Chest Pain Flashcards
(112 cards)
What are the two main character types of chest pain?
- Somatic chest pain (originating from pericardium, pleura, chest wall) = well-localised, sharp
- Visceral chest pain (originating from cardiac muscle itself) = dull, aching, heavy /crushing
Common associated symptoms with chest pain…
- Dyspnoea
- Cough - respiratory cause?
- Haemoptyisis - PE?
- Nausea and vomiting
- Sweating
- Palpitations -arrhythmia?
- Dizziness/ syncope
Difference between general inspection of cardiac chest pain and respiratory chest pain …
- Cardiac chest pain = grey, clammy, unwell
- Respiratory chest pain = cyanosed, dyspnoaeic
What can be heard on auscultation in heart failure?
- Cardio = gallop rhythm
- Chest = crackles indicating fluid on the lungs from pulmonary oedema
Differential diagnosis for chest pain…
- Cardiac : ACS (central crushing chest pain), pericarditis (pleuritic chest pain worse on lying down), stable angina (relived by rest), arrhythmia (palpitations), myocarditis
- Vascular: aortic dissection (tearing chest pain radiating to back between shoulder blades)
- Respiratory: PE (pleuritic chest pain, VTE risk factors), pneumonia (associated infective sx e.g. purulent sputum), pneumothorax (sudden pleuritic chest pain with SoB)
- Gastro: GORD (retrosternal burning chest pain, associated with eating) , oesophageal spasm, referred pain from cholecystitis, pancreatitis
- Other causes = shingles (dermatomal distribution across chest wall), panic disorder (associated with panic attacks)
Describe the pathophysiology of ACS?
- Endothelial injury: injury leads to inflammatory response leading to accumulation of LDLs which are then oxidised to reactive oxygen species.
- Plaque formation: These irritants then attract macrophages which phagocytose the LDLs to form fatty streaks.
- Plaque rupture: continued inflammation attracts smooth muscle cells which form a fibrous cap that then develops into an atheroma. The top of the atheroma forms a hard plaque which can rupture. This exposes a collagen-rich cap which causes platelets to aggregate on this exposed collagen, forming a thrombus.
Typical presentation of ACS…
- Retrosternal, central crushing chest pain - radiates up the jaw and down left arm
- Associated sx: nausea, sweating, palpitations, shortness of breath
What ECG changes are seen in STEMI ?
> Mins- hours: hyperacute T wave enlargement
0-12 hrs: ST segment elevation
1-12 hrs: Q -wave development (deeper and wider than normal)
Days: T-wave inversion
Weeks: T-waves will normalise, Q waves persist (sign of previous MI if already present)
What ECG changes are seen in NSTEMI/UA?
> ST segment depression
> T-wave inversion
What are the ECG criteria for thrombolysis in STEMI?
- > 2mm in ST segment elevation in adjacent chest leads
- > 1mm in adjacent limb leads
- LBBB
What artery supplies the anterior aspect of the heart?
Left anterior descending artery (branch of LCA) ; supplies right ventricle, left ventricle and intraventricular septum
What artery supplies the lateral aspect of the heart?
Left circumflex artery (branch of LCA) which supplies left atrium and left ventricle.
What artery supplies the posterior aspect of the heart?
Right coronary artery distributed along posterior surface; supplies right atrium and right ventricle
What artery supplies the inferior aspect of the heart?
Right marginal artery which moves along right and inferior border of the heart ; supplies right ventricle and apex.
Anterior STEMI will show ECG changes in leads…
- V1, V2, V3, V4 ST elevation
- Reciprocal ST depression in III and aVF
Lateral STEMI will show ECG changes in leads…
- aVL, V5,V6 ST elevation
- Reciprocal ST depression in III and aVF
Inferior STEMI will show ECG changes in leads…
- II, III and aVF ST elevation
- Reciprocal ST depression in I and aVL
Posterior STEMI will show ECG changes in leads…
V1, V2, V3 ST depression, with tall and wide R wave
*will most likely require additional V7,V8,V9 leads across the back for more detailed trace.
What else can cause ST elevation?
- Pericarditis
- Hyperkalaemia
- Massive PE
- Aortic dissection
- Many of which can cause chest pain too!!
What blood tests should be requested for investigation of ACS?
- FBC =in case of anticoagulant use
- U&Es = baseline renal function for use of IV contrast in angiography
- CRP= underlying infection
- LFTs and clotting profile =bleeding risk if vascular intervention required
- Cardiac enzymes = troponins, CK, AST, LDH
What are the guidelines for troponin levels in ACS management?
- Troponin level taken at ED admission greater than 99th percentile (normal levels = <14ng/L)
- Another measurement 3 hours later (needs to be a significant change seen)
Apart from troponin, what other cardiac enzymes are used for ACS diagnosis?
- Creatinine kinase: returns to baseline within 48 hrs, so can identify re-infarcts
- LDH
- AST
What else can cause troponin rise?
Other causes of myocardial damage:
- Tachyarrhythmia
- Heart failure
- Pericarditis
- Chest trauma
- Sepsis
- Cardiomyopathy
Initial management of ACS…
- Aspirin 300mg PO and another antiplatelet (prasugrel 60mg/ticagrelor 180mg)
- High flow oxygen (only if hypoxic)
- IV access : Diamorphine 2.5-10mg + Metoclopramide 10mg
- GTN spray - unlikely to be effective in STEMI
* *ECG within 10 minutes = identify subtype of ACS