Other Factors Influencing Cardiac Output + Heart Failure

Electrolytes and Cardiac Output

Concentration of certain electrolytes in the ECF influence the length and magnitude of an action potential and cardiac output

Body Temperature

SA node fires more rapidly at higher body temperatures and more slowly at lower body temperatures

Age and Physical Fitness

Age and physical fitness influence heart rate and cardiac output

young children and the elderly often have a higher resting heart rate

athletes often have a lower resting heart rate

Heart Failure

Any condition that reduces the heart’s ability to function effectively as a pump

Causes include reduced contractility due to myocardial ischemia and/or myocardial infarction, valvular diseases, cardiomyopathy, electrolyte imbalances

Left Ventricular Failure

Blood backs up within the pulmonary circuit, known as Pulmonary Congestion, resulting in Pulmonary Edema from fluid driven out of the pulmonary capillaries into the lungs

Peripheral Edema

Blood backs up in the systemic capillaries as a result of Systemic Congestion, forcing fluid into the tissues, commonly seen in the legs and feet

Heart Failure Treatment

Treatment is aimed at increasing cardiac output via lifestyle modifications, medications, and surgery if necessary

Heart Failure Lifestyle Modifications

Weight loss and mild exercise plus dietary sodium and fluid restrictions are suggested

Heart Failure Drug Therapy

Drug therapy increases cardiac output by reducing congestion by promoting fluid loss from the kidneys, increasing the heart’s contractility so that it pumps more effectively, and decreasing afterload so the ventricles have to pump against lower pressure