arrhythmias-pathophysiology, presentation and investigation

Question 1

on an ECG what is the P-R interval?

Answer 1

the time for the depolarising of the heart to pass through the AV node

Question 2

what are the investigations that must becarried out for atrial fibrillation?

Answer 2

24 hr 12 lead ECG
bloods: U and E (electrolyte abnormalities such as potassium, magnesium and calcium) thyroid function
echocardiogram

Question 3

what are the presentations of atrial fibrillation?

Answer 3

asymptomtic
palpitation
dyspnoea
chest pain
fatigue
embolism

Question 4

what are the therpaeutic approaches for the treatment of atrial fibrillation?

Answer 4

digoxin
beta blockers
CCB
all above with direct oral anticoagulants or aspirin

class Ic/III +/- DC cardioversion
pace and ablation if AV node
Substrate modification eg Pulmonary vein ostial ablation,
maze procedures

Question 5

what are the 2 types of supravantricular tachycardia?

Answer 5

AV-nodal re-entrant tachycardia

AV re-entrant tachycardia

Question 6

what are the treaments for supreventricu,ar tachycardia?

Answer 6

no treatment
radiofrequancy ablation
drugs

Question 7

what are the characteristics of AF on an ECG?

Answer 7

irregular rhythm and no siscernable p-waves

Question 8

what does this ECG show?

Answer 8

ventricular fibrilation

Question 9

is ventricular fibrillation supportive of life?

Answer 9

no

Question 10

what are the presentations of ventricular tachycardia?

Answer 10

palpitations
chest pain
dyspnoea
dizziness
syncope

Question 11

what are the investigations carried out for ventricular tachycardia?

Answer 11

bloods
echocardiogram
angiography
ECG

Question 12

what are the signs of supraventricular tachycardia on an ECG?

Answer 12

narrow QRS complex

regular rhythm

Question 13

what is the apperance of ventricular fibrillation on an ecg?

Answer 13

random disorganised appearance

Question 14

what are the causes of ventricular fibrillation?

Answer 14

ischaemia - MI
heart failure
inherited causes such as long QT, bragada, catecholaminergic polymorphic ventricular tachycardia
eectrolyte abnormalities such as hyperkalaemia

Question 15

what are the indications of ICD therapy?

Answer 15

cardiace arrest due to VF/VT
sustained VT causing syncope or significant compromise
sustained VT with poor LV function

Question 16

what does second degree heart bloock look like on a heart block?

Answer 16

Mobitz type 1: P-R interval is prolonged until there i no coduction through to the ventricle and there is just a p-wave on its own.
Mobitz type 2: p-wave interval remains constant occasionally p wave not followed by QRS complex, this happens randomly

Question 17

what does complete heart bloock look like on a heart block?

Answer 17

p wave rate is regular but they bear no relation to the QRS complexes

Question 18

what are the indications for a temporary pace maker?

Answer 18

-i ntermittent or sustained symptomatic bradycardia,
particularly syncope
- prophylactic when patient at high risk for development
of severe bradycardia eg 2nd or 3rd degree AV block,
post anterior MI, even when asymptomatic

Question 19

what are the indications for a permanent pacemaker?

Answer 19

-symptomatic or profound 2nd/3rd degree AV block,
particularly when cause (?) unlikely to disappear
- probably Mobitz type II 2nd/3rd degree AV block even if
asymptomatic
- AV block associated with neuromuscular diseases
- after (or in preparation for) AV-node ablation
alternating RBBB/LBBB
- syncope when bifascicular/trifascicular block and no
other explanation
- sinus node disease associated with symptoms
- carotid sinus hypersensitivity/malignant vasovagal
syncope