Johnston Conduction Disturbances & Hypertrophy of Atria and Ventricle Flashcards

1
Q

What is an AV block?

A
  • block in cardiac conduction system that causes a disruption of atrial to ventricular electrical conductioni
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the criteria for a first degree AV block?

A
  • PR interval more than 0.20 sec
  • P wave precedes QRS
  • Minor AV defect with delay at or below AV node
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What causes a 1st degree AV block?

A
  • Atherosclerosis
  • Htn
  • Diabetes
  • FIbrosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is happening, what is rate and rhythm?

A

Sinus Bradycardia

PR interval= 7x .04= 0.8 so first degree AV block

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is Mobitz I (Wenchkenbach) 2nd degree AV block?

A
  • Progressive lengthening of PR interval, prolongation prior to a dropped QRS
  • Grouped beats
  • Progressive lengthening of the PR interval results from earlier arrival in relative refractory period of the AV conduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Etiology of Mobitz I?

A
  • All things that cause 1 AV block
  • Digitalis toxicity
  • Ischemic events particularly Inferior MI
  • Myocarditis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What will a QRS complex look like on a second degree AV block Mobitz type 1?

A

Narrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is this

A
  • Inferior wall MI-ST elevations
  • Lead 2 rhythm strip on the bottom has 4 beats followed by dropped QRS
  • Each PR interval before the dropped beat is longer and longer
  • Mobitz I 4:3 (4 atrial beats to 3 ventricular beats)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is Mobitz type II 2nd degree AV block is seen with what? What is the prognosis and why?

A
  • Seen in anterior wall infarctions
  • Worse prognosis than Mobitz I
  • Because the block is distal to AV node
    • occurs at bundle HIS
    • both bundle branches
    • Fascicular branches
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens with the PR interval on Mobitz II?

A
  • It is normal, there is no prolongation before dropping a QRS, it occurs randomly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is third degree heart block? What is the solution if it is sustained? Where does it occur?

A
  • aka complete heart block
  • P waves don’t relate to QRS, two independent rhythms are present
    • pacemaker is solution
  • Can occur above or below AV node
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where does 3rd degree heart block occur and what is the rate of each? What do QRS complexes look like?

A
  • Above has a junctional rhythm with narrow QRS rate of 40-55
  • Below AV has ventricular pacemaker with a wide QRS and rate of 20-40
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is happening?

A
  • complete heart block
  • Independent atrial activity
  • junctional escape rhythm bc QRS is narrow and rate is in 50’s
  • P waves are at rate of 125
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is this?

A

1 AVB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the characteristics of bungle branch blocks?

A
  • Wide QRS complex greater than three small squares 0.12 seconds
  • ST segment has T waves sloping off in opposite direction to the QRS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What leads do you look at for a right bundle branch block?

A

V1

AVL

V6

V2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Morphology of leads for a RBBB?

A

R, S, Rprime

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Complete right bungle branch block

A

Wide QRS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is happening

A
  • lead 1 deep S wave and similar on AVL and V6
  • RSR’ on V1 and widening on V2
  • Complete RBBB
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is LBBB?

A
  • Q wave is missisng
  • Should be seen in V5 and V6 but not there
  • monophasic R, wide RS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What leads do you look at for LBBB

A

Leads I

and AVL

V1 and V6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is a Hemiblock?

A
  • Blockage of one of two main divisions of the left bundle branch
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What type of hemiblock is more common?

A

Left anterior hemiblock (LAH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Criteria for left anterior hemiblock (fascicular) block?

A
  • Left axis deviation, usually >-60
  • Small Q in leads I and AVL
  • Small R in II, III and AVF
  • Increased QRS voltage in limb leads
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the crierria for left posterior hemiblock?

A
  • Right axis deviation greater than 120
  • Small R in leads I and AVL
  • Small Q in II III and AVF
  • Usually normal QRS
  • Increased voltage in QRS limb leads
26
Q

Etiology of LAH?

A
  • Conduction system often associated with MI (LAD occlusion)
27
Q

what is this?

A
  • Left Anterior Hemiblock
  • Left axis deviation
  • small Q leads in I and AVL
  • Small R in II III and AVF
28
Q

what is this?

A
  • Left posterior hemiblock
  • Right axis
  • Small R in I and AVL
  • Small Q in II III and AVF
29
Q

What causes Atrial enlargement?

A
  • Response to increase volume in the chamber
  • Increase resistance to blood flow out of the chamber
30
Q

What will RAE show on an ECG?

A
  • Tall & pointed
31
Q

What causes Right atrial enlargement?

A
  • Tricuspid valve disease or underlying pulmonary disease
  • Mitral Stenosis or Mitral Regurgitation cause pulmonary hypertension
32
Q

What is this?

A

Right atrial enlargement

33
Q

What will LAE show on ECG?

A
  • P mitrale (“M” signs to P wave)

Notched P wave

34
Q

What causes LAE?

A
  • MS
  • MR
35
Q

What is this?

A
  • LAE
  • B is wide and deep negative component of P wave
  • A has M shaped P wave
36
Q

What are A B and C?

A
  • A is LAE
  • B is RAE
  • C is P waves originating out of AV node
37
Q

What is the most common cause of LVH?

A
  • Hypertension
  • other causes include AS, AR, hypertrophic cardiomyopathy and coarctation of aorta
38
Q

HOw will QRSS respond to LVH?

A
  • QRS voltage and interval will increase producing deeper S waves over RV and taller R waves over LV
39
Q

what is this?

A
  • R wave in AVL is 17 mm in height
  • R wave in V6 is 25+
  • ST segment in V6 slopes down (strain pattern)
  • Left ventricle hypertrophy
40
Q
A

Voltage is huge usually indicates hypertrophy

this is LVH

41
Q

What are some indications for RVH?

A
  • RAD 90 or more
  • R voltage increased
  • R:S ratio greater than 1
42
Q

What causes RVH?

A
  • Chronic lung disease
  • RVOT obstruction
  • VSD
  • Tetralogoy of fallot
  • Pulmonic stenoisis
  • Tratnsposition vessels
  • MS
  • TR
43
Q

What does having a low or high K do to the heart?

A
  • High: slows conduction, raises resting membrane potential, and widens QRS
  • Low: lowers resting mem pot, enhances automaticity
44
Q

What does having a high or low Ca do the heart?

A
  • Low: prolongs QT interval, triggers arrhythmias
  • High: shortens QT
45
Q

What causes hypokalemia?

A
  • Diuretics
  • Metabolic alkalosis
  • high aldosterone
  • Beta agonist OD
  • Diarrhea
46
Q

What does ECG of hypokalemia show?

A
  • U waves
  • Increase QT interval
  • Flat or inverted T
47
Q

What do arrows show?

A

U waves of Hypokalemia

48
Q

Etiology of hyperkalemia?

A
  • Renal failure
  • Metabolic acidosis
  • DKA
  • cell breakdown
49
Q

ECG of hyperkalemia?

A
  • Peaked T wave
  • Wide QRS
  • Increased PR interval
  • Loss of P wave
50
Q

what is happening, what could be wrong with this patient?

A
  • Hyperkalemia possibly due to CKD
  • no P waves
  • Wide bizzarre QRS
  • Magnitude of T wave is very tall pointed and peaked
51
Q

Etiology of Hypercalcemia?

A
  • Hyperparathyroidism
  • Malignancy
  • Granulomatous disorder
  • Endocrine disorders such as adrenal insufficiency and hyperthyroid
52
Q

What does ECG of Hypercalcemia show?

A
  • QT interval shortened
  • Short ST segment
53
Q

Helpful pic

A
54
Q

How will hypothermia present?

A
  • Bradycardia
  • J wave (notch of T wave)
  • Temp less than 35 (95)
55
Q

Pulmonary embolus symptoms?

A
  • Sudden dyspnea clear lung normal x ray
  • Tachy
56
Q

What will PE show on ECG?

A
  • S1 Q3 T3
  • T wave inversion seen on V1-V4
  • Transient RBBB
  • Non specific ST-T changes
57
Q

What is wolff parkinson-White syndrome (WPW)?

A
  • Short PR interval
  • Slurred upstroke of QRS (delta wave)
  • Accessory AV conduction pathway (bypasses normal AV conduction)
  • They are prone to suddenly develop fast heart rates, born with it
58
Q

What is Brugada syndrome?

A
  • RBBB with ST elevation (looks like skii slope)
  • These people are susceptible to deadly arrhythmias
  • Asian males AD
  • Due to sodium channelopathy
59
Q
A

WPW

60
Q

What is Wellens syndrome?

A
  • diffuse T wave inversion in V2 and V3
  • LAD stenosis
61
Q

Long QT syndrome?

A
  • QT interval more than half of the cardiac cycle
  • Predisposed to ventricular arrhythmias