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('''CHF'''), also called '''congestive cardiac failure''' ('''CCF''') or just '''heart failure''', is a condition that can result from any structural or functional
Cardiac disorder that impairs the ability of the
Heart to fill with or pump a sufficient amount of
Blood through the body. It is not to be confused with "''cessation of heartbeat''", which is known as
Asystole , or with
Cardiac Arrest , which is the cessation of normal cardiac function with subsequent hemodynamic collapse leading to
Death . Because not all patients have
Volume Overload at the time of initial or subsequent evaluation, the term "heart failure" is preferred over the older term "congestive heart failure".
Congestive heart failure is often undiagnosed due to a lack of a universally agreed definition and difficulties in diagnosis, particularly when the condition is considered "mild". Even with the best therapy, heart failure is associated with an annual mortality of 10%.
1 It is the leading cause of hospitalization in people older than 65.
2
There are many different ways to categorize heart failure, including:
The symptoms depend largely on the side of the heart which is failing predominantly. If both sides are functioning inadequately, symptoms and signs from both categories may be present.
Given that the left side of the heart pumps blood from the
Lung s to the organs, failure to do so leads to congestion of the lung veins and symptoms that reflect this, as well as reduced supply of blood to the tissues. The predominant respiratory symptom is shortness of breath on exertion (
Dyspnea , ''dyspnée d'effort'') - or in severe cases at rest - and easy fatigueability.
Orthopnea is increasing breathlessness on reclining, measured in the number of pillows required to lie comfortably.
Paroxysmal Nocturnal Dyspnea is a nighttime attack of severe breathlessness, usually several hours after going to sleep. Poor circulation to the body leads to
Dizziness ,
Confusion and
Diaphoresis and cool extremities at rest.
The right side of the heart pumps blood returned from the tissues to the lungs to exchange
CO2 for
O2 . Hence, failure of the right side leads to congestion of peripheral tissues. This may lead to
Peripheral Edema or
Anasarca and
Nocturia (frequent nighttime urination when the fluid from the legs is returned to the bloodstream). In more severe cases,
Ascites (fluid accumulation in the abdominal cavity) and
Hepatomegaly (painful enlargement of the
Liver ) may develop.
Heart failure may decompensate easily; this may occur as the result of any intercurrent illness (such as
Pneumonia ), but specifically
Myocardial Infarction (a heart attack),
Anaemia ,
Hyperthyroidism or
Arrhythmias . These place additional strain on the heart muscle, which may cause symptoms to rapidly worsen. Excessive fluid or salt intake (including
Intravenous fluids for unrelated indications), and medication that causes fluid retention (such as
NSAIDs and
Thiazolidinedione s), may also precipitate decompensation.
In examining a patient with possible heart failure, a health professional would look for particular
Signs . General signs indicating heart failure are a laterally displaced
Apex Beat (as the heart is enlarged) and a
Gallop Rhythm (additional heart sounds) in case of decompensation.
Heart Murmur s may indicate the presence of valvular heart disease, either as a cause (e.g.
Aortic Stenosis ) or as a result (e.g.
Mitral Regurgitation ) of the heart failure.
Predominant left-sided clinical signs are
Pulmonary Edema (abnormal lung sounds due to fluid accumulation), evidence for
Pleural Effusion s (fluid collection in the pleural cavity), and
Cyanosis (due to poor absorption of oxygen by fluid-filled lungs).
Right-sided signs are peripheral edema, ascites and hepatomegaly, an increased
Jugular Venous Pressure and
Hepatojugular Reflux and
Parasternal Heave .
Echocardiography is commonly used to support a clinical diagnosis of heart failure. This modality uses
Ultrasound to determine the proportion of blood entering the heart that is pumped by each heartbeat, the
Ejection Fraction . Echocardiography can also identify valvular heart disease and assess the state of the
Pericardium (connective tissue sac surrounding the heart). Echocardiography may also aid in deciding what treatments will help the patient, such as medication, insertion of an
Implantable Cardioverter-defibrillator or
Cardiac Resynchronization Therapy .
Chest X-ray s are frequently used to aid in the diagnosis of CHF. In the compensated patient, this may show
Cardiomegaly (visible enlargement of the heart), quantified as the ''cardiothoracic ratio'' (proportion of the heart size to the chest). In left ventricular failure, there may be evidence of vascular redistribution ("upper lobe blood diversion"),
Kerley Lines , cuffing of the areas around the
Bronchi , and interstitial edema.
An
Electrocardiogram (ECG/EKG) is used to identify arrhythmias,
Ischemic Heart Disease ,
Right and
Left Ventricular Hypertrophy , and presence of conduction delay or abnormalities (e.g.
Left Bundle Branch Block ).
Blood Test s routinely performed include
Electrolyte s (
Sodium ,
Potassium ), measures of
Renal Function ,
Liver Function Tests ,
Thyroid Function Test s, a
Complete Blood Count , and often
C-reactive Protein if infection is suspected. A specific test for heart failure is
B-type Natriuretic Peptide (BNP), which is found to be elevated in heart failure. BNP can be used to differentiate between causes of dyspnea due to heart failure from other causes of dyspnea. If myocardial infarction is suspected, various
Cardiac Marker s may be used.
Heart failure may be the result of
Coronary Artery Disease , and its prognosis depends in part on the ability of the
Coronary Arteries to supply blood to the
Myocardium (heart muscle). As a result,
Coronary Catheterization may be used to identify possibilities for revascularisation through
Percutaneous Coronary Intervention or
Bypass Surgery .
Various measures are often used to assess the progress of patients being treated for heart failure. These include
Fluid Balance (calculation of fluid intake and excretion), monitoring
Body Weight (which in the shorter term reflects fluid shifts).
No system of diagnostic criteria has been agreed as the
Gold Standard for heart failure. Commonly used systems are the "Framingham criteria"
3 (derived from the
Framingham Heart Study ), the "Boston criteria",
4 the "Duke criteria",
5 and (in the setting of acute myocardial infarction) the "
Killip Class ".
6
''Functional'' classification is generally done by the NYHA score.Criteria Committee, New York Heart Association. ''Diseases of the heart and blood vessels. Nomenclature and criteria for diagnosis, 6th ed.'' Boston: Little, Brown and co, 1964;114. This score documents severity of symptoms, and can be used to assess response to treatment. While its use is widespead, the NYHA score is not very reproducible and doesn't reliably predict the walking distance or exercise tolerance on formal testing.
7 The classes (I-IV) are:
- Class I: no limitation is experienced in any activities; there are no symptoms from ordinary activities.
- Class II: slight, mild limitation of activity; the patient is comfortable at rest or with mild exertion.
- Class III: marked limitation of any activity; the patient is comfortable only at rest.
- Class IV: any physical activity brings on discomfort and symptoms occur at rest.
Causes and contributing factors to congestive heart failure include the following (with specific reference to left (L) or right (R) sides):
The treatment of CHF focuses on treating the symptoms and signs of CHF and preventing the progression of disease. If there is a reversible cause of the heart failure (e.g. of smoking and drinking alcohol.
Patients with CHF are educated to undertake various non-
Pharmacological measures to improve symptoms and prognosis. Such measures include:Smith A, Aylward P, Campbell T, et al. Therapeutic Guidelines: Cardiovascular, 4th edition. North Melbourne: Therapeutic Guidelines; 2003. ISSN 1327-9513
- Moderate physical activity, when symptoms are mild or moderate; or bed rest when symptoms are severe.
- Weight reduction – through physical activity and dietary modification, as Obesity is a risk factor for heart failure and Ventricular Hypertrophy .
- Sodium restriction – excessive Sodium intake may precipitate or exacerbate heart failure, thus a "no added salt" diet (60–100 Mmol total daily intake) is recommended for patients with CHF. More severe restrictions may be required in severe CHF.
- Fluid restriction – patients with CHF have a diminished ability to Excrete Free Water load. They are also at an increased risk of Hyponatremia due to the combination of decreased sodium intake and Diuretic therapy. Generally water intake should be limited to 1.5 L daily or less in patients with Hyponatremia , though fluid restriction may be beneficial regardless in symptomatic reduction.
There is a significant evidence–practice gap in the treatment of CHF; particularly the underuse of agents,
Vasodilator agents, positive
Inotrope s,
ACE Inhibitor s,
Beta Blocker s, and
Aldosterone Antagonist s (e.g.
Spironolactone ). It should be noted that while intuitive, increasing heart function with some drugs, such as the positive
Inotrope Milrinone , leads to increased mortality
89.
and reduce
Ventricular Hypertrophy .
Angiotensin II Receptor Antagonist therapy (also referred to as AT
1-antagonists or angiotensin receptor blockers), particularly using
Candesartan , is an acceptable alternative if the patient is unable to tolerate ACEI therapy.
1213
Diuretic therapy is indicated for relief of congestive symptoms. Several classes are used, with combinations reserved for severe heart failure:
Until recently, ,
Carvedilol , and extended-release
Metoprolol .
Digoxin , once used as first-line therapy, is now reserved for control of ventricular rhythm in patients with
Atrial Fibrillation ; or where adequate control is not achieved with ACEI plus loop diuretic. There is no evidence that positive inotropes reduce mortality in CHF, although some studies suggest a decreased rate in hospital admissions. It is contraindicated in cardiac tamponade and restrictive cardiomyopathy
The combination of
Isosorbide Dinitrate/hydralazine is the only
Vasodilator regimen, other than ACE inhibitors or angiotensin II receptor antagonists, with proven survival benefits. This combination appears to be particularly beneficial in CHF patients with an African American background, who respond less effectively to ACEI therapy.
1415
Patients with
NYHA Class III or IV, left ventricular ejection fraction (LVEF) of 35% or less and a QRS interval of 120
Ms or more may benefit from cardiac resynchronization therapy (CRT; pacing both the
Left and
Right Ventricle s), through implantation of an
Bi-ventricular Pacemaker , or surgical remodelling of the heart. These treatment modalities may make the patient symptomatically better, improving quality of life and in some trials have been proven to reduce mortality.
The COMPANION trial demonstrated that CRT improved survival in individuals with
NYHA Class III or IV heart failure with a widened
QRS Complex on
EKG .
16 The CARE-HF trial showed that patients receiving CRT and optimal medical therapy benefited from a 36% reduction in all cause mortality, and a reduction in cardiovascular-related hospitalization.
17
Patients with
NYHA Class II, III or IV, and LVEF of 35% (without a QRS requirement) may also benefit from an
Implantable Cardioverter-defibrillator (ICD), a device that is proven to reduce all cause mortality by 23% compared to placebo. This mortality benefit was observed in patients who were already optimally-managed on drug therapy.
18
Another current treatment involves the use of left
Ventricular Assist Device s (LVADs). LVADs are battery-operated mechanical pump-type devices that are surgically implanted on the upper part of the abdomen. They take blood from the left ventricle and pump it through the aorta. LVADs are becoming more common and are often used by patients who have to wait for heart transplants.
The final option, if other measures have failed, is
Cardiac Transplant Surgery (heart transplant) or implantation of an
Artificial Heart . A radical new type of surgery, which is largely untested and is still in its first stages of development, was invented by Brazilian doctor
Randas Batista in
1994 . It involves removal of a swath of the
Left Ventricle , to make contractions more efficient and prevent backflow of blood into the
Left Atrium through the
Bicuspid Valve .
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The growing number of patients with Stage D heart failure (intractable symptoms of fatigue, shortness of breath or chest pain at rest despite optimal medical therapy) should be considered for palliative care or hospice, according to American College of Cardiology/American Heart Association guidelines.
Among several
Clinical Prediction Rule s for prognosing acute heart failure, the 'EFFECT rule' slightly outperformed other rules in stratifying patients and identifying those at low risk of death during hospitalization or within 30 days.
19 Easy methods for identifying low risk patients are:
- ADHERE Tree rule indicates that patients with Blood Urea Nitrogen < 43 mg/dl and Systolic Blood Pressure at least 115 mm Hg have less than 10% chance of inpatient death or complications.
- BWH rule indicates that patients with Systolic Blood Pressure over 90 mm Hg, respiratory rate of 30 or less breaths per minute, serum Sodium over 135 mmol/L, no new ST-T wave changes have less than 10% chance of inpatient death or complications.
- http://www.americanheart.org/heartfailure American Heart Association's Heart Failure web site - information and resources for treating and living with heart failure.
- Congestive Heart Failure information from Seattle Children's Hospital Heart Center
- www.heartfailure-europe.com Patient information website of SHAPE (Study Group on Heart failure Awareness and Perception in Europe)
