bundle branch blocks

I work on a medical tele floor and occ. we will have pts whos 12 lead they had in the ED shows a BBB. We use the 5 lead (EASI lead) on our unit.

Ive taken 2 cardiac classes offered by our hospital but I dont remember them covering BBB... they did cover heartblocks, a fib/flutter, v tach/fib, sinus brady/tachy, etc.

Often times, when I look at the 2 leads that print out on our unit for the pt when we interpret the strips, I will see if they have a reported BBB either a wide QRS and/or a notched QRS.

Can anyone give me a run down of BBBs and how to determine if they are R or L?

Perhaps the easiets way to quickly determine if the BBB is right or left is on 12-lead. Look at V1. If deflection is positive it's likey Rt BBB. if deflection is primarily negative...most likely a Lt BBB. There are other (more precise) ways/criteria to determine rt-vs-lt BBB, but this is the easiest, is quick, and usually very accurate.

Also, in 3-lead telemetry it's very hard to identify rt-vs-lt BBB. In 5-lead telemetry, MCL correlates with V1...so is more 'accurate' in determining rt-vs-lt BBB but it's still rough. Best to look at 12-lead

A bundle branch block has a long qrs complex (>120ms).

A right bundle branch block typically causes prolongation of the last part of the QRS complex, and may produce a slight right axis deviation. The ECG will show a terminal R wave in lead V1 and a slurred S wave in lead I.

A left bundle branch block widens the entire QRS, and in most cases produces a left axis deviation. The ECG will show a QS or rS complex in lead V1 and a monophasic R wave in lead I. Another normal finding with bundle branch block is appropriate T wave discordance. In other words, the T wave will be deflected opposite the terminal deflection of the QRS complex.

If you use a 5 lead tele system, look at V1. Just like Dinith88 said, if you have MCL use that and place the brown lead where you would normally place V1 (because it can be moved around to give a view of any of the precordial leads V1-6). and he's also right on about the positive vs negative deflections, if you use that way of looking at it you'll probably get it every time. cardiology can get pretty tough sometimes, but there are "easy rules" to simplify things.

I have been having a difficult time understanding the differences between the following:

Left posterior hemiblock, left anterior hemiblock, left bundle branch block, and right bundle branch blocks..

This is what I have to share, please make any suggestions

Left Posterior Hemi Block: incomplete BBB

Must have right axis deviation

small Q wave in lead III is normal

small R wave in lead I

QRS

Left Anterior Hemiblock - incomplete BBB

must have left axis

small Q wave in lead I is normal (does not indicate an old MI)

lead II QRS has mostly a negative deflection

Lead III has a small positive defelected R wave and deep S wave

QRS <.12>

Left BBB - Complete BBB

looks wider QRS > .12

Could it have left axis?

little R waves lead V1 V2

ST depression and T wave inversion is normal in V5 V6

The bunnyear look especially in V1, V2 (bunny ears could be present in others)

Rigth BBB - Complete BBBB

could have left axis

Is it possible to have a right axis?

QRS > .12

QRS is positive defected, with larger bunny waves in leads V1 V2 (bunny ears could be present in others)

ST depression and T wave inversion is normal in RBB in leads V1 V2

My questions are.....

Do hemiblocks contain bunny ears?

What are the possibilities with complete R BBB and axis deviation... I have found literature on right BBB could have a left axis.... what about a right axis?

What are the possibilities for a complete L BBB and axis deviation (right vs left....)

If anyone could help me I would appreciate it!