Download Heart Failure—Definition

Chapter 20
Heart Failure
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Heart Failure—Definition
• Heart failure is a clinical syndrome characterized by shortness
of breath, dyspnea on exertion (DOE), paroxysmal nocturnal
dyspnea (PND), orthopnea, and peripheral or pulmonary
edema.
• Heart failure is a general term used to describe the general
clinical syndrome regardless of the kind of heart failure or the
etiology that produces the symptoms.
• The revised guidelines recently published by a joint American
College of Cardiology (ACC) and American Heart Association
(AHA) task force use the preferred term heart failure rather
than congestive heart failure because patients with chronic
heart failure rarely demonstrate the rales and alveolar edema
associated with congestion.
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Acute Versus Chronic
• Describes the onset and intensity of symptoms
• Acute: sudden onset over days or hours
• Chronic: develop over months to years
• If the cause of acute symptoms is not reversed, then
heart failure will become chronic.
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Question
• Left ventricular diastolic heart failure is characterized by
which of the following?
– A. Pulmonary congestion on CXR
– B. Ejection fraction greater than 40%
– C. Decreased contractility
– D. Decreased ventricular volume
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Answer
•
A. Pulmonary congestion on CXR
•
Rationale: In left ventricular diastolic failure, the left
ventricle is unable to fill completely, resulting in
diminished cardiac output with a normal or high ejection
fraction. Conditions associated with the development of
diastolic failure are stiff and poorly compliant ventricles
from aging, uncontrolled hypertension, or volume
overload, combined with a fast heart rate or atrial
fibrillation.
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Left-Sided Heart Failure
• Failure of the left ventricle to fill or empty properly
• Leads to increase in ventricular pressures and pulmonary
vascular congestion
• Systolic dysfunction
– Decrease in contractility
– EF less than 40%
• Diastolic dysfunction
– Impaired relaxation and filling
– EF may be as high as 80%.
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Right-Sided Heart Failure
• Failure of the right ventricle to pump adequately
• Left-sided heart failure is the most common cause.
• Can result from pulmonary disease or pulmonary
hypertension
• PE is the common cause of acute right-sided heart
failure.
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Classification Systems
• New York Heart Association Functional Classification
– Measure of how much the symptoms of heart failure
limit the activities of patients
• American College of Cardiology/American Heart
Association Guidelines
– Outline four stages of heart failure that are useful for
organizing the prevention, diagnosis, management,
and prognosis for patients with heart failure
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Question
• Is the following statement true or false?
• The underlying result of heart failure is insufficient
cardiac output.
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Answer
• True
• Rationale: The underlying result of all types of heart
failure is insufficient cardiac output. That is, the volume
of blood pumped by the heart in 1 minute is inadequate.
Some patients may have a normal cardiac output at rest,
but they do not have the reserve function to increase
cardiac output to meet the increased demands of
exercise, hypoxemia, or anemia.
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Factors That Determine Cardiac Output
• Underlying result of heart failure is insufficient CO.
• Oxygen demand
– CO increases to meet increased O2 demand.
• Mechanical factors
– Stroke volume and heart rate
• Neurohormonal mechanisms
– Catecholamines
– Renin–angiotensin–aldosterone system
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Pathophysiology
• Cardiomyopathy
• Dysrhythmias
– Atrial dysrhythmias
– Ventricular dysrhythmias
• Acute decompensated heart failure
– Triggered by alcohol, anemia, hypoxemia,
hypertension, ischemia, and worsening left
ventricular function
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Assessment
• History
–
Onset
–
Duration
• Comorbid diseases
• Medications
• Psychosocial factors
• Substance abuse
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Physical Examination
• General findings
• Vital signs
• Neck
• Lungs
• Heart
• Abdomen
• Extremities
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Laboratory Studies
• CBC
• Iron studies
• Thyroid function tests
• Electrolytes, BUN
• BNP
• LFTs
• HIV
• Lipid panel
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Diagnostic Studies
• Electrocardiography
• Echocardiography
• Radionuclide ventriculography
• Chest radiography
• Exercise testing
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Question
• All of the following are indications for hemodynamic
monitoring except which of the following?
– A. The patient does not respond to empirical therapy
for heart failure.
– B. The patient has an increased BNP.
– C. Differentiation between pulmonary and cardiac
causes of respiratory distress is necessary.
– D. Complex fluid status needs to be evaluated.
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Answer
• B. The patient has an increased BNP.
• Rationale: The first type is the patient who is empirically
treated with inotropes and intravenous (IV) diuretics but
has not responded appropriately to diuresis with
improved symptoms. The second type of patient has both
COPD and heart failure. At times, only pulmonary artery
pressure measurements can differentiate the source of
the current decompensation. The third type of patient
continues to have congestion associated with peripheral
edema or ascites and has renal function values indicating
worsening azotemia.
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Hemodynamics
• Indications for hemodynamic monitoring
– The patient does not respond to empirical therapy for
heart failure.
– Differentiation between pulmonary and cardiac
causes of respiratory distress is necessary.
– Complex fluid status needs to be evaluated.
• Pulse oximetry monitoring
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Management of Acute Decompensation of Heart
Failure
• Airway and breathing
–
Intubation
–
Diuresis
• Circulation
– Optimize hemodynamics.
–
Increase contractility.
–
Vasodilation
–
Heart rate
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Management of Chronic Heart Failure
• Pharmacological treatment
–
Angiotensin-converting enzyme inhibitors
–
Digoxin
–
Diuretics
–
Spironolactone
–
Calcium channel blockers
–
Nitrates
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Nonpharmacological Treatment
• Role of the patient
– Sodium restriction, alchohol cessation, exercise,
medication adherence, fluid restriction
• Implantable cardioverter–defibrillator
– For syncopal episodes or survivor of sudden death
• Biventricular pacing
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Patient Education
• Medications
• Diet
• Daily weights
• Activity
• When to call the doctor
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