RSMU Class of 2008

Differentiation of atrial fibrillation and ventricular fibrillation

today we learned to differentiate between artrial fibrillation and ventricular fibrillation.

Atrial fibrillation is presented as F waves (multiple P waves with irregular intervals) and in between these F waves, there can be occasional QRS complex. QRS complex should be regular form and normal duration (unless in the case of left? bundle branch block).

Ventricular fibrillation is presented as sinusoid waves (akin to sine graph). There should not be any element of standard ECG (thus, there is not PQRST). Usually the venticular contraction rate is more than 300/min.

It should be noted that ventricular fibrillation can look quite similar to ventricular tachycardia. In ventricular tachycardia, some element of standard ECG can still be found, eg: there can be R within the complex. So remember, ventricular fibrillation in ECG is presented as classical sinusoid waves.

Management for fibrillation

Ventricular fibrillation: manual CPR > DC-shock starting from 200J > CPR > 300J > CPR > 360J
Atrial fibrillation: premedication IV analgesic > DC-shock 100J > 150J

Easier Formula to Count Heart Rates

usually, we use the classical ECG formula to count heart rates
Heart Rates = 60 / (R-R small boxes * 0.04) for 25mm/s OR
Heart Rates = 60 / (R-R small boxes * 0.02) for 50mm/s

today, we got enlighten to cancel the decimals, thus receive easier formula
Heart Rates = 1500 / R-R small boxes for 25mm/s OR
Heart Rates = 3000 / R-R small boxes for 50mm/s

Correct Naming of Extrasystole

Bigemini = 1 normal : 1 extrasystole
Trigemini = 1 normal : 2 extrasystole?
Quadrigemini = 1 normal : 3 extrasystole?

Correct Placing of ECG leads

Standard lead: red = right hand, yellow = left hand, green = left leg, black/control = right leg
Chest lead: V1 =4th intercostal to the right of sternum
V2=4th intercostal to the left of sternum
V4 = apex
V3 = between V2 and V4
V5= 5th intercostal at anterior axillary line
V6 = 5th intercostal at the mid-axillary line