Read Time:6 Minute, 48 Second

Sinus arrhythmia

» If the difference between the maximum and minimum P-P (R-R) is more than 0.1 sec (or more than 10% compared to the mean), then this is sinus arrhythmia
» Respiratory arrhythmia : sinus arrhythmia is associated with the phases of breathing
» No difference in P-P values – rigid sinus node (damage to sinus node cells)

Normal rhythm :
» Must be sinus, that’s means each P wave is followed by QRS complex

» Must be regular – the difference between the longest and the shortest R-R interval does not exceed 0.1 sec

» Must be equality of all R-R intervals and P-P intervals

» If the rhythm is not sinus + not regular = atrial fibrillation (or atrial flutter with abnormal conduction)

Important notes :

» If the speed is 50 mm/sec;
1 mm = 0.02 sec
» If the speed is 25 mm/sec;
1 mm = 0.04 sec
» Normal HR : 60 : 90 beats per minute

Atrial arrhythmias

Atrial Flutter

» Frequent and regular excitation of the atria. In the atria, there are 250 to 400 impulses per minute, each of which causes a contraction of the atria

»There are no P waves on the ECG, instead F waves (similar to a sawtooth curve)

» F waves are best seen in II, III, aVF, V1, V2

» Ventricular conduction can be regular or irregular

Atrial Fibrillation

» In the atria, from 400 to 700 impulses are formed per minute, in response to which there is a contraction of groups or individual muscle fibers of the atria, but there is no coordinated atrial systole.

» Waves f (fibrillation), have different shapes, can be large and small, better detected in III, aVF and right chest leads. [ V1, V2 ]

» Conduction to the ventricles is irregular

Ventricular arrhythmias

Ventricular arrhythmia can be :
» Flutter or fibrillation, according to heart rate & no. of F-waves
» Extrasystoles any type

Ventricular Flutter

» Frequent (200-300 per minute) rhythmic excitation and CONTRACT of the ventricles, usually hemodynamically ineffective, with a rapid transition to ventricular fibrillation.

» ECG – sinusoidal curve with frequent, rhythmic, wide waves

» With ventricular flutter, it is impossible to distinguish between the isoelectric line and the elements of the ventricular complex

Ventricular Fibrillation

» Disorderly irregular excitement and contraction of individual muscle fibers at a frequency of 300-500 per minute. There are no coordinated ventricular contractions, circulatory arrest develops

RA : Right Atrium
LA : Left Atrium
RV : Right Ventricle
LV : Left Ventricle
RCA : Right coronary artery

Rt : Right
Lt : Left
mv : Milli volt
MI : Myocardial Infarction
bpm : beat per minute

LI : Lead 1
LII : Lead 2
LIII : Lead 3
LAD : Left anterior descending coronary artery

aV_R : Augmented Voltage on Right arm
aV_L : Augmented Voltage on Left arm
aV_F : Augmented Voltage on Foot
Lcx : Left circumflex coronary artery