Heart Blocks and Heart failure Flashcards Preview

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Flashcards in Heart Blocks and Heart failure Deck (23)
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1
Q

What causes an upward deflection on the recording of an ECG?

A

Net current towards the electrode

2
Q

PR interval normal length

A

0.12-.2 seconds

3
Q

QRS complex normal length

A

0.8-0.1seconds

4
Q

QT interval normal length?

A

0.4-0.43 seconds

5
Q

ST interval normal length

A

0.32 seconds

6
Q

What could a high amplitude of the P wave be caused by?

A

Atrial hypertrophy

7
Q

When might the T wave be inverted?

A

Mobitz 1

8
Q

What causes a longer ST interval?

A

Mobitz 1

9
Q

What are the heart rates at tachycardia, flutter and fibrillation?

A

150-200, 200-300, 300

10
Q

First degree heart block caused by?

A

Blockage between SA and AV node so slows conduction

11
Q

What does first degree heart block show on an ECG?

A

Prolonged PR interval

12
Q

What does Mobitz 1 show on an ECG?

A

progressive prolongation of the PR interval culminating in a non-conducted P wave thus the QRS complex is not evoked. PR interval is longest immediately before dropped beat

13
Q

What does Mobitz 2 show on an ECG?

A

Intermittent non- conducted P waves- RR interval surrounding P wave is always a multiple

14
Q

What is Mobitz 1 caused by?

A

Progressive fatigue of AV nodal cells

15
Q

What is Mobitz 2 caused by?

A

Failure of Bundle of His to conduct. Likely to be due to structural damage, patients already have left bundle branch block and 2nd degree AV block is produced by intermittent failure of the remaining fasicles

16
Q

What does 3rd degree heart block show on an ECG?

A

Complete dissociation of P wave and QRS complex

17
Q

What are the symptoms of 3rd degree heart block?

A

Severe bradycardia with independent atrial and ventricular rates

18
Q

What are the consequences of 3rd degree heart block?

A

Chamber contractions ou to sync, so atrial contact against closed tricuspid result in cannon wave where the blood goes back into jugular vein and the external jugular vein can be seen pulsing

19
Q

What are symptoms of atrial fibrillation?

A

Usually asymptomatic but sometimes gives congestive symptoms

20
Q

Treatment for atrial fibrillation

A

Flecanide, B blockers, Amodarone, Dronedarone

21
Q

Why does atrial fibrillation need to be treated?

A

As blood pools develop in atria- clots form- mural thrombosis

22
Q

Circus movements of heart?

A

electrical signal doesn’t complete its circuit but takes an alternative one due to the tissue being in abnormal non-refractory state

23
Q

What causes non-refractory state?

A

Unidirectional block and transient bidirectional block