Heart Failure

Definition/Description

Heart failure is a complex clinical syndrome of symptoms and signs that suggest impairment of the heart as a pump supporting physiological circulation[1]. It occurs when the heart becomes less efficient at pumping blood around the body at the right pressure in order to sustain bodily functions to a high standard[1]. It commonly is a result of myocardial muscle dysfunction or loss, and is characterised by left ventricle dilation or hypertrophy, elevated cardiac filling pressure and/or inadequate peripheral oxygen delivery, at rest or during stress[2].

The condition can be acute, transient, or chronic:

  • Acute is the first presentation of heart failure or a sudden onset of heart failure
  • Transient is when heart failure is recurrent or episodic
  • Chronic is heart failure that is persistent, worsening, or decompensate. It usually offset at first by compensatory mechanisms to maintain tissue perfusion, but eventually cardiac function declines and symptoms develop.[1]

Classification

Heart failure can be classified into three different types:

Left Ventricular Failure (LVF): this is the most common form of heart failure, gradually pushing up pressure in the left atrium and pulmonary vascular system. The resulting pulmonary hypertension may force fluid into the alveoli creating a pulmonary oedema. This can cause compensatory mechanisms[3]:

  • Fast acting neural systems increase sympathetic acting, raising heart rate and myocardial contractility
  • The slower response of the retin-antiogtensin mechanism promotes the retention of sodium and water by the kidney, increasing preload and encouraging myocardium to contract

The compensatory mechanisms raise the workload of the left ventricle further because angiotensin is an arterial vasoconstrictor and increases the afterload. Other factors that can increase the workload of the left ventricle are increased volume load as in aortic valve regurgitation, or increased resistance to flow such as with systemic hypertension.[2]

Right Ventricle Failure (RVF): this generally occurs secondary to cardiopulmonary disorders such as pulmonary hypertension, right ventricle infraction, congenital heart disease, pulmonary embolism or COPD. It is usually irreversible unless the ventricles is underloaded e.g. by lung transplant for pulmonary hypertension. Enlargement of the right ventricle that has resulted from lung disease is referred to as cor pulmonale and is caused by hypoxic vasoconstriction and pulmonary hypertension.[3]

Congestive Cardiac Failure (CCF): combination of LVF and RVF with congestion in the pulmonary and systemic circulations[3]


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Helpful Terminology:

  • Stroke volume: volume of blood ejected by the ventricle in one contraction, usually 70ml
  • End diastolic volume: volume of blood in the ventricle at the end of filling, just before it contracts, usually 120ml
  • Ejection fraction: stroke volume expressed as a percentage of end diastolic volume, normally >55%
  • Systolic heart failure: reduced or weakened pumping action of the heart, with ejection fraction <55%
  • Diastolic heart failure: low compliance of myocardium, but with normal contraction and normal ejection fraction
  • Preload: degree of stretch applied to the ventricle before contraction
  • Afterload: load that the ventricle must overcome to eject blood[3]

NYHA GRADING[4]

CLASS PATIENT SYMPTOMS
I No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, dyspnea (shortness of breath
II Slight limitation of physical activity. Comfortable at rest. Ordinary physical activity results in fatigue, palpitation, dyspnea (shortness of breath).
III Marked limitation of physical activity. Comfortable at rest. Less than ordinary activity causes fatigue, palpitation, or dyspnea
IV Unable to carry on any physical activity without discomfort. Symptoms of heart failure at rest. If any physical activity is undertaken, discomfort increases.
[5]

Epidemiology

It is estimated that around 800,000 people in the UK suffer from heart failure, a number which will continue to rise due to an ageing population, improved survival rates following a heart attack, and more effective treatments.[2] The prevalence of heart failure doubles with each decade. The British Heart Foundation statistics estimate the incidence and prevalence of heart failure in the UK, using the Clinical Practice Research data, show that both rise steeply with age.[2] The British Heart Foundation reports that 0.9% of men and 0.7% of women in the UK suffer from heart failure, rising to 13.1% of men and 11.9% of women aged over 75 years old.[2]


Heart failure is the leading cause of hospitalisation in the elderly population and accounts for one million inpatient bed-days[1]. Survival rates for heart failure patients are variable, dependent on the age and severity of disease of the patient, and the quality of care they receive[1]. Outcomes are consistently poor for patients who receive suboptimal care, but input from heart failure specialists and prescription of evidence-based heart failure therapies have a significant impact on prognosis and life expectancy[2]. The National Heart Failure Audit has reported around one in ten patients dying in hospital, and of those who survive between one-quarter and one-third dying within the year of their admission[2]. However these mortality rates are beginning to reduce, reflecting more consistent implementation of guidelines for recommended practice.[2]

Aetiology

It is rare for heart failure to be derived from one cause, it is normally multi-factorial. A number of health conditions increase your chances of developing heart failure but in general it is causes by an excess workload placed on the heart[3]. Excess workload on the heart involves on or both ventricles and is thought to relate to oxidative stress and inflammation which leads to one or more of the following:[3]

  • Impaired contractibility of the myocardium e.g. after acute coronary syndromes
  • Increased afterload e.g. with hypertension or aortic valve stenosis
  • Increased preload e.g. with mitral or aortic valve regurgitation

In addition anaemia, overactive thyroid gland (hyperthyroidism), pulmonary hypertension, diabetes, chronic renal impairment, chronic obstructive pulmonary disease (COPD), and asthma are reported as potential causes of heart failure.[1]

Pathophysiology

In response to increased load, the left ventricular myocardium hypertrophies.The greater size and number of myocytes raises myocardial oxygen demand and increases diffusion distance for oxygen. Some muscel fibres become ischaemic, leading to pathcy fibrosis, stiffness and reduced contractability[1]. The workload may cause the ventricle to stretch and dilate, leading to further force being required to maintain cardiac output[1]. Systolic failure is by reduced ejection fraction and diastolic failure is by reduced end-diastolic volume. Metabolic effects include loss of bone mineralisation, skeletal muscel and fat[3].

The stiffness and reduced contractibility push up end-diastolic pressure, which is transmitted back along the pulmonary veins to the pulmonary capillaries, which causes fluid to be forced into the interstitial spaces and, if severe, into the alveoli, causing pulmonary oedema. The increased pulmonary vascular pressure raises the afterload of the right ventricle, in the same way as chronic systemic hypertension raises the afterload of the left ventricle[2]. Hypertrophy, patchy fibrosis, stiffness and reduced contractibility of the right ventricular myocardium then ensues, as with left ventricle, and congestive cardiac failure develops[1].


Clinical Manifestations

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Typical

  • Breathlessness
  • Ankle swelling
  • Fatigue
  • Orthopnea
  • Reduced Exercise Tolerance

These are the typical signs and symptoms of heart failure. Howerver heart failure may be hard to diagnose using only these characteristics, especially in women, elderly, pregnant or obese patients as they are fairly common and wide spread symptoms found in many other diseases. Due to this, suspected heart failure and patients following this pattern should be assessed carefully and using different methods to get a full picture of the condition.

Fatigue is an essential symptom of heart failure. The cause of fatigue includes low cardiac output, peripheral hypoperfusion, skeletal muscle deconditioning and is confounded by difficulties in quantifying this symptom.
Peripheral oedema, raised venous pressure, and hepa- tomegaly are the characteristic signs of congestion of systemic veins. Clinical signs of heart failure should be assessed in clinical examinations including palpation, observation and auscultation of the patient.

More Specific 

  • Elevated Jugular Venous Pressure
  • Heptojugular Reflux
  • Third Heart Sound (Gallop Rhythm)
  • Laterally Displaced Apical Impulse
  • Cardiac Mumur

Physiotherapy and Other Management

Effective treatment for heart failure should aim to:

  • Strengthen the heart
  • Improve symptoms
  • Reduce the risk of a flare-up or worsening of symptoms
  • Improve Quality of Life
  • Offer longevity

With all patients, especially heart failure populations, the complex interations between the multidisciplinary teams involved is imperative.

A Physiotherapists role is to be involved before an incident occurs as a preventatitve method (if possible) whilst also improving quality of life, continuing recovery immediately after surgery and providing education to leading a more balanced life.

The other members of the MDT is vast but includes:

Surgeons and consultants- to operate if needed, numerous operations are avaliable and may be suitable for certain patients.

For example:

  • Heart Valve Surgery
  • Angioplasty or Bypass
  • Left Ventricular Assist Devices
  • Heart Transplant


However this is individual and would need to be discussed with the consultant in charge of the case.

Nutritionalsts- to work out a diet plan to suit the individual needs of the patient. As diet is a risk factor for CHD this is an extremely important member of the MDT for further prevention.

Councellor- as Heart failure is normally a lifelong condition the patient may have difficulty coming to terms with the impact this will have on their life. A counciller will be avalaibe for sessions on coping with the disease.

Personal Trainer- as with a Physiotherapist will help to provide a more balanced lifestyle and improve fitness levels. This is something that will not only give the patient goals to work towards but also important social interaction wth someone who is seen as less of a medical figure and therefore add more normality to the individuals day to day life.

Family and Friends- This suppourt network is an extremely important factor contributing to recover of a patient and should not be overlooked.

The list of people involved in this team is huge and is not exhaustive in this piece, however , Pharmastists, Social Groups, Gp’s, Nurses and Podiatrists are all members of this MDT.

Recovery cannot occur without input and communication from every member of the team.

Prevention

There are many factors that increase the risk of developing heart failure. And with some lifestyle changes and sometimes drug intervention this risk could be dramatically reduced. Hypertension and smoking are major risks for heart failure.

Stop smoking
Quitting smoking is noted as the single best way to reduce risk of heart failure. Smoking has many physiological effects forcing the heart to walk harder.
Smoking increasing viscosity of the blood, slowing the blood and therefore increasing risk of thrombosis (blood clots). It also causes damage to the arterie lining leading to atherosclerosis and reduction in artery diamater.

Reduce blood pressure.
High blood pressure increases the work demand put on the heart to transport blood around the body, this increased work causes a hypertrophic reaction of the heart muscle, eventually leading to a weakened or stiff heart.
Blood pressure medications and exercise can be used to modulate blood pressure.

Reduce Cholesterol Level
High levels of cholesterol in can cause furring and narrowing of the arteries termed atherosclerosis and eventually heart failure.

Lose weight
Being overweight increases demand placed on the heart and increases risk of heart failure and attack.

Eat a healthy diet
A healthy diet can help reduce your risk of developing coronary heart disease and therefore heart failure.
Keep active
Regular physical activity will help keep the heart healthy and also maintain a healthy weight.

Reduce Alcohol intake
Drinking excess of the recommended amount of alcohol per week can increase your blood pressure.
Heavy drinking for long periods of time can cause damage to your heart muscle leading directly to heart failure.

Cut your salt intake
Excessive salt intake increases blood pressure and again, increases stress put on the heart.

Resources

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Dickstein, K.ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure. European Journal of Heart Failure. 2008. Aug;10:933-989.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 British Society for Heart Failure. National Heart Failure Audit. London. November 2013.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Hough, A. Physiotherapy in Respiratory and Cardiac Care: An Evidence Based Approach. Hampshire. Cengage Learning EMEA; 2014.
  4. http://www.heart.org/HEARTORG/Conditions/HeartFailure/AboutHeartFailure/Classes-of-Heart-Failure_UCM_306328_Article.jsp#.WF1jIFN97IU
  5. classification system of heart failure