26 - Congestive Heart Failure

Question 1

What is heart failure?

Answer 1

Inadequate blood flow for metabolic needs

Question 2

What are the primary and secondary causes of heart failure?

Answer 2

Primary

• This is what we will talk about in this course
• Cardiac origin, periphery affected

Secondary

• Peripheral cause, cardiac affected
• Sepsis, anemia, toxins, etc.

Question 3

Describe systolic heart failure

Answer 3

Remember systolic = contraction, so systolic heart failure is when the heart cannot contract enough (weakened contractility) and the heart can’t empty
- Ejection fraction will be

Question 4

Descrie diastolic heart failure

Answer 4

Remember diastolic = relaxation, so diastolic heart failure is when muscular hypertrophy prevents the heart from filling properly

• Ejection fraction will be >50%
• Hypertension will occur without ischemia

Question 5

Describe the pathophysiology of heart failure

Answer 5

• Begins with decreased cardiac output
• Compensated by increased volume (retention of Na+ and water)
• Cardiac response

Question 6

How does the heart respond to heart failure?

Answer 6

• Increased filling volume (LVEDV)
• Increased fiber length, which allows increased force of contraction
• Starling law

Question 7

Describe the Starling law curves

Answer 7

• Up to a limit, stroke volume and LVEDV increase in tandem.
• In HF, the LVEDV is up but the stroke volume (LVEDV-LVESV) is down.
• Less is pumped out per cycle.

Question 8

What does the body do in HF when senses a drop in tissue perfusion and interprets it as ischemia?

Answer 8

• Increases contractility, rate, peripheral resistance (Epinephrine, norepinephrine)
• Increases ischemia (systolic) or hypertrophy (diastolic) (Increased O2 demand, increased work load)
• Renin/angiotensin activated as if hypovolemic

Question 9

What are the “upstream” consequences in HF?

Answer 9

• Left ventricular failure leads to pulmonary congestion and dyspnea
• Right ventricular failure leads to systemic congestion and edema

Question 10

What are the “downstream” consequences in HF?

Answer 10

• Left ventricular failure leads to poor organ perfusion and therefore decreased function (renal, cerebral, cardiac –> Na+/H2O retention, confusion, ischemia)
• Right ventricular failure leads to lower filling pressures, creating diastolic failure (can’t fill)

Question 11

What is the most common cause of R ventricular failure?

Answer 11

Left ventricular failure

• Pulmonary vascular congestion from left ventricular failure increases the workload on the right ventricle
• Eventually the right ventricle will fail

Question 12

What are symptoms of L ventricular failure?

Answer 12

• Dyspnea: exertion, recumbent, nocturnal, resting
• Diminished exercise capacity (output down)
• Nocturia (recumbent diuresis)
• CNS impairment (memory, insomnia, etc; end organ)

Question 13

What are symptoms of R ventricular failure?

Answer 13

• Peripheral edema (Includes hepatosplenomegaly, legs up to back!)
• Edema of bowel wall can impair med absorption

Question 14

What is the NYHA functional classification of HF?

Answer 14

Classes I-IV to determine level of heart failure

Question 15

Describe class I

Answer 15

• No functional limitation
• Ordinary physical activity does not cause undue fatigue, dyspnea or palpitations
• Normal life expectancy for comorbidities
• At-risk population

Question 16

Describe class II

Answer 16

• Slight limitation of activity
• Ordinary activity precipitates dyspnea, fatigue, palpitations or angina
• 25% risk in 1 year

Question 17

Describe class III

Answer 17

• Market limitation
• Less than normal activity precipitates symptoms
• Marked limitation of physical activity
• Less than ordinary physical activity leads to symptoms
• 50% risk in 1 year

Question 18

Describe class IV

Answer 18

• Symptoms at rest
• Unable to carry on any physical activity without discomfort
• 50% risk in 1 year

Question 19

What would you see on physical examination in left HF?

Answer 19

• Pallor, cool extremities
• Anxiety, dyspnea at rest
• Pulses normal to rapid, weak
• Blood pressure varies
• Pulmonary rales, pleural effusion

Remember: usually not “pure” Left HF.

Question 20

What would you see on physical examination in right HF?

Answer 20

• Hepatojugular reflux
• Kussmaul’s sign
• – Paradoxical JVD from increased R chest pressures
• – Inhalation normally increases blood return.
• Congestive hepatomegaly (Ascites)
• Edema – symmetrical, pitting, dependent

Question 21

What would you see in a cardiac exam?

Answer 21

• Kussmaul’s sign
• Cardiomegaly
• S3 almost universal (LV or RV)
• S4 rare; absent in A fib.
• Pulsus alternans
• Murmurs
• – Systolic: MR, AS, TR
• – Diastolic: AI
• Cardiac cachexia (late)

Question 22

What would you see in laboratory test?

Answer 22

• Electrolyte abnormalities (GFR, lytes)
• Liver enzyme elevations (stasis)
• Findings related to precipitating causes (e.g. TSH)

Question 23

What would you see in an x-ray?

Answer 23

• Cardiomegaly
• Pulmonary congestion
• Pleural effusion
• Kerley lines

Question 24

What is the prognosis of HF patients?

Answer 24

• Overall US mortality is 50% in 5 yr; one year 30-40%

- Most die of 1) pump failure or 2) tachyarrhythmias

Question 25

What makes the prognosis worse?

Answer 25

``` Male gender CAD S3 Low/narrow pulse pressure High number NYHA functional class Reduced exercise capacity ```

Question 26

What are the therapy goals?

Answer 26

- Relieve symptoms – make the patient feel better - Improve NYHA functional class (Challenging once patient has progressed to class 3 or 4) - Decrease frequency and intensity of treatment (might reduce cost; inconsistent finding) - Delay progression of myocardial dysfunction - Reduce premature HF mortality

Question 27

What does HF therapy depend on?

Answer 27

The stage of HF

Question 28

What are the two most beneficial therapies of HF?

Answer 28

- ACEi | - Beta-blockers

Question 29

Describe stage A therapy

Answer 29

Pre-symptoms, at risk but heart is okay - ACE inhibitors are drug of choice - Beta blockers may be beneficial - Aim to prevent dysfunction and HF or any irreversible damage

Question 30

Describe stage B therapy

Answer 30

Cardiac structure changes without symptoms Drugs of choice - ACEi - Beta blockers - Diuretics - Digoxin (?) Goal is to prevent worsening dysfunction, reduce hospitalizations, etc.

Question 31

Describe stage C therapy

Answer 31

Cardiac structure changes with symptoms Drugs of choice - ACEi - Spironolactone - Diuretics - Beta blockers Goal is to reduce premature HF mortality, reduce disability and hospitalization and reduce symptoms

Question 32

Describe stage D therapy

Answer 32

Advanced disease with continued symptoms Drugs cannot salvage the patient! - ACEi will improve symptoms and reduce premature HF mortality Goals - Palliation - Reduce hospitalizations - Bridge patient to transplant

Question 33

How important are ACEi?

Answer 33

VERY | - ACEIs are now mandatory agents for treating HF

Question 34

How do ACEi work?

Answer 34

Adverse effects of angiotensin II in HF—mediated by AT-1 receptors: - Myocyte hypertrophy - Myocyte apoptosis - Presynaptic facilitation of norepinephrine release - Direct myocyte toxicity - Proliferation of fibroblasts

Question 35

Should you use ARBs instead of ACEi?

Answer 35

Angiotensin Receptor Blockers - No, generally stick with ACEi - May be useful in combination

Question 36

When should vasodilators be used?

Answer 36

When ACEi are not tolerated

Question 37

What are two beta blockers

Answer 37

Metoprolol - Beta-1 antagonist Carvediolol - Beta-1 antagonist with vasodilator properties

Question 38

What do you do when a patient responds poorly to therapy?

Answer 38

Strategies for improvement - Patient education (compliance) - Review diagnoses, retest - Modify therapy

Question 39

Why do patients sometimes respond poorly?

Answer 39

- Poor compliance - Advanced myocardial dysfunction - Co-existing diseases (e.g. renal, liver)