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Cardiovascular Alterations and Management 217

wall is affected, with a small infarction often resulting in
a dyskinetic wall (altered movement), whereas a large TABLE 10.1 The PQRST criteria for assessing
infarction may result in akinesis (no movement). chest pain 110
The location and impact of the infarction will depend on
which coronary artery has been obstructed: P Precipitating Exercise and activity
Stress and anxiety
● Left anterior descending (LAD) affects the function of Cold weather
the left ventricle and interventricular septum, includ- Palliating Stop activity
ing ventricular conduction tissue. Patients with antero- Rest
septal MI are at high risk of heart failure, cardiogenic Nitroglycerin
shock and mortality due to pump deficits. Q Quality Heavy, tight, choking, vice-like,
● Circumflex (CX) affects the left ventricle lateral and constricting
5
posterior walls and the SA node in 50% of people. R Region, Radiation Left side of chest, shoulder, arm and jaw
The impact on pump efficiency of lateral and posterior Retrosternal and radiating to the neck
wall necrosis is not as severe as anteroseptal infarcts, S Severity Rate pain on scale of 1 (no pain) to 10
although patients are at more risk of arrhythmias. (worst pain possible)
● Right coronary artery (RCA) affects the inferior wall of
the left ventricle and the right ventricle, as well as the T Time Pain lasts longer than 10 minutes
despite nitroglycerin
AV node in most patients and the SA node in 50% of Pain comes and goes but lasts longer
people. There is potentially severe impact on ventricu- than 20 minutes
lar function if both the inferior wall and the right Hudak CM, Gallo BM, Morton PG. Critical care nursing, A holistic approach.
ventricle are affected, as well as a high risk of arrhyth- (7 Ed) Philadelphia: Lippincott 1998.
th
mias due to SA and AV node involvement.
Clinical Features
Patients with AMI most often present with chest pain. delayed diagnosis and treatment and a higher mortality
7
This pain is described as central crushing retrosternal (50%) than with typical symptoms (18%). Differentiat-
pain, which lasts longer than 20 minutes and is not ing this pain from any previous pain is also useful. The
relieved by nitrate therapy. The pain may radiate to the brief history should include a short cardiovascular risk
neck, jaw, back and shoulders and is often accompanied profile: (a) previous cardiac history such as angina, MI,
by ‘feelings of impending doom’, sweating and pallor. revascularisation; and (b) family history, smoking, hyper-
Nausea is often associated with the pain, due to vagal tension, diabetes.
nerve stimulation. Depending on the size and location of
the AMI, patients may also present as sudden death and Practice tip
with varying degrees of syncope and heart failure. Women
may present with different symptoms. Because of changes in neuroreceptors, older patients and dia-
betic patients may not describe the typical anginal pain.
Patient Assessment and Diagnostic Features Women also may not describe classic angina symptoms and
4
A key feature of assessment of the patient with chest pain may use different descriptors from men. Be alert for prodromal
is the use of protocols and guidelines to promote rapid symptoms, such as increased shortness of breath, weakness
assessment so that revascularisation procedures such as and fainting.
thrombolysis and percutaneous coronary intervention
(PCI) can be implemented as soon as possible. This
means that assessment may begin as early as in the ambu-
lance, with ECG transmission to hospital ED where rapid, A more complete history, which includes detailed infor-
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early triage models of care are in place. Additionally mation about risk factors, can be acquired when the
assessment also needs to determine whether there are any patient is stabilised. This information will be essential to
contraindications for thrombolysis. guide patient education, rehabilitation and to plan dis-
The assessment method used depends on the condition charge. Recurrent chest discomfort requires urgent reas-
of the patient but should occur within 10 minutes of sessment, including immediate ECG.
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arrival. This initial history will focus on the nature of
symptoms such as pain. Pain assessment is complex, and Physical examination
the use of an acronym such as PQRST (see Table 10.1) is Physical appearance varies and depends on the impact of
useful to incorporate precipitating and palliative factors, pain, size and location of the infarction in the individual.
qualitative descriptors, location, radiation and length of Heart rate and blood pressure may be raised due to
time. A pain scale is included to help rate the intensity of anxiety. Impaired left ventricular function may result in
pain. Asking patients for descriptive words is useful in dyspnoea, tachycardia, hypotension, pallor, sweating,
assessment as many patients will deny pain and instead nausea and vomiting. Impaired right ventricular function
use words such as pressure, tightness or constriction. It is may be indicated by jugular vein distension and peri-
essential not to ignore other presentations, as patients pheral oedema. Abnormalities in heart sounds may be
with atypical symptoms, such as women, often have a present, including a muffled and diminished first heart