Heart Failure

Basics

Description

CHF, now referred to simply as “heart failure” (HF), is a heterogeneous clinical syndrome resulting from either impaired filling or ejection of blood from the ventricle
HF often results in progressive debility, episodes of acute decompensation
High (>50%) 5-yr mortality
Affects ∼5.1 million Americans
Estimated 2013 cost of CHF is >$30 billion
Leading Medicare diagnosis for hospitalized patients ≥65 yr old
Acute decompensated heart failure (ADHF): Acute onset of new or worsening symptoms of HF (hr–days)
- Common reason for presentation to the ED:
  - 70% are recurrent exacerbations of chronic HF
  - 15% are new diagnosis of HF
  - 5% end-stage/terminal event
- ADHF may result from worsening cardiac pump function, or from changes in preload or afterload:
  - Precipitating events include rapid increase in sympathetic tone, concomitant illness, arrhythmia, myocardial ischemia, progressive valve disease, intravascular volume increase
- 4 common phenotypical presentations based on adequacy of perfusion (warm versus cold) and presence of congestion (wet vs. dry)
Chronic HF is a progressive failure state (mo–yr) characterized by structural and functional changes, with two main subclasses:
- Heart failure with reduced ejection fraction (HFrEF):
  - Impaired contractility or pump function causing decreased ejection fraction (EF <40%)
  - Estimated prevalence 50%
  - Many have concomittent diastolic dysfunction
- Heart failure with preserved ejection fraction (HFpEF) EF >50%
  - Impaired ventricular relaxation and compliance resulting in decreased cardiac filling
  - More common in older patients, women, patients with HTN
ACCF/AHA stages: Progressive stages denote nonreversible cardiac dysfunction. A–D, where A = risk but no disease, and D = refractory HF
NYHA classification: Functional classes I–IV, where I has no limit on physical ability and IV has symptoms of HF at rest. Patients may improve class with therapy

Etiology

Underlying causes and acute precipitants:

HF may result from disorders of the heart valves, endocardium, myocardium, pericardium, and metabolic derangements
Decreased myocardial contractility:
- Ischemic cardiomyopathy
- Nonischemic cardiomyopathies:
  - Familial, obesity, diabetic
  - Endocrine: Hypothyroid, acromegaly,
  - Pregnancy-related dilated CMP
  - Toxin-related (alcohol, cocaine, chemotherapy)
  - Inflammatory: Infectious and noninfectious myocarditis (viral, Chagas, SLE, HIV)
  - Tachycardia-induced
  - Amyloidosis
  - Cardiac sarcoidosis
Increased pressure states:
- HTN
- Valvular abnormalities
- Congenital heart disease
- RH failure due to pulmonary hypertension: Primary PAH, OSA, COPD, CTEPH, IPF, and others
- Pulmonary embolism
Volume overload:
- Dietary indiscretion (sodium overload)
- Drugs leading to sodium retention (glucocorticoids, NSAIDs)
- Overload due to transfusion or IV fluid
High demand states:
- Hyperthyroidism, thyrotoxicosis
- Pregnancy
- A-V fistula
- Beriberi (thiamine deficiency)
- Paget disease
- Severe anemia
- Aortic insufficiency
Pediatric etiologies: Volume/pressure overload lesions vs. acquired HD:
- First 6 mo: VSD and PDA
- Older children: Subvalvular aortic stenosis, coarctation
- Acquired dysfunction: Nonspecific age of onset, including myocarditis, valvular disease, and cardiomyopathies; cocaine/stimulant abuse in adolescents

There's more to see -- the rest of this topic is available only to subscribers.