 63% +/- 3%; P = NS) and 60 patients with CAD (36 men with a mean age of 57 +/- 10 y and EF of 59% +/- 3% and 24 women with a mean age of 59 +/- 10 y and EF of 60% +/- 3%), paired with regard to age, heart rate, and medical treatment by transthoracic echocardiography with the assessment of mitral and pulmonary vein flow parameters, propagation of mitral filling waves, and tissue Doppler variables of mitral annulus motion (MAM). The impact of gender was assessed separately for the healthy participants and the CAD group.

RESULTS

In healthy participants, the velocity of mitral inflow early wave and the systolic velocity of the pulmonary vein flow were significantly higher in women than in men: 77 +/- 18 versus 65 +/- 19 cm/second (P < 0.05) and 64 +/- 14 versus 57 +/- 11 cm/second (P < 0.05), respectively. On the other hand, velocities of MAM in the atrial and systolic phases were higher in men than in women: 13 +/- 2 versus 12 +/- 2 cm/second and 11 +/- 2 versus 10 +/- 2 cm/second, respectively (P < 0.05). The opposite tendency was observed in the CAD group: the ratio of early mitral inflow velocity to atrial mitral inflow velocity was significantly higher in male patients (1.1 +/- 0.5 vs 0.8 +/- 0.2; P = 0.007) and there was a trend toward faster early wave propagation in men (40 +/- 9 vs 36 +/- 8 cm/s; P = 0.08).

CONCLUSIONS

Our data suggest more efficient early diastolic filling in postmenopausal women than in age-matched men in healthy participants but an opposite relationship in patients with CAD.