Congestive heart failure can be caused by a number of factors, including pressure and volume overload, muscle loss, primary muscle disorder, or severe peripheral demands, such as high output failure. The heart muscle has decreased contractility in the most common type of heart failure. This causes a decrease in cardiac capacity, which is insufficient to satisfy the body's peripheral demands. The following are the four primary determinants of left ventricular (LV) performance: (1) Muscle contractility is reduced from the inside out. (2) Increased preload or left atrial loading pressure causes pulmonary obstruction and dyspnea. (3) While systemic blood pressure is often reduced, systemic vascular resistance (afterload) rises, lowering cardiac output even more. (4) A rise in heart rate is commonly associated with an increase in sympathetic tone and circulating catecholamines as a compensatory mechanism. There is often an imbalance between myocardial oxygen supply and demand in patients with coronary disease.