Ventricular Fibrillation

Question 1

ECG features of VF?

Answer 1

HR: 300-600
Very irregular rhythm
Absent P wave
Fibrillatory baseline

Coarse -> fine

Question 2

Causes of VF/contributory factors?

Answer 2

MI, ischaemia, myocardial scarring,

Intracellular calcium accumulation, the action of free radicals, metabolic alterations, and autonomic modulation are important influences on the development of VF during ischemia.

Question 3

Pathophysiology of VF?

Answer 3

Often:
Chaotic ventricular depolarization (?erratic propagation of impulses -> through variably refractory myocardial cells -> penetrant patterns) -> leads to complete disco ordination of myocardial

Question 4

Tetralogy of Fallot:

Answer 4

RV ouflow obstruction
Ventricular Septal Defect
Aorta dextroposition
RV hypertrophy

Question 5

What is eisenmenger syndrome assoc with?

Answer 5

Pulmonary hypertension, reversal of flow and cyanosis.

Question 6

What is ebstein anomaly?

Answer 6

Apical displacement of septal and posterior tricuspid valve leafets

Question 7

Commotio cordis?

Answer 7

Traumatic blow to the chest -> VT/VF

Question 8

Why might stroke or intracranial haemorrhage lead to QT interval prolongation?

Answer 8

Lesions in the hypothalamus

Question 9

WPW?

When might progress to VF?

Answer 9

• AD: incomplete penetrance.
• Accessory pathway

If extremely rapid conduction over accessory pathway.

Question 10

RBB and ST elevation in leads V1 and V2
No structural abnormality.
What and how treat?

Answer 10

Brugada

ICD