Cardiology

Question 1

What is the Bezold-Jarisch reflex?

Answer 1

Triad of apnoea, bradycardia, hypotension
Rare cause of syncope

Pressure sensors (Inhibitory mechanoreceptors) in left ventricle become stimulated
- Due to AMI, contraction of undefilled ventricle (postural), or drugs
Activation of high-pressure C-fiber afferent nerves
Activation of parasympathetic vagal response
Paradoxical bradycardia and decreased contractility
Sudden hypotension
Pulmonary vagal afferents cause apnoea

Question 2

List the functions of:
- B1 adrenergic receptors
- B2 adrenergic receptors
- B3 adrenergic receptors

Answer 2

B1: cardiac muscle - ionotropy, chronotropy, lusitropy, dromotropy

B2: bronchodilatiob, vascular smooth muscle relaxation (vasodilation)

B3: sympathetic mediation of lipolysos and thermogenesis

Question 3

What is the best test for cardiac sarcoidosis?

Answer 3

Cardiac PET

FDG avid areas

Cardiac MR with gadolinium may show you established fibrosis

Question 4

Indications for CABG?

Answer 4

Left main disease
Triple vessel disease
MVD with LVEF <40%

If no left main or LAD, even if diabetic, probably no benefit over PCI