Final answer:
Preload is the ventricular stretch at diastole, afterload is the resistance during systole, and contractility is the heart muscle's capacity to contract. Intermittent claudication is pain from inadequate blood flow during exercise.
Step-by-step explanation:
Preload, Afterload, and Contractility Concepts
- Preload refers to the initial stretching of the cardiac myocytes (heart muscle cells) prior to contraction, which relates to the volume of blood in the ventricles at the end of diastole (resting phase). Afterload is the pressure against which the heart must work to eject blood during systole (contraction phase). Contractility refers to the intrinsic ability of cardiac myocytes to contract at a given preload. Positive factors affecting heart contractility include increased sympathetic stimulation, whereas negative factors could be hypoxia or acidosis.
Intermittent Claudication
- Intermittent claudication is a condition characterized by pain and cramping in the lower leg caused by inadequate blood flow to the muscles, which typically occurs during exercise and is relieved by rest.
Anti-hypertensive Medications
- Two classes of anti-hypertensive medications include Calcium Channel Blockers and Angiotensin-Converting Enzyme (ACE) Inhibitors. An example of a calcium channel blocker is amlodipine, which works by relaxing blood vessels and decreasing cardiac workload. An ACE inhibitor example is lisinopril, which lowers blood pressure by preventing the formation of a substance that causes blood vessels to tighten.