Section II Flashcards
Multifocal Atrial Tachycardia
rhythm always irregular; rate of 100-200 bpm; has p wave; identify at least 3 different p wave morphologies to diagnose
Wandering Atrial Pacemaker
MAT with less than 100 bpm; different p wave morphologies, changes ever 2-3 beats
Paroxysmal Supra-ventricular Tachycardia
rhythm always regular; rate 150-250 bpm; ST depression
Wolf Parkinson White Syndrome
Bypass AV node using bundle of kent; shortened PR interval; widened QRS due to premature activation; delta wave
Lown-Gonong-Levine syndrome
Accessory pathway is James fiber (intranodal); ventricular conduction occurs (unlike WPW); normal QRS, no delta wave; shortened PR interval
1st Degree AV Block
PRI > .2 sec;
Wenckebach; 2nd Degree AV Block; Mobitz I;
block within the AV node;
PR interval increases with each pulse; after dropped QRS; sequence repeats
Mobitz II; 2nd Degree AV Block
Block below AV node in bundle of His;
Presence of dropped beat without progressive PR interval lengthening
Complete Heart Block; 3rd Degree AV Block
No atrial impulses make it to activate ventricles; Block in AV node or lower;
irregular rhythm; QRS width vary; p waves sometimes distort QRS or T wave
Right Bundle Branch Block
Depolarization of right ventricle delayed;
QRS > .12sec; V1 & V2 would have RSR’ waves;
I, aVL, V5, V6: late deep S waves
R’ Wave
caused by right ventricular depolarization after left ventricle due to right bundle branch block
Left Bundle Branch Block
Left ventricular depolarization delay;
QRS > .12 sec; QS pattern in V1/V2; iverted T wave in V5/V6; small notch in R wave in V5/V6 may be visible
Right Atrial Enlargement
p-wave aplitude > 2.5mm in inferior leads (II,III, AVF)
low voltage in lead I, down-sloping PR segment in lead II,III: emphysema
Left Atrial Enlargement
p-wave > .12 sec in lead II; possible notch in p wave
Right Ventricular hypertrophy
QRS in lead I more neg than positive;
Lead V1 R wave > S wave;
Lead V6 S wave > R wave
