Heart Failure occurs when the heart is failing to move blood adequately around the body.
What does the cardiovascular system do?
The cardiovascular system (CVS) consists of the heart, lungs and blood vessels. It is responsible for transportation of vital nutrients, gases and hormones throughout the body. The heart functions as the central pump with the blood vessels the pipes of the body. The CVS is controlled by a number of internal and external systems, which keep the CVS in balance with the needs of the body.
The heart is a pear shaped organ positioned centrally within the chest cavity with the apex extending over to the left nipple. The heart is a divided into a right and left side, each side has an atrium and ventricle. Heart valves and the contraction of the heart muscle control blood flow through the heart. The right side receives de-oxygenated blood from the major veins of the body and pumps this blood into the lungs. The left side of the heart then receives oxygen rich blood from the lungs and pumps this blood into the Aorta and arteries of the body. This pumping action is a complex well-coordinated activity that cannot be fully explained here. The heart receives its blood supply via the left and right coronary arteries.
This image was sourced using a google image search
Poor or abnormal function of the cardiovascular system
May be a result of:
- Insufficient blood supply due to dehydration, bleeding or swelling;
- A poor blood supply to the heart, where there is not enough oxygen and other nutrients for its work;
- Poor lung function or obstruction to blood flow in the lungs, which places a strain on the heart muscle;
- Too many or too few electrolytes (eg. potassium, magnesium) that cause irregular heartbeats or dangerous rhythms in the heart.
- Weakness of blood vessel walls.
- Heart muscle weakness
What is Heart Failure?
Heart Failure occurs when the heart fails in its ability to work as a functional pump to move blood adequately around the body. Heart failure can occur when the pumping function of the heart is abnormal; this is called Systolic Heart Failure. This type of Heart failure is the most common. Heart failure can also occur when the heart is unable to fill properly with blood, despite normal muscle contraction. This is called Diastolic Heart Failure. Some patients have a combination of both of these features and have Combined Heart Failure.
The main cause of heart failure in Australia, and also the rest of the western world, is Ischaemic Heart Disease (I.H.D). This disease affects the heart because there is a decrease in the amount of oxygen that is able to get to the cells of the heart muscle. High Blood pressure also contributes significantly to the development of this disease process. It may occur very rapidly, for example if the person has a major heart attack, or it may occur over time and become a chronic condition. There are other causes which are much more uncommon such as valvular disease, cardiomyopathy and chronic arrhythmias.
What happens in Intensive Care/ Coronary Care?
When a person is admitted with heart failure the main aims of therapy are to rest the person, to reduce the workload of the heart and to improve the pumping ability of the heart. This treatment is generally drug therapy, which aids in improving the pumping action of the heart muscle and treatment to ensure the proper volume of blood in the body. Patients may be admitted to either an Intensive Care Unit or a Coronary Care Unit. Close monitoring of vital signs will be done using a bedside monitor and oxygen saturation monitor. In more severe cases an arterial line and a pulmonary artery catheter may be required. They will receive supplemental oxygen usually via a oxygen mask however non-invasive ventilation using a CPAP machine (mask attached to a breathing machine) may be used for patients with acute pulmonary oedema. Occasionally a patient will need full respiratory support using an endotracheal tube (breathing tube) and ventilator (the breathing machine).
Signs and Symptoms
- Difficulty in breathing (especially when laying down) due to collection of fluid in the lungs;
- Increased fatique and decreased exercise tolerance due to the heart’s inability to increase its workload with increased demand;
- Increased weight and swelling of hands, legs or feet due to fluid retention;
- Low blood pressure due to failure of the cardiovascular system to compensate for the failing heart.
Tests that may be done in the intensive Care Unit
Treatment of the patient will depend on the severity of their presentation. Patients with mild to moderate symptoms will generally be managed by the cardiac team in a coronary care unit (or combined ICU/CCU). However some patients may present with severe symptoms and may require the full support of an ICU. In a number of cases where the heart failure is extremely severe the doctors use mechanical devices to improve cardiac output (amount of blood the heart can pump) such as an intra aortic balloon pump or a ventricular assist device.
A variety of drug therapies are used to treat heart failure:
- ACE inhibitors – this group of drugs deceases the workload of the heart by lowering blood pressure and preventing fluid retention by the kidneys;
- Diuretics - increase urine production to treat the fluid retention
- Vasodilators - dilate blood vessels which decrease the workload of the heart;
- Beta blocking agents - slow the heart rate and this decreases the workload of the heart;
- Antiarrhythmic drugs - keep the heart in a normal heart rhythm;
- Inotropic drugs -strengthen heart contraction
How long will the patient remain in Intensive Care?
The time that the person will remain in Intensive Care or Coronary Care will vary depending on the prognosis of the patient. The prognosis of patients with heart failure depends primarily on the nature of the underlying heart disease and if the precipitating factor bringing the person into hospital can be treated effectively. Some patients with severe heart failure may require to be put on a waiting list for a heart transplant. The team of specialist doctors and Nurses working in the Intensive Care Unit will be able to help give you information on each specific case.
The information contained on this page is general in nature and therefore cannot reflect individual patient variation. In addition it reflects Australian intensive care practice which may differ from other countries. It is meant as a back up to specific information which will be discussed with you by the Doctors and Nurses caring for your loved one. ICCMU attests to the accuracy of the information contained here BUT takes no responsibility for how it may apply to an individual patient. Please refer to the full disclaimer.
Heart Failure Version 1 (Authors Mark Mclennan CNC NRAHS and Kaye Rolls CNC ICCMU)
First Published April 2005, revised October 2005