Angina pectoris

Question 1

What is angina pectoris?

Answer 1

Chest discomfort (heaviness/ tightness) due to myocardial ischaemia.

May radiate to arm/s, neck, jaw or teeth

Question 2

What are the types of angina?

Answer 2

• Stable angina; induced by effort & relieved by rest
• Unstable (crescendo); increasing frequency or severity with minimal/ no exertion
• Decubitus angina; precipitated by lying down (flow no longer pooling in legs)
• Variant Prinzmetal angina; coronary artery spasm without provocation
• Cardiac syndrome X; due to coronary microcirculation problem (vasodilation issue?)

Question 3

What can precipitate angina & why?

Answer 3

• Emotion & exertion; adrenaline release ⇒ tachycardia
  
  • ⇒ Diastolic time decreases ⇒ less perfusion time & lowering O2 supply
  • ⇒ Inc O2 demand
• Cold; peripheral vasoconstriction ⇒ Inc BP ⇒ Inc afterload of heart ⇒ Inc force of contractility & SV (frank-starling?) ⇒ Inc O2 demand
• Heavy meals; blood diverted to mesenteric system ⇒ low pressure in aorta ⇒ lowering coronary perfusion!

Question 4

What are causes of angina?

Answer 4

Decreased oxygen supply;

• Atheroma
• Arteritis/ small vessel disease/ vasculitis
• Embolism & Hypotension
• Anaemia/ Polycythemia (high RBC making blood viscous and slow)/ Carboxyhaemoglobinaemia (CO)
• Chronic lung disease
• Aortic stenosis (both: 1. low pressure..)

Increased oxygen demand;

• Tachyarrhythmias
• Hyper-
  
  • hypertrophic cardiomyopathy (HCM)
  • hyperthyroidism (inc HR)
  • pulmonary hypertension
• Pregnancy
• Aortic stenosis (both: 2. compensatory hypertophy increases demand)

Question 5

What are the risk factors for angina?

Answer 5

• Sex: male
• Age : older
• Diabetes mellitus
• BP high
• Elevated cholesterol (hyperlipidaemia)
• ​Tobacco
• Sedentary
• Family history

Question 6

What are the associated symptoms of angina?

Answer 6

• Dyspnoea
• Nausea
• Sweatiness
• Faintness

Question 7

What are the possible investigations for angina?

(Theres another question on hospital guidelines)

Answer 7

• ECG
  
  • Normal, or
  • ST depression (subendocardial ischaemia/ infarct causing arrow of charge to go towards it…)
  • Flat/ inverted T waves (why?)
• Exercise ECG
  
  • CAD: ST seg depression or fall in BP (after 6 minutes Bruce protocol)
• Cardiac CT
  
  • Coronary Ca²⁺ score
• Coronary angiography
• Stress echo; dobutamine
• EXCLUDE other/ precipitating factors factors;
  
  • Anaemia
  • Diabetes
  • Hyperlipidaemia
  • Thyrotoxicosis
  • Temporal arteritis

Question 8

Outline the UHNS guidelines for investigation angina

Answer 8

1. ECG - ST elevation/ LBBB?
   
   • Yes - refer for MI (see guidelines)
2. No - single troponin assay
3. Calculate Heart Score
   
   • ​​History (0-2)<!--=3 - unlikely cardiac</li-->
   • ECG (0-2)
   • Age (0-2)
   • Risk factors (0-2)
   • Troponin I score (0-2)
4. >3 - Refer for cardiac assessment
   
   1. ​Give aspirin 300mg
   2. Consider GTN/ opiod

Question 9

Outline the management for angina

Answer 9

• Modify risk factors
  
  • stop smoking, exercise, weight loss, control hypertension & diabetes
  • Give statin is cholesterol >4mmol/L
• Aspirin
• B-blocker
  
  • eg Attenolol
• Nitrates
  
  • GTN spray or sublingual tabs
• Long-acting calcium antagonists
  
  • eg Amlopidine, Diltiazem
• K⁺ channel activator
  
  • eg Nicorandil

Question 10

What are the indications for referral for treatment?

Answer 10

• Diagnostic uncertainty
• New angina of sudden onset
• Recurrent angina if past MI/ CABG
• Angina uncontrolled by drugs
• Unstable angina

Question 11

What are surgical treatments for angina?

Answer 11

• Percutaneous Coronary Intervention (PCI)
  
  • aka percutaneous transluminal coronary angioplasty (PTCA)
  • Balloon dilatation of stenotic vessels
  • Indicated if poor/ intolerant responce to medical therapy, not suitable for/ refractory angina after CABG
• Coronary artery byspass graft (CABG)
  
  • When; left main stem disease, multi-vessel disease, multiple severe stenoses, unsuitable/ failed angioplasty, refractory angina
  • How; saphenous/ mammary artery used as graft
  • Off/ on-pump (during surgery)?; off = lower mortality & complications. on = less need for re-vascularisation