Week 3 Flashcards
What is the pathway of blood flow through the heart?
Returns from the periphery, enter through the vena cave, it empties 1st into the R atrium then it crosses the AV valves into the R ventricles, R ventricles pump through the pulmonic valve into the pulmonary trunk, which then splits into the R and L pulmonary arteries, which goes to the lungs, gets oxygen diffused at the capillary alveolar interphase, blood then returns through the 2 pulmonary veins which converges to the L atrium, blood then flows from the L atrium, across the bicuspid valve(mitral valve), into the L ventricle, which then pumps blood through the aortic semilunar valve, then into the aorta, then into the systemic circulation that perfuses our tissues
What happens during diastole in regards to the heart valves?
The semilunar valves(pulmonary and aortic valves) are closed, because the ventricles is relaxed due to less pressure behind the valves. The AV valves(mitral and tricuspid) are open as blood is entering into the chambers
What happens during systole in regards to the heart valves?
The mitral and tricuspid valves are closed, which allow for them to create a high pressure chamber, to egress blood across the pulmonic valve and aortic valve
What are heart valves?
Passive structures that respond to pressure.
What helps keeps the AV valves closed during systole?
Chordae tendinae
What causes a valve to open?
When contraction increases pressure within a given chamber greater than the downstream pressure. (more related to semilunar valves, especially the pulmonic and the aortic valve)
What causes a valve to close?
When contraction ends and pressure decreases below downstream pressure
What is the pressure across the aortic valve?
Anywhere between 80-100
What are the AV valves on the left side?
Bicuspid or mitral valve
What are the AV valves on the right side?
Tricuspid (3 leaflets)
What do the Chordae tendinae and Papillary muscles do during systole in the AV valves?
They become taut to prevent them from opening.
- Prevent inversion of valves during ventricular systole.
- Can become damaged from MI causing back flow “regurgitation”.
What are the semilunar valves?
Aortic and Pulmonic
What are the characteristics of the semilunar valves?
- Three leaflets on each
- No papillary muscles or chordae tendonae
- Do not lie back against the walls of the aorta or pulmonary artery
What are the general symptoms of Cardiac Valvular Disease?
- Easy Fatigue
- Dyspnea
- Palpitations
- Murmur
- Chest Pain
- Pitting Edema
- Orthopnea
- Dizziness
What is a murmur?
What we hear when there is turbulent flow across the valve.
Why do patients with a cardiac valvular disease get chest pain?
If we impair the pressure gradient, we impair the egress of blood out of the heart, and across the valves, we may impair myocardial performance, especially as we increase workload, if we can’t maintain demand, we may get transient ischemia and chest pain
Why do patients with a cardiac valvular disease get pitting edema?
If we have an impaired ability to get blood out of the heart, we can create backflow. Backflow on the right goes into the peripheral veins and back flow on the L, it will eventually go back to the lungs and eventually impair the R side
What is orthopnea?
Shortness of breath when laying flat, due to the fact that when you lay flat, blood shunts into the central part of the body, which increases pre-load/stilling, which is essential putting more fluid into a flooded system, which it can’t handle, causing backflow into the lungs
What is concentric remodeling?
Classified as an increased relative thickness, with a normal L ventricular mass
What is concentric hypertrophy?
Classified as an increased relative thickness, with an increased L ventricular mass
What is concentric remodeling and concentric hypertrophy typically in response to?
L pressure overload, with the earliest response typically being concentric remodeling
Why is concentric remodeling and concentric hypertrophy done?
In an attempt to limit wall stress and to allow for normal L ventricular systolic function and performance
How does concentric remodeling and concentric hypertrophy become a pathological change?
If we have sustained elevated pressures like we see in HTN, or an aortic stenosis,
What does concentric remodeling and concentric hypertrophy lead to when it becomes pathological?
L ventricular diastolic dysfunction, an impaired ability to relax, and potentially diastolic heart failure