11: Treatment of Heart Failure

Question 1

Describe left heart failure.

Answer 1

• Congestive
• Pulmonary edema - “I can’t breath”
• PND - “I can’t sleep”
• Orthopnea

Question 2

Describe right heart failure.

Answer 2

• Low perfusion
• Hepatomegaly
• Peripheral edema - “My shoes don’t fit”
• JVD
• Ascites
• Cool extremities
• S3 gallop
• “I can’t think, I’m not hungry.”

Question 3

For “wet” patients, describe treatment.

Answer 3

• If cold too, give vasodilators and then diuretics (need to reduce high SVR first)
• If warm, give vasodilators and diuretics simultaneously

Question 4

What medications increase contractility?

Answer 4

• Dobutamine
• Milrinone
• Dopamine
• Digoxin

Question 5

What drugs improve survival of heart failure?

Answer 5

• B-blockers
• ACEI
• Angiotensin Receptor Blockers (ARB)
• Aldosterone antagonists
• Nitrates/Hydralazine
• Digoxin

Question 6

Loop diuretics

1. Examples
2. Mechanism
3. Net effect
4. Side Fx
5. Other

Answer 6

1. Furosemide, bumetanide, torsemide
2. Inhibit Na/K/2Cl co-transporter in **thich ascending loop of Henle **(stay in tubule)
3. ↓preload
4. Electrolyte imbalances
5. Over time, cause ↑RAAS activty

Question 7

Digoxin

1. Mechanism
2. Net effect
3. SFx
4. Other

Answer 7

1. Inhibits Na/K ATPase in cardiac myocytes –> ↑IC sodium –> ↑Na/Ca exchange –> ↑IC Ca –> increased myocyte contractility
2. Acute improvement of CO via ↑contractility
3. N/V, seeing yellow, arrhythmias (PVCS, AJR, heart block)
4. Withdrawal worsens HF; lower doses lead to increased survival

Question 8

Thiazide diuretics

1. Examples
2. Mechanism
3. Net effect
4. Other

Answer 8

1. HCTZ, metolazone, chlorthalidone
2. Inhibit Na/Cl co-transporter in distal convuluted tubule
3. ↓preload
4. Works for loop diuretic resistance: short term: ↓response to 2nd diuretic dose; long-term: progressive hypertrophy of distal nephron –> ↑distal sodium reabsorption –> thiazide necessary to restore diuresis

Question 9

Angiotensin Converting Enzyme Inhibitors (ACEIs)

1. Examples
2. Mechanism
3. Net effect
4. SFx
5. Other

Answer 9

1. Captopril, Enalpril, Lisinopril, Ramipril, Trandolapril (-pril)
2. In the name
3. ↓afterload, ↓adrenergic tone, ↑renal blood flow, reverse fibrosis/remodeling
4. Cough via bradykinin escape pathway, hyperkalemia, renal insufficiency, angioedema, HoTN
5. Contraindicated in pregnancy

Question 10

Beta-blockers

1. Examples
2. Background
3. Mechanism
4. Net effect
5. SFx
6. Other

Answer 10

1. Metoprolol, Bisoprolol, Carvedilol, Esmolol, Labetolol (-lol)
2. Chronic activation of sympathetic nervous system in HF causes compensatory tachycardia –> ↑NorE, long-term exposure to catecholamines toxic to myocardium; chronic beta receptor stimulation –> down-regulation/desensitization –> poor contractility
3. Re-set appropriate adrenergic myocyte signaling through beta receptor pathway
4. ↑EF, ↓arrhythmia burden
5. Bronchospastic airway disease, heart block, pulmonary edema, cardiogenic shock, leg ischemia, mask hypoglycemia, raise LDL/triglycerides
6. Never treat sinus tachy w/ beta-blockers

Question 11

Aldosterone Antagonists

1. Examples
2. Mechanism
3. Net effect
4. SFx

Answer 11

1. Spironolactone, Eplerenone
2. Inhibits Na/K transporter at the collecting duct (decreased Na absorption, decreased K excretion); inhibits RAAS
3. Potassium-sparing mild diuretic; anti-fibrotic action in cardiac myocytes
4. Hyperkalemia, advanced renal dysfunction, HoTN, gynecomastia (enlargement of male breasts)

Question 12

Inotropic Therapy

1. Examples
2. Mechanism
3. Net effect
4. SFx

Answer 12

1. Dobutamine (beta receptor agonist), milrinone (phosphodiesterase inhibitor), dopamine (beta receptor agonist)
2. Dobutamine: ↑cAMP; Milrinone: Inhibit PDE3 –> ↑cAMP
3. ↑contractility, ↑mortality
4. Dobutamine: hypersensitivity eosinophilic myocarditis; milrinone: peripheral/pulmonary vasodilator

Question 13

Angiotensin Receptor Blockers (ARBs)

1. Examples
2. Mechanism
3. Net effect
4. SFx
5. Other

Answer 13

1. Candesartan, Valsartan, Losartan (-artan)
2. Direct AT1 receptor antagonist
3. ↓afterload, ↓adrenergic tone, ↑renal blood flow, reverse fibrosis/remodeling
4. Hyperkalemia, renal insufficiency, angioedema, HoTN
5. Contraindicated in pregnancy