Arrythmias And Ecg

Question 1

Vaughan Williams classification of antiarrythmatic drugs ?
ClassIa -inhibit na channel,stimulates potassium channel prolong repolarisation.

Class Ib:-INHIBITS NA+ FAST CHANNEL, SHORTENS REPOLARIZATIOn

CLASS IC: INHIBITS NA+ CHANnels

CLASS II: β BLOCKERs

CLASS III: PROLONGS REPOLARIZATIOn
ClassIV

Answer 1

ClassIa:-quinidine,procainamide,disopyramide.
Class Ib:-lidocaine,mexilitene,phenytoin.
Class Ic:- flecainide,propafenone.

Question 2

Premature atrial contraction or extra atrial systoles means ?
Blocked pac ?
Aberrancy pac?
Normal pac ?

Answer 2

Pac common in childhood in absence of heart disease.
Blocked pac:-If pac occur very early den both av node and bundle of his are refractory so impulse don’t pass to ventricles .u will be having only abnormal p wave.
Aberrancy pac:-if pac occur little late than blocked pac den av node is not refractory and bundle of his is refractory so it looks like right bundle branch block.it is called ashman aberrancy.we see M and W wave appearance.
Note:-right bundle branch will have longer refractory period
Normal pac:- if pac occurs little late than blocked pac den both av node and bundle of his is not refractory den normal p wave followed by qrs normal qrs.

Question 3

In lead 1 and avf normally p wave is positive or negative ?

Answer 3

Normally it is positive.