Cardiovascular system

In older people there are changes in the heart and blood vessels secondary to aging and adaptations to it.

The cardiovascular system is made up of the heart and blood vessels, arteries and veins. The function of the heart, as is already known, consists of pumping the blood so that it circulates through the arteries to carry oxygen and other nutrients to the body and collect waste products through the veins.

The heart basically consists of four chambers, two atria and two ventricles. The atria function as entry chambers for blood from the veins, while the ventricles push blood into the arteries. The control of the passage from one to the other is carried out by the valves; in this way the heart functions as a hydraulic pump.

Both the heart and the blood vessels have a similar structure: an inner or intimate layer (endocardium in the heart), a muscular layer, especially important in the ventricles and almost nonexistent in the veins, and an outer layer (adventitia) of fibrous material that protects the whole.

With the passage of time, the arteries lose elasticity due to the increase in the thickness of the muscular middle wall, which hinders the passage of blood due to the narrowing of the caliber of the vessel and facilitates the development of arterial hypertension. There is also a deposit of fats (cholesterol) in the intima, which calcify to form plaques, which increases the size of the arterial wall and worsens stiffness.

In the veins, the changes are scarce and take place basically in the lower extremities. Due to the thinness of the muscular middle layer, the veins suffer significantly the effect of the weight of the blood column and if it cannot be compensated (with the movement of the legs, for example), varicose veins appear.

Multiple changes in the heart

• Increase in the thickness of the left ventricular wall due to an increase in collagen and fat between the muscle cells, which decrease in number.
• Increased thickness of the inner layer of all heart chambers.
• Increase in the thickness of the heart valves, which also calcify.
• Decrease in "pacemaker" cells (the cardiac cells responsible for creating the electricity that generates the heartbeat), with fibrosis of the tissue that conducts the electrical impulse.

The consequences of these modifications are very important:

• Lower exercise tolerance capacity, with greater difficulty in recovering from it.
• Greater difficulty both in filling the heart chambers (diastole) and in emptying them (systole), leading to heart failure.
• Greater difficulty for the correct opening and closing movement of the heart valves, which in the long run influences the general pumping function of the heart.
• Increased periods when the regular rhythm of the heart is lost (arrhythmias), so that the regularity of filling and emptying of the heart chambers is affected. Sometimes eddies can be created in the blood flow that can facilitate the appearance of clots that can later travel through the arteries and block blood circulation (thrombosis and embolisms)

All these changes produce a decrease in the cardiovascular functional reserve capacity and are independent of the effects of smoking, arteriosclerosis or other diseases. This decrease in the reserve means that, even in situations of apparent normality, it is very easy for cardiovascular failure to occur and that restoring normality is more complicated than in younger people and requires longer periods of convalescence.