STEMI

Question 1

Define Acute coronary syndrome

Answer 1

A collection of syndromes resulting from acute myocardial ischaemia. Includes: Unstable angina, NSTEMI, and STEMI

Question 2

Describe the presentation of acute coronary syndrome

Answer 2

Acute central crushing chest pain >20 min duration Sweating, nausea, dyspnoea, palpitations

Question 3

How may presentation of MI differ in elderly and diabetic patients?

Answer 3

They may experience ‘Silent’ MIs. These may present with syncope, pulmonary oedema, vomiting, acute confusion, stroke, and diabetic hyperglycaemic states.

Question 4

Name 3 conditions that mimic the pain of acute coronary syndrome

Answer 4

Pericarditis Dissecting aortic aneurysm Pulmonary embolism Oesophageal reflux, spasm, rupture (Boerhavve syndrome) Biliary tract disease Perforated peptic ulcer Pancreatitis

Question 5

Categorise acute coronary syndrome on treatment

Answer 5

STEMI: requires reperfusion therapy on presentation NSTEMI and UA: not treated with thrombolysis

Question 6

Differentiate the types of acute coronary syndrome

Answer 6

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

Question 7

Outline the initial emergency management of acute coronary syndrome

Answer 7

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

Question 8

Outline the initial investigations for acute coronary syndrome

Answer 8

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

Question 9

What is the criteria for prior MI?

Answer 9

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

Question 10

Describe the presentation of STEMI

Answer 10

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

Question 11

What ECG changes are seen in STEMI?

Answer 11

ST elevation or new LBBB (V1 and V6) May have T wave inversion or pathological Q waves

Question 12

Describe the evolution of STEMI on ECG

Answer 12

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

Question 13

Which vessel is occluded in the following?

Answer 13

Anteroseptal STEMI: Left anterior descending artery

ST elevation of:

• 0.2+ mV in leads V1-3
• 0.1+ mV in all other leads

Question 14

Which vessel is occluded in the following?

Answer 14

High lateral STEMI: Left diagonal branch of LAD

Question 15

Which vessel is occluded in the following?

Answer 15

Posterior STEMI: Posterior descending artery

Inverted changes seen in V_1-3

Posterior leads V_7-9 indicated

Question 16

Which vessel is occluded in the following?

Answer 16

Inferior MI: Right coronary artery

Question 17

What vessel is occluded in an anteroseptal STEMI, and which leads would be abnormal?

Answer 17

Left anterior descending artery V1-4

Question 18

What vessel is occluded in a lateral STEMI, and which leads would be abnormal

Answer 18

Left marginal artery V5-6

Question 19

What vessel is occluded in a high-lateral STEMI, and which leads would be abnormal?

Answer 19

Left circumflex artery I and aVL

Question 20

What vessel is occluded in an inferior STEMI, and which leads would be abnormal?

Answer 20

Right coronary artery II, III, aVF

Question 21

Which lead would be abnormal in a right ventricular STEMI?

Answer 21

VR4

Question 22

Which leads would be abnormal in a posterior STEMI

Answer 22

V7-9 or V1-3 reciprocal ST depression

Question 23

Outline the medical intervention for STEMI

Answer 23

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

Question 24

List the absolute contraindications for beta-blockers

Answer 24

HR <60 SBP <100 Moderate to severe heart failure AV conduction defect Severe airway disease

Question 25

List the relative contraindications for beta-blockers

Answer 25

Asthma CCBs and/or beta-blockers Critical limb ischaemia Large inferior MI involving right ventricle

Question 26

List 3 complications of STEMI

Answer 26

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

Question 27

What are the benefits of reperfusion therapy for MI

Answer 27

Lowers: Mortality* LV dysfunction Heart failure Cardiogenic shock Arrhythmias

Question 28

What are the indications for Percutaneous coronary intervention?

Answer 28

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)

Question 29

Name 3 complications of percutaneous coronary intervention

Answer 29

Bleeding from puncture site Stroke Recurrent infarction Need for emergency CABG Death

Question 30

What scoring system is used to assess operative mortality in cardiac surgery?

Answer 30

EuroSCORE

Question 31

When is thrombolysis used as reperfusion therapy?

Answer 31

A primary PCI programme is unavailable Patient cannot undergo cathertisation without delay (within 90 min of pain onset, ideally 60)

Question 32

Outline the indications for thrombolysis

Answer 32

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)

Question 33

What drug is used for thrombolysis?

Answer 33

Reteplase IV: Tissue plasminogen activator *Increased risk of haemorrhage Streptokinase

Question 34

List the absolute contraindications for thrombolysis

Answer 34

Haemorrhagic or ischaemic stroke <6 months CNS neoplasia Recent trauma or surgery GI bleed <1 month Bleeding disorder Aortic dissection

Question 35

List the relative contraindications for thrombolysis

Answer 35

Warfarin Pregnancy Advanced liver disease Infective endocarditis

Question 36

List 3 complications of thrombolysis

Answer 36

Bleeding (up to 10%) Hypotension Intracranial haemorrhage Reperfusion arrhythmias Systemic embolisation Allergic reaction Increased risk of cardiac rupture in elderly patients*

Question 37

Outline a discharge plan following a STEMI

Answer 37

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