VT

Question 1

Definition?

Answer 1

Constant rapid ventricular contraction rates, can be sustained or non-sustained. Sustained VT is a ventricular rhythm faster than 100 bpm lasting 30 secs or needing to be terminated earlier due to haemodynamic instability.

Question 2

RF?

Answer 2

• CAD
• AMI
• LV systolic dysfunction
• Hypertropic cardiomyopathy
• Long/short QT syndrome
• Brugada syndrome
• Ventricular pre-excitation
• Arrhythmogenic right ventricular cardiomyopathy
• Electrolyte imbalance
• Drug toxicity
• Chagas disease/cardiomyopathies

Question 3

ddx?

Answer 3

• SVT aberrancy-doesn’t meet criteria of VT
• SVT with pre-excitation-“
• Electrical artefact-motion or tremor
• Sepsis-sinus rhythm and cultures
• Panic-sinus rhythm and A/D scores high
• Hyperthyroidism-snus rhythm or AF-raised TSH and low TSH
• Acute haemorrhage-sinus, bleeding
• Pheochromocytoma-high adrenaline, sinus tachy, evidence of tumour or high steroid hormones
• Pericarditis-concave up ST elevation and PR depression and CXR/echo findings
• Caffeine-sinus tachy

Question 4

EPIDEMIOLOGY?

Answer 4

Age: Elderly
Sex: Male
Ethnicity:

Question 5

Aetiology?

Answer 5

• Cardiac scars
• Conduction disorders
• Drugs
• Long QT syndrome
• Congenital long-QT syndrome
• Acquired long QT syndrome
• Drugs
• Antiarrhythmics
• Electrolyte imbalances

Question 6

CP?

Answer 6

• Asymptomatic if non-sustained
• Palpitations
• Hypotension
• Syncope
• Chest pain/pressure
• Cardiogenic shock
• Loss of consciousness
• Progression to VF
• Sudden cardiac failure

Question 7

Pathophysiology?

Answer 7

• Monomorphic VT
• Re-entry circuit
• Polymorphic VT-abnormal ventricular repolarisation
• Decreased cardiac output-non-synchronised rhythm leads to less blood flow into ventricles hence low cardiac outputs causing haemodynamic compromise and so signs of this show

Question 8

Investigations?

Answer 8

• ECG-
  
  • wide complex tachycardia (QRS 120 milliseconds or greater) at a rate of 100 bpm or greater; may show presence of atrioventricular dissociation,
  • previous myocardial infarction;
  • QRS duration: >140 milliseconds with right bundle branch block morphology, or
  • QRS duration >160 milliseconds with left bundle branch block morphology (this does not apply to patients on anti-arrhythmic drugs);
  • right superior axis or left bundle branch block morphology and any right axis;
  • baseline ECG may demonstrate QT interval prolongation or evidence of Brugada syndrome or arrhythmogenic right ventricular cardiomyopathy
• Electrolytes-hypokalaemia and hypomagnesaemia
• Troponin I
• CK-MB

Question 9

Management all?

Answer 9

• Cardioversion

* Anti-arrhythmics-amiodarone

Question 10

management torades de pointes?

Answer 10

• IV mg sulphate and correct electrolyte imbalances
• Isoprenaline infusion
• Temp/permanent pacing

Question 11

management catecholamines?

Answer 11

• Beta-blockers
• Implantable cardioverter defib
Catheter ablation

Question 12

Non-sustained?

Answer 12

• Electrolyte imbalances correction
• Catheter ablation
ICD

Question 13

Prognosis?

Answer 13

• Idiopathic-good-should be evaluated carefully or can be ablated to be cured
• Non-idiopathic-high risk of death if left untreated
Heart disease adversely affects prognosis

Question 14

Complications?

Answer 14

• Malfunction of implantable cardioverter defibrillator system malfunction
• V fib
• Sudden cardiac death
• Infection
• Cardiomyopathy
Amiodarone-thyroid dysfunction