Morphological abnormalities

Question 1

What two factors affect structure change in the heart?

Answer 1

-pressure
-volume

Question 2

What are the general categories of morphological abnormalities?

Answer 2

-chamber enlargement
-LQTS
-electrolyte abnormalities

Question 3

What is the ECG criteria for LAE?

Answer 3

In lead II :
biphasic P wave >40ms between 2 peaks/ notching p waves
-total p wave duration >120ms
-P mitrale
-ratio between the duration of P wave in lead II and the duration of the PR segment is 1:6
p axis - -30 and +45
In V1:
-biphasic p wave with terminal -ve portion > 40ms duration >1mm deep

Question 4

What are some causes of LAE?

Answer 4

In isolation - mitral regurg
-associated with LVH -systemic hypertension, aortic stenosis, mitral incompetence, hypertrophoic cardiomyopathy

Question 5

What is the ECG criteria for RAE?

Answer 5

-p pulmonale ( peaky P’s)
>2.5mm in II, III and AVF
>1.5mm in V1 and V2
duration and amplitude increase
-axis above 75 degrees
-increased area under initial positive portion of p wave in V1 to >0.06mm/sec

Question 6

What are some causes of RAE?

Answer 6

pulmonary hypertension due to:
-Chronic lung disease
-tricuspid stenosis
-Congenital heart disease

Question 7

What is LVH?

Answer 7

-heart muscle has gotten bigger in the LV
-increased afterload
-we will have hypertension, aortic stenosis, coaptation

Question 8

what is the diagnostic criteria for LVH?

Answer 8

soklow criteria
S wave in V1 + R wave in V5/6 >3.5mV

Question 9

What is the Non voltage criteria for LVH?

Answer 9

Increased R wave peal time> 50ms in V5/6
-LV strain pattern- ST depression and T wave inversion in left sided leads

Question 10

What is the diagnostic criteria for RVH?

Answer 10

soklow criteria
R wave in V1 + S wave in V5/6 >1.1mV

Question 11

What are some causes of RVH?

Answer 11

pulmonary hypertension
-mitral stenosis
-PE
-congenital heart diseas
-arrhythmogenic RV cardiomyopathy

Question 12

What is the non voltage criteria for RVH?

Answer 12

axis +110 or more
-Dominant R wave in V1
-Dominant S wave in V6
-QRS duration <120ms

Question 13

What are the three subtypes of long QT?

Answer 13

LQTS1- potassium affected
LQTS2- potassium affected
LQTS3- sodium affected

Question 14

What are some causes of long QT?

Answer 14

-congenital
-aquired
-ischemia
-hyperthyroidism
-drugs- beta blockers, antipsychotics

Question 15

Why is long QT so serious?

Answer 15

-prone to tachyarrhythmias
-cause VT/ polymorphic
-leads to sudden cardiac death

Question 16

What causes long QT?

Answer 16

caused by a gene mutatuon that affects the sodium potassium channels within the cell membrane of the cardiac cycle

Question 17

What is brugada syndrome?

Answer 17

• mutation in the cardiac sodium channel gene/ sodium channelopathy
  -associated with a coved ST segment elevation in V1 and V2

Question 18

How can we get brugadads to show on an ECG?

Answer 18

-ajmaline,
-excersise testing

Question 19

Describe type 1 brugada ECG changes

Answer 19

J wave amp- >/2mm
T wave - negative
-ST-T config = coved
ST segment terminal portion= gradually descending

Question 20

Describe type 2 brugada ECG changes

Answer 20

J wave amp- >/2mm
T wave - positive or biphasic
-ST-T config = saddleback
ST segment terminal portion= elevated>/1mm

Question 21

Describe type 3 brugada ECG changes

Answer 21

J wave amp- >/2mm
T wave - positive
-ST-T config = saddleback
ST segment terminal portion= elevated<1mm

Question 22

Describe the ECG changes with hyperkalaemia

Answer 22

5.5-6.5mmols/l - T waves become abnormally tall and narrow and symetrical

6.5-7.0mmols/l - P waves become broade/flatter, R wave height decreases, QRS complexes become wider, ST changes

7.0-7.5mmols/l- further widening and distortion of the QRS, prolongation of the QT

above 7.5mmols/l - VF

Question 23

What are the normal levels of calcium ?

Answer 23

2.2- 2.67 mmol/l

Question 24

Describe the QT changes with hypercalcaemia and hypocalcemia

Answer 24

Hyper- QT-0.48s
QTc- 0.52

Norm- QT-0.36s
QTc-0.41

Hypo- QT-0.26s
QTc- 0.36

Question 25

What are some causes of hypocalcemia?

Answer 25

-dieuretics -hypoparathyroidism -pregnancy -hypo/hyperventilation

Question 26

What are some causes of hyperparathyroidism?

Answer 26

-hyperparathyroidism -renal failure -adrenal abnormalities

Question 27

What is the difference between true dextrocardia, situs invertus and technical dextrocardia on an ECG?

Answer 27

True - mirror image of ECG with absent R wave progression in left sided chest leads Technical - lead 1 is inverted but V1-6 R wave progression is normal sinus invertus - same as true

Question 28

What is true dextrocardia?

Answer 28

-congenital abnormality - heart is on the right side -other organs such as stomach and liver are still in their normal left sided positions -symptomatic due to associated heart defects -apply leads on the right side to get a true reading

Question 29

What is technical dextrocardia?

Answer 29

-artifact in ECG reading -organs are none, no symptoms -re apply leasds to get a normal reading

Question 30

What is situs invertus?

Answer 30

-congenital abnormality -heart is a mirror image on the right side -all organs are a mirror image of normal -apply leads on right side to get true reading -normal assymptomatic unless other conditions develop