138 Heart Failure

Question 1

HF as syndrome, criteria

Answer 1

• Heart failure (HF) is a syndrome
• HF is when the heart:

1. Cannot produce enough cardiac output to meet the metabolic demands of the body OR
2. Can only produce enough cardiac output at the expense of ­cardiac filling pressures OR
3. Both #1 and #2 above (low cardiac output and elevated filling pressures)

•HF has been variably defined as…

–A renal problem: Na+ and fluid retention

–Forward failure vs backward failure

–Right-sided failure vs left-sided failure

–Systolic HF vs diastolic HF

–A neurohormonal problem

–An electromechanical problem

•Often multifactorial

Question 2

•5-year survival after HF hospitalization

Answer 2

Only 30-35%

Question 3

Systolic Dysfunction à HF with Reduced Ejection Fraction (HFrEF)

Answer 3

Question 4

Key pathophysiology of HF#1: decreased CO

(symptoms/signs)

Answer 4

•Symptoms:

–Fatigue, dyspnea, exercise intolerance, end-organ failure (e.g., ¯urine output)

•Signs:

–Hypotension, hypothermia

–Cool extremities, weak carotid upstroke

–Cardiac cachexia

Question 5

Diastolic Dysfunction à Heart Failure with Reduced Ejection Fraction (HFrEF)

Answer 5

Question 6

Key pathophysiology of HF#2: ­increased FP

Answer 6

•increased ­LV filling pressures:

–Pulmonary venous congestion

–Symptoms: dyspnea, orthopnea, PND

–Signs: pulmonary rales

•­increased RV filling pressures:

–Systemic venous congestion

–Symptoms: leg swelling, abdominal bloating

–Signs: ­JVP, ascites, hepatomegaly, edema

causes of increased filling pressures:

• Impaired LV or RV relaxation
• Reduced LV or RV compliance (­stiffness)
• Fluid overload (e.g., renal failure)

Question 7

Systolic dysfunction vs systolic HF

Answer 7

Question 8

Diastolic dysfunction vs diastolic HF

Answer 8

Question 9

HFrEF vs HFpEF

Answer 9

Question 10

HF with preserved EF (HFpEF

Answer 10

• Sounds like “huff puff”, EF > 45-50%
• 40-50% of patients with HF have HFpEF
• Prevalence is increasing
• Heterogeneous pathophysiology:

–Diastolic dysfunction

–Chronotropic incompetence

–Abnormal ventricular-vascular coupling

–Extracardiac cause of fluid overload (renal)

Question 11

Neurohormonal activation in HF

Why is neurohormonal activation bad?

Answer 11

Sympathetic nervous system:

• decrease in CO leads to decreased perfusion pressure sensed by carotid baroreceptors
• Results in increased sympathetic outflow
• Initially a good thing:

–The body is trying to preserve BP

–BP = CO x TPR = HR x SV x TPR

–­SNS increases HR, contractility, vasoconstriction

Why is neurohormonal activation bad?

• Natriuretic peptides are good
• SNS, RAAS, AVP activation: all bad
• Initially they are compensatory
• They very quickly worsen the HF syndrome

–Sodium and water retention: ­congestion

–Vasoconstriction: ­afterload = ¯CO

–Ang II, aldosterone: ­cardiac fibrosis

Question 12

Deleterious Effects of Angiotensin II

Answer 12

Question 13

Arginine vasopressin (AVP, ADH)

Answer 13

Question 14

Natriuretic peptides (NPs)

Answer 14

Question 16

Cardiac remodeling in HF

Answer 16

Question 17

•3 common types of electric problems in HF:

Answer 17

–Scar formation = focal re-entry = ventricular tachycardia

–Atrial enlargement/overload = atrial fibrosis = atrial fibrillation / atrial flutter

–Electric remodeling = intra- and interventricular dyssynchrony à further deterioration in cardiac output

Question 18

Triggers of Decompensation in HF

Answer 18

• Sodium intake
• Renal failure
• Fluid administration
• Uncontrolled hypertension
• Infection
• Fever
• Chronic obstructive pulmonary disease

Question 19

Common Symptoms and Exam Findings in HF Left vs Right Sided

Answer 19

Question 20

Heart Failure staging and class system

Answer 20

Question 21

Right Heart Failure

Answer 21

• RV is Highly Compliant
• Accepts preload readily
• Needs preload: “Preload sensitive”
• Afterload sensitive
• RV afterload can be:

–Pulmonic stenosis

–Pulmonary arterial hypertension

–Intrinsic lung disease

–Sleep apnea

–LV failure

Question 22

High Output Cardiac Failure

Answer 22

•High Cardiac Output

–Hyperthyroidism (Increased Stroke Volume)

–Severe Anemia (Increased Stroke Volume)

–Vasodilatation (thiamine deficiency)

–Arterio-venous fistula

• Leads to circulatory overload
• Leads to elevated filling pressures
• May lead to cardiac dilatation

Question 23

Key Summary HF

Answer 23

• •HF is a common, costly, deadly syndrome
• •2 main pathophysiologic abnormalities
  
  • –Decreased cardiac output and/or
  • –Elevated cardiac filling pressures
• •Systolic and diastolic HF:
  
  • –Equivalent symptoms, severity, and neurohormonal activation
  • –Differ by underlying anatomic structure/function only
• •Maladaptive neurohormonal activation: key factor causing the downward spiral in HF