Left sided heart failure is the term used
to describe the incapacity of the left heart to supply tissues with
blood. Left heart has two chambers known as left atrium and ventricle,
which communicate thorough the mitral valve. The left atrium (the left
upper chamber of the heart) receives oxygenated blood from the lungs,
through pulmonary veins and this blood will be delivered to left
ventricle (the lower left chamber). The whole amount of blood is pumped
by left ventricle in the aorta (which is the main artery of the body)
and then into the less large arteries that supply all the tissues and
organs (kidney, liver, digestive organs, brain, limbs). Imagine blood
flowing in the arteries as a liquid passing through a tube (pipe) and
all the factors and interactions between them, which have great
influence on the amount of blood that in the end each tissue will get
and also the influence on the whole organism: e.g. blood consistency (a
viscous blood will allow clots to appear), pressure that blood develops
on arterial wall, the influence of arterial walls pressure on blood flow
etc.
What is the cause for left sided heart failure?
Left sided heart failure is caused by different pathologies:
- congenital heart diseases,
- heart attack (the ischemia determines cardiac cells to die and a part of the heart is no longer functional),
- coronary heart disease (a chronic ischemia of the heart tissue, a
chronic deprivation of oxygen will determine tissues changes in order to
adapt to the new condition and in the end cardiomyopathy and left sided heart failure)
- high blood pressure forces the left heart to increase its labor and
force, and the only way this can be possible is to increase number of
muscle fibers (but the numbers of vessels will remain unchanged, so the
same number of vessels will supply a larger number of muscle fibers,
which will determine heart ischemia with all the consequences that
result from this condition) and increase inside pressure (this pressure
will act on heart walls to and will press the vessels which won’t be
able to fill enough and this will lead to ischemia)
- another cause of left sided heart failure is heart valves pathology:
leaking valves (an amount of blood remains in the heart chambers
creating a blood deficit in the tissues and forcing heart, at the next
contraction, to throw in the aorta a larger amount of blood, this means a
greater labor, which in time will lead to left sided heart failure) or
narrow valves (the heart muscle must defeat the obstacle represented by
the narrow valves),
- heart muscle infection will determine cardiomyopathy and left sided heart failure,
- excessive alcohol consumption will determine dilated cardiomyopathy and left sided heart failure,
- thyroid dysfunctions,
- heart muscle disorders,
- major cardiac arrhythmia (irregular heart beats).
What happens in the systemic blood circulation, when there is a left sided heart failure?
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| Left sided heart failure |
Compromise of left ventricular function will result in poor systemic
circulation: muscle weakness, cool extremities, fatigue, low tolerance
to effort, fainting, chest pain, palpitations, rapid heart beats,
dizziness, confusion, memory impairment. Backward failure of left
ventricle results in pulmonary congestion (blood will remain in the
pulmonary veins creating a great pressure and determining shortness of
breath, first on exertion and then at rest), hypoxemia (low level of
oxygen in the blood), cyanosis (blue coloring of the extremities,
because of the hypoxemia), tachypnea (increased rate of breathing),
pulmonary edema (because of the great pressure in the pulmonary veins,
the fluid from the blood will go through veins walls into the lung).
Valvular heart disease may occur due to the increased pressures in heart
chambers and pulmonary veins. Another symptom of
left sided heart failure is paroxysmal nocturnal dyspnea (sudden and severe breathlessness attack during night, several hours after going to sleep).
If you have signs of left sided heart failure please call an MD for medical advice.
