Term
| symptoms of first degree heart block |
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Definition
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Term
| symptoms of second/third degree heart blocks |
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Definition
| syncope, dizziness, fatigue, chest pain, SHOB |
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Term
| EKG abnormality with 1st degree block |
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Definition
| PR interval (normally .12-.20 seconds) is > .20 seconds with every beat |
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Term
| causes of first degree blocks |
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Definition
| drugs (beta blockers), post MI, regular aging process, hypo or hyperkalemia |
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Term
| treatment of first degree heart block |
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Definition
usually none since usually asymptomatic
correct underlying cause if drug-related
monitor for progression into 2nd/3rd |
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Term
| what are the two kinds of 2nd degree blocks |
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Definition
type 1: mobitz I, or wenkebach
type 2: mobitz II |
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Term
| EKG abnormality with a 2nd degree mobitz 1/wenkebach |
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Definition
| not every P wave will be followed by a QRS complex |
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Term
| what is happening in the heart during a second degree heart block (either type) |
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Definition
| some impulses from the sinus node are conducted and others are not; the cause of the non-conducted impulses is the intermittent AV node block |
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Term
| what is the difference between type 1 and type 2 second degree blocks |
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Definition
| the pattern in which the P waves are blocked at the AV node |
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Term
| what is the key EKG abnormality happening during a Wenkebach/mobitz 1 |
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Definition
the progressive lengthening of the PR interval;
impulses traveling from the SA node to the AV node progressively take longer and longer until one is completely blocked
"longer, longer, longer, drop" |
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Term
| treatment for wenkebach/mobitz 1 |
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Definition
typically none because it's usually asymptomatic
if symptomatic (rare), may do atropine or pacing |
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Term
| physiologically speaking, where in the heart does the actual "block" occur, causing a wenkebach? |
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Definition
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Term
| physiologically speaking, where in the heart does the "block" occur causing a mobitz II? |
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Definition
| below the AV node, either at the bundle of His (uncommon) or the bundle branches (more common) |
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Term
| what EKG abnormality will you find with a mobitz II? |
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Definition
a few regular, fully conducted beats followed by one or more non-conducted P waves
the PR interval does not steadily increase until a beat is dropped, as it would with a wenkebach |
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Term
| in a mobitz II, since not all P waves are being conducted, what would be the ultimate response on HR? |
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Definition
bradycardia
normal atrial firing but only sporadic ventricular response |
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Term
| difference in EKG with a block at the bundle of His vs. a bundle branch block |
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Definition
bundle of His= QRS will be normal as ventricular conduction is not affected
bundle branch= widened QRS (conduction through the ventricles is delayed) |
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Term
| possible causes of mobitz II blocks? |
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Definition
acute MI
post-cardiac surgery, or cath complication
sometimes age related degenerative changes
not normally a side effect of meds |
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Term
| treatments for 2nd degree block type 2? (mobitz II) |
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Definition
hold any drugs that may slow conduction
temporary pacing if bradycardic
dopamine if hypotensive |
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Term
| when people say "complete heart block" they are referring to a... |
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Definition
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Term
| what is happening in a 3rd degree block |
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Definition
complete absence of communication between the atria & ventricles
the SA node continues to fire regularly (60-80 bpm)
since the impulses are not being conducted, either the AV node will take over pacing the ventricles (40-60 bpm) or the ventricles will pace themselves (20-40 bpm) |
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Term
| what will the EKG look like for a 3rd degree block |
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Definition
regular P-P intervals
regular QRS complexes
but P waves and QRS complexes will be entirely dissociated, with no relationship between the two
there will be more P waves than QRS complexes |
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