Acute coronary syndrome resident survival guide: Difference between revisions

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Acute coronary syndrome (ACS) refers to any group of symptoms attributed to obstruction of the coronary arteries.  Acute coronary syndrome may refer to either unstable angina (UA), non-ST elevation myocardial infarction (NSTEMI), or ST elevation myocardial infarction (STEMI).
{{Acute coronary syndrome intern survival guide}}
'''For the page on unstable angina, click [[Unstable angina|here]].'''


'''For the page on acute myocardial infarction, click [[Myocardial infarction|here]].'''
'''[[NSTEMI resident survival guide|Click here for NSTEMI/UA resident survival guide]]'''


{{CMG}}; {{AE}} {{CP}}; [[Priyamvada Singh|Priyamvada Singh, M.D.]] [mailto:psingh@perfuse.org]
'''[[STEMI resident survival guide|Click here for STEMI resident survival guide]]'''
 
==Clinical Presentation==
*Substernal / precordial chest pressure / heaviness / pain
* Pain radiation to shoulder or arm / neck / jaw
* [[Nausea]] and/or [[vomiting]]
* [[Shortness of breath]]
* [[Diaphoresis]]
* [[Heartburn]]/ burning sensation in chest
* [[Dizziness]]
* [[Palpitations]]
* Near syncope / [[syncope]]
 
==Initial Work-up==
* Ensure patency of airway, check for adequate breathing and [[circulation]].
* Vital signs ([[pulse rate]], [[blood pressure]], [[respiratory rate]], [[temperature]], and [[oxygen saturation]] maintain pSO2 to > 92%)
* [[EKG|12-lead EKG]] (compare with old EKG if possible)
* [[Cardiac enzymes]] (three sets of [[troponin]], [[CK]], [[CK-MB]] at six hour intervals; first set may be normal, but order all three sets)
* Obtain [[complete blood count]] and [[basic metabolic panel]].
* [[Chest x-ray]]
* [[Oxygen]] (titrate for oxygen saturation levels >92%)
* IV access
* Give IV [[morphine]] for persistent discomfort or anxiety
* 325mg non-enteric coated [[aspirin]] by mouth (or per rectum if patient cannot take orally)
* If patient is not hypotensive and inferior myocardial infarction has been ruled out by EKG, give 0.4mg [[nitroglycerin]] sublingually up to three times, at 5 minute intervals, until chest pain improves.
* If pulmonary embolism is suspected [[D-dimer]]s should be obtained.
 
{| class="wikitable"
|-
| colspan="1" style="text-align:center; background:SteelBlue"| '''Important'''
|-
|style="text-align:center; background:LightSteelBlue"|Follow up with all pending tests and lab results as soon as these become available. For information on evaluating the results go to the apppropriate section on this page.
|-
|}
 
==History and Symptoms==
*'''History of Present Illness:'''
** Chest pain history; ask about onset, duration, nature, intensity, location, progression, radiation to arm, neck, jaw (acute coronary syndrome) or to back (aortic dissection), aggravating (pleuritic and pericarditis chest pain worsens with respiration) and relieving factors (such as [[nitrate]]s or rest), constant or intermittent. Ask about any precipitating factors (trauma, physical strain, emotional distress).
** Ask about associated symptoms (head to toe): Headache, confusion, fever, photophobia, vision changes, bleeding, nausea, vomiting, apetite, weight loss, shortness of breath, palpitations, cough, sputum, abdominal pain, bowel symptoms, urinary symptoms.
 
*'''Past Medical History''': History of stable/[[unstable angina]], past [[myocardial infarction]]. Ask about history of [[hypertension]], [[diabetes]], [[hyperlipidemia]], [[hypercoagulable state]], [[stroke]] and [[TIA]].
 
*'''Past Surgical History''': [[Percutaneous coronary intervention]], [[coronary artery bypass graft]].
*'''Social History''': History of smoking, alcohol use, illicit drug use.
 
*'''Family History''': Family history of premature coronary artery disease in a first degree male relative <55 years of age, or a first degree female relative <65 years old. Family history of myocardial infarction, hypertension, diabetes, stroke, or hypercoagulable state.
 
*'''Medications''': Obtain a list of home medications.
 
*'''Allergies''': Obtain a history of allergic reactions.
 
==Physical Examination==
* '''General'''
** Check for alertness, and orientation with time, place, and person
** Patient leaning forward can point towards pericarditis
*'''HEENT''':
** Auscultate [[carotid artery]] (check for bruit)
** [[Jugular venous distension]], check for [[hepatojugular reflex]]
* '''Cardiovascular''':
** '''Vital signs'''
*** Pulse Rate (rate, rhythm. volume, quality, symmetry, all 4 limbs. [[Aortic dissection]]- Diminution or absence of pulses)
***Blood pressure (check for symmetry in all the limbs)
** '''Inspection''': Check for displacement of the apex.
** '''Palpation''': Confirm the findings of inspection (cardiac apex), musculo-skeletal tenderness, crepitus (esophageal rupture,subcutaneous emphysema), feel for any thrill (possible regurgitation), heave (right ventricular hypertrophy)
** '''Auscultation''':
*** Heart sounds (muffled in [[cardiac tamponade]], [[Pericardial effusion]]), [[Heart sounds|S3]] and [[Heart sounds|S4]] ([[Heart failure]])
*** Murmur (commonly regurgitation murmur)
*** Pericardial rub - ([[Pericarditis]], commonly tricuspid area sounds like scratching), and gallop
* '''Respiratory''':
** '''Inspection''': Observe for symmetry of chest movement, evidence of flail chest, tracheal deviation (pneumothorax).
** '''Palpation''' : Check for muscle tenderness, tracheal deviation, and chest wall movement.
** '''Percussion''': Percuss all lung fields for dullness (effusion), or hyperresonance to percussion on the affected side (pneumothorax).
** '''Auscultation''': Decreased breath sounds (effusion and tension pneumothorax), [[crackle]]s ([[pleural effusion]]) rales ([[heart failure]]).
*'''Extremities''': Check for [[pedal edema]].
 
==Differential Diagnosis==
* [[Aortic dissection]]
* [[Pulmonary embolism]]
* [[Esophageal rupture]]
* [[Cardiac tamponade]]
* [[Tension pneumothorax]]
==Diagnosis==
 
===EKG Findings===
====Electrocardiogram in Unstable angina / NSTEMI====
* No changes
* [[Non specific ST / T wave changes]]
* Flipped or inverted [[T wave]]s
* [[Electrocardiogram|ST Depression]] as shown below. Greater magnitudes of downsloping ST depression are associated with a poorer prognosis.
 
 
[[image:unstable-angina.jpg|framed|center|400px|ST Depression in a patient with unstable angina]]
 
====Electrocardiogram in STEMI====
* ≥2 mm of ST segment elevation in 2 contiguous precordial leads
* ≥1mm in other leads (2 contiguous)
* An initial Q wave or abnormal R wave
* Additionally, new [[left bundle branch block]] and those with a true posterior MI are considered STEMI
* Specific types of STEMI:
** [[STEMI|Anterior STEMI]]: ST elevation in the precordial leads + I and aVL (Left anterior descending artery)
** [[STEMI|Posterior STEMI]]:  ST elevations in II, III  and aVF, reciprocal ST depressions in V1-V3, may  have component of inferior ischemia (Left Circumflex artery)
** [[Right ventricular myocardial infarction|Inferior STEMI]]: ST elevation in II, III and aVF. When inferior MI is suspected a R - sided precordial leads is useful (ST elevation). Reciprocal changes in I and aVL (Right coronary artery or Left circumflex artery)
 
===Chest X Ray Findings===
* '''[[Aortic dissection]]''': Suspect aortic dissection if  findings include increased aortic diameter, widened mediastinum, and/or pleural effusion (hemothorax) in the absence of [[CHF]]
*'''[[Pulmonary embolism]]''': May not appreciate any abnormalities on chest x ray.
*'''[[Tension pneumothorax]]''': No pulmonary vessels are visible beyond the visceral pleural line. Tracheal deviation away from the collapsed area of lung will be seen.
*'''[[Esophageal rupture]]''':The most common findings are [[pleural effusion]], [[pneumothorax]], [[pneumomediastinum]], or subcutaneous emphysema.
*'''[[Heart failure]]''': [[Cardiomegaly]], and pulmonary congestion ([[Kerley B lines]]),  may be seen. Obliteration of costophrenic angle may be seen in pleural effusion.
 
===Laboratory Findings===
*Check for elevation in '''CK''', '''CK-MB''', and '''troponin''' levels. If EKG changes are not present but enzymes are elevated, this can point to a diagnosis of Non-ST elevation myocardial infarction.
*Check '''basic metabolic panel''' for electrolyte abnormalities and correct accordingly. BUN and Creatinine levels should be checked in preparation the possible need for contrast during PCI.
* Elevated '''D-dimer''' levels >500ng/ml is considered abnormal, and may be indicative of a pulmonary embolism.
 
 
==Treatment==
 
===General Management===
If positive EKG findings are present consistent with acute coronary syndrome, OR if the patient history is highly suggestive of acute coronary syndrome despite a negative EKG, perform the following measures.
* Page the cardiology fellow and activate the cardiac catheterization lab.
* Give the patient loading doses of
** [[Aspirin]] 325mg non-enteric coated by mouth or per rectum, if not given previously.
**[[Clopidogrel]] 600mg by mouth loading dose OR [[ticagrelor]] 180mg loading dose.
** [[Heparin]] 60 to 100 units/kg, up to a maximum of 4000 units for an aPTT of 50 to 70 seconds.
** [[Atorvastatin]] 80mg or [[simvastatin]] 40mg.
** [[Metoprolol]] by mouth if there are no signs of heart failure, hemodynamic compromise, bradycardia, or severe reactive airway disease.
===Reperfusion Strategy===
*[[Percutaneous coronary intervention]] (with or without bare metal or drug eluting [[stent]] placement) is preferred.
*[[Fibrinolytic therapy]] should be administered if percutaneous coronary intervention is not available within 90-120 minutes, if there are no contraindications and symptoms have been present for less than 12 hours.
* If the patient has had symptoms for more than 12 hours, fibrinolytic therapy is not indicated and the patient may undergo an emergent PCI if there is evidence of continued [[ischemia]].
===Post-PCI Management===
* Monitor patient on telemetry for any abnormal rhythms.
* Monitor patient on cardiac monitor for vital signs.
* Obtain a post-procedure [[EKG]] if the patient becomes symptomatic.
* Obtain an [[echocardiogram]].
* Patient should remain on maintenance doses of aspirin and ticagrelor/clopidogrel. Continue the patient on a beta blocker, ACE inhibitor and statin.
* Check for any bleeding from the catheterization site and any other site.
* Check for pulses.
* Refer to [[cardiac rehabilitation]].
 
==Other Diagnostic Work-up==
* If [[esophageal rupture]] is suspected, a contrast-enhanced esophageal radiography is diagnostic.
* If [[pulmonary embolism]] is suspected, spiral CT scan should be obtained.
* If [[aortic dissection]] is suspected, obtain a CT scan with contrast.
* If [[cardiac tamponade]] is suspected, obtain an [[echocardiogram]].

Latest revision as of 17:22, 15 April 2015

Acute coronary syndrome (ACS) refers to any group of symptoms attributed to obstruction of the coronary arteries. Acute coronary syndrome may refer to either unstable angina (UA), non-ST elevation myocardial infarction (NSTEMI), or ST elevation myocardial infarction (STEMI).

Click here for NSTEMI/UA resident survival guide

Click here for STEMI resident survival guide