Assessment and Observation of the Cardiovascular System

Introduction

The cardiovascular system is one of the body's fundamental life-sustaining systems; therefore, it is essential that nurses are able to accurately and comprehensively assess this system. This chapter introduces the fundamental knowledge and skills nurses require to do so. It begins with an overview of the fundamental anatomy and physiology of the cardiovascular system. The chapter then explains the processes involved in collecting a general health history for the cardiovascular system, and in performing a physical examination of the cardiovascular system. Finally, this chapter considers a number of special observation and assessment techniques which may be used in the physical examination of the cardiovascular system.

Important note

This section of the chapter assumes a basic knowledge of human anatomy and physiology. If you feel you need to revise these concepts, you are encouraged to consult a quality nursing textbook.

Fundamental anatomy and physiology of the cardiovascular system

The cardiovascular system is comprised of the heart and the system of vessel which transport blood (containing oxygen and nutrients) to, and metabolic wastes from, all parts of the body. It is a dynamic system, with the capacity to adjust to changing conditions and demands (e.g. exercise, temperature changes, stress, etc.). The cardiovascular system does this by, for example, constricting and dilating blood vessels and altering cardiac output, etc.

The heart is the organ responsible for moving blood, oxygen and nutrients around the cardiovascular system. It is a pump comprised of four chambers - two atria (smaller top chambers) and two ventricles (larger bottom chambers). The right side of the heart receives deoxygenated blood from the body via the superior and inferior vena cavae, and pumps it into the pulmonary circulation (i.e. to the lungs) for reoxygenation. Deoxygenated blood leaves the heart via a large vessel known as the pulmonary artery. The left side of the heart receives oxygenated blood from the pulmonary veins, and pumps it into the systemic circulation (i.e. to the body) for use. Oxygenated blood leaves the heart via a large vessel known as the aorta.

There are four valves which control the flow of blood through the chambers of the heart:

• The two atrioventricular valves (separating the atria from the ventricles), including the tricuspid valve (on the right) and the mitral valve (on the left).
• The two semilunar valves, including the pulmonary valve (separating the right ventricle from the pulmonary artery) and the aortic valve (separating the left ventricle from the aorta).

As you saw earlier in this section of the chapter, the heart is the organ responsible for moving - or, more accurately, pumping - blood, oxygen and nutrients around the cardiovascular system. The term 'cardiac cycle' is used to describe the processes involved. There are two key phases of the cardiac cycle:

• Diastole - during this phase, the ventricles relax and fill with blood from the atria. The movement of blood from the atria to the ventricles, through the atrioventricular valves, occurs because the pressure of the blood in the atria is higher than the pressure of the blood in the ventricles, and the atria also contract to facilitate this process. At the end of diastole, the ventricles are filled with blood.
• Systole - during this phase the ventricles contract, forcing blood through the semilunar valves and into the pulmonary artery (from the left ventricle) and the aorta (from the right ventricle). At the end of systole, the ventricles are mostly emptied of blood.

The cardiac cycle, as described above, is controlled by the heart's electrical conduction system. At the beginning of each cardiac cycle, an electrical impulse originating in the sinoatrial node (at the top of the heart) travels across the heart to the atrioventricular node (in the centre of the heart), down the 'bundle of His' and through the 'Purkinje fibres' (at the base of the heart). The movement of this electrical impulse through the heart results in the contraction of the atria and then the ventricles.

When oxygenated blood leaves the heart at the end of each cardiac cycle, it enters the peripheral vascular system - that is, the system of vessels that takes blood to (and then from) the tissues. The arteries are the vessels which carry oxygenated blood to the body; blood moves through these vessels via the pressure generated with each contraction of the ventricles. The veins are the vessels which carry deoxygenated blood back to the heart; blood moves through these vessels via a series of passive valves. Small vessels called capillaries permeate, and allow blood to perfuse every part of the body.

It is important to note that the lymphatic system works in tandem with the cardiovascular system; therefore, in assessing the cardiovascular system the nurse is also indirectly assessing the lymphatic system. The lymphatic system is the network of nodes and associated structured designed to move lymphatic fluid through the interstitial spaces. It has a variety of functions, but a particularly important role in the immune system.

Cardiovascular system - focused health history

As you saw in the previous chapter of this module, health observation and assessment involves three concurrent steps:

When assessing a patient's cardiovascular system, the nurse must commence by collecting a health history. This involves collecting data about:

Component	Rationale
Present health status	Chronic illnesses, even if they are not related directly to dysfunction in the cardiovascular system, can cause damage to this system. They may do so by: (1) narrowing the peripheral vessel and increasing the workload of the heart (e.g. diabetes, hypertension), (2) increasing the volume of the fluid to be moved by the heart (e.g. diabetes, renal failure), and / or (3) increasing the heart rate and causing constriction of the pulmonary capillaries (e.g. chronic hypoxia). Current medications, either prescribed or over-the-counter, which: (1) may be taken to treat pre-existing cardiovascular problems, and / or (2) may cause side effects which affect the cardiovascular system - such as dysrhythmias (e.g. tricyclic antidepressants, phenothiazines, lithium), thrombophlebitis (e.g. hormonal contraceptives), fluid retention (e.g. corticosteroids), tachycardia (e.g. theophylline), problems with platelet aggregation (e.g. aspirin), hypertension (e.g. pseudoephedrine), some herbal remedies (e.g. stimulating / depressing cardiac function), etc. Nurses should also be aware that 'street' drugs, such as cocaine and amphetamine, can also have significant effects on the cardiovascular system. Exercise. Research consistently suggests that frequent physical activity, consistent with UK national recommendations, reduces the risk of a variety of cardiovascular disease. Stress, and coping mechanisms, as these can be predictors of cardiovascular risk. Dietary habits. Research consistently suggests that consuming a diet consistent with UK national recommendations, reduces the risk of a variety of cardiovascular disease. Consumption of some foods, including foods high in saturated fat, can increase cardiovascular risk. Alcohol consumption, as excessive alcohol intake, as per the UK national recommendations, is associated with cardiovascular diseases such as hypertension and cardiomyopathy. Caffeine consumption, as excessive caffeine intake (e.g. in coffee, energy drinks, some supplements, etc.) can result in tachycardia. Tobacco smoking (past and current), as tobacco nicotine results in vasoconstriction, hypertension and an increased cardiac workload.
Past medical history	Congenital heart disease/s or heart defect/s (e.g. heart murmur), and how these have been treated, as this can give a nurse important information about how to structure their physical examination. Other significant childhood illnesses, including those affecting the cardiovascular system, such as rheumatic fever. Surgeries on the heart or the blood vessels, why this surgery was performed and the outcome/s. This may provide a nurse with additional information about existing cardiovascular problems. Previous cardiac tests, including electrocardiograms (ECGs), 'stress tests' and other tests. The results of these tests may provide a nurse with baseline data about the health of the client's heart.
Family history	Family history of heart conditions, especially among first-degree relatives, as this can provide important information about the types of heart disease for which a person may have a congenital risk.

In some cases, a person will present with a specific problem related to their heart (e.g. chest pain, dyspnoea, cough, nocturia, fatigue, syncope, oedema, leg pain, etc.). If this is the case, a nurse must gather a more focused health history. Remember, nurses can assess a patient's symptoms using the strategy remembered by the 'OLD CARTS' mnemonic (introduced in a previous chapter of this module).

Chest pain is a particularly significant symptom indicating dysfunction in the cardiovascular system. If a patient complains of pain, they should be rapidly assessed using the strategy remembered by the 'PQRST' mnemonic (introduced in a previous chapter of this module). The location, quality, quantity, chronology, associated manifestations and aggravating / alleviating factors of the chest pain a patient experiences can provide important information about the cause of this pain - and allow the patient's health care team to make a differential diagnosis. Review the information in the following table:

Cause of Pain	Factors Enabling Differential Diagnosis
Stable angina, or chest pain resulting from myocardial hypoxia, which occurs predictably (with physical exertion) due to a partial blockage of a cardiac vessel	Pain located the precordial / retrosternal regions, radiating from the left to the right arm, interscapular and / or epigastric regions; pain may be described as 'pressure', 'burning', 'sharp' or 'dull'; pain quantity is variable but usually worse with activity; pain lasts between 1 minute and 1 hour; pain is associated with dyspnoea, diaphoresis, palpitations, nausea, weakness; pain is aggravated by exertion, stress, cold; pain is alleviated by rest, glyceryl trinitrate (GTN), beta (β) blockers, calcium channel blockers, etc.
Unstable angina or chest pain resulting from myocardial hypoxia, which occurs unpredictably due to a partial blockage of a cardiac vessel	Pain located the precordial / retrosternal regions, radiating from the left to the right arm, jaw, interscapular and / or epigastric regions; pain may be described as 'pressure', 'squeezing', 'crushing, 'burning', 'dull' or sharp'; pain is often 10/10 on the pain scale; pain has a sudden onset, and progresses over a period of 30 to 40 minutes; pain is associated with dyspnoea, diaphoresis, palpitations, nausea, weakness; pain is aggravated by exertion (but often occurs at rest); pain is alleviated by β-blockers, aspirin, heparin, oxygen, etc.
Myocardial infarction ('heart attack'), or chest pain resulting from myocardial hypoxia, which occurs due a complete blockage of a cardiac vessel	Pain located the precordial / retrosternal regions, radiating from the left to the right arm, jaw, interscapular and / or epigastric regions; pain may be described as 'pressure', 'squeezing', 'crushing, 'burning', 'dull' or 'sharp'; pain is often 10/10 on the pain scale; pain has a sudden onset, and progresses over a period of >1 hour to 2 to 3 days; pain is associated with dyspnoea, diaphoresis, palpitations, nausea, weakness; pain is aggravated by exertion (but often occurs at rest); pain is alleviated by β-blockers, aspirin, heparin, oxygen, etc.
Mitral valve prolapse, where the two halves of the mitral valve bulge upwards during ventricular contraction	Pain is located anywhere in the chest, it may be localised or diffuse but does not radiate; pain is variable, but often described as 'sharp'; pain has a sudden onset, and it may last seconds or persist for days; often there are no associated symptoms, however pain may be associated with palpitations, dyspnoea and dizziness; pain may be aggravated by a person's position (e.g. lying on the left side); pain may be relieved by GTN, analgesics and positional change, etc.
Acute pericarditis, or inflammation of the pericardium (the sac-like tissue surrounding the heart), often due to infection	Pain may be located in the precordial, posterior neck or trapezius region; pain may be pleuritic (i.e. related to the movement of the lungs during inhalation / exhalation) or positional (e.g. reclining); pain is often 4/10 to 6/10 on the pain scale; pain has an onset of hours to days; pain is often associated with fever, dyspnoea and orthopnoea; pain may be relieved by positional change (e.g. leaning forward) and treatment of the pericarditis.

As highlighted in the above table, unstable angina and myocardial infarction have very similar signs and symptoms. The key assessment a nurse may perform to differentiate between these conditions is an electrocardiogram (ECG). You will study ECGs in detail in a later section of this unit.

It is important for nurses to realise that there are a number of conditions not related to the cardiovascular system which may result in chest pain. These conditions include (but are not limited to):

• Panic disorder, a condition where a patient experiences recurrent, disabling panic attacks with respiratory and cardiovascular symptoms (e.g. chest pain, dyspnoea, heart palpitations, diaphoresis, nausea, trembling, etc.).
• Peptic ulcer disease, a condition where there is a break in the lining of the stomach, often caused by a bacterial infection or the use of anti-inflammatory medication.
• Gastro-oesophageal reflux disease (GORD), a condition where the lower oesophageal sphincter fails to close properly, and acid from the stomach leaks into, and erodes, the oesophagus.
• Costochondritis, a condition involving inflammation of the cartilage where the ribs attach to the sternum.

As you collect a general health history from a patient, it is important that you assess and identify risk factors for: (1) hypertension, and (2) coronary artery disease. These are two of the most common cardiovascular diseases in the United Kingdom. The common risk factors of each are listed in the table below:

Risk Factors for Hypertension

Risk Factors for Coronary Artery Disease

Age. Family history. African or Caribbean descent. Diet with high amounts of salt. Lack of exercise. Overweight, obesity. Consumption of large amounts of alcohol. Smoking. Long-term sleep deprivation. Some medical conditions (e.g. kidney disease, diabetes, long-term kidney infection, obstructive sleep apnoea, glomerulonephritis, some endocrine disorders, lupus, scleroderma). Some medications (e.g. the combined oral contraceptive pill, some steroids, non-steroidal anti-inflammatory medications [NSAIDS], some over-the-counter cough / cold medications, some herbal remedies, some recreational drugs [e.g. cocaine, amphetamine], some selective serotonin-noradrenaline reuptake inhibitor [SSNRI] antidepressants).

Age. Family history. Gender (men are more at risk). Hypertension. Raised or altered levels of blood cholesterol, and / or triglycerides with low HDL-cholesterol. Diabetes. Smoking. Lack of exercise. Overweight, obesity. Consumption of large amounts of alcohol. Smoking. Excessive or chronic stress.

It is important to highlight that some of these risk factors for cardiovascular disease are non-modifiable (e.g. age, family history, gender); however, many are modifiable - that is, a person is capable of making changes to them to reduce their risk. As part of their fundamental health promotion role, it is important that nurses are able to provide patients with advice about how to address the risk factors identified during assessment.

Cardiovascular system - physical examination

Once a cardiovascular health history has been obtained, as described in the previous section of this chapter, a nurse may commence a physical examination of the patient's cardiovascular system. A stepwise process of physically examining the patient's cardiovascular system, with normal (expected) and common abnormal findings, is presented in the following table:

Component	Normal (Expected) Findings	Abnormal Findings
Assess general appearance by inspecting the patient	The patient should appear at ease, with skin colour appropriate for their ethnicity, and breathing in a regular, unlaboured manner.	Dyspnoea, use of accessory muscles, cyanosis, pallor, etc.
Assess the peripheral vascular system by: Palpating the temporal, carotid, brachia, radial, femoral, popliteal, posterior tibial, dorsalis pedis pulses. Measuring the blood pressure (BP).	Rate 60-100 beats per minute; regular rhythm; easily palpable (normal amplitude); smooth and rounded contour. BP approximately 80-120mmHg.	Tachycardia; bradycardia; tenderness; oedema; irregular rhythm; 'bounding' or 'thready' pulse, etc. Hypertension; hypotension; orthostatic hypotension; wide pulse pressure, etc.
Inspecting and palpating the upper and lower extremities for turgor.	The skin turgor should be elastic, without tenting or oedema.	Tenting (e.g. when pulled, the skin does not immediately fall back into place); oedema (including pitting oedema).
Inspecting and palpating the upper and lower extremities for skin integrity, colour, temperature and capillary refill.	Extremities should be symmetric, without oedema. Skin should be intact. Nail beds should be pink, with an angle of 160 at the nail bed. Capillary refill time (CRT -refer to the explanation following) should be ≤2 seconds.	Asymmetry in the extremities (particularly in their circumference); thickened skin; skin damage; coolness in the extremities; marked pallour or mottling; CRT ≥2 seconds; nails with an angle of >160 to the nail bed ('clubbing').
Asses the heart by: Inspecting the anterior chest wall for contour, pulsations, lifts, heaves, retractions, etc.	The chest wall should be symmetric, with gentle contours. The apical pulse may or may not be visible.	Chest wall is asymmetrical; sternal depression; retraction; very obvious or displaced apical pulsations, etc.
Palpating the location of the apical pulse.	The apical pulse should be felt at or near the fifth intercostal space, near the left midclavicular line.	The site of the apical pulse is displaced, usually downward or laterally.
Measuring the heart rate (HR).	HR is 60-100 beats per minute, with a regular rhythm.	Tachycardia; bradycardia; irregular rhythm
Measuring the oxygen saturation (SpO2).	SpO2 is within the normal range of 98-100%.	SpO2 is <98%.
Assessing the heart sounds.	The first heart sound (S1, at systole) has a low pitch, and the second heart sound (S2, at diastole) has a higher pitch. Each sound should be distinct.	The heart sounds are accented, diminished, muffled or variable; there is no distinction between S1 and S2 - i.e. there is a 'murmur'.

As you saw in the above table, assessing the heart sounds is a key skill for nurses. There are two normal heart sounds: S₁, at systole, has a low pitch, and S₂, at diastole, has a higher pitch. However, there are a number of abnormal sounds a nurse may identify during their assessment; read the information in the following table:

Abnormal Heart Sound	Possible Cause
A heart sound additional to S1 and S2, during diastole.	This is referred to as the S3 heart sound. This is often due to fluid overload in the ventricles (e.g. due to heart failure, or mitral / tricuspid regurgitation, etc.). It is important for nurses to note that an S3 heart sound is often normal in children and adolescents.
A heart sound additional to S1, S2 and S3, during diastole.	This is referred to as the S4 heart sound. This is often due to non-compliance of the ventricle (e.g. due to hypertrophy, coronary artery disease, etc.). It is important for nurses to note that an S4 heart sound is often normal in children and adolescents.
A high-pitched 'snapping' sound.	Often due to thickening, stenosis or other deformities in the mitral and / or tricuspid valves.
A 'clicking' sound during systole.	Often due to deformities o the aortic or pulmonic valve.
A rubbing sound.	Often due to inflammation of the layers of the pericardium.
A low- to medium-pitched, coarse sound with a crescendo-decrescendo pattern.	Often due to stenosis of the aorta (if heard over the aortic valve area or the left sterna border), or stenosis of the pulmonary artery (if heard over the pulmonary valve or second / third intercostal spaces).
A low- to high-pitched, 'blowing' sound.	Often due to aortic regurgitation (if heard over the second intercostal space), or pulmonic regurgitation (if heard over the third / fourth intercostal spaces).
A low-pitched 'rumbling' sound.	Often due to stenosis of the mitral and / or tricuspid valves).
A high-pitched, harsh 'blowing' sound.	Often due to regurgitation of the mitral valve (if heard at the apex of the heart) or the tricuspid valve (if heard at the fifth intercostal space).

Abnormal heart sounds are often referred to as 'murmurs'. They are generally classified into one of two types:

1. Diastolic murmurs occur during diastole, or the period when the ventricles contract and fill with blood. Most diastolic murmurs are caused by obstructions to the movement of blood into the ventricles, often due to problems with the semilunar and / or atrioventricular valves.
2. Systolic murmurs occur during systole, or the period when the ventricles contract and eject blood. Most systolic murmurs are caused by obstructions to the movement of blood out of the ventricles, often due to problems with the semilunar and / or atrioventricular valves. Other common causes of systolic murmurs are structural deformities of the pulmonary arteries and / or the aorta, structural deformities of the cardiac muscle (e.g. septal defect), severe anaemia, and thyrotoxicosis, etc.

Special assessment techniques for the cardiovascular system

There are a number of special assessment techniques particular to the cardiovascular system:

• Electrocardiogram (ECG). As you saw in an earlier section of this chapter, a key tool to assess the cardiovascular system, and one which can be particularly useful in assisting with a differential diagnosis, is the ECG. An ECG is a measurement of the electrical activity in the heart during a cardiac cycle. An ECG recording is made using an ECG machine, with a number of probes (referred to as leads) attached to the skin around the patient's heart and to their peripheries. Nurses should refer to the particular machine used by their organisation to determine the correct placement of ECG leads.

An ECG machine depicts a cardiac cycle as illustrated in the image following (note that an ECG records multiple cardiac cycles over a period of time):

In this measurement: The P wave represents the contraction of the atria. The QRS complex represents the contraction of the ventricles (systole). This complex masks the relaxation of the atria. The T wave represents the relaxation of the ventricles Diastole).

As noted, in an earlier section of this chapter, an ECG is the key assessment a nurse may perform to differentiate between unstable angina and myocardial infarction - conditions with very similar signs and symptoms. Essentially, myocardial infarct is apparent on an ECG, often - though not always - with changes to the section of the ECG recording between the S- and T-sections (indicative of an ST-segment myocardial infarct, or 'STEMI'). Angina is not apparent on ECG.

It is worth noting here that the interpretation of ECG measurements can be very complex. In the UK, it is generally the responsibility of suitably-trained medical practitioners to interpret ECG measurements and, subsequently, make diagnoses. However, it is important for nurses to be able to identify obvious problems evident on an ECG recording - such as STEMI, described above.

• Capillary refill time (CRT). Another simple, but very important, assessment technique unique to the cardiovascular system is capillary refill time, often abbreviated to 'CRT'. Measuring CRT allows a nurse to assess the function of a patient's vascular system at the level of the capillaries. A nurse measures CRT by gently squeezing the pads of a patient's fingers, or their nail beds, until they blanche (whiten). The pressure is then released and the time for the capillaries to refill, or the colour of the pads / nail beds to return to normal, recorded. CRT should be should be ≤2 seconds.
• Pitting oedema. This is an assessment technique which may identify problems with the cardiovascular system and / or the lymphatic system - specifically, fluid retention and swelling of the tissues. When assessing for pitting oedema, the nurse gently presses the pads of their first and middle fingers into the tissue covering the bottom half of the patient's shin. If an indentation remains after the nurse's fingers are lifted, pitting oedema is present. Pitting oedema is scored as follows:

Score	Description	Measurement
1	The pit is barely perceptible.	2mm
2	The pit is deeper than with 1; it rebounds in a few seconds.	4mm
3	The pit is deep; it rebounds in 10-20 seconds.	6mm
4	The pit is deeper that with 3; it rebounds in >30 seconds.	8mm

It is important to highlight that, in most clinical settings, the depth of pitting oedema is not measured. However, nurses should be confident in estimating the depth of the pitting oedema which they observe on a patient during assessment.

• Clubbing of the fingers. This occurs when the angle of the base of the nail bed, where it joins to the tissues of the fingers, is >160. Clubbing is very obvious on inspection, and does not need to be measured. Clubbing indicates that a patient may be experiencing chronic hypoxia.

It is important for nurses to note that there are a variety of other supplementary techniques which may be used to assess the cardiovascular system. Additional assessments to assist with differential diagnosis of cardiovascular problems include chest X-rays or CT scans, blood tests to assess for cardiac biomarkers (i.e. chemicals, such as troponin, which are released into the blood after damage to the heart muscle), and perhaps ultrasound. Although nurses generally do not perform these assessments, they have an important role in preparing the patient and in interpreting and communicating relevant findings.

Conclusion

As you have seen throughout this chapter, the cardiovascular system is one of the body's fundamental life-sustaining systems; therefore, it is essential that nurses are able to accurately and comprehensively assess this system. This chapter has introduced the fundamental knowledge and skills nurses require to do so. It began with an overview of the fundamental anatomy and physiology of the cardiovascular system. The chapter then explained the processes involved in collecting a general health history for the cardiovascular system, and in performing a physical examination of the cardiovascular system. Finally, this chapter considered a number of special observation and assessment techniques which may be used in the physical examination of the cardiovascular system.

'Hands-on' scenario

The observation and assessment of a patient experiencing chest pain, to develop a differential diagnosis

Melissa is a graduate nurse working in the Accident and Emergency (A&E) Department of a large hospital in London. She is preparing to receive a patient arriving via road ambulance. The only information Melissa has about this patient is that he is a fifty-nine year old male who is experiencing chest pain, which the attending paramedics believe to be of cardiac origin. Melissa's role in the care of this patient will be to assist in his assessment - including (1) collecting a health history and (2) physically examining the patient. Because the patient's chest pain is believed to be of cardiac origin, Melissa's health history and physical examination will focus on the cardiovascular system.

The patient is transferred from the ambulance receiving area and into a critical care bay in the A&E Department. Melissa immediately begins observing the patient. She firstly looks for any issues which may immediately threaten the life or wellbeing of the patient. Melissa notices that the patient is conscious and alert, though he is clearly experiencing significant discomfort. He has an oxygen mask in-situ, and is dyspnoeic with clear intercostal retractions and accessory muscle use. The skin of his face, upper extremities and torso appears pale, mottled and diaphoretic.

Melissa begins the first stage of the assessment process - the collection of a health history. In this case, the health history is provided by the paramedic who attended to the patient in the community. Because of the acuity of the situation, the paramedic provides only the information which is necessary for the patient's immediate care. The paramedic tells the A&E team:

"This is Mr Donald Jones. He is a fifty-nine year old male. Approximately twenty minutes ago, Donald's wife telephoned paramedics to state that Donald was experiencing chest pain of sudden onset whilst he was sitting watching television. The pain is located in the precordial region, radiating into both arms, the jaw and the epigastric region. Donald describes this pain as 'squeezing' and 'crushing', at 10/10 on the pain scale. Donald is also experiencing dyspnoea and nausea. Donald has no significant past medical history. Donald is receiving 8 Litres of oxygen per minute via a nasal mask. He has had 15 milligrams of intravenous morphine during transport, but he states that his pain remains at 10/10. An ECG was performed during transport, and is attached to Donald's notes."

As Melissa is listening to this health history, she progresses to the next stage of the assessment process - the physical examination, with a focus on the cardiovascular system. Prior to commencing her assessment, Melissa provides Mr Jones with a brief explanation of what she plans to do and why, and obtains Mr Jones' consent. Melissa then commences the physical examination. Because of the urgency of the situation, she focuses her physical examination as follows:

Melissa assess the peripheral vascular system by: Measuring the blood pressure (BP).	Melissa finds that Mr Jones has hypertension, with a blood pressure of 98/138mmHg. This is an ABNORMAL finding.
Inspecting and palpating the upper and lower extremities for skin integrity, colour, temperature and capillary refill.	Melissa finds that Mr Jones' skin is pale and mottled, that he is diaphoretic, that his nail beds are cyanotic, and that his CRT is >2 seconds. These are all ABNORMAL findings.
Melissa assesses the heart by: Inspecting the anterior chest wall for contour, pulsations, lifts, heaves, retractions, etc.	Melissa finds that Mr Jones' chest wall is symmetric, with gentle contours. The apical pulse is slightly visible. These are all NORMAL findings.
Measuring the heart rate (HR).	Melissa finds that Mr Jones is tachycardic, with a heart rate of 105 beats per minute. His heart rhythm is irregular, and is pulse is 'thready'. These are ABNORMAL findings.
Measuring the oxygen saturation (SpO2).	Melissa finds that Mr Jones oxygen saturation is 94%. This is an ABNORMAL finding.
Assessing the heart sounds.	Melissa finds that Mr Jones heart sounds are accented and variable. This is an ABNORMAL finding.

The health history and physical examination provide Melissa with important information about the current state of Mr Jones' cardiovascular system, and the possible causes of his chest pain. From the heath history, she learned that Mr Jones' chest pain occurred suddenly, whilst the patient was at rest; Melissa knows the most common causes - but not the only causes - of such pain are myocardial infarction and unstable angina. From her physical examination, Melissa also knows that Mr Jones' heart is working harder than normal (evidenced by Mr Jones' tachycardia and hypertension), but that it is failing to compensate for the dysfunction that is occurring (evidenced by Mr Jones' pale and mottled skin, his significant dyspnoea, his cyanosis, his CRT >2 seconds and his low oxygen saturation). However, although it has provided useful baseline information, so far the physical examination has not provided Melissa with any further information which could inform a differential diagnosis; this is because the data Melissa has collected during the physical examination could relate equally to myocardial infarction OR unstable angina.

For this reason, Melissa looks at another key tool to assess the cardiovascular system, and one which can be particularly useful in assisting with a differential diagnosis - the electrocardiogram (ECG). An ECG was performed by the paramedics, and Melissa accesses the printout. She identifies changes to the section of the ECG recording between the S- and T-sections - these changes are characteristic of an ST-segment myocardial infarct, or 'STEMI'. These changes would not be apparent if Mr Jones was experiencing unstable angina, or any other disorder - either related to the cardiovascular system, or not - which causes chest pain.

Although myocardial infarction generally, and STEMI specifically, place a patient at significant risk of disability and death, Melissa knows that rapid and appropriate intervention can significantly improve outcomes. Melissa's contribution to Mr Jones' assessment - including the collection of a health history, and physical examination - enabled: (1) a comprehensive current state of Mr Jones' cardiovascular system, and (2) a diagnosis of the cause of his chest pain. This allows rapid treatment to commence, and increases the likelihood of a positive outcome for the patient.

Reference list

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National Institute of Health and Clinical Excellence. (2010). Chest Pain of Recent Onset: Assessment and Diagnosis. Retrieved from: https://www.nice.org.uk/guidance/cg95

National Institute of Health and Clinical Excellence. (2013). Myocardial Infarction with ST-Segment Elevation: Acute Management: Retrieved from: https://www.nice.org.uk/guidance/cg167?unlid=688318161201611953530

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