Differentials

Question 1

Causes of an irregular pulse

Answer 1

• Sinus arrhythmia
• Atrial extrasystoles
• Ventricular extrasystoles
• AF
• Atrial flutter with variable response
• Second-degree heart block with variable response

Question 2

Causes of a tachycardia in sinus rhythm

Answer 2

• Physiological:
  
  • Exercise
  • Pain
  • Excitement/anxiety
  • Fever
• Endocrine: Hyperthyroidism
• Iatrogenic:
  
  • Sympathomimetics e.g. Salbutamol
  • Vasodilators

Question 3

Causes of a tachycardia not in SR

Answer 3

• Supraventricular:
  
  • Atrial flutter
  • Atrial fibrillation
  • Supraventricular tachycardia
• Ventricular:
  
  • Ventricular tachycardia

Question 4

Causes of a bradycardia in SR

Answer 4

• Physiological:
  
  • Sleep
  • Athletic training
• Endocrine: Hypothyroidism
• Iatrogenic:
  
  • Beta blockers
  • Digoxin
  • Verapamil
  • Diltiazem

Question 5

Causes of a bradycardia not in SR

Answer 5

• Sinus problems
  
  • Carotid sinus hypersensitivity
  • Sick sinus syndrome
• Heart blocks:
  
  • Second degree heart block
  • Complete heart block

Question 6

Causes of an increased pulse volume

Answer 6

• Physiological:
  
  • Exercise
  • Pregnancy
  • Advanced age
  • Increased environmental temperature
• Pathological:
  
  • CV:
    
    • HTN
    • PVD
    • AR
  • Fever
  • Anaemia
  • Thyrotoxicosis
  • Paget’s disease of the bone

Question 7

Causes of secondary hypertension

Answer 7

• Pituitary:
  
  • Cushing’s syndrome (ACTH secreting pituitary microadenoma)
• Aorta:
  
  • Coarctation of the aorta
• Adrenal:
  
  • Conn’s syndrome (Aldosterone-secreting tumour of the adrenal cortex)
  • Phaeochromocytoma (neuroendocrine tumour, NB may also be extra-adrenal)
• Renal:
  
  • Renal artery disease (incl renal artery stenosis)- suspect if other vascular disease
  • PCKD

Question 8

Causes quiet first heart sound

Answer 8

• Low cardiac output
• Poor LV function
• Rheumatic MR
• Long P-R interval (first degree heart block)

Question 9

Causes loud first heart sound

Answer 9

• Increased cardiac output
• Large stroke volume
• Mitral stenosis
• Short P-R interval
• Atrial myxoma (rare)

Question 10

Causes variable intensity of first heart sound

Answer 10

• AF
• Extrasystoles
• Complete heart block

Question 11

Causes quiet second heart sound

Answer 11

• Low cardiac output
• Calcific aortic stenosis
• Aortic regurgitation

Question 12

Causes loud second heart sound

Answer 12

• Systemic HTN (aortic component)
• Pulmonary HTN (pulmonary component)

Question 13

Causes systolic murmurs

Answer 13

• Ejection systolic:
  
  • Flow murmur
  • Innocent systolic murmur (athlete, pregnancy)
  • Atrial septal defect
  • Severe anaemia
  • Aortic stenosis
  • Pulmonary stenosis
  • Hypertrophic cardiomyopathy
  • Flow murmur aortic regurg
• Pansystolic:
  
  • Mitral regurg
  • Tricuspid regurg
  • VSD
  • Leaking mitral or tricuspid valve