Heart Failure

  • Medical Author:
    Erica Oberg, ND, MPH

    Dr. Erica Oberg, ND, MPH, received a BA in anthropology from the University of Colorado, her doctorate of naturopathic medicine (ND) from Bastyr University, and a masters of public health (MPH) in health services research from the University of Washington. She completed her residency at the Bastyr Center for Natural Health in ambulatory primary care and fellowship training at the Health Promotion Research Center at the University of Washington.

  • Medical Author: Mimi Guarneri, MD, FACC, ABIHM
    Mimi Guarneri, MD, FACC, ABIHM

    Dr. Mimi Guarneri, MD, FACC, ABIHM, is board certified in cardiovascular disease, internal medicine, nuclear medicine, and holistic medicine. Dr. Guarneri is president of the American Board of Integrative Holistic Medicine and serves as Senior Advisor to the Atlantic Health System for the Center for Well Being and Integrative Medicine. Dr. Guarneri is founder and director of Guarneri Integrative Health, Inc. and Taylor Academy for Integrative Medicine Education and Research located at Pacific Pearl La Jolla in La Jolla, CA.

  • Medical Editor: John P. Cunha, DO, FACOEP
    John P. Cunha, DO, FACOEP

    John P. Cunha, DO, FACOEP

    John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.

Quick GuideHeart Disease: Causes of a Heart Attack

Heart Disease: Causes of a Heart Attack

What causes heart failure?

The cause of heart failure is a weakened or thickened cardiac muscle. For example, in chronic high blood pressure (hypertension), the heart must pump extra forcefully against the additional blood pressure. First it becomes enlarged and thickened. But over time, the heart weakens, scarring (fibrosis) develops, and it becomes less efficient at pumping. It can become larger (dilated) and weak or thickened and stiff. When the risk factors for heart failure are present, there usually is inflammatory stress, which further damages the cardiac muscle depleting cells of energy and antioxidants.

What are heart failure stages or classifications?

While doctors define heart failure in stages or classifications, it represents a progression of heart muscle weakness. Sometimes people refer to this process as chronic heart failure but technically that term isn't correct.

The New York Heart Association (NYHA) puts the stages of heart failure into four classifications:

  • Class I: no limitations in activity. Normal activities can be performed.
  • Class II: mild limitations and mild symptoms with activity; no symptoms at rest
  • Class III: noticeable limitations in activity; only comfortable at rest
  • Class IV: symptoms occur at any level of activity and uncomfortable even resting

The American Heart Association along with the American College of Cardiology grades heart failure in four stages, and takes into account that heart failure can be present even before symptoms appear:

  • Stage A: No heart failure, but at high risk due to another medical condition that can lead to heart failure, such as high blood pressure, diabetes, obesity, or coronary artery disease.
  • Stage B: The heart has been damaged by the patient's other medical condition(s) or other factors, but no symptoms are present yet.
  • Stage C: The heart is damaged and the patient is experiencing heart failure symptoms.
  • Stage D: The patient has severe heart failure that requires specialized care, despite receiving treatment (end-stage).

How is heart failure diagnosed?

  • Heart failure can be diagnosed by physical exam, reported symptoms, or chest X-ray.
  • An echocardiogram test can identify a low ejection fraction or a thickened, stiff heart muscle.
  • Echocardiograms may be used to distinguish between systolic and diastolic types of heart failure.
  • Blood tests such as BNP (beta naturetic peptide) suggest heart failure.
  • Algorithms and guidelines exist to score and weigh signs and symptoms to help make the diagnosis.
Medically Reviewed by a Doctor on 9/22/2016

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