Elevated heart rate is associated with poor cardiovascular outcomes. The reduction of heart rate is one of the goals in the treatment of patients with heart failure and reduced ejection fraction. The studies that involve the use of ivabradine, a drug which acts solely by decreasing heart rate, have shown that this effect, per se, reduces the risk of hospital admission and death in these patients. This review examines the results of studies that show reductions in the rate of myocardial oxygen consumption and shear stress, as well as increase in myocardial perfusion related to the reduction of heart rate.

 

Cardiac tamponade is a condition in which the heart is compressed by excess fluid in the pericardial space, which can result in diastolic filling impairment, subsequent cardiac dysfunction, and even cardiac collapse. Cardiac tamponade is an uncommon sequela of chest contusions from blunt chest trauma that brings with it a severe risk of sudden death. We present a small series of cases with successf treatment for cardiac injuries: a young man who was struck by a bull cart and an old man with chronic kidney disease receiving stent graft placement for superior vena cava syndrome. This report highlights the need to remain alert for cases of tamponade, and measures such as emergent pericardiocentesis should first be administered to maintain the hemodynamics of vital organs such as the heart.