STEMI Flashcards
Define Acute coronary syndrome
A collection of syndromes resulting from acute myocardial ischaemia. Includes: Unstable angina, NSTEMI, and STEMI
Describe the presentation of acute coronary syndrome
Acute central crushing chest pain >20 min duration Sweating, nausea, dyspnoea, palpitations
How may presentation of MI differ in elderly and diabetic patients?
They may experience ‘Silent’ MIs. These may present with syncope, pulmonary oedema, vomiting, acute confusion, stroke, and diabetic hyperglycaemic states.
Name 3 conditions that mimic the pain of acute coronary syndrome
Pericarditis Dissecting aortic aneurysm Pulmonary embolism Oesophageal reflux, spasm, rupture (Boerhavve syndrome) Biliary tract disease Perforated peptic ulcer Pancreatitis
Categorise acute coronary syndrome on treatment
STEMI: requires reperfusion therapy on presentation NSTEMI and UA: not treated with thrombolysis
Differentiate the types of acute coronary syndrome
STEMI: ST-elevation or LBBB on 12-lead ECG, with positive cardiac markers NSTEMI: No ST-elevation, with positive cardiac markers UA: No ST-elevation, with negative cardiac markers *Cardiac markers: Troponin I, CK-MB
Outline the initial emergency management of acute coronary syndrome
Transfer to CCU/HDU for continuous ECG monitoring and access to defibrillator if needed. ABC assessment: exclude hypotension, locate murmurs, identify and treat acute pulmonary oedema IV access 12-lead ECG Diamorphine 2.5-10mg IV PRN + metoclopramide 10mg Oxygen (controlled oxygen therapy 2-5L/min if hypoxic) Nitroglycerine 2 puffs sublingual (unless hypotensive) Aspirin 300mg PO
Outline the initial investigations for acute coronary syndrome
FBC and U&Es: maintain K+ between 4-5 mmol/L LFTs Glucose Lipids CK-MB: abnormal if 2x upper-limit of normal Troponin I* Portable CXR: Cardiomegaly and pulmonary oedema
What is the criteria for prior MI?
Any one of the following: -Pathological Q waves in absence of non-ischaemic cause -Imaging evidence of region loss of myocardium that is thinned and fails to contract, in the absence of non-ischaemic cause -Pathological finds of a prior MI
Describe the presentation of STEMI
Severe chest pain, may radiate to left arm, neck, jaw Not relieved by sublingual GTN >20 min duration Autonomic: Pale, clammy, sweating, weak pulse and hypotensive, brady- or tachycardia Atypical: Dyspnoea, fatigue, epigastric pain, syncope
What ECG changes are seen in STEMI?
ST elevation or new LBBB (V1 and V6) May have T wave inversion or pathological Q waves
Describe the evolution of STEMI on ECG
Mins to hrs: ST elevation and hyperacute T wave Hrs to 1 day: T wave inversion and Q wave 1 week: Coronary T wave Months: Q wave
Which vessel is occluded in the following?
Anteroseptal STEMI: Left anterior descending artery
ST elevation of:
- 0.2+ mV in leads V1-3
- 0.1+ mV in all other leads
Which vessel is occluded in the following?
High lateral STEMI: Left diagonal branch of LAD
Which vessel is occluded in the following?
Posterior STEMI: Posterior descending artery
Inverted changes seen in V1-3
Posterior leads V7-9 indicated
Which vessel is occluded in the following?
Inferior MI: Right coronary artery
What vessel is occluded in an anteroseptal STEMI, and which leads would be abnormal?
Left anterior descending artery V1-4
What vessel is occluded in a lateral STEMI, and which leads would be abnormal
Left marginal artery V5-6
What vessel is occluded in a high-lateral STEMI, and which leads would be abnormal?
Left circumflex artery I and aVL
What vessel is occluded in an inferior STEMI, and which leads would be abnormal?
Right coronary artery II, III, aVF
Which lead would be abnormal in a right ventricular STEMI?
VR4
Which leads would be abnormal in a posterior STEMI
V7-9 or V1-3 reciprocal ST depression
Outline the medical intervention for STEMI
Diamorphine 2.5-10mg IV PRN + Metoclopramide 10mg Oxygen (controlled oxygen therapy 2-5L/min if hypoxic) Nitroglycerine: 2 puffs sublingual (unless hypotensive) Aspirin 300mg PO Correct electrolyte imbalances: Low K+ and Mg2+ may be arrhthmogenic. Maintain K+ between 4-5 mmol/L Limit infarct size -Beta blockers: give early to all patients unless contraindicated -ACEi: given within 24hr of presentation -Reperfusion: Thrombolysis or PCI
List the absolute contraindications for beta-blockers
HR <60 SBP <100 Moderate to severe heart failure AV conduction defect Severe airway disease
List the relative contraindications for beta-blockers
Asthma CCBs and/or beta-blockers Critical limb ischaemia Large inferior MI involving right ventricle
List 3 complications of STEMI
Sudden death Pump failure/pericarditis Ruptured papillary muscle or septum Embolism Aneurysm/arrhythmias -LV aneurysm: persistent ST elevation with LV failure Dressler’s syndrome: secondary autoimmune pericarditis 2-6wk post MI
What are the benefits of reperfusion therapy for MI
Lowers: Mortality* LV dysfunction Heart failure Cardiogenic shock Arrhythmias
What are the indications for Percutaneous coronary intervention?
All patients with chest pain and ST elevation/new LBBB Thrombolysis contraindicated Rescue PCI: if patient symptomatic post-thrombolysis or develops cardiogenic shock ST elevation of > 2mm in 2 or more consecutive anterior leads (V1-V6), or ST elevation of greater than 1mm in greater than 2 consecutive inferior leads (II, III, avF, avL)
Name 3 complications of percutaneous coronary intervention
Bleeding from puncture site Stroke Recurrent infarction Need for emergency CABG Death
What scoring system is used to assess operative mortality in cardiac surgery?
EuroSCORE
When is thrombolysis used as reperfusion therapy?
A primary PCI programme is unavailable Patient cannot undergo cathertisation without delay (within 90 min of pain onset, ideally 60)
Outline the indications for thrombolysis
Typical history of chest pain within previous 12h Plus one of: ST elevation in 2 consecutive ECG leads - >1mm in limb leads or >2mm in chest leads New LBBB on ECG Posterior infarct (V7-9 or reciprocal depression in V1-3)
What drug is used for thrombolysis?
Reteplase IV: Tissue plasminogen activator *Increased risk of haemorrhage Streptokinase
List the absolute contraindications for thrombolysis
Haemorrhagic or ischaemic stroke <6 months CNS neoplasia Recent trauma or surgery GI bleed <1 month Bleeding disorder Aortic dissection
List the relative contraindications for thrombolysis
Warfarin Pregnancy Advanced liver disease Infective endocarditis
List 3 complications of thrombolysis
Bleeding (up to 10%) Hypotension Intracranial haemorrhage Reperfusion arrhythmias Systemic embolisation Allergic reaction Increased risk of cardiac rupture in elderly patients*
Outline a discharge plan following a STEMI
Aspirin + Prasugrel ACEi Beta-blocker/CCB Statin GTN Modifiable risk factors: Manage lipids, diabetes, BP, smoking, diet and weight control 1 month off work Inform DVLA - no driving for 4 weeks, 1 week if successful angioplasty
