Toward a New Strategic Public Health Science for Policy, Practice, Impact, and Health Equity.

The COVID-19 pandemic and its social and health impact have underscored the need for a new strategic science agenda for public health. To optimize public health impact, high-quality strategic science addresses scientific gaps that inform policy and guide practice. At least 6 scientific gaps emerge from the US experience with COVID-19: health equity science, data science and modernization, communication science, policy analysis and translation, scientific collaboration, and climate science. Addressing these areas within a strategic public health science agenda will accelerate achievement of public health goals. Public health leadership and scientists have an unprecedented opportunity to use strategic science to guide a new era of improved and equitable public health.

Strain echocardiography to describe left ventricular function pre- and postexercise in elite basketball athletes: A feasibility study.

BACKGROUND: Elite athletes show structural cardiac changes as an adaptation to exercise. Studies examining strain in athletes have largely analyzed images at rest only. There is little data available regarding the change in strain with exercise. Our objectives were: to investigate the feasibility of strain analysis in athletes at peak exercise, to determine the normal range of left ventricular (LV) global longitudinal strain (GLS) within this population postexercise, to describe how LV GLS changes with exercise, and to determine whether any clinical characteristics correlate with the change in GLS that occurs with exercise. METHODS: We conducted a cross-sectional study on elite athletes who participated in the 2016-2018 National Basketball Association Draft Combines. Echocardiograms were obtained at rest and after completing a treadmill stress test to maximal exertion or completion of Bruce protocol. Primary outcomes included GLS obtained at rest and peak exercise. Secondary outcome was the change in GLS between rest and exercise. Univariate relationships between various clinical characteristics and our secondary outcome were analyzed. RESULTS: Our final cohort (n = 111) was all male and 92/111 (82.9%) were African American. Mean GLS magnitude increased in response to exercise (-17.6 ± 1.8 vs -19.2 ± 2.6, P < .0001). Lower resting heart rates (r = .22, P = .02) and lower heart rates at peak exercise (r = .21, P = .03) correlated with the increase in LV GLS from exercise. CONCLUSIONS: Strain imaging is technically feasible to obtain among elite basketball athletes at peak exercise. Normative strain response to exercise from this study may help identify abnormal responses to exercise in athletes.

Role of t-tubule remodeling on mechanisms of abnormal calcium release during heart failure development in canine ventricle.

The goal of this work was to investigate the role of t-tubule (TT) remodeling in abnormal Ca2+ cycling in ventricular myocytes of failing dog hearts. Heart failure (HF) was induced using rapid right ventricular pacing. Extensive changes in echocardiographic parameters, including left and right ventricular dilation and systolic dysfunction, diastolic dysfunction, elevated left ventricular filling pressures, and abnormal cardiac mechanics, indicated that severe HF developed. TT loss was extensive when measured as the density of total cell volume, derived from three-dimensional confocal image analysis, and significantly increased the distances in the cell interior to closest cell membrane. Changes in Ca2+ transients indicated increases in heterogeneity of Ca2+ release along the cell length. When critical properties of Ca2+ release variability were plotted as a function of TT organization, there was a complex, nonlinear relationship between impaired calcium release and decreasing TT organization below a certain threshold of TT organization leading to increased sensitivity in Ca2+ release below a TT density threshold of 1.5%. The loss of TTs was also associated with a greater incidence of triggered Ca2+ waves during rapid pacing. Finally, virtually all of these observations were replicated by acute detubulation by formamide treatment, indicating an important role of TT remodeling in impaired Ca2+ cycling. We conclude that TT remodeling itself is a major contributor to abnormal Ca2+ cycling in HF, reducing myocardial performance. The loss of TTs is also responsible for a greater incidence of triggered Ca2+ waves that may play a role in ventricular arrhythmias arising in HF.NEW & NOTEWORTHY Three-dimensional analysis of t-tubule density showed t-tubule disruption throughout the whole myocyte in failing dog ventricle. A double-linear relationship between Ca2+ release and t-tubule density displays a steeper slope at t-tubule densities below a threshold value (∼1.5%) above which there is little effect on Ca2+ release (T-tubule reserve). T-tubule loss increases incidence of triggered Ca2+ waves. Chemically induced t-tubule disruption suggests that t-tubule loss alone is a critical component of abnormal Ca2+ cycling in heart failure.

Left atrial size and strain in elite athletes: A cross-sectional study at the NBA Draft Combine.

INTRODUCTION: Atrial dilatation is common but of unclear physiologic significance in high-performance athletes. Myocardial deformation analysis utilizing speckle-tracking echocardiography has emerged as a promising tool to evaluate atrial function. In a cohort of elite basketball players attending the National Basketball Association (NBA) Draft Combine, we investigate changes in left atrial (LA) size as well as function as measured by strain. METHODS AND RESULTS: From 2013 to 2018, all male athletes who attended the NBA Draft Combine in Chicago, IL, received a cardiac evaluation including a comprehensive transthoracic echocardiogram. Using the P-wave as the reference point, speckle-tracking was utilized to measure LA booster, conduit, and reservoir strain over one cardiac cycle. Left atrial volume index (LAVI) of ≥34 mL/m2 was considered enlarged. 307 athletes received cardiac evaluation including a transthoracic echocardiogram, with 272 studies amenable for atrial strain analysis. Mean age was 21.0 years. Mean LAVI was 34.5 mL/m2 and LAVI was enlarged in 131 (48.2%) athletes. Comparing LA strain in those with enlarged vs normal sized atria, reservoir strain was significantly reduced (32.1% [SD 6.0%] vs 35.2% [SD 8.2%], P < .001), as was conduit strain (22.9% [SD 5.2%] vs 25.7% [SD 7.4%], P < .001), with no difference seen in booster strain (9.2% [SD 2.1%] vs 9.4% [SD 2.7%], P = .45). CONCLUSION: In this group of elite basketball players, LA enlargement was common and associated with reduced LA reservoir and conduit strain, with no difference in LA booster strain.