cardio Flashcards
How much can 1 antihypertensive reduce BP by?
How far does this go? eg. 3-4 drugs
10/5 mmHg
It only applies up to 2 drugs (20/10 mmHg), does not apply to 3 or more antihypertensives
Which antihypertensives are not used in congestive heart failure? Why?
Non-DHP CCB eg. Verapamil, Diltiazem
They have very negative inotropic effects, which will decrease the contractility of the heart, worsening the heart failure
Which antihypertensives used in pregnancy?
Which cannot be used?
Can: LMN (Labetalol, Methyldopa, Nifedipine)
Cannot: ACEi / ARB, Direct renin inhibitors eg. Alisikiren
Antihypertensive to be used in Diabetes with proteinuria
What antihypertensive CANNOT be used in Diabetes and WHY?
With proteinuria: ACEi
Beta Blockers, as it will mask symptoms of hypoglycemia ie. lowering heart rate
Why are ACEi used in proteinuria?
ACEi help to reduce the amount of protein leaked into the urine by lowering the pressure in the glomeruli by inhibiting the RAAS system, decreasing blood vessel constriction in the kidneys
What are the antihypertensive classes and their MOA?
ACEi
ARB
BB
DHP CCB
Non-DHP CCB
Thiazide Diuretics
ACEi: blocks ACE (angiotensin converting enzyme) which converts Angiotensin 1 to Angiotensin 2
ARB: blocks Angiotensin 2 receptors, preventing the effects of Angiotensin 2 on blood vessels and kidneys
Beta blockers: block the beta-adrenergic receptors of the heart, slowing the heart rate and contractility
DHP CCB (focus on the blood vessels): block calcium channels by blocking Ca2+ influx into vascular smooth muscles → causing vasodilation
Non-DHP CCB (focus on the heart): block calcium channels in the heart → reduce contractility and thus cardiac output
Thiazide diuretics: Block Na+Cl- transporter in the distal convoluted tubule, thus preventing reabsorption of sodium chloride → lower fluid volume (hence lower BP) + causing Ca2+ to leave the lumen (urine side) to the interstitium (can help with hypercalciuria)
Which antihypertensives are teratogenic (2 points)
ACE / ARB
Direct renin inhibitors eg. Alisikiren
Which beta blockers are selective? (3 points) and for which receptor?
BAM (bam adebayo is selective)
Bisoprolol
Atenolol
Metoprolol
Selective for beta 1 receptors
Which beta blockers are worse for asthma and why? (2 points)
Non selective BB, as they block beta 1 receptors which cause bronchoconstriction
Eg: Propranolol, Carvedilol
Counselling points for ACEi / ARBs (3 points)
1) Hyperkalemia (chest tightness, muscle weakness)
2) Angioedema (swelling of eyes, lips similar to allergic reaction)
3) Dry cough (for ACEi only)
BP considered to be emergency
> 180/110
Definition of hypertension
When should hypertension be treated immediately (instead of waiting)
> 140/90
When patient has other comorbidities eg. heart disease, renal disease, DM with organ damage
Start lifestyle modifications if patient only has risk factors for ASCVD eg. obesity, old age, hyperlipidemia, DM with no organ damage
How does heart failure occur? (Start when the heart pumping ability is weakened..)
3 points
1) Heart pumping ability is weakened, leading to poor perfusion to the tissues, including the kidneys. Kidneys interpret this as low blood volume (even when total body fluid is excessive)
2) Kidneys activate RAAS system. AT2 causes vasoconstriction, and cardiac remodelling. Aldosterone causes sodium and water retention
3) Additional fluid retention causes volume overload, leading to congestion in both the lungs and the limbs (pulmonary oedema and dyspnea, peripheral oedema)
LVEF of HFrEF, HFmrEF and HFpEF
Left ventricular ejection fraction LVEF
HFrEF: 40% or less
HFmrEF: 41-49%
HFpEF: 50% or more
What are the fantastic 4 for HF
1) ARNI / ACEi
2) Beta blocker (BCM XL)
3) MRA
4) SGLT2i (Dapa or Empa)
+ Loop diuretics for fluid retention
What is the role of ARNi in HF?
Why may it worsen dry cough than normal ACEI / ARB
ARNI contains ARB eg. Valsartan and Neprilysin Inhibitor eg. Sacubitril
Valsartan inhibits AT2 from binding to adrenal glands, inhibiting RAAS system (which was activated in HF)
Sacubitril inhibits Neprilysin, causing accumulation of natriuretic peptides. Neprilysin breaks down natriuretic peptides (ANP, BNP, CNP) which are beneficial as they promote vasodilation, diuresis and reverse modelling
Sacubitril will also cause accumulation of bradykinin. Valsartan also cause accumulation of bradykinin -> bradykinin causes dry cough
Why is UFH or LMWH (Enoxaparin) used for first 5 days of warfarin for VTE treatment?
Warfarin reduces protein C and S, which are the body’s natural anticoagulants. In the initial phase of warfarin, protein C and S are low, causing the body to be in hypercoagulability state (clots happen easily) + Clotting factors 2, 9, 10 have long half lives and will fall slowly
Clots happen easier, hence need LMWH or UFH to bridge warfarin’s low onset
What is the target HR in AF?
What is used for rhythm control in AF?
< 80 in normal patients, < 70 in patients with HF
Agents from 1st -> 4th line (BCDA)
1) BB
2) non-DHP CCB
3) Digoxin
4) Amiodarone
Why cant BB and non DHP be used together in HF?
will cause heart block
When should rhythm control be preferred over rate control in AF?
- Young (< 65yo), still can benefit from being in sinus rhythm
- High likelihood of being able to maintain sinus rhythm
- 1st AF episode
- Short history
- AF caused by temporary event
What are the agents used for rhythm control in AF? When should use which agent?
For patients with no structural HD eg. HF, valvular disease
1) Sotalol (Class 3)
2) Flecainide (Class 1C - “PRN pill in pocket”)
3) Propafenone (Class 1C- “PRN pill in pocket”)
For patients with structural HD eg. HF, valvular disease
1) Amiodarone (class 3)
