Car 4 - Heart Failure Flashcards
How do we estimate the pressure in the left atrium? What would be a normal pressure?
Using a pulmonary capillary wedge pressure (PCWP) using a Swan-Ganz catheter. It is also a good approximation of LV diastolic pressure. PCWP lees than 12. LV less than 12. LV diastolic pressure around 10.
How would the PCWP be compared to LV diastolic pressure in Mitral stenosis?
PCWP would be higher than LV diastolic pressure because LV is contracting against a partially closed valve, so the pressure inside the atrium will rise and PCWP is equal to LA.
What is Heart failure?
Constellation of sings and symptoms caused by abnormal cardiac structure or function. Can be acquired (ischemic) or inherited.
What are 5 symptoms of Heart failure?
Exercise intolerance. Fatigue. SOB. Pulmonary rales. Peripheral edema.
Why would congestive heart failure cause pulmonary edema?
Because decrease in LV contractility causes pulmonary venous congestion, causing pulmonary edema.
Why would congestive heart failure cause Peripheral edema?
Because of two reasons: Decreased in LV contractility causes pulmonary venous congestion, causing decreased RV output causing peripheral edema. Also, decreased LV contract, causes decreased CO, elevating RAA system, increasing renal Na and H2O reabsorption, causing increase in systemic venous pressure and preload, causing peripheral edema.
How can the body increase cardiac output in decreased LV contractility?
Low LV contractility will initially decreased CO. It will try to increase it by increased sympathetic activation and increasing RAA, which increases renal Na and H20 reabsorption, increasing systemic venous pressure and preload, causing increased CO.
What are the causes of decrease LV contractility?
Chronic HTN. Ischemic cardiomyopathy.
What are three ways to stimulate renin production?
Sympathetic nervous system stimulating Beta1-receptors on the kidneys. Or macula densa cells sense low Na in glomerular filtrate. Or JG apparatuse senses low BP.
What three organs are involved in the Renin-angiotensin-aldosterone system?
Kidneys (make renin). Liver (make angiotensinogen). Lungs (make angiotensin converting enzyme ACE).
What two things does angiotensin II do?
Potent vasoconstrictor. Stimulates adrenal glands to secrete aldosterone.
What are the symptoms of Left-sided heart failure?
Dyspnea on exertion (DOE). Cardiac dilation. Pulmonary edema (paroxysmal nocturnal dyspnea, orthopnea). Think of pulmonary symptoms when thinking of left-sided failure.
What are the symptoms of Right-sided heart failure?
Peripheral edema (pedal edema, pre-sacral edema). Jugular venous distention (JVD). Hepatic congestion (nutmeg liver).
What is BNP and what does it do?
AKA B-type natriuretic peptide or brain natriuretice peptide. Hormone produced by cardiac cells in response to ventricular stretch. Causes vasodilation and increase increase excretion of Na and water in urine. We measure BNP to measure CHF.
How does poor cardiac output result in an increase in aldosterone?
Decrease in CO equals decreased BP, which is then detected by JG cells, causing the release of renin. Renin activates the RAAS causing increase in aldosterone.
