arrythmias and conduction defects

Question 1

Atrial fribrilation classification

Answer 1

1st episode or recurrent episode.
if recurrent and terminates spontaneously- paroxysmal AF (less than 7 days).
persistant if not terminating in under 7 days.

can also have permanent AF.

Question 2

Aetiology of AF + signs and symptoms

Answer 2

sepsis, mitral valve pathology, ischaemic heart disease, thyrotoxicosis, HTN.

nees to have atrial dilation and then a trigger- alcohol, infections, MI,PE, stress, electrolite imbalance.

Question 3

signs, symptoms and investigations of AF and what you would find

Answer 3

palpittions, dyspnea, chest pain, irregularly irregular pulse, apex to radial pulse defecit.

Question 4

management of AF.

Answer 4

initiallye establish if stable or unstable by the blood pressure. if unstable electrical ablation

rate control wokrs better in older, rythem in younger

rate control- accept pulse will be irreg but slow it down. should be first line (B blocker- not in asthma/ CCB- not in Heart faliure) digoxin also used- but 2nd line, use B blocker first.

rythum control- get back to sinus rythm. see photo for indications and drugs

Question 5

atrial arrythmias- atrial flutter

Answer 5

a re-entry tacycardia. one ectopic focus.

super fast depolarisations (300 a min) usually 2:1 conducted to vents (I.e 150 vent contractions)

poor atria contraction.

lots of P waves with Q at regular intervals. Saw tooth ECG

associated with structural heart disease.

mgt simalar to AF.

Question 6

what is the cause of ventricular tacycardia and how can it be treated

Answer 6

generally normal electrical propogation is inhibited by a scar.
you then get recurrent depolarisations at the ‘twig’ of the ventricles, as scar slows conduction to greater than the refractory period.

causes: IHD, cardiomyopathy, electrolite imbalance, drugs, ion channel disease.

Question 7

complete heart block

Answer 7

where the SAN and AVN do not talk to each other any more.

causes: inferior MI, Anterior MI (due to septal infarction with necrosis of the bundle branches)
Idiopathic fibrosis of the conducting system
Cardiac surgery, especially surgery occurring close to the septum e.g. mitral valve repair
Inflammatory conditions,
Autoimmune,
Infiltrative myocardial disease,
Hyperkalaemia
Drugs

need urgent admission for monitoring and pacing, ususally pacemaker. - this is definative management usually.