6.8.2013

Question 0

J point in ECG corresponds to which phases of cardiac action potential

Answer 0

Phase 1 and early phase 2

Question 1

Action potential of epicardial and endocardial cells

Answer 1

Epicardial action potential is shorter because outward K+ movement of phase 1 is prominent in it

Question 2

ST segment of ECG corresponds to which phase of cardiac action potential

Answer 2

Phase 2

Question 3

Cause of spontaneous diastolic depolarisation

Answer 3

Funny channel

Question 4

Ion responsible for phase 0 of pacemaker action potential

Answer 4

Calcium

Question 5

RMP of pacemaker cells

Answer 5

-60mV

Question 6

ECG marker of sinus node discharge

Answer 6

None

Question 7

Components of P wave

Answer 7

First half is due to rt atrial activity,second half is due to left atrial activity

Question 8

Duration and amplitude of p wave

Answer 8

Less than 2.5 boxes(0.10S and 0.25mV)

Question 9

Duration of QRS complex

Answer 9

0.06-0.10S

Question 10

Normal PR interval

Answer 10

0.12-0.20 s

Question 11

Causes of QRS prolongation

Answer 11

Ventricular hypertrophy
Bundle branch block
Premature activation of ventricles by accessory pathway

Question 12

QT interval

Answer 12

Longest QT that can be recorded in 12 lead ECG

Question 13

Rule of thumb for QT interval for HR more than 70bpm

Answer 13

QT interval is equal to or less than half of RR interval

Question 14

Bazett formula

Answer 14

QT interval in seconds/root of RR interval

Question 15

Normal QTc

Answer 15

Men- 0.42s

Women- 0.44s

Question 16

Prolonged QTc interval

Answer 16

Men- more than 0.44s

Women and children- more than 0.46s

Question 17

Relationship between QT interval and action potential

Answer 17

Total duration of action potential

Question 18

Calculation of QTc,which RR interval is measured

Answer 18

Preceding RR interval

Question 19

U waves are best visible in which leads

Answer 19

V2 and V3

Question 20

U waves and heart rate

Answer 20

Visible when heart rates are less than 65

Rarely visible in heart rates above 95

Question 21

Mechanism of U wave

Answer 21

Repolarisation of HIS Purkinje system

Question 22

Abnormal U wave

Answer 22

When they are equal to or exceed the T wave

Question 23

In ECG phase 4 of action potential is reflected by

Answer 23

TQ segment

Question 24

Osborne wave is also known as

Answer 24

J wave

Question 25

What is Osborne wave?

Answer 25

Marked elevation of j point that results in h shaped QRS

Question 26

Cause of Osborne wave

Answer 26

Hypothermia | Hypercalcemia

Question 27

Epsilon waves

Answer 27

Notch in the end of QRS seen in V1-V3 in arrythmogenic rt ventricular dysplasia

Question 28

Most upright p wave deflection is seen in

Answer 28

Lead 2

Question 29

Measurement of duration of p wave

Answer 29

Atleast 3 leads that are measured simultaneously | Leads 1,2,V1

Question 30

Cause of prolonged p wave

Answer 30

Lt atrial hypertrophy | Intraatrial block

Question 31

Atrial Repolarisation wave

Answer 31

Ta wave

Question 32

Prolonged PR interval

Answer 32

The whole 12-lead ECG is measured for the longest PR interval preferably leads I, II, and V1

Question 33

Duration of QRS complex

Answer 33

0.06-0.10s

Question 34

Low voltage QRS complexes

Answer 34

Tallest QRS in limb lead is less than 5mm and in chest leads is less than 10mm

Question 35

Causes of low voltage QRS complexes

Answer 35

``` Peripheral Edema Anasarca Ascites Pericardial effusion Pleural effusion Obesity Emphysema ```

Question 36

Prolonged QTc in bundle branch block or intra ventricular conduction defect of more than 0.12s

Answer 36

QTc more than 0.50s

Question 37

QT dispersion

Answer 37

Difference btw longest and shortest QT interval | If more than 100ms,predisposition for ventricular arrythmia

Question 38

J point elevation

Answer 38

Seen in normal individuals | Due to difference in potentials during early repolarisation and resultant current flow btw epicardium and endocardium

Question 39

Normal ST elevation is seen in

Answer 39

Younger healthy males

Question 40

Morphology of normal ST elevation

Answer 40

Concave | Seen more prominently in V2

Question 41

Male pattern of ST elevation

Answer 41

More than 1mm | Sharp take off of more than 20 degrees

Question 42

ST elevation due to early Repolarisation

Answer 42

Associated with j point Commonly seen in V4 Frequently accompanied by tall and peaked T waves

Question 43

ST elevation with inversion of T waves in precordial leads V3-V4

Answer 43

Normal variant

Question 44

Causes of abnormal ST elevation

Answer 44

``` MI coronary vasospasm Acute pericarditis Ventricular aneurysm Ventricular hypertrophy Hyperkalemia Brugada syndrome Left bundle branch block ```

Question 45

Repolarisation of M cells

Answer 45

End of T wave

Question 46

Abnormal T waves

Answer 46

Notched More than 5mm in limb leads or more than 10mm in chest leads Symmetrical Inverted

Question 47

Causes of prominent U waves

Answer 47

Quinidine | Hypokalemia

Question 48

Causes of inverted U waves

Answer 48

Myocardial ischemia Hypertension Valvular regurgitation

Question 49

Mechanism of epsilon wave

Answer 49

Post excitation of free wall of right ventricle