Heart block and other conduction failures Flashcards

1
Q

First Degree

A

PR interval > 5 little boxesA
All P waves followed by QRS
Often asymptomatic
Delayed AV node transmission

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2
Q

Type 1 Second Degree

A

PR interval gets longer until QRS wave fails to follow P wave
Likely cause AV node damage

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3
Q

Type 2 Second Degree

A

Some P waves blocked and not followed by QRS
PR interval remains the same
Problem in Bundle of His
Treatment: implant pacemaker

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4
Q

Third Degree

A
Atrial signals consistently fail to arrive at ventricles
Consistent ventricular rate 30-40 bmp 
PR interval varies radically 
Intrinsic Ventricular rate (<60 bpm)
Atrial beats consistent
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5
Q

Escape Beats

A

Late
Triggered by natural rhythmicity of non-atrial tissue
Occur when atrial signal is delayed

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6
Q

Premature Beats

A

Early
Due to irritable tissue
Triggered often in ventricular tissue or by AV node - ectopic beats

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7
Q

Atrial Fibrillation

A

Disorganised electrical activity in atria
No P wave - flat wiggly line instead
Fast and irregular ventricular rate - Many signals reach AV node
Common in elderly
Stroke risk - can lead to thrombus formation

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8
Q

ST segment Elevation

A

Interval = duration from start of x to end of y
Segment = from end of x to start of y
ST segment - end of QRS to start of T - elevation = sign of acute MI
Isoelectric baseline - end of T to next P

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9
Q

Premature ventricular contraction

A

Unusually wide, weird-looking ventricular electrical activity
No S wave - instead a wide negative dip where T wave should be
Often beat triggered in middle of myocardium - ventricles electrically unsynchronised
Delayed inefficient conduction

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10
Q

Respiratory Sinus Arrythmia

A

Heart beat faster on inspiration than expiration
Children and athletes
Observe ventricular rate - inverse of RR interval

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