Heart Blood Flow
Let’s get started.
Deoxygenated blood flows into the heart through the superior vena cava (the SVC), inferior vena cava (the IVC) and the coronary sinus. The SVC and IVC bring blood back to the heart from the rest of the body and the coronary sinus returns blood that was used for coronary blood flow– that’s the blood that perfuses the heart muscle.
Deoxygenated blood fills the right atrium then the tricuspid valve opens, sending blood into the right ventricle. Once the right ventricle fills, the pulmonary valve opens and blood enters the pulmonary artery, traveling to the lungs where it is oxygenated.
The oxygenated blood then flows through the pulmonary vein into the left atrium. Once the left atrium fills, the mitral valve opens, sending blood into the left ventricle, which fills then sends oxygenated blood through the aortic valve into the aorta then on to the rest of the body. Oxygenated blood is sent to the tissues to distribute oxygen and returns in veins to the SVC and IVC to be reoxygenated.
As you can see, the heart and circulatory system is just a large, closed circuit pump. As nurses, we need to be able to understand the flow of the cardiovascular system and how a problem in one area of the heart will affect the patient and the rest of the system. Take a moment to think about all the different factors that can affect the heart’s pumping ability… valve stenosis, regurgitation, or prolapse, pulmonary hypertension, and heart failure to name a few.
Now let’s test your knowledge with a couple practice questions…
You note a diagnosis of mitral valve regurgitation on your patient’s chart. You know the mitral valve lies between…
- The right atrium and right ventricle
- The left atrium and left ventricle
- The right atrium and the pulmonary artery
- The right atrium and left atrium
If you said b. The left atrium and left ventricle, that is correct! Mitral valve regurgitation allows blood to flow backwards across the valve, flowing from the left ventricle back into the left atrium of the heart. This question demonstrates why it is important to know your cardiac blood flow, even without knowing much about mitral regurgitation, we know where the valve is located and can deduce what signs and symptoms may occur, including left ventricular hypertrophy, left atrial enlargement, shortness of breath, cough, pulmonary congestion, and increased pulmonary pressure.
Let’s try one more.
While reading a patient’s health history, you notice the patient has a diagnosis of right sided heart failure. You understand that right sided heart failure will cause blood to back up into the:
- Systemic circulation
If you said c. the systemic circulation, that is correct! Think of heart failure as pump failure, when the right side of the heart is not pumping properly, the blood backs up into the patient’s vascular system. Clinical manifestations for right heart failure include edema in the legs and feet, ascites, jugular venous distension, and many more.
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