Download RBBB LBBB LAFB LPFB

RBBB LBBB LAFB LPFB
RBBB
rSR pattern in right precordial leads (V1-2)
OR: single wide R wave, qR pattern
S wave on lateral leads (I, aVL, V5 V6) is slightly wide
QRS > 0.12 secs
If QRS < 0.12 secs and all other criteria met = incomplete RBBB
V1-V3 often have ST depression and T inversion
Any ST elevation = suspicious of AMI
LBBB
QRS > 0.12 secs
LAD
Broad monophasic R wave in I and V6
Deep wide S wave in V1 (often no R wave)
ST segments and T waves are directed in opposite direction to main QRS vector in all
leads (“appropriate discordance”)
LAFB
LAD
qR complex (small q large R) or R wave in I and aVL
rS complex (small r large S) in III
Absence of other causes of LAD
LAD causes:
LAFB
LBBB
Inferior AMI
LVH
Ventricular ectopy
Paced beats
WPW
LPFB
Less common than LAFB
Usually occurs with RBBB
RBBB + Fascicular block = “Bifascicular block”
RAD
qR (small q large R) in III
Absence of other causes of RAD
RAD causes:
LPFB
Lateral AMI
RVH
Acute lung disease: PE
Chronic lung disease: COAD
Ventricular ectopics
Hyperkalaemia
OD of Na+ blockers (eg TCA)
Young slim people – heart more horizontal
Trifascicular Block
= Complete Right Bundle Branch Block
+ Left Anterior Hemiblock
+ Long PR interval
Combination of RBBB, LAFB and long PR interval has been called 'trifasicular' block
and implies that conduction is delayed in the third fascicle (often the left posterior
fascicle) and a permanent pacemaker may be needed. However there are other causes
of a long PR interval such as delayed conduction in the AV node or atrium so
'trifascicular block' is not a true ECG diagnosis
LVH
Sokolow + Lyon (Am Heart J, 1949;37:161)
S V1+ R V5 or V6 > 35 mm
Cornell criteria (Circulation, 1987;3: 565-72)
SV3 + R avl > 28 mm in men
SV3 + R avl > 20 mm in women
Framingham criteria (Circulation,1990; 81:815-820)
R avl > 11mm, R V4-6 > 25mm
S V1-3 > 25 mm, S V1 or V2 +
R V5 or V6 > 35 mm, R I + S III > 25 mm
Romhilt + Estes (Am Heart J, 1986:75:752-58)
Point score system