Sex Differences in Cardiac Flow Dynamics of Healthy Volunteers

Abstract

To further understand the relationship between cardiac function and flow, on the basis of sex, by quantifying cardiac flow characteristics and relating them to cardiac muscle performance in young adults. Materials and Methods:In this cross-sectional study, cardiac four-dimensional flow MRI and two-dimensional cine MRI were performed in 20 male and 19 female volunteers aged 20-35 years. Velocity-based metrics of flow, kinetic energy (KE), vorticity, and efficiency indexes were quantified, as well as cardiac strain metrics.Results: Peak systolic blood KE (men: 4.76 mJ ± 2.66 [standard deviation]; women: 3.36 mJ ± 1.43; P = .047) was significantly higher in the male left ventricle (LV) than in the female LV. Peak systolic vorticity index (men: 0.008 radian • m 2 /mL • sec ± 0.005; women: 0.014 radian • m 2 /mL • sec ± 0.007; P = .007), peak diastolic vorticity index (men: 0.007 radian • m 2 /mL • sec ± 0.006; women: 0.014 radian • m 2 /mL • sec ± 0.010; P = .015), and cycle-average vorticity (men: 0.006 radian/sec ± 0.001; women: 0.011 radian/sec ± 0.002; P = .001) were significantly higher in the LV of women than they were in the LV of men. Radial, circumferential, and long-axis strain metrics were significantly higher in the female LV than in the male LV (P < .05). Circumferential systolic and diastolic strain rates displayed moderate correlation to peak systolic (r = −0.38; P = .022) and diastolic vorticity (r = 0.40; P = .015) values, respectively. Results are reported as mean ± standard deviation. Conclusion:LV vorticity metrics were observed to be higher in women than in men and displayed moderate correlation to cardiac strain metrics. The methods and results of this study may be used to further understand the sex-based cardiac efficiency relationship between cardiac function and flow.

The Effects of Biological Sex on Sepsis Treatments in Animal Models: A Systematic Review and a Narrative Elaboration on Sex- and Gender-Dependent Differences in Sepsis

“…The neural-hemodynamic balance between cardiac output and peripheral resistance, mediated by the sympathetic nervous system, appears to have important sex-dependent differences with consequential effects for blood pressure regulation under healthy and diseased conditions ( 135 , 136 ). From a cardiac performance standpoint, healthy females appear to have higher myocardial perfusion ( 137 ), cardiac strain ( 138 ), cardiac flow dynamics ( 139 ), and more favorable LV twist mechanics following acute reductions in preload ( 140 ). These considerations may explain the differing hemodynamic responses encountered by healthy men and women following exposure to endotoxin.…”

Sex Matters: A Comprehensive Comparison of Female and Male Hearts

“…Male and female characteristics and sex differences are reported in percent, with the male heart as the baseline. Negative values in red indicate that the female parameter is smaller, positive values in yellow indicate that the female parameter is larger; arrows indicate reported statistically significant differences; quantitative data are represented as mean absolute value ± SD; [1] Zhu et al ( 2014 ); [2] Molina and DiMaio ( 2012 ); [3] Molina and DiMaio ( 2015 ); [4] Vasan et al ( 1997 ); [5] Kou et al ( 2014 ); [6] Rutkowski et al ( 2020 ); [7] Sandstede et al ( 2000 ); [8] Tandri et al ( 2006 ) [9] Maceira et al ( 2010 ); [10] Maceira et al ( 2013 ); [11] Ramaekers et al ( 1998 ); [12] Argiento et al ( 2012 ) .…”

Stent interventions for pulmonary artery stenosis improve bi-ventricular flow efficiency in a swine model

“…We cannot rule out the possibility that greater RVEF in the intervention group could be a result of differential response to anesthesia rather than a true difference in myocardial function. This study also used only male swine so we were unable to assess for any potentially important sex differences [ 40 ].…”

“…First, we calculated the percentage of energy dissipation directly due to vorticity as a novel metric of ventricular flow-structure interactions. Statistical correlations between flow parameters and ventricular kinematics [ 40 ] are useful but may only be associations and lack a direct physical basis. We propose a new metric by recognizing that viscous energy dissipation is due to two components, vorticity and surface strain rate [ 41 ].…”