Heart Failure and Pulmonary Edema

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Heart Failure and Pulmonary Edema
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Definition

• Normal cardiac output is 5 lpm and increases to
  gt25 lpm with exercise
• Heart failure is when the heart cant maintain a
  high enough CO to perfuse the tissues
• 4 classifications
• Class 1 (mild) no limitation of activity or
  symptoms
• Class II (mild) slight limitationOK at rest
  but ordinary activity causes symptoms
• Class III (mod) marked limitation of
  activityless than ordinary activity causes
  symptoms
• Class IV (severe) unable to carry out any
  activity symptoms at rest

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Causes of Heart Failure

• Myocardial dysfunction
• Pressure overload
• Volume overload
• Impaired filling
• Arrhythmias/tachycardia
• High output
• Most common cause is ischemic heart disease

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Cardiovascular Compensatory Mechanisms

• Heart failsCO drops causing
• Sympathetic activation
• Increases contractility and heart rate
• Also increases myocardial work
• Causes arterial vasoconstriction, which increases
  afterload and work
• Can increase myocardial damage
• Renin-angiotensin activation
• Increases aldosterone levels causing fluid
  retention
• This increases preload, which increases
  myocardial work
• This can further increase myocardial damage

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Left Heart Failure

• More common than right heart failure
• Can lead to pulmonary edema as the hydrostatic
  pressure forces fluid into alveolar and
  interstitial spaces in the lungs
• Pulmonary edema will occur at lower pressures if
  the oncotic pressure is low

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Right Heart Failure

• Causes systemic congestion and is usually due to
  left heart failure
• Cor pulmonale is right heart failure due to
  chronic lung disease

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Pathophysiology

• Systolic (contractile) dysfunction
• Usually due to ischemic disease
• Cardiac output is maintained by compensatory
  mechanisms
• Diastolic (relaxation) dysfunction
• Usually due to ischemic disease
• Reduced LV compliance decreases filling
• Affects about 1/3 of all heart failure patients
  and precipitated by tachycardia and/or atrial fib

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Clinical Features

• Low CO causes
• Fatigue
• Anorexia
• Exercise limitation
• Symptoms of LV failure
• SOB
• Hypoxemia
• Orthopnea
• Paroxysmal nocturnal dyspnea
• Frothy pink sputum production
• Symptoms of RV failure
• Jugular venous distension
• Hepatomegaly
• Ascites
• Ankle edema

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Diagnosis

• Cardiac enzymes
• EKG
• CXR
• Echocardiography
• Ejection Fraction

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Management

• Afterload reduction
• Improves LV function and CO
• May cause hypotension
• Preload reduction
• Relieves symptoms
• Doesnt increase CO except when afterload is
  indirectly reduced

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Acute LV Failure

• Sitting position
• Supplemental oxygen
• Loop diuretics
• Pulmonary venodilation
• Reduce LV preload
• Relieve dyspnea
• Reduces volume
• Nitrates
• Increase venous capacitance
• Dilates coronary arteries
• Morphine
• Decreases preload from vasodilator effects
• Relieves anxiety
• Correction of arrhythmias

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Low Output LV Failure

• ACE inhibitors
• Reduce afterload
• Increase CO
• Reduce symptoms
• Increase survival
• Beta blockers
• Reduce myocardial ischemia and arrhythmias
• May precipitate pulm edema, heart block, or
  bronchospasm
• Calcium channel blockers
• Reduce hypertension
• Coronary vasodilation
• Impair contractility
• Digoxin
• Inotropic effects
• Especially effective with atrial fib
• anticoagulants

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Right Ventricular Failure

• Diuresis
• Reduces systemic edema
• Oxygen therapy
• Relieves cor pulmonale