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DIAGNOSIS AND INVESTIGATION
THE key question facing clinicians in
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a patient with chest pain is whether | |||||
the presentation relates to underlying | |||||
ischaemia or to another cause . | |||||
Differentiating ischaemic from | |||||
non-ischaemic pain can be challenging | |||||
, as in many instances patients with | |||||
ischaemic chest pain appear well on | |||||
presentation . | |||||
Cardiac ischaemic chest pain is | |||||
described as a central pressure sensation | |||||
on the chest , radiating up to the | |||||
jaw and extending into the left arm | |||||
( although pain may radiate down the | |||||
right arm or both arms ). The pain is | |||||
classically retrosternal , deep , diffuse , | |||||
difficult to localise , builds in intensity | |||||
over time , and may be triggered |
by physical or emotional stress , or occur at rest . 8 New onset or otherwise unexplained shortness of breath is also a frequent presenting feature . 9 Chest pain that is reported as ‘ stab- |
Figure 1 . Atherosclerosis . |
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bing ’ or ‘ sharp ’ in nature , pleuritic or shifting in location is less suggestive of ischaemia . 8
However , patients with ischaemia do not always present classically . Other presenting complaints include nausea and vomiting , fatigue , syncope , diaphoresis , lightheadedness or vague abdominal symptoms . 8 These may be the dominant symptoms in elderly , diabetic and other high-risk patients ; take particular care when assessing this cohort of patients as chest pain , while usually present , may not be reported by the patient . 2
Think of pericarditis when a patient presents with chest pain that increases with inspiration or when lying back and is lessened by leaning forward , and there is a history of a preceding viral illness . An ECG in pericarditis may demonstrate down sloping PR segments and widespread ST-segment elevation . 10
The assessment of chest pain is time critical . Note that a history ,
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US Centers for Disease Control and Prevention / bit . ly / 3L3PYeV |
Box 1 . Differential diagnoses of chest pain
• Life-threatening : — Acute coronary syndrome . — Pulmonary embolism . — Aortic dissection . — Oesophageal rupture .
• Other causes : — Non-coronary cardiac :
• Aortic stenosis .
• Aortic regurgitation .
• Hypertrophic cardiomyopathy .
— Pericarditis . — Myocarditis . — Oesophagitis . — Peptic ulcer disease . — Gall bladder disease . — Pneumonia . — Pneumothorax . — Costochondritis . — Herpes zoster .
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history of previous ACS , percutaneous coronary intervention ( PCI ) or coronary artery bypass graft in the preceding six months . 2 About 28 % of patients with these high-risk features will have a proven ACS . 13 If a patient presents with these high-risk features , it is imperative that access to cardiac defibrillation is available and that emergency services transport the patient to ED . 2
Risk scores and clinical assessment tools ( HEART , see table 1 , and Emergency Department Detection of Chest Pain Score [ EDACS , see table 2 ]) are available to clinicians in ED to assist with the evaluation , treatment and disposition of patients that present with chest pain . 14 , 15 These tools are of particular value where HS troponin assays are not available , such as in rural and remote sites . As many rural GPs often work routinely in the ED , it is important to be aware and comfortable with both tools . The HEART score is designed to be used in any patient deemed appropriate for an ACS workup on presenta-
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examination , ECG and single troponin |
tion to ED and is used to objectively |
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are unable to exclude the diagnosis of an ACS . It is therefore imperative in the outpatient setting that patients in whom there is a reasonable suspi- |
Box 2 . The pulmonary embolism rule-out criteria
• Aged 50 years or older .
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stratify patients into low , moderate and high-risk groups . 14 The EDACS assessment tool is designed for use in patients with chest pain or anginal |
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cion of an ACS are referred to an ED for definitive risk stratification / assessment . Box 1 lists the differential diagnoses of chest pain .
It is also vital to identify other life-threatening conditions such as pulmonary embolism ( PE ) and acute aortic dissection , which may be potentially reversible . The diagnosis of a PE is difficult as no single sign or symptom supports or rules out the diagnosis . The Pulmonary Embolism Rule-out Criteria ( PERC ) is a clinical decision-making
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Figure 2 . Autopsy specimen of aorta has been opened lengthwise to reveal luminal surface studded with lesions of atherosclerosis . |
• Heart rate of at least 100 beats / minute .
• Arterial oxygen saturation ( SpO2 ) of 94 % or less on room air .
• Previous PE or deep venous thrombosis .
• Unilateral leg swelling .
• Haemoptysis .
• Recent trauma or surgery .
• Exogenous oestrogen use .
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symptoms that may be potentially low risk and appropriate for an early discharge from ED . 15 These scoring systems aim to reduce the number of unnecessary investigations , therapies and inpatient admissions ; however , they cannot rule out ACS . 2
The Global Registry of Acute Coronary Events ( GRACE ) score will assist with determining risk and prognosis in patients with diagnosed ACS and estimates their in-hospital and six-month to three-year mortality . The GRACE
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tool designed for primary practice to |
uses eight variables : age , heart rate , |
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help rule out a PE in the outpatient set- |
back pain that accompanies chest pain , |
of chest pain should raise suspicion of |
ischaemia may also be masked in the |
systolic blood pressure , Killip class |
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ting ( see box 2 ; this rules out PE if no criteria are present and pre-test probability is 15 % or less ). 11
In low-risk patients where a diagno-
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unequal pulse volume or systolic blood pressure difference between the arms should raise suspicion of the diagnosis . 9 Urgently refer any patient with a |
infarction . Acute myocardial ischaemia may affect all components of the ECG trace ( see figures 3 , 4 and 5 ). The most dra- |
presence of left ventricular hypertrophy or left bundle branch block . 12 It is thus imperative that ECGs are repeated in patients with suspected ACS . Sugges- |
( a staging system that uses physical examination and the development of heart failure ), creatinine concentration , elevated biomarkers of myocardial |
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sis of PE is being considered , a negative PERC criteria ( for all features ) indicates a low enough level of risk ( less than 2 %) |
suspected acute dissection to the nearest ED .
In an uncomplicated MI , physi-
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matic of these is ST-segment elevation ( STE ) indicating transmural ischaemia , while ST-segment depression ( STD ) |
tive and high-risk features of a possible cardiac cause of chest pain identified on the initial assessment include ongo- |
injury , cardiac arrest on presentation and ST-segment deviation . 16 Further work is ongoing in this field . 17 |
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that further testing is unlikely to yield |
cal examination may be negative . Evi- |
and T wave inversion ( TWI ) may indi- |
ing or repetitive chest pain , an elevated |
Biomarkers of cardiomyocyte injury |
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benefit to the patient . While no history or examination finding is specific or sensitive to the |
dence of heart failure or the presence of a new murmur ( which may represent mitral regurgitation due to papil- |
cate diffuse subendocardial ischaemia . 12 Note that the ECG may also be normal at the time of presentation or |
troponin , persistent ECG changes , haemodynamic compromise , sustained ventricular tachycardia , syncope , |
( typically troponin ) are mandatory in patients with suspected ACS and complement the clinical assessment |
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diagnosis of an acute aortic dissection , |
lary muscle dysfunction ) in the context |
only show minor changes . Evidence of |
known left ventricular dysfunction and |
and ECG in formalising the |
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