Lecture 17 Flashcards
What does chest pain signify?
There is a spectrum (life-threatening > non-urgent)
How do you come to a diagnosis?
- history
- clinical examination
- investigations (ECG, blood tests- FBC)
What are some causes of chest pain?
Split into categories
Respiratory: pleuritic chest pain
-diseases affecting lung: cause chest pain if affects parietal pleura
(Pneumonia/pulmonary embolism: lung tissue infarcts and inflames irritating pleura)
MSK
- broken rib (point tenderness, breathing in/cough makes it painful = can be described as pleuritic pain= sharp)
- costochondritis (inflammation of costal chonditis)
- muscle spasms
Cardiac
- MI/angina (related to coronary arteries: heart becomes ischaemic)
- pericarditis (sharp pain, localised, made worse on breathing in/coughing= pleuritic pain, non-ischaemic)
Gastro-intestinal
-oesophagus (reflux-burning up middle of chest, made worse after eating/flat in bed)
Symptoms with pneumonia/chest infection:
Ask this to determine if there is a respiratory cause for their chest pain
- short of breath
- coughing up sputum
- fever
-check for DVT if pulmonary embolism
What is the nervous system involved in cardiac pain?
Pain carried through visceral nervous system: autonomic
Cardiac muscles in pain- due to coronary arteries
What is the nervous system involved in pleuritic pain?
Pain carried from somatic nervous system
Pain due ti irritation to parietal pleura
What is visceral pain described as?
- dull
- poorly localised
- centre of chest
- worsened with exertion
- may radiate to shoulder/jaw
How is pleuritic chest pain described?
-sharp
-well localised
-worsened by inspiration/coughing/positional movement
(Pericarditis/MSK disorders mimic pleuritic chest pain)
What is ischameia?
Restriction of blood supply to tissues causing a shortage in oxygen needed for cellular metabolism
What is pericarditis?
Inflammation of pericardium
In who is pericarditis more common?
Men and adults
What is pericarditis caused by?
Viral infection (e.g. any recent coughs/cold)
What may be heard on auscultation in a person with pericarditis?
Pericardial rub (normal lub-dub, but can hear a rustling noise on top of it) -heart rubs against inflamed layer of pericardium
How is the chest pain eased/aggravated in pericarditis?
Eased: sitting up/leaning forward
Aggravated: inspiration/cough/lying flat
Describe the pain the patient would feel in pericarditis:
Sharp, localised to the front of chest
What on an ECG signifies pericarditis?
ST elevation, widespread, saddle shaped: all leads
Wouldn’t see this in MI: only in region affected by infarct
Difference between unstable angina and stable angina?
Unstable: chest pain at rest
Stable: chest pain upon exertion
What is ischaemic heart disease/disease of coronary arteries (encompasses angina/MI) caused by?
Atherosclerosis
- fatty deposits in arteries followed by a fibrous plaque over it
- cause occlusion
- plaque can rupture
What are the modifiable/non-modifiable risk factors for atherosclerosis?
Same therefore as for ischaemic heart disease Modifiable: -smoking -hypertension -diabetes type 2 -obesity -sedentary lifestyle -dyslipidaemia (high amounts of lipids in blood)
Non-modifiable
- advanced age
- family history
- male sex
What occurs in stable angina?
Narrowing of arteries by stable atherosclerotic plaque: fixed occlusion
- heart tissue only becomes ischaemic when metabolic demands of the cardiac muscle are greater than what can be delivered via coronary arteries (exercise)
- relieved by rest
- cardiac sounding chest pain
- chest pain doesn’t last long
What does acute coronary syndrome encompass?
- unstable angina
- NSTEMI/STEMI: MI
(Stable angina is not acute, usually chronic)
How is stable angina different from an acute coronary syndrome?
ACS: are acute myocardial ischaemia caused by atherosclerotic coronary artery disease
(Something with plaque has changed causing sudden increase in occlusion of artery)
-may have history of stable angina until plaque ruptures forming a thrombus and greater occlusion
-therefore if occlusion is significant enough you may get pain at rest/necrosis of myocardial tissue
What determines whether a person will have unstable angina/MI after atherosclerotic plaque rupture?
Degree of occlusion
Unstable angina:
-lumen become more narrow, causing heart tissue ischaemia
MI:
-large thrombus on plaque (can sometimes fully occlude artery)
-significant occlusion, muscle deprived leading to tissue death/infarcted
What would you see in the blood from the myocytes in unstable angina/MI?
Unstable angina:
-myocytes don’t die/necrose so no cardiac enzymes leak out
MI:
-myocytes rupture and cardiac enzymes (troponin) leak from necrosed cardiac muscle cells
What are the features of unstable angina?
Similar to stable angina (occurs under exertion and relieved by GTN spray) EXCEPT -pain at rest -pain more intense -pain lasts longer Deteriorating further = MI
What ECG changes may we see in unstable angina?
- ST depression
- T wave inversion
- can be normal
What would you see in blood tests for unstable angina?
Troponin negative
What are the features of MI?
MI presents very similar to unstable angina
- going to shoulder and jaw
- pain at rest
- autonomic features= nauseous/sweaty/pallor
What is the ECG and blood tests for someone with an MI?
ECG
STEMI: ST elevation (don’t wait for blood test- straight to angioplasty)
NSTEMI: ST depression/T wave inversion (ischaemic)
Blood test: troponin positive
How you you know where the MI occured?
Localisation determines anatomical region of the STEMI
What is the difference between STEMI and NSTEMI in terms of thickness?
STEMI: full thickness of myocardium
NSTEMI: sub endocardial injury (between endocardium and myocardium)
