3: Congestive Heart Failure

Question 1

what is: the deficiency in ability of the heart to deliver blood to meet metabolic demands of peripheral tissues?

Answer 1

congestive heart failure;

(NOTE: The heart MAY deliver blood to meet metabolic needs at an elevated filling pressure)

Question 2

why is congestive heart failure accompanied by organ congestion?

Answer 2

Accompanied by organ congestion due to failure of heart to keep
pace with venous return (“congestive heart failure”)

Question 3

epidemiology of congestive heart failure (CHF)

Answer 3

• Common end-stage of many forms of chronic heart diseases
• Affect 5 million people annually, 1 million hospitalization and 0.3 million death

Question 4

what are the classifications of congestive heart failure? (four key)

Answer 4

• Systolic dysfunction (pump failure)
• Diastolic dysfunction (> 65 yo, stiffness, more woman)
• Affected side of heart
  
  • Right-sided CHF
  • Left-Sided CHF – *most common cause of ischemia

Question 5

how does frank-starling mechanism adapt cardiac output?

Answer 5

increased stretch augments myocardial contractility

Question 6

what are the neurohumoral responses in cardiac output adaptive mechanisms?

Answer 6

• Adrenergic activation: Increased heart rate & contractility, vasoconstriction
• Renin-Angiotensin-Aldosterone system
• Atrial Natriuretic Factor (ANF), Brain Natriuretic Peptide (BNP)

Question 7

when does CHF result (with regards to cardiac output adaptive mechanisms)?

Answer 7

Congestive Heart Failure results when these mechanisms can no longer compensate for increased demand

Question 8

how does the myocardium change in cardiac adaptive mechanisms?

Answer 8

Myocardial hypertrophy w/o chamber dilation:
– Physiologic (in athlete): ↑capillary density; ↓heart rate and pressure
– Pathologic (as in HT)

Question 9

general pathology of CHF:

describe the FORWARD EFFECT

Answer 9

• Decreased arterial perfusion –> organ hypoxia
• Kidney (“pre-renal azotemia”)
• Brain

Pathology depends on the type of failure

Question 10

general pathology of CHF:

describe the BACKWARD EFFECT

Answer 10

• Pooling of blood in venous system –> congestion, edema
• Liver
• Lung

Pathology depends on the type of failure

Question 11

what are histological changes of left-sided Congestive Heart Failure?

(ACUTE changes)

Answer 11

• boxcar nuclei (these will enlarge in LV remodeling)
• – Acute changes
  
  • Congestion: distension of alveolar capillaries
  • Interstitial edema: transudation of fluid into perivascular interstitial spaces
  • Alveolar edema: fluid enters alveolar spaces
  • Alveolar hemorrhage: leakage of RBCs

Question 12

what are histological changes of left-sided Congestive Heart Failure?

(chronic changes)

Answer 12

• boxcar nuclei (these will enlarge in LV remodeling)
• – Chronic changes
  
  • Hemosiderin-laden macrophages in alveoli (“heart failure cells”)
  • Interstitial fibrosis
  • Pulmonary arterial hypertension vascular changes

Question 13

Pathology of Left-Sided CHF:

gross pathology

Answer 13

Gross pathology:

• Heavy (>500g each)
• Exude pink, foamy fluid on sectioning

Question 14

what is the MOST COMMON cause of Right-Sided congestive heart failure?

Answer 14

**Secondary to L-sided failure & isolated R-sided failure

((MOST common cause of Right sided HF is Left-sided Heart failure)

Question 15

define: cor pulmonale

and causes

Answer 15

• Right Ventricular enlargement in response to Pulmonary Arterial hypertension –> Edema
  
  • Caused by either:
    
    1. intrinsic lung disease
    2. abnormal pulmonary vasculature

Question 16

which diseases of pulmonary parenchyma predispose patients to Cor Pulmonale?

Answer 16

• chronic obstructibe pulmonary disease (COPD)
• cystic fibrosis
• diffuse PIF
• pneumoconioses
• bronchiectasis

Question 17

which diseases of pulmonary vessels predispose patients to Cor Pulmonale?

Answer 17

• Recurrent pulmonary thromboembolism
• primary pulmonary hypertension
• extensive pulmonary arteritis
• vascular obstruction
• extensive pulmonary tumor microembolism

Question 18

which disorders affecting chest movement predispose patients to Cor Pulmonale?

Answer 18

• Kyphoscoliosis,
• Marked obesity - marked obesity doesn’t affect chest movement in practice
• Neuromuscular diseases

Question 19

which disorders inducing pulmonary arterial constriction predispose patients to Cor Pulmonale?

Answer 19

• Metabolic acidosis,
• hypoxemia,
• chronic altitude sickness - some people are attempting Mt Everest and not taking the time to acclimate to the decreased O2 tension
• obstruction of major airway
• idiopathic alveolar hypoventilation

Question 20

how does pathology of ACUTE COR PULMONALE (CP) differ from CHRONIC COR PULMONALE?

Answer 20

• ACUTE CP: dilatation of RV, heart failure
• CHRONIC CP: RV wall thickening, may exceed 1 cm

Question 21

what are the gross pathological changes of Right-sided CHF on the liver?

Answer 21

• Liver: “congestive hepatomegaly”
• Gross: “Nutmeg liver” (centrilobular congestion)

Question 22

what are the MICROSCOPIC pathological changes of Right-sided CHF on the liver?

Answer 22

Depends upon severity and duration of CHF

• Congestion, distension of central veins and sinusoids (due to being filled w/ blood, “red infarct”)
• Centrilobular atrophy
• Centrilobular hemorrhage, hepatocyte necrosis
• Fibrosis (cardiac sclerosis) beginning in centrilobular zones; may rarely progress to cirrhosis (“cardiac cirrhosis”)

Question 23

how does Right-sided Congestive Heart Failure affect the serosa-lined spaces? (pericardial, pleural, peritoneal)?

Answer 23

Fills w/ transudate fluid (ascites, pleural & pericardial effusions)

Question 24

how does Right-sided Congestive Heart Failure affect the skin and subcutaneous tissue?

Answer 24

• skin is cold and sweaty
• legs, feet, and ankles start to swell as blood is backing up in veins (pitting edema)

Tx w/ dialysis if kidneys are failing; tx is diuretics to decrease the fluid