Clinical Pathophysiology Made Ridiculously Easy: Cardiovascular System Flashcards
(47 cards)
Which valve lies between right atrium and right ventricle?
Tricuspid valve
*tRIcuspid is on the RIght
Which valve lies between right ventricle and it’s outflow vessel?
Pulmonic valve
Which valve lies between left atrium and left ventricle?
Mitral valve
*mitraL is on the Left
Which valve lies between left ventricle and its outflow vessel?
Aortic valve
Which valves snap shut during systole, preventing back flow?
The tricuspid and mitral valves
Which valves snap shut during diastole, preventing back flow?
The pulmonary and aortic valves
Where would you hear abnormal lungs sounds on a pt with left heart failure?
You may hear crackles in the bases of the lungs as a result of excess fluid. The worse the failure the more fluid in the lungs, the higher up in the lung fields these cracks will be heard.
In the absence of other illnesses, what kind of fluid do you find in the lungs during Left Heart Failure: transudative or exudative?
Transudative fluid, which is from increased intralumenal pressure from fluid backed up from the left ventricle.
What is the effect on the body of Left Heart Failure? What signs and symptoms would you find?
You would have decreased flow from the left heart to the body, which would cause blood to back up in the pulmonary vasculature. This would cause increased pressure in the pulmonary veins, which causes transudation of fluid into the lungs. You would then have pulmonary edema which causes dyspnea, and possibly crackles in the lung bases.
What is the cause of Right Heart Failure? Why?
Left Heart Failure. Because backup of flow in left heart can increase pressure in the pulmonary vasculature, left heart failure can cause pulmonary HTN and subsequent right heart failure.
Which ventricle is “stronger” and why?
Left ventricle is stronger. Right ventricle is not as strong since it pumps blood into the lower pressure pulmonary system, compared to the higher-resistance (higher pressure) system of the peripheral vasculature that the left ventricle pumps into.
Which ventricle has thicker walls? Why?
Left ventricle has thicker walls than the right because the left ventricle pumps into the higher-resistance, higher pressure system of the peripheral vasculature. Right ventricle, with thinner walls, pumps into the low pressure pulmonary system.
Where does the blood back up in right heart failure? What would you notice on physical exam?
The blood in the right ventricle comes from the body, or the venous return via the superior and inferior venae cavae. On PE you would see elevated jugular venous pressure (JVP). the jugular veins in the neck are a straight shot to the superior vena cava. You would also possibly see ascites, hepatic congestion, peripheral edema, etc.
What is preload? What creates it?
The pressure that fills the ventricles during diastole. More specifically, preload is the blood pressure in the left ventricle at the end of diastole, right before the ventricles contract. It is created by blood coming from the venous system.
What is afterload?
The resistance that the heart faces during systole. It is the systemic vascular resistance or the resistance to flow in the arterial tree against which the heart must work. (AFTERLOAD is created by ARTERIES)
What are the goals of tx for heart failure? How is this accomplished?
Increase forward flow, decrease backup of flow. You increase forward flow by increasing cardiac output. To decrease backup, you must decrease workload on the heart. So you increase the heart’s ability to pump, and decrease how much it has to pump against.
What two mechanisms do you use to increase forward flow (increasing cardiac output)?
- Increase the force of ventricular contraction (inotropes, e.g., digoxin/digitalis, dopamine/dobutamine, amrinone/milrinone).
- Decrease rate of contraction to increase filling time (beta-blockers, e.g., propranolol, metoprolol). The increased filling time increases amount of blood pumped at a time, increasing cardiac output.
What’s the strategy to decreasing fluid backup by decreasing heart’s work?
To decrease work, you should try to decrease both the preload and the afterload (since heart’s job is to pump the preload against the afterload). You can decrease preload by decreasing venous return which you can do by dilating the veins, slowing the return of blood to the heart, (nitrates dilate veins). You can also use diuretics, which decrease intravascular fluid volume.
To decrease afterload, you can use arterial dilators (e.g., ACE inhibitors, hydralazine)
What is the MOA of digoxin in CHF?
It increases contractility of the heart, which helps increase cardiac output, which helps with forward flow.
What is the MOA of beta-blockers? (propranolol, metoprolol, etc)
*
What is the MOA of ACE inhibitors? What are examples?
*
What is the MOA of hydralazine?
*
How do the kidneys get involved in CHF?
During CHF there is decreased cardiac output, and as a result the perfusion pressure in the kidneys decreases, (this is called decreased effective blood volume, the volume is the same but the amount that reaches the kidneys decreases). When the kidneys sense a decrease in perfusion pressure activates the renin-angiotensin-aldosterone system to increase perfusion pressure.
What is the MOA of the Renin-Angiotensin-Aldosterone system?
- Kidneys sense a decrease in perfusion pressure and releases Renin.
- Renin increases the conversion of angiotensinogen to angiotensin I.
- Angiotensin I gets converted to angiotensin II by the angiotensin converting enzyme (ACE).
- Angiotensin II causes vasoconstriction, which raises blood pressure.
- Angiotensin II also stimulates aldosterone release from the adrenal glands.
- Aldosterone causes sodium resorption by the kidneys, which causes water to follow it, which increases intravascular volume.
- Increased vasoconstriction and increased blood volume raises blood pressure.
- Also, Antidiuretic Hormone (ADH) gets released from the posterior pituitary gland when there is perceived low volume status in the blood vessels and in the kidney.
- ADH causes water reabsorption in the kidneys which also increases volume and increases blood pressure.
