My heart will go on
Where is aldosterone produced (specific)?
Zona glomerulosa (outer layer) of the adrenal cortex
Where do SGLT2 inhibitors exert their effects?
Proximal convoluted tubule of the nephron
How does spironolactone work in heart failure treatment?
Binds to mineralocorticoid receptors (competitive antagonist) to prevent aldosterone effects, leading to less sodium and water reabsorption and increased potassium retention
A dry cough may present in patients taking lisinopril due to increased amounts of which molecule?
Bradykinin
True/False: Patients with heart failure with preserved ejection fraction are not recommended to take diuretics
False
True or False: Direct factor Xa inhibitors are recommended for patients with HFrEF with sinus rhythm.
False: Anti-coagulants are only recommended for patients with HF who also have abnormal rhythms.
What are the differences between chronotropy, inotropy, and dromotropy? Which of these do selective beta-blockers affect?
Chronotropy - heart rate
Inotropy - heart contractility
Dromotropy - speed of conduction through the heart
Beta-1 adrenergic blockers decrease heart rate and contractility (negative chronotropy and negative inotropy)
Why is carvedilol contraindicated in patients with asthma?
Carvedilol blocks both B1 and B2 adrenergics -- B2 blockade in the airways causes bronchoconstriction, which can worsen asthma
Name 4 effects of aldosterone in the nephrons
- Increased reabsorption of sodium
- Increased potassium excretion
- Increased acid excretion
- Bicarb excretion and chloride reabsorption
How do ANP and BNP cause vasodilation?
Increased cGMP production in smooth muscle cells --> increased protein kinase G --> calcium channel suppression and inhibition of myosin light chain kinase
A student asks why Entresto (Sacubitril/Valsartan) contains an ARB and not an ACE inhibitor. What is the reason?
Neprilysin, the enzyme inhibited by Sacubitril, breaks down bradykinin in addition to BNP and ANP. Since ACE inhibitors increase bradykinin as well, there would be a significantly greater risk of angioedema.
What are the five pillars (categories) of heart failure medications (according to our lecture on CHF)?
1. Beta-blockers
2. ACEis/ARBs/Entresto
3. Mineralocorticoid receptor antagonist
4. SGLT2 inhibitors
5. Diuretics