The study compares the physical and biologically effective doses (BED) received by the heart and cardiac substructures using three-dimensional conformal RT (3D-CRT), intensity-modulated radiotherapy (IMRT), and simple IMRT (s-IMRT) in postoperative radiotherapy for patients with left-sided breast cancer. From October 2008 to February 2009, 14 patients with histologically confirmed left-sided br...

AIM Intervention fidelity refers to the degree to which an experimental manipulation has been implemented as intended, but simple, robust methods for quantifying fidelity have not been well documented. Therefore, we aim to illustrate a rigorous quantitative evaluation of intervention fidelity, using data collected during a high-intensity interval training intervention. DESIGN Single-group mea...

The cardiac refractory period prevents the heart from tetanic activation that is typically used in noncardiac striated muscle tissue. To what extent the refractory period prevents successive action potentials to activate the excitation-contraction coupling process and contractile machinery at supra-physiological rates, such as those present during ventricular fibrillation, is unknown. Using mul...

BACKGROUND Although maximal heart rate (HR max) is widely used to assess exercise intensity in sport training, and particularly in soccer, there are limited data with regards to the use of age-based prediction equations of HR max in soccer players. The aim of this study was to compare the measured-HR max with two prediction equations (Fox-HR max = 220 - age and Tanaka-HR max = 208 - 0.7 × age) ...

BACKGROUND Current guidelines recommend that caffeinated products should be avoided for at least 12 hours prior to regadenoson administration. We intended to examine the effect of caffeine consumption and of timing of last dose on hemodynamic effects after regadenoson administration for cardiac stress testing. METHODS 332 subjects undergoing regadenoson stress testing were enrolled. Baseline ...

conclusions large-scale studies on the healthy black african population could assess the relationship between diastolic dyssynchrony and changes in myocardial performance related to racial differences. results the frequency of some dyssynchrony markers was similar to that of other studies. the difference between maximal time-to-peak systolic velocity and minimal time-to-peak systolic velocity w...

Advanced heart failure, also be defined as stage D heart failure, characterized by advanced structural heart disease and marked symptoms of heart failure at rest despite dietary modification, salt restriction and maximal medical therapy including ACE inhibitors, angiotensin II receptor blockers, digitalics, diuretics and beta blockers. These patients require frequent hospitalizations and specia...