CARDIOVASCULAR ASSESSMENT CONTINUED
PHYSIOLOGY OF THE CARDIOVASCULAR SYSTEM
- Blood Pressure is determined by:
Blood Pressure is determined by many factors in the body. Normal blood pressure is determined by the cardiac output, the velocity, the resistance of the blood vessels and by other factors. Systolic pressure refers to the initial force of contraction of the heart. Diastolic pressure refers to the pressure of the blood vessels after the initial force of contraction of the heart. In other words, the diastolic pressure is due to the elasticity of the arteries as they “snap” back after the initial “stretch” due to the systolic pressure. Blood pressure is probably one of the most important measures of the overall cardiovascular system that exists. Take the patient’s blood pressure lying down and then standing up. If there is a difference of more than 15-20 MM Hg, this may be an indication of one or more problems. Persons with hypertension that is poorly controlled, may have orthostatic hypertension. This may also indicate aortic disease or cerebrovascular disease.
As you remember, the pulse pressure is the difference between the two pressure readings (systolic & diastolic). The pulse pressure is very important because it can indicate certain major problems in the cardiovascular system. Shock can be diagnosed, in part, by blood pressure readings and the pulse pressure. The pulse pressure is normally determined by the general condition of the heart, arteries and the amount of circulating blood.
- Autonomic Nervous system control:
Autonomic Nervous system control of the cardiovascular system includes control of the heart rate, cardiac output, blood vessels and amount of blood volume. Cardiac muscle is under the influence of the sympathetic and parasympathetic nervous systems.
The sympathetic (cervical) system secretes norepinephrine and innervates the cardiac plexus. It increases the SA node rate, it increases the AV node conduction and increases the contractile force of the myocardium. The parasympathetic division (cholinergic fibres) secretes acetylcholine and also innervates the cardiac plexus. This branch decreases the SA node, AV node and the contractility of the heart. Together, they work to regulate the heart rate, blood pressure and other vital cardiovascular functions. Blood vessel contraction is controlled in the like manner. The sympathetic division causes vasoconstriction of most blood vessels, thus raising the blood pressure and circulating volume. The parasympathetic division causes vasodilation for most vessels.
- The Pressoreceptor System:
The Pressoreceptor System originates in the arch of the aorta. Here are located sensitive nerve endings which help to control blood pressure and heart rate. Receptors are also located in the carotid sinus, vena cavae and the pulmonary arteries. When these receptors sense low pressure, the signal is fed to the medulla, where then the sympathetic division impulse is increased, causing the pressure to rise (either due to increased pulse rate or increased contractility). The opposite actions occur when there is high blood pressure. The nervous stimulation acts to bring the pressure back to normal by either vasoconstriction or vasodilation; by increased heart rate or decreased rate; by increased contractility or decreased contractility. Whichever combination occurs, the result will be the same; to bring the pressure back to normal.
Summary (history and chief complaint)
Now that you have refreshed your memory concerning anatomy and physiology of the cardiovascular system, you are ready to begin the examination. Before you go to the patient’s room, read pertinent data that has already been recorded. In many hospitals, the patient’s old charts from previous admissions are available. Read the old charts and obtain a summary of important data such as:
Previous admissions to hospital
- Reasons for admission
- Allergies
- Chronic medical problems
- Current and past drugs taken
- Social supports
- Discharge information
Next, interview the patient to discover the history of the present illness. The History of present illness means: What contributed to their coming to the hospital? You will ask for present symptoms and other recent symptoms that would be pertinent to this present illness. Perhaps they had some symptom at home that is now gone. You should question them in detail to confirm any historical data that you found in the old chart. Do not record any information from the old chart as fact, until confirmed by the patient in your interview.
When you enter the room to interview your patient, the first thing to do is introduce yourself and explain that you will be interviewing them. Try to make them relax as much as possible. If they are just being admitted to the hospital, they will probably be very apprehensive. Use a blend of subtle humor and calm soothing conversation to help the patient relax. One important consideration is not to rush them. Often times you are interviewing the patient under rushed conditions. Rushing them will make them even more anxious. Give them time to answer questions. Do not interrupt them when they are trying to answer; let them finish before you ask another question.
We will discuss charting and recording later. However, be sure that you record patient’s statements accurately. Put what they say in quotes when applicable. This is extremely important to remember…..be accurate! Many times the patient is unfamiliar with medical terms, and they might express a symptom in lay terms. Quote them as much as possible when you record their statements or comments. You might not understand what the patient means when they describe something in lay terms. For example, the patient might describe that they feel “crawly” when they took penicillin last year. Perhaps “crawly” means they were having an allergic reaction or maybe not. In any case, bring it to the attention of the physician and record what they say in quotes.
Once you have completed the history of the present illness, ask the patient to describe any symptoms that seem important. Ask them to describe in detail, their symptoms, pain or bowel habits; what ever is important and relates to their diagnosis. For example, eating habits for a patient who has abdominal pain: Ask how many meals do they eat each day; Do you eat meat? Do you eat dairy products? Do you drink coffee? Then ask: How much of these foods; what times of day do you eat? Etc.
You might get some interesting responses to the detailed questions that might explain some of their symptoms. Record the responses and ask more detailed questions if necessary. Remember to have the patient fully explain all symptoms in detail.
Since we are concentrating on the cardiovascular system for this text, we will ask the patient to give us those pertinent details. First ask the patient if he/she has been told that they have any of the following conditions:
- “heart attack” or “heart trouble”
- Myocardial infraction
- Angina or “heart pain” or angina pectoris
- Congestive heart failure
- Congenital heart problems or heart problems you were born with
- Rheumatic fever or rheumatic heart disease
- Coronary heart disease
- Heart arrhythmias or heart murmurs
You should use the precise medical terms mentioned above. Many patients might remember the term if they heard it. Some patients have been hospitalized so many times that they will be able to use the exact term for their illness. Now remember that you looked at their chart (if it was available). That will give you an edge, but remember to confirm the problems with them directly. Some patients will not know the medical term for any past problems they had. In that case, you should ask them to describe the condition. Use some of the terms mentioned above.
Next, ask what medications they have taken for their heart problem. Of course, they might have answered this question and others, in the above general medical history. However, have them give more details, since we are now concerned primarily with the cardiovascular part of the history.
Find out the following for each drug:
- Drub name and dosage
- What you take it for
- Frequency
- Does it work for you or help at all?
- When was the last dose you took?
Next, assess their use of alcohol and nicotine. Get details of the type of alcohol and/or “recreational” drugs used and the frequency and their smoking habits. Alcohol, cocaine, nicotine and other drugs can directly affect the heart, causing arrhythmias and other cardiac conditions.
Assess social factors that might affect the patient should major surgery be required. If the patient is facing a severe debilitating condition, the physician would need to know the patient’s educational background and the resources they have at home and at the job. Will this illness affect their job or career? These are questions the nurse should anticipate will be important later on in their hospitalization.
Recording the findings: There are many different ways to record your observations. Some facilities utilize narrative charting forms. Other facilities use problem-oriented charting. Still others have computerized medical records. However, it does not matter how you record the findings; just be sure that you do record the findings. This includes vital signs, history and other data.
ASSESSMENT TECHNIQUES
- INSPECTION
As you prepare to begin the actual exam, you already have obtained and recorded the patient history and you arm yourself with pertinent data such as their chief complaint and allergic history. Also keep in mind to allow a certain amount of time in order to complete a thorough exam. Many nurses do not have large blocks of time for completion of the assessment, but you must be as thorough as possible. If this is an admission assessment, you must allow enough time to be complete. If this is an on-going assessment, not as much time will be required.
Begin exam:
- Patient undresses, but allow for privacy
- Have the patient sit upright and inspect the thorax from the front
- Now inspect from the back of the patient
You will inspect for posture and symmetry of the thorax, color of the skin, gross deformities of the skin or bone structure, the neck, face, eyes and any abnormal contours. Breathing patterns will also be noted. Be especially aware of cyanosis.
Central cyanosis is a condition which will cause the lips, mouth and conjunctiva to become blue. Peripheral cyanosis will cause blue discoloration mainly in the lips, ear lobes and nail beds. Peripheral cyanosis might indicate a peripheral problem of vasoconstriction, and would generally be less severe than central cyanosis, which could indicate heart disease and poor oxygenation.
Thorax:
Inspect for symmetry of thorax, PMI (point of maximum intensity), PMI is easier to find if patient will lie on left side. PMI may also be palpated (see next section): skin color of thorax.
Eyes:
Arcus senilis; is a light gray ring surrounding the iris, common in older patients; in younger patients it might indicate a type of lipid metabolism disorder, which is a precursor to coronary artery disease.
Xanthelasma; yellowish raised plaques on skin surrounding eyes; can also appear on the elbows; this is a possible indication of, or sign of, hypercholesterolemia, often a precursor to coronary artery disease (atherosclerosis).
- PALPATION
Palpation, or touching, is the next part of the exam. In the step above, if we noted any abnormalities, we will now palpate and evaluate them further.
- Skin: temperature, texture, moisture, lumps, bumps, tenderness
Examination of extremities for edema might also indicate a cardiovascular problem. Examine the feet, ankles, sacrum, abdomen, trunk and face for edema. If you notice puffiness or frank edema, then palpate the area for pitting edema. Most facilities recognize the following scale:
+1 pitting edema - 0 to ¼ inch indentation
+2 pitting edema - ¼ to ½ inch indentation
+3 pitting edema - ½ to 1 inch indentation
+4 pitting edema - more than 1 inch indentation
- Breathing: lay hands on chest at different locations and feel the respiratory patterns, feel the ribs elevate and separate during normal breathing.
- Pre-cordial areas: feel the pounding of the heartbeat, normal and abnormal pulsations on the chest wall; PMI, as mentioned above
- Arteries: Assess all pulses:
You undoubtedly assessed the apical pulse earlier when you took the patient’s vital signs, if not, now is the time. Assess the following pulses:
- Apical heart rate: monitor for a full minute, note rhythm, rate, regularity
- Radial pulse: monitor for a full minute, note rhythm, rate, regularity. Note any differences from right to left radial, a large difference, might indicate arterial blockage or even enlarged ventricles. If pulse is regular but volume diminishes from beat to beat, this might indicate left-sided heart failure and is called pulsus alternans. If the volume of the pulse diminishes on inspiration, might indicate constrictive pericardial disease, the condition is called pulsus paradoxus.
- Carotid, brachial, femoral, popliteal, posterior tibialis and dorsalis pedis pulses: when checking these pulses, do it the same way as the others mentioned in this section; right then left side. When you check the carotid, press gently and do not rub. Do not palpate carotid on persons with known carotid disease or bruits; listen with stethoscope instead; and do not palpate both carotid pulses at the same time.
Carotid artery:
- Plateau pulse—slow rise and slow collapse pulse; may be caused by aortic stenosis; slow ejection of blood through a narrowed aortic valve.
- Decreased amplitude—(grade I pulse); due to hemorrhagic shock; pulse is weak due to decreased blood volume.
- Bounding pulse (grade IV)—can be due to hypertension, thyrotoxicosis, others; associated with high pulse pressure, the upstroke and downstroke of the pulse waves are very sharp.
- It is common to use +1, +2, etc., when recording pulses:
- 0 = absent
- +1 = diminished
- +2 = normal pulses
- +3 = full pulse or slight increase in pulse volume
- +4 = bounding pulse or increased volume
- Veins: neck, arms, legs, etc.
VEINS: CVP, Central Venous Pressure:
In order to assess the patients CVP, start by having the patient sit in bed and then lean backwards at about a 45 degree angle. Let the patient relax for a few seconds while you look for the internal jugular vein. In most persons in which the vein’s pulsating is visible, the vein will be seen to pulsate at the level of the sternal notch (Angle of Louis). If the level of pulsation is more than three (3) cm above the level of the sternal notch, it is a sign that the CVP is elevated. An elevated CVP may be indicative of right sided heart failure, obstruction of the superior vena cava, or constrictive pericarditis. Normal pressure in the venous circulation run from five (5) to twelve (12) centimeters of water pressure. The CVP would usually be measured by placing a catheter into a large vein and attach it to manometer or strain gauge.
If you find evidence of elevated CVP, may further confirmation the findings that you just saw. The hepato-jugular reflux test may be used. This test is performed by placing your hand in the area of the right upper quadrant of the abdomen. Once you have placed your hand on the abdomen, exert firm pressure directly into the abdomen for one full minute, and at the same time, observe the jugular vein. If the pulsation you observed begins to definitely rise over the highest level of pulsation seen, then this confirms that the CVP is elevated.
Jugular veins:
The pulsations from veins are different from the arterial pulsations that can be palpated in the neck area:
- the venous pulse is easily compressed by gentle pressure, in contract to the carotid pulse, which requires firm pressure to obliterate.
- the normal venous pulse descends upon inspiration and rises on expiration, but carotid pulse remains unaffected by respirations.
- a venous pulse usually collapses in the sitting position, while the carotid arterial pulse is not affected by changes in position.
- a venous pulse normally has more components than the arterial pulse. It consists of three positive deflections
----the a, c, and v waves---
and two negative deflections, the x and y descents. Normally this is when the venous pulse waves are the most prominent. If venous pressure is high, the pulsations may be better observed if client is sitting.
The “a” Wave: The predominate wave in the neck; reflects the pressure transmission caused by arterial contraction; begins just before the first heart sound; it can be palpated by feeling the jugular pulse, while auscultating the apex of the heart; the a wave also occurs just prior to the carotid pulsation.
The “c” Wave: This is a reflection of the onset of right ventricular contraction; begins at the end of the first heart sound; is usually not visible in the neck veins.
The “v” Wave: Represents arterial filling with atrioventricular valve closed; very small and is considered a passive filling wave.
The “x” Decent: Is a negative wave following the c wave; represents atrial diastole.
The “v” wave is followed by a y descent, a negative wave produced when the tricuspid valve opens, allowing blood to pour into the right ventricle.
Hair: Observe and feel the consistency and texture of the person’s hair. Very fine hair shafts may indicate hyperthyroidism. Very course hair, might indicate hypothyroidism. Both conditions of the thyroid, may have adverse effects on the cardiovascular system.
PERCUSSION
This technique has a very limited place for most nurses in assessment of our patients. As discussed earlier, percussion refers to “tapping” the chest wall with the fingers, in order to elicit sounds which indicate abnormalities. We will discuss and demonstrate the technique, but remember that it is a very limited tool. Much information obtained by percussion, can be more easily be determined by auscultation.
The technique for percussion involves hyperextending the fingers of one hand and placing the middle distal phalanx firmly on the chest wall. Hold your opposite hand close to the hand on the patient. Retract the middle finger of that second hand; strike the finger firmly at the top of the distal phalanx. After striking the finger, quickly remove it and move to another area and repeat the same motions.
Percuss the precordial area of the chest, listening for a resonant sound which indicates normal tissue beneath the fingers. When percussing over the lung tissue, the sound will be resonant, a semi-hollow, medium pitched sound. When percussing over denser tissues, the heart, the sound will be flat or “dull” in pitch. These are normal sounds. If the patient is sensitive or indicates pain or difficulty breathing, stop the percussion and go on with the other parts of your assessment.
AUSCULTATION
Auscultation is defined as listening to the sounds produced by the body, with or without the use of a stethoscope. Some sounds may be loud enough to hear without the use of the stethoscope. Although, when we think of auscultation, and the cardiovascular system, most nurses think of listening to the chest and heart through the stethoscope. As you know, the heart sounds heard are due to the closure of the heart valves under pressure of the blood flow. The stethoscope can also be used to listen to other sounds that could be of importance to the cardiovascular system.
Heart Sounds:
Auscultation of heart sounds should usually follow the general medical assessment and the general assessment of the cardiovascular system. The nurse should first think about the results of the general assessment and then proceed to listen to heart sounds. In many cases, the first part of the assessment will give you a clue of what to listen for upon auscultation. For example, if the patient states in his/her history that he/she has had cardiac surgery, or a valve replaced, etc., then it will alert the nurse to listen for particular sounds or murmurs.
In most persons, there are two major sounds that can be heard. The “lub” and “dub” are called S1 and S2 respectively, and are the two most prominent and easily heard sounds. S1 and S2 follow each other closely.
The time between 1 and 2 is shorter than the time from end of S2 to the beginning of the next cycle and S1 of the next beat. The time interval between S1 and S2 also corresponds to systolic phase of the cardiac cycle.
Two additional heart sounds may be audible in the cardiac cycle, these are S3 and S4.
S3 can sometimes be heard immediately after S2. S3 is the sound of early, rapid diastolic filling of the ventricles. It is not often heard in adults, but is heard very commonly in children. S4 is the last heart sound, and like S3, it is rarely heard in the adult, except in disease conditions such as congestive heart failure or multiple sclerosis.
Origins of heart sounds:
S1 - Closing of the atrioventricular valves (Mitral and Tricuspid):
corresponds with the carotid pulse; ventricular systole heard
loudest at the mitral and tricuspid areas
S2 - closing of the aortic and ulmonic valves
heard loudest at the aortic area
Each of the two major heart sounds is made up of rushing blood and of two valves closing at the same time. Normally the pair of valves open and close at the same time, causing a clear and distinct sound. At certain times, the valves may close at slightly different times, or one may close very slightly slower than the corresponding valve. This causes one of the heart sounds to be distinctly “split” or having and “echo” sound.
This may be a naturally occurring phenomenon, called “physiological splitting”, or it may be due to a disease, called pathological splitting. When S1 valve closures can be heard separately, there may be a conduction defect present or even a mechanical defect. Of course, even young and healthy children and some adults can still have normal splitting of S1 and S2.
In review, the two common heart sounds are S1 and S2. They each are made up of two distinctly separate sounds of two valves closing in unison. When assessing the patient for heart sounds, the nurse must first obtain a patient history; inspection, palpation and possibly percussion will also usually be performed before you begin to auscultate. Ideally, the nurse must know the patient’s heart rate and the regularity of rhythm before auscultation is performed.
S3 and S4 are two “normal” heart sounds that may sometimes be heard in the cardiac cycle. Splitting is usually a normal situation arising from asynchronistic closure of two valves responsible for each of S1 and S2.
Referring back to this figure
the CHEST landmarks are used for auscultation of the heart. In the below figure these same positions are marked ON THE HEART ITSELF (note blood flow).
The next figure illustrates the names of these precise positions.
Begin to auscultate the heart sounds, by having the patient lie comfortably on his/her back at about a 45 degree angle. Have them put their hands at their sides and then explain what you are going to do. You may have to tell some patients to relax and to breathe normally, as anxiety may sometimes make them breathe rapidly and noisily and interfere with your procedure.
First, start at point number one, above the aortic area. Then proceed to the pulmonic, 2nd pulmonic, right ventricular, apical and then epigastric area. Each of these areas allows for the clearest heart sound for that valve it is named for. The aortic region, for example, is the best place to listen to the aortic valve, tec., even though the valve is not actually located at that precise area.
Heart sounds are generally easy to hear; but sometimes due to patient and other conditions, it may be difficult to hear clearly. Use the diaphragm of the stethoscope and place it gently on the chest in the areas indicated. The diaphragm will be best for listening to the high-pitched sounds of S1, so auscultate using the diaphragm at all points.
Do not “drag” the stethoscope along the skin. Excess noise will be generated by this action. Have the patient breath normally and put them in a supine position. Sometimes the sounds may be better heard in a sitting position. Try both ways if you have difficulty hearing the sounds.
Murmurs:
A heart murmur is a very general term used to describe any one of the variety of abnormal sounds heard in the heart due to turbulent or rapid blood flow through the heart, great blood vessels and/or heart valves (whether the heart valves are normal or are diseased). Most nurses associate murmurs with an abnormal heart valve. However, there are a variety of other conditions that can cause murmurs. Murmurs can also be caused by the forward flow of blood across a constricted or otherwise irregular valve, or into a dilated heart chamber or dilated vessel. They can also be caused by the backward flow of blood through an incompetent valve or a septal defect. Murmurs are usually described as a “rushing” or “swooshing” sound.
Murmurs are usually related to defects in valves or ventricular septal defect, or atrial septal defect. When auscultating murmurs, the nurse should record the timing, characteristics,* location and radiation of murmur. *characteristic include: loudness, intensity, pitch and quality of murmur. These assessment factors are discussed in more detail in the next few paragraphs.
Gallops:
The bell of the stethoscope may be used for low frequency sounds (they are better amplified by the bell). S3 and S4 gallops are generally low-pitched sounds and are heard best with the bell of the stethoscope while the patient is stretched out on his left side. Many nurses prefer to auscultate the heart sounds a second time with the bell of the stethoscope in order to detect any sounds that might be missed with the diaphragm.
S3 gallop, the ventricular gallop, occurs at the end of ventricular systole. It is often caused by the sound of blood prematurely rushing into the ventricle that is stiff or dilated due to failure, coronary artery disease or pulmonary hypertension.
Clicks:
Sounds described as “clicks” are extra sounds often heard in those patients with mitral valve prolapsed, aortic stenosis or those with prosthetic heart valves. Opening “snaps” are usually caused by mitral stenosis or stenosis of the tricuspid valves.
Rubs:
Sounds referred to as “rubs’ occur when the visceral and parietal layers of the pericardium rub together. The sound is produced when inflammation is present due to uremic pericarditis, myocardial infarction or other inflammatory condition.
Next: Cardiovascular Assessment Continued