Exercise physiology of the left atrium: quantity and timing of contribution to cardiac output.

Although the phases of left atrial (LA) function at rest have been studied, the physiological response of the LA to exercise is undefined. This study defines the exercise behavior of the normal left atrium by quantitating its volumetric response to graded effort. Healthy subjects (n = 131) were enrolled from the Health eHeart cohort. Echocardiograms were obtained at baseline and during ramped supine bicycle exercise. Left ventricular volume index, stroke volume index (LVSVI), left atrial end-systolic volume index (LAESVI), left atrial end-diastolic volume index (LAEDVI), and left atrial emptying fraction (LAEF), reservoir fraction, and conduit fraction were analyzed. The LVSVI increased with low exercise but did not increase further with peak exercise; cardiac output increased through the agency of heart rate. The LAESVI and LAEDVI decreased and the LAEF increased with exercise. As a result, the LA reservoir volume index was static throughout exercise. The reservoir fraction decreased from 46% at rest to 40% with low exercise (P < 0.001) in association with increased LVSVI and remained similar at peak exercise. The conduit volume index increased from 20 mL/m2 at rest to 24 mL/m2 at low exercise and stayed the same at peak exercise. Similarly, the conduit fraction increased from 54% at rest to 60% at low exercise (P < 0.001) and did not change further with peak exercise. Although atrial function increased with exercise, the major contribution to the augmentation of LV stroke volume is LA conduit fraction, a marker of active ventricular relaxation. Furthermore, the major determinant of raising cardiac output during high-level exercise is heart rate.NEW & NOTEWORTHY Diseases of the left atrium (LA) are major sources of disability (e.g., strokes and fatigue), but its exercise physiology has been unstudied. Such knowledge may allow early recognition of disease and suggest therapies. We show that in normal subjects, low-level exercise decreases LA volume and increases its ejection fraction. However, these changes offset each other volumetrically, and the contribution to LV filling from a full to an empty LA (reservoir function) is static. Higher levels of exercise do not change LA reservoir contribution. Blood flowing directly from the pulmonary vein to LV (conduit flow) impelled by augmented LV active relaxation (suction) is the major source of a modest increase in LV stroke volume. The major source of increased cardiac output with exercise is heart rate. During all stages of exercise, the LA works hard but only to keep up. We believe that our findings provide an additional set of benchmarks through which to quantitate LA pathology and gauge its progression.

Left atrial mass: relationship between gross anatomy and quantitative echocardiography.

BACKGROUND: Left atrial (LA) enlargement is associated with increased risk of adverse cardiovascular outcomes. Unlike the left ventricular mass, LA mass has not been described. We sought to define the anatomic mass of the LA using anatomic specimens from autopsy. We hypothesized that LA mass could be estimated by echocardiography. METHODS AND RESULTS: Using anatomic specimens of 22 subjects who died and underwent post mortem examination as well as echocardiogram, we defined normal LA mass by weighing anatomic specimens of those with normal LA volume on echocardiogram. Using 17 subjects with normal LA volume on echocardiogram, we found their LA mass on anatomic specimens to be 25.5 ± 6.3 grams (14.4 ± 3.2 g/m2). We developed an echocardiographic measure of LA mass and validated this measurement with paired LA anatomic specimens. We found the normal LA mass on echocardiogram to be 25.4 ± 6.3 g (14.4 ± 2.8 g/m2) which correlated well with anatomic specimens (ß = 0.99; Confidence interval CI 0.6-1.4, P < .0001; Pearson correlation coefficient r = 0.83). Furthermore, we defined the normal LA volume to mass ratio as 1.38 ± 0.45. CONCLUSIONS: LA mass is an additional parameter with which may contribute to the study of LA morphology.

Comparison of Dietary Patterns, Perceptions of Health, and Perceived Barriers to a Heart Healthy Diet Before and After Coronary Artery Angiography.

Poor dietary patterns are associated with coronary artery disease (CAD) and cardiovascular events. The aim of this study was to determine whether reported dietary patterns change after undergoing invasive coronary angiography. Participants without a history of coronary revascularization were prospectively enrolled before undergoing coronary angiography at a tertiary center between February 2015 and February 2017. Enrolled participants completed the Rate Your Plate (RYP) survey at baseline (before angiography), 1-month, and 6-month follow-ups. RYP scores range from 24 to 72 (higher scores indicate healthier dietary patterns) are presented as median (interquartile range), and are compared from baseline to follow-up using a nonparametric related-sample test. No dietary guidance was given outside of usual care. Of the 400 participants, 326 (82%) completed at least 1 follow-up survey with no differences in baseline characteristics of participants who had at least 1 versus no follow-up survey. The median RYP score significantly improved from baseline (53 [47 to 57]) to 1-month (58 [52 to 62]) and 6-month (59 [54 to 63]) follow-ups (p <0.001). Angiography demonstrated severe CAD in 125 (38%) and normal or nonobstructive CAD in 201 (62%) participants. RYP scores significantly improved over time in both groups (p <0.001), but the percent change in RYP score over time was greater in participants with versus without severe CAD (13.9% [5.8 to 22.5] vs 9.6% [4.8 to 19.1], p = 0.03). In conclusion, self-reported dietary patterns improved after invasive coronary angiography, particularly in the subset with CAD. Future studies to determine how best to utilize the periprocedural period to further improve dietary patterns in this population are warranted.

Electrophysiological and Contractile Effects of Disopyramide in Patients With Obstructive Hypertrophic Cardiomyopathy: A Translational Study.

Disopyramide is effective and safe in patients with obstructive hypertrophic cardiomyopathy. However, its cellular and molecular mechanisms of action are unknown. We tested disopyramide in cardiomyocytes from the septum of surgical myectomy patients: disopyramide inhibits multiple ion channels, leading to lower Ca transients and force, and shortens action potentials, thus reducing cellular arrhythmias. The electrophysiological profile of disopyramide explains the efficient reduction of outflow gradients but also the limited prolongation of the QT interval and the absence of arrhythmic side effects observed in 39 disopyramide-treated patients. In conclusion, our results support the idea that disopyramide is safe for outpatient use in obstructive patients.

Association between diet quality and measures of body adiposity using the Rate Your Plate survey in patients presenting for coronary angiography.

BACKGROUND: Diet is a modifiable risk factor for cardiovascular disease; however, dietary patterns are historically difficult to capture in the clinical setting. Healthcare providers need assessment tools that can quickly summarize dietary patterns. Research should evaluate the effectiveness of these tools, such as Rate Your Plate (RYP), in the clinical setting. HYPOTHESIS: RYP diet quality scores are associated with measures of body adiposity in patients referred for coronary angiography. METHODS: Patients without a history of coronary revascularization (n = 400) were prospectively approached at a tertiary medical center in New York City prior to coronary angiography. Height, weight, and waist circumference (WC) were measured; body mass index (BMI) and waist-to-height ratio (WHtR) were calculated. Participants completed a 24-question RYP diet survey. An overall score was computed, and participants were divided into high (≥58) and low (≤57) diet quality groups. RESULTS: Participants in the high diet quality group (n = 98) had significantly lower measures of body adiposity than did those in the low diet quality group (n = 302): BMI (P < 0.001), WC (P = 0.001), WHtR (P = 0.001). There were small but significant inverse correlations between diet score and BMI, WC, and WHtR (P < 0.001). These associations remained significant after adjustment for demographics, tobacco use, and socioeconomic factors. CONCLUSIONS: Higher diet quality scores are associated with lower measures of body adiposity. RYP is a potential instrument to capture diet quality in a high-volume clinical setting. Further research should evaluate the utility of RYP in cardiovascular risk-factor control.

The recent national lipid association recommendations: how do they compare to other established dyslipidemia guidelines?

The National Lipid Association (NLA) recently released recommendations for the treatment of dyslipidemias. These recommendations have commonalities and differences with those of other major societies with respect to risk assessment, lifestyle therapy, targets of therapy, and the use of non-statin agents. In this review, we compare the basic elements of the guidelines from each major society to provide clinicians with a comprehensive document reviewing the key principles of each.

Cardiovascular disease knowledge and weight perception among Hispanic and non-Hispanic white women.

BACKGROUND: While knowledge of cardiovascular disease (CVD) has improved, it remains low among minority women, thereby contributing to disparities and posing health challenges. Moreover, substantial numbers of women do not recognize that excess weight imposes CVD risk and increases morbidity and decreases survival. In order to test the hypothesis that CVD knowledge is reduced among overweight and obese women, CVD knowledge and weight perception was compared among Hispanic and non-Hispanic white (NHW) women. METHODS: Data from 382 Hispanic and 301 NHW women, participants in the Heart Health in Action database (n=829), were analyzed from a structured behavioral risk factor surveillance system (BRFSS) questionnaire to assess demographics, risk factors, and CVD knowledge. Multivariable logistic regression analysis was utilized to test for differences between Hispanic and NHW women regarding knowledge with covariates of age, education, and body mass index (BMI). RESULTS: Hispanics (27%) were less likely than NHW (88%) to correctly identify the leading cause of death among women, (p<0.0001). Years living in the United States did not relate to the percentage of respondents who correctly identified the leading cause of death among women or knew the symptoms of a heart attack. Differences between Hispanic and NHW remained significant after adjustment for age, education, and BMI (p<0.0001). Hispanics (69.4%) were less likely than NHW (82.9 %) to correctly estimate weight (p<0.0001). Underestimation of weight was greater among Hispanics (24.8%) than NHW (5.0%); 48.5% of overweight Hispanic participants versus 12.7% of overweight NHW participants underestimated weight (p<0.0001) and 17.2% of obese Hispanic versus 0% of NHW obese participants (p=0.001) underestimated weight. The percentage underestimating the silhouette corresponding to their weight was related to years in the United States: 29.3% for<10 years, 38.3% with 10-19 years, and 49.3% with ≥20 years (p=0.01 for trend). CONCLUSIONS: Effective prevention strategies for at-risk populations need to target CVD knowledge and awareness among overweight and obese Hispanic women.

Gender differences in clinical outcomes among diabetic patients hospitalized for cardiovascular disease.

BACKGROUND: The risk of incident cardiovascular disease (CVD) has been shown to be greater among diabetic women than men, but gender differences in clinical outcomes among diabetic patients hospitalized with CVD are not established. We aimed to determine if hemoglobin A1c (HbA1c) was associated with 30-day and 1-year CVD rehospitalization and total mortality among diabetic patients hospitalized for CVD, overall and by gender. METHODS: This was a prospective analysis of diabetic patients hospitalized for CVD, enrolled in an National Heart, Lung and Blood Institute-sponsored observational clinical outcomes study (N = 902, 39% female, 53% racial/ethnic minority, mean age 67 ± 12 years). Laboratory, rehospitalization, and mortality data were determined by hospital-based electronic medical record. Poor glycemic control was defined as HbA1c ≥7%. The association between HbA1c and clinical outcomes was evaluated using logistic regression; gender modification was evaluated by interaction terms and stratified models. RESULTS: Hemoglobin A1c ≥7% prevalence was 63% (n = 566) and was similar by gender. Hemoglobin A1c ≥7% vs <7% was associated with increased 30-day CVD rehospitalization in univariate (odds ratio [OR] = 1.63, 95% CI 1.05-2.54) and multivariable-adjusted models (OR 1.74, 95% CI 1.06-2.84). There was an interaction between glycemic control and gender for 30-day CVD rehospitalization risk (P = .005). In stratified univariate models, the association was significant among women (OR 4.83, 95% CI 1.84-12.71) but not among men (OR 1.02, 95% CI 0.60-1.71). The multivariate-adjusted risk for HbA1c ≥7% versus <7% among women was 8.50 (95% CI 2.31-31.27) and 1.02 (95% CI 0.57-1.80) for men. A trend toward increased 30-day/1-year mortality risk was observed for HbA1c <6% vs ≥6% for men and women. CONCLUSIONS: Risk of 30-day CVD rehospitalization was 8.5-fold higher among diabetic women hospitalized for CVD with HbA1c ≥7% vs <7%; no association was observed among men. A trend for increased 30-day/1-year mortality risk with HbA1c <6% deserves further study.

Women at risk for cardiovascular disease lack knowledge of heart attack symptoms.

BACKGROUND: It is not known whether cardiovascular disease (CVD) risk level is related to knowledge of the leading cause of death of women or heart attack symptoms. HYPOTHESIS: Women with higher CVD risk estimated by Framingham Risk Score (FRS) or metabolic syndrome (MS) have lower CVD knowledge. METHODS: Women visiting primary care clinics completed a standardized behavioral risk questionnaire. Blood pressure, weight, height, waist size, fasting glucose, and lipid profile were assessed. Women were queried regarding CVD knowledge. RESULTS: Participants (N = 823) were Hispanic women (46%), non-Hispanic white (37%), and non-Hispanic black (8%). FRS was determined in 278: low (63%), moderate (29%), and high (8%); 24% had ≥3 components of MS. The leading cause of death was answered correctly by 54%, heart attack symptoms by 67%. Knowledge was lowest among racial/ethnic minorities and those with less education (both P< 0.001). Increasing FRS was inversely associated with knowing the leading cause of death (low 72%, moderate 68%, high 45%, P = 0.045). After multivariable adjustment, moderate/high FRS was inversely associated with knowing symptoms (moderate odds ratio [OR] 0.52, 95% confidence interval [CI]: 0.28-0.98; high OR 0.29, 95% CI: 0.11-0.81), but not the leading cause of death. MS was inversely associated with knowing the leading cause of death (P< 0.001) or heart attack symptoms (P = 0.018), but not after multivariable adjustment. CONCLUSIONS: Women with higher FRS were less likely to know heart attack symptoms. Efforts to target those at higher CVD risk must persist, or the most vulnerable may suffer disproportionately, not only because of risk factors but also inadequate knowledge.

Attention-deficit hyperactivity disorder reduces automatic attention in young adults.

Previous ERP studies have provided mixed information about ADHD, especially in adults and when conscious attention to stimuli is not required. We used the auditory N1 to assess automatic attention in adults with and without ADHD. While participants watched a silent video, trains of 5 tones (400-ms onset-to-onset time) were presented with intertrain intervals (ITIs) of 1 or 5 s. The P1, N1, P2, and N2 were analyzed. Compared to controls, participants with ADHD had relatively little N1 attenuation after the 5-s ITI, which was driven by uniformly small N1s to all tones. However, after the 1-s ITI, the ADHD group had relatively large N2s to all 5 tones in the train. The reduced N1 in adults with ADHD indicated reduced automatic attention to salient sound stimuli, which may be due to reduced function of brain-stem arousal mechanisms. However, the increased N2 in these participants suggests they had developed certain compensatory mechanisms.

The Sensory Gating Inventory as a potential diagnostic tool for attention-deficit hyperactivity disorder.

Diagnoses of attention-deficit hyperactivity disorder (ADHD) are often made rapidly in physicians' offices without thorough assessment. We examined whether adults diagnosed with ADHD would score differently from controls on a modified Sensory Gating Inventory (SGI: Hetrick et al. in Schizophr Bull 38:178-191, 2012; Kisley et al. in Psychophysiol 41:604-612, 2004), which would facilitate rapid and easy preliminary assessment of ADHD status. The modified SGI was administered to 22 controls and 22 adults with physician diagnoses of ADHD. Analysis was performed on the 17 SGI items and the three categories to which they belong (Perceptual Modulation, Distractibility, and Over-Inclusion). The Distractibility category, and its individual items, showed large group differences. In spite of a relatively small sample size, we found large effect sizes between those with and without ADHD diagnoses. The SGI is a simple, quick, paper/pencil method that may be used to facilitate accurate diagnosis of individuals experiencing ADHD symptoms, which may be especially useful when evaluations are made in settings such as physicians' offices.

Relationship between cardiovascular disease knowledge and race/ethnicity, education, and weight status.

BACKGROUND: Inadequate cardiovascular disease (CVD) knowledge has been cited to account for the imperfect decline in CVD among women over the last 2 decades. HYPOTHESIS: Due to concerns that at-risk women might not know the leading cause of death or symptoms of a heart attack, our goal was to assess the relationship between CVD knowledge race/ethnicity, education, and body mass index (BMI). METHODS: Using a structured questionnaire, CVD knowledge, socio-demographics, risk factors, and BMI were evaluated in 681 women. RESULTS: Participants included Hispanic, 42.1% (n = 287); non-Hispanic white (NHW), 40.2% (n = 274); non-Hispanic black (NHB), 7.3% (n = 50); and Asian/Pacific Islander (A/PI), 8.7% (n = 59). Average BMI was 26.3 ± 6.1 kg/m(2) . Hypertension was more frequent among overweight (45%) and obese (62%) than normal weight (24%) (P < 0.0001), elevated total cholesterol was more frequent among overweight (41%) and obese (44%) than normal weight (30%) (P < 0.05 and P < 0.01, respectively), and diabetes was more frequent among obese (25%) than normal weight (5%) (P < 0.0001). Knowledge of the leading cause of death and symptoms of a heart attack varied by race/ethnicity and education (P < 0.001) but not BMI. Concerning the leading cause of death among women in the United States, 87.6% (240/274) NHW answered correctly compared to 64% (32/50) NHB (P < 0.05), 28.3% (80/283) Hispanic (P < 0.0001), and 55.9% (33/59) A/PI (P < 0.001). Among participants with ≤12 years of education, 21.2% knew the leading cause of death and 49.3% knew heart attack symptoms vs 75.7% and 75.5%, respectively, for >12 years (both P < 0.0001). CONCLUSIONS: Effective prevention strategies for at-risk populations need to escalate CVD knowledge and awareness among the undereducated and minority women.