No doubt, these are initially helpful to maintain the cardiac output, but sooner or later they become not only inadequate but also harmful; and features of heart failure with all the consequences and complications set in. The manifestations of heart failure vary depending on many factors and little explanation is needed to understand the pathophysiology and features of heart failure better.Heart has failed! ...then what?
That is the crux of the issuewhat happens when the heart fails to function and pump according to the need of the body? It is really fascinating how that faithful organ puts into action all its reserve capacity and how the other organs in the body also adjust their functions to compensate for this loss in hearts capacity.
These compensatory changes are mainly directed towards an increase in heart rate and blood pressure, expansion in blood volume by retention of salt and water by the kidneys, and structural changes like thickening (hypertrophy) of heart muscle and dilatation of heart chambers.
No doubt,
these are initially
helpful to
maintain the
cardiac output, but sooner or later they become not only
inadequate but
also harmful;
and
features of heart
failure with all the consequences
and complications
set in.
No doubt, these are initially helpful to maintain the cardiac output, but sooner or later they become not only inadequate but also harmful; and features of heart failure with all the consequences and complications set in. The manifestations of heart failure vary depending on many factors and little explanation is needed to understand the pathophysiology and features of heart failure better.
The circulation of blood in the body takes place through a close circuit of two interconnected loops of conduits, something like figure-of-eight (8), with the heart at the centre. As the heart contracts and relaxes, one of the loops carries oxygen-rich blood with nutrients to the different parts of the body and brings impure blood back to the heart.
This is called systemic circulation. The other loop is smaller and is called pulmonary circulation. It takes impure blood from the heart to lungs for oxygenation and then back to the heart for distribution through systemic circulation. Any loss of cardiac function results in either a reduction in forward flow (downstream effect) or a backward stagnation (upstream effect), or more commonly, a combination of both.
The forward flow reduction shall impair supply of oxygen and nutrients whereas backward stagnation shall cause congestion. Depending on which side of the heart is affected, the brunt will be borne by the pulmonary or systemic circulation; but as the circulation is a close ended one, the effects will be evident in all parts of the body.
So, what are the clinical features? Impairment of forward flow shall deprive the tissue of oxygen and vital nutrients
causing weakness, easy fatigability and reduction in exercise capacity.
The person may have chest pain or angina because oxygen supply to the heart itself is affected. Backward stagnation shall cause congestion in the lungs with cough, wheezing, and breathlessness, especially on exertion and after lying down; and congestion in the body with pedal oedema, abdominal
pain and swelling, liver enlargement, neck vein distension, weight gain etc.
In fact a bloated, breathless and bed-ridden patient is the typical picture of heart failure; but that is seen only at the advanced stage. In the early stage the symptoms and signs may be more subtle but it is important to recognize heart failure at that time, so that appropriate steps may be taken to prevent progression and complications.
How can you suspect heart failure in the early stage? Anyone with heart diseases or risk factors should be alert to any of the symptoms like undue fatigue, breathlessness, foot or ankle swelling, abdominal pain or swelling, recent weight gain etc. and get a check-up done to rule out heart failure. It is useful to remember the mnemonic FACES as advised by Heart Failure Society of America.
F Fatigue
A Activities restricted
C Chest congestion
E Edema or swelling
S Shortness of breath
While any one of them can be a pointer to the development of heart failure, one should understand that these symptoms are not specific for heart failure. There are many conditions like chronic lung diseases, obesity, anaemia, thyroid disease, kidney and liver diseases, etc. which can produce them. However it is always a good idea to rule out heart failure so that future morbidity and mortality can be prevented by timely action.
How do we make a diagnosis? Heart failure is not a specific disease but only a clinical condition (often called a syndrome). Therefore it is mostly diagnosed clinically by presence of certain symptoms and signs and supported by objective evidence of cardiac dysfunction.
For example any patient of coronary disease, hypertension, diabetes or risk factors for heart diseases, who complains of breathing difficulty, easy tiredness, swelling of legs or recent weight gain, can be presumed to have heart failure.
Then certain tests like ECG, chest X-ray, laboratory tests and other imaging studies are needed to confirm the diagnosis. One very important test is echocardiography or simply echo to find out the ejection fraction (EF) as a marker of cardiac function.
The EF is the percentage of blood that is pumped out in a single contraction and is a measurement of how well the heart is pumping. People with a
healthy heart usually have an ejection fraction of 50 percent or more.
Most people with heart failure, but not all, have an ejection fraction of 40 percent or less. Some patients who have failure in relaxation can even have a normal ejection fraction, making it difficult to diagnose heart failure in such patients.
