Week 5 - Cardiology Flashcards
What is the 1st line investigation for patients with chest pain, palpitations or blackouts?
ECG
For what 2 conditions is an ECG life-saving?
- Arrhythmias
2 Acute Myocardial Infarction
What are 2 ways to determine the heart rate in an ECG?
- 300 divided by the number of large squares between each QRS complex
- Number of QRS complexes across ECG (10sec) x6
What is the normal range for an ECG PR interval?
- <1 large square
- <200ms
What is the normal range for an ECG QRS interval?
- <3 small squares
- <120ms
What is the normal range for an ECG QT interval?
- <11 small squares
- <440ms
What are the 5 questions to determine an ECG rhythm?
- What is the QRS rate?
- Are the QRS complexes regular?
- Is the QRS broad or narrow?
- Are there P waves?
- What is the P:QRS relation?
Describe normal sinus rhythm?
- Normal QRS rate
- Regular QRS complexes
- Narrow QRS complex
- P waves present
- 1:1 P:QRS relation
Describe complete AV block?
- Slow QRS rate
- Regular QRS complexes
- Can be broad or narrow QRS
- P waves present
- No P:QRS relation
Describe Second degree AV block?
- Normal/Slow QRS rate
- Irregular QRS complexes
- Narrow QRS
- P waves present
- 1:1 or 2:1 P:QRS relation
What is left axis deviation in an ECG?
-30 to -90 degrees (predominantly negative QRS in II and aVF)
Describe the normal morphology of the P, QRS & T wave?
- P wave is positive in the inferior leads
- ST segment is flat
- T wave has the same polarity as the QRS
What leads would show ST elevation in an anterior ST elevation in acute coronary occlusion?
V1-4
What leads would show ST elevation in a lateral ST elevation in acute coronary occlusion?
- Lead I
- aVL
- V5&6
What leads would show ST elevation in an inferior ST elevation in acute coronary occlusion?
- Lead II
- Lead III
- aVF
What 2 things are needed to show ST elevation MI?
- Does the patient have signs of MI
2. Reciprocal ST depression in the opposite leads of ST elevation
Describe Pericarditis on the ECG?
- No reciprocal ST depression
- ST elevation across all the leads so not fitting a coronary distribution!
Describe a supraventricular tachycardia?
- Fast QRS rate
- Regular QRS complex
- Narrow QRS
- Can’t tell if there are P waves due to QRS going to quickly
- No idea about the P:QRS relation
Describe regular broad complex tachycardia?
- Fast QRS rate
- Regular QRS complexes
- Broad QRS
- No idea if there are P waves
- No idea about P:QRS relation
What is the gold standard for EBM?
RCT
What are guidelines evidence A?
Data derived from multiple randomised clinical trials or meta-analyses
What are guidelines evidence B?
Data derived from a single randomised clinical trial or large non-randomised studies
What are guidelines evidence C?
Consensus of opinion of the experts &/or small studies, retrospective studies, registries
What is a clinical trial?
Evaluation of a new therapeutic intervention (drug, device, procedure/surgery) in human volunteers