Racial difference in receiving computed tomography for head injury patients in emergency departments.

Study Objective: Prior studies have suggested potential racial differences in receiving imaging tests in emergency departments (EDs), but the results remain inconclusive. In addition, most prior studies may only have limited racial groups for minority patients. This study aimed to investigate racial differences in head computed tomography (CT) administration rates in EDs among patients with head injuries.

Statistics at high-altitudes: Relevance for the interpretation of metrics that reveal cardiac morphology and performance.

Survey of four ratio-based metrics, commonly used to evaluate left ventricular performance. The numerator of each ratio is plotted against the corresponding denominator, implying that the slope of the colored line reflects the value of the ratio. Similar graphs can be constructed for the other cardiac compartments.

Ventricular Ejection Fraction and Global Strains in Connection with the Volume Regulation Graph.

Ejection fraction (EF) is traditionally considered useful to infer ventricular function. Newer metrics such as global function index (GFI) and various strains add supplemental diagnostic or prognostic value. All these candidates refer to dimensionless ratios, rather than to the characteristics of the underlying components.

Sex-specific Evaluation of Ventricular Ejection Fraction and End-Systolic Volume Applied to Cardiac Resynchronization Therapy.

Cardiac resynchronization therapy (CRT) can decrease the risk of heart failure (HF) events in relatively asymptomatic patients with a reduced ejection fraction (EF) and wide QRS complex. However, individual response to this type of therapy varies widely. Often based on either EF increase or end-systolic volume (ESV) decrease as criterion, a subgroup of super-responders has been described.

Pulse Pressure is Sex-Specifically Associated with the Ratio of Diastolic and Systolic Arterial Pressure in Healthy Children, and Differently During Night Versus Daytime Recordings.

Noninvasive blood pressure recordings typically focus on systolic blood pressure (SBP) and diastolic pressure (DBP). Derived metrics are often analyzed, e.g.

[A critical analysis of ejection fraction].

Ejection fraction (EF) is defined by the ratio of end-systolic volume (ESV) and end-diastolic volume (EDV). The resulting fraction is a dimensionless number whose interpretation is ambiguous and most likely misleading. Despite this limitation, EF is widely accepted as a clinical marker of cardiac function.

Various Approaches to Define the Volume Intercept of the Ventricular End-Systolic Pressure-Volume Relationship: Implications for Statistical Analysis.

Ventricular pump function is often characterized by the (non)linear end-systolic pressure-volume relationship (ESPVR). For each working point on that curve the tangent along with the intercept (Vo) reflect contractile state. Vo on the abscissa is an extrapolated point without physiological meaning, and may be negative.

The Ratio of Diastolic and Systolic Arterial Pressure is Associated with Pulse Pressure.

Pulse pressure (PP) is defined as the difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP). The metric PP is not unique, as numerous combinations of SBP and DBP yield the same value for PP. Therefore, we introduced the PP companion (PPC) which is calculated using the Pythagorean theorem.

Ventricular and Atrial Ejection Fractions are Associated with Mean Compartmental Cavity Volume in Cardiac Disease.

Ejection fraction (EF) is considered to provide clinically useful information. Despite its enormous popularity, with more than 75,000 citations in PubMed, only few studies have traced the origin(s) of its foundation. This fact is surprising, as there are perhaps more papers published that criticize EF, than the number of publications that actually provide a solid (mathematical) basis for its alleged applicability.

Sex-Specific Interpretation of Coronary Flow Reserve and Fractional Flow Reserve Metrics, Including Their Companions.

Background: Impairment of coronary flow is usually evaluated by considering the ratio of two measurements. Fractional flow reserve (FFR) estimates impact on an epicardial artery by taking mean post-stenotic pressure divided by mean aortic pressure, both obtained during adenosine induced hyperemia. Coronary flow reserve (CFR) compares hyperemic flow or velocity with the baseline situation, also as a ratio.

Heart Failure Phenotypes Require Sex-Specific Criteria Which Are Based on Ventricular Dimensions.

Ejection fraction (EF) is often used as a criterion to establish diagnostic phenotypes of heart failure (HF). Because EF is a derived metric based on end-systolic volume (ESV) and end-diastolic volume (EDV), it is more logical to consider ESV or EDV as cut-off marker. We concentrate on the impact of ESV, which has the advantage of being linearly related to EDV and nonlinearly with EF, both with highly significant correlations.

Polar Coordinate Description of Blood Pressure Measurements and Implications for Sex-Specific and Personalized Analysis.

Vascular properties and their associated impact on cardiovascular risk factors are often evaluated by metrics such as pulse pressure (PP) and the augmentation index (AIx). All derived metrics are essentially based on the combination of blood pressure recordings. These clinically used metrics typically concern a difference (as in PP) or a ratio (as in AIx).

Ratiology and a Complementary Class of Metrics for Cardiovascular Investigations.

Cardiovascular investigations often involve ratio-based metrics or differences: ejection fraction, arterial pressure augmentation index, coronary fractional flow reserve, pulse pressure. Focusing on a single number (ratio or difference) implies that information is lost. The lost companions constitute a well-defined but thus far unrecognized class, having additive value, a physical dimension, and often a physiological meaning.