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Supraventricular extrasystoles

Sinus extrasystoles

» Sinus node reentry
» Normal sinus form P, unchanged ventricular complex
» The post-extrasystolic pause is equal to the length of the normal sinus cycle

Atrial extrasystoles

» Extraordinary altered P wave, narrow QRS, supraventricular type, incomplete compensatory pause

» With lower atrial extrasystole, the P wave can be negative in II, III, aVF

AV extrasystoles

» The extrasystolic impulse arising in the AV node propagates in two directions: retrograde to the atria and the usual way to the ventricles. Therefore, the QRS complex has an unchanged appearance, and the excitation of the atria is manifested by a negative P wave, which is either layered on the ventricular complex and is not visualized on the ECG, or follows the QRS, layering on the ST

» The compensatory pause can be complete or incomplete.
» Usually organic, rare. May be on the background of an overdose of cardiac glycosides

Ventricular extrasystoles

» Impulses arising in the ventricular myocardium
» ECG – premature dilated (QRS more than 0.14 s)
» Deformed ventricular complex
» Full compensatory pause
» No extraordinary P wave

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

» Normal QRS complex duration = 0.06-0.10 sec.

Monomorphic ventricular extrasystole

Monomorphic Ventricular tachycardia

Bigeminy ventricular extrasystole

Trigeminy ventricular extrasystole

Quadrigeminy ventricular extrasystole

Others ventricular extrasystole

Examples

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