Cardiovascular system function is vital to life and the proper functioning of the other systems of the body. Understanding it requires some knowledge of the basic medical lingo pertaining to its normal function and the signs and symptoms of its dysfunction. The health literacy that accompanies it, in turn, enhances communication in health care and can improve healthcare outcomes.
What Is the Function of the Cardiovascular System?
In simple terms, the primary function of the cardiovascular system is to carry substances vital to life to cells and tissues and to transport waste products from cells and tissues to sites of elimination from the body.
The most important substance it brings to cells and tissues is oxygen from the lungs. Other important substances it delivers include glucose, other nutrients, hormones, electrolytes, red blood cells, white blood cells, clotting proteins, other blood elements, immune system mediators, etc. Oxygen is the most important of the group though, because cells cannot survive more than between 4 and 6 minutes without it.
Carbon dioxide is the main waste product that it removes from tissues. It transports it by way of veins and the pulmonary circulation to the lungs for elimination. It also transports other products of metabolism to the kidneys, liver and skin for elimination from the body. By and large the pulmonary circulation is the workhorse of the excretory function of the cardiovascular system though. The reason is carbon dioxide is the most abundant waste product of metabolism.
Cardiovascular Symptoms and Signs
Cardiovascular symptoms are sensations that a person experiences which are indicative of disease or dysfunction of the heart or heart/and or blood vessels as a unit.
Cardiovascular signs are clues of disease or dysfunction of the heart or heart and blood vessels as a unit, detectable by someone else, usually during a physical examination.
Pronunciation of Terms
Blood pressure (BP) – The force exerted against the walls of arteries when the heart pumps out blood and when it relaxes to fill up with blood. The top number is the systolic blood pressure. It is the force exerted when the heart pumps. The lower number is the diastolic blood pressure. It is the force when the heart relaxes.
Heartbeat – A single complete cardiac cycle. As such, it includes the contraction of the right and left heart muscle during pumping, the relaxation of the right and left heart chambers during filling and the linked electrical events. Contrary to popular belief, it is not the same as the pulse, even though the two correlate to some degree. An EKG correlates with it more precisely though.
Heart rate – The number of times per minute the heart pumps blood out and relaxes to refill with blood. Listening to the heart sounds with a stethoscope and viewing an electrocardiogram are ways to determine it.
Heart sounds – The normal sounds heard with a stethoscope when the heart pumps blood out and when it relaxes to fill with blood. The closure of valves produces the sounds. S1 is the first heart sound of the cardiac cycle. The closure of the mitral and tricuspid valves during systole produces it. S2 is the second heart sound of the cardiac cycle. Closure of the aortic and pulmonic valves during diastole produces it.
A gallop is an abnormal extra heart sound (S3 or S4) often audible if there is disease of the heart muscle.
S3 is the third heart sound of the cardiac cycle. It is normally present only in children and physically active young adults but not in older people. When it is present in people 40 years of age and older it is usually a sign of left or right congestive heart failure. Rapid overfilling of the left or right ventricle is the cause of it. Since it is a low frequency sound it requires the listener to use the bell of a stethoscope to hear it. The bell is the hollow cup-shaped part of the stethoscope used for listening. The S3 cadence is like the word Kentucky. The first 2 syllables of Kentucky are S1 and S2. The third syllable is the S3.
Pulse rate – The number of pulsations per minute in an artery caused by the pumping of the heart. It is equal to the heart rate as long as the heart rhythm is regular. Placing a finger over an artery and counting the number of pulsations in one minute is the way to determine it. It is not the same as the heart rate however, if the rhythm is irregular.
Heart murmur – An abnormal blowing, humming, or fluttering sound heard with a stethoscope placed over the heart. Valvular heart disease causes it. The abnormal sound is due either to reverse flow or partial blockage of forward flow across the valve.
Peripheral edema – Is excessive amounts of fluid in the tissues of the extremities (limbs). It most commonly involves the lower extremities. It is pitting which means that when pressure is applied with a finger it leaves an indentation for a few minutes. There are various causes but congestive heart failure is a common one.
Sick sinus syndrome – Is a group of heart rhythm disturbances due to malfunctioning of the sinus node. It may cause the heart rate to be too fast, too slow, or alternate between the two. Either heart rate extreme associated with it can be a cause of syncope.
Tachycardia – A heart rate of greater than 100 bpm (beats per minute) at rest. Sinus tachycardia is the appropriate term if the fast heart rate is regular and originates from the normal natural pacemaker of the heart (sinoatrial node). There are various other terms for the tachycardia if the heart rhythm is irregular.
Ventricular fibrillation – Is a rapid and irregular chaotic heart rhythm. The impulses originate from various locations in the ventricles and travel outside of the normal conduction pathways causing the ventricles to quiver rather than contract normally. Because of the ineffective pumping of blood the blood pressure drops. It is the most serious of all cardiac arrhythmias. If not terminated within seconds to minutes it can be life-threatening. It is commonly occurs with cardiac arrest.
Ventricular tachycardia – Is a rapid heart rate in which the impulses originate from one of the lower chambers of the heart instead of from the right atrium. The rate is usually 100 bpm or greater.
Angina – Chest pain caused by insufficient blood flow to the heart (ischemia). It is classically but not always a pressure-like pain in the middle of the chest which might radiate into the left arm, left shoulder, left neck and/or left jaw. It is most commonly, but not always, brought on by physical activity or emotional stress. It might be relieved within minutes of placing a nitroglycerin tablet under the tongue.
Claudication – Pain in the calves, buttocks, and/or thighs brought on by walking and less often by standing. It is the result of poor circulation from peripheral arterial disease of the lower extremities.
Orthopnea – The need to elevate one’s head with two or more pillows or the equivalent to avoid experiencing short of breath while lying supine or on one’s back. It is a symptom of congestive heart failure.
Palpitations – The sensation of a rapid, hard, or irregular heartbeat. It can be the symptom of an arrhythmia.
Syncope – Brief loss of consciousness or fainting.