Week 6 - Heart Failure

Question 1

What are the 2 types of left sided heart failure

Answer 1

• Less blood is pumped causing ↓ blood to reach organs = ↓ O2 and nutrients

1. Heart failure with reduced ejection fraction (HFrEF)
   - is SYSTOLIC HF
   - ventricles fills with normal amount of blood BUT contraction is weak = eject less blood
   - EF < 40 = systolic HF
   - CAUSES: coronary heart disease, obesity, stress, hypertension
2. Heart failure with preserved ejection fraction (HFpEF)
   - is DIASTOLIC HF
   - ventricles fill with less blood (due to thickened ventricular muscle = can’t expand / stiff = reduced ventricular volume) BUT contraction is strong
   - EF > 50%
   - CAUSE: hypertension

Question 2

Symptoms of HF

Answer 2

MAIN SYMPTOM = oedema (fluid retention in lower limbs or lungs)
- fluid around lungs = struggle to breath

1. Left sided HF
   - restlessness / fatigue
   - tachycardia
   - confusion
   - pulmonary congestion e.g. cough, wheeze, tachypnea
2. Right sided (not important)
   - another condition called cor pulmonale

Question 3

How is Systolic HF classed

Answer 3

NVHA (4 stages)
- Stage 1 = no limitation, physical activity doesn’t cause HF symptoms
- Stage 2 = slight limitation during physical activity + experience some HF symptoms
- Stage 3 = marked limitations (i.e. visible struggles) during physical activity + experience HF symptoms
- Stage 4 = can’t do any physical activity + can have HF symptoms at rest too

Question 4

How is systolic HF (HFrEF) managed

Answer 4

• Start non-pharmacological then use pharmacological treatment

Goals of Therapy:
- modify / control risk factors
- manage structural heart changes
- reduce morbidity + mortality
- prevent oedema
- improve HF symptoms

Question 5

List the non-pharmacological treatments for systolic HF (HFrEF)

Answer 5

1. Preventing further cardiac injury
   - stop smoking
   - reduce weight if obese
   - control hypertension
   - control diabetes
   - reduce / eliminate alcohol intake
2. Restrict salt / fluid intake
   - avoid drinking too much water (1.5-2L daily)
   - avoid excess salt (1500mg daily)
3. Increase physical activity
   - e.g. walking, lifting but NO vigorous exercise (will worsen HF)
4. Get influenza + pneumococcal vaccines
5. Monitor for thyroid disease (hypothyroidism can mask HF symptoms)
6. Screen + treat depression

Question 6

List the 4 MAIN pharmacological treatments for systolic HF (HFrEF)

Answer 6

Controlling RASS System:
1. ACE Inhibitors (ACEi - 1st line)
2. ACE Inhibitor Alternatives (if above contraindicated)

Controlling Sympathetic Nervous System
1. B-blockers (1st line)

ADD ONS to ACEi / ARBs or B-blockers
1. Aldosterone Receptor Antagonist

DIURETICS (loop)
- e.g. Furosemide and Thiazide

Question 7

Explain how the RASS system controlled in systolic HF (HFrEF) treatment

Answer 7

1. ACE Inhibitors (ACEi - 1st line)
   - prevents conversion of angiotensin I to II = ↓ vasoconstriction
   - ↓ production of aldosterone + vasopressin, ↓ Na+ / H20 retention,
   - ↓ sympathetic stimulation
   - ↓ breakdown of bradykinin = vasodilation
   - can’t use in pregnant women / people with dry cough
   - DOSE: start low then double every 1-4 weeks to reach target dose
   - e.g. ramipril, captopril
2. ACE Inhibitor Alternatives (if above contraindicated)
   - Angiotensin Receptor Blockers (ARBs e.g. losartan, valsartan)
   - Hydralazine and Nitrate Combination
   - Sacubitril Valsartan

Question 8

Explain how the Sympathetic Nervous System is controlled in systolic HF (HFrEF)

Answer 8

1. B-blockers (1st line)
   - B-blockers + ACEi started at same time
   - ↓ heart rate + workload on heart by blocking affects of sympathetic neurotransmitter on heart + vascular system
   - ↓ vasoconstriction + ventricular arrhythmia
   - e.g. Bisoprolol, Metoprolol, Carvedilol (also a1-receptor blocker = ↓ BP)
   - ONLY 4 drugs licensed for use in HF = need to switch if on diff. B-blocker + DON’T STOP abruptly
   - DOSE: start low then ↑ till reach maximum tolerated dose (when heart rate is at target)

ADD ONS to ACEi / ARBs or B-blockers
1. Aldosterone Receptor Antagonist
- added on if still experiencing symptoms AFTER maximising doses of ACEi or B-blockers
- blocks effects of aldosterone (retention)
- ↓ ventricular arrhythmia and BP
- ↓ Na+ / H2O retention, ↓ K+ and Mg+ loss
- e.g. Spironolocatone

Question 9

Explain how diuretics work in the treatment for systolic HF (HFrEF)

Answer 9

DIURETICS
- Added if have fluid retention + results aren’t controlled
- Inhibit reabsorption of Na+ in ascending LoH or distal tubule
- ↓ oedema, pulmonary congestion and ↑ exercise tolerance
- e.g. Furosemide (loop diuretic = strongest + safest)
- can be combined with other diuretics
- e.g. Thiazide (contraindications if renally impaired)

Question 10

List specialist treatments to for systolic HF (HFrEF)

Answer 10

1. Ivabradine
   - Used if have stage 2-4 HF, all other drugs have been tried + maximised BUT heart rate is still >75 (not well controlled)
   - Used when B-blockers are contraindicated + EF is < 35%
   - Inhibits SAN = ↓ heart rate
2. Digoxin
   - Used in severe cases, after ACEi + B-blocker given (at maximised doses) but still have symptoms
   • ↑ exercise tolerance + cardiac contractility
   • ↓ heart rate by inhibiting myocardial Na-K ATP
   • ↓ renal absorption of Na+

Question 11

List the pharmacological treatments for diastolic HF (HFpEF)

Answer 11

NO treatment for condition ONLY SYMPTOMATIC RELEIF

• Control hypertension, systolic BP and diastolic BP
• Use CCB
• Use diuretics for relief from oedema