cct EXAM QUESTIONS AND CORRECT
DETAILED ANSWERS WITH
RATIONALES (VERIFIED ANSWERS)
What is a vector in the heart? - Answers - ✔✔ The purpose of electrocardiographic
investigation is to find out something about the heart itself by means of an accurate
knowledge of its electric action. This may be repre- sented by the so-called heart-vector,
a directed quantity, indicating in which direction elec- tricity is propagated by the heart.
Left Axis Deviation (LAD) - Answers - ✔✔ 30-90 degrees
Right Axis Deviation (RAD) - Answers - ✔✔ +90 to +180
normal axis - Answers - ✔✔ -30 to +90
Extreme Axis Deviation - Answers - ✔✔ -90, 180
normal axis qrs in v1 & v2 - Answers - ✔✔ pos / pos (thumbs up / thumbs up)
LAD qrs in v1 & v2 - Answers - ✔✔ pos / neg (thumb up / thumb down)
RAD qrs in v1 & AvF - Answers - ✔✔ neg / pos (thumb down / thumb up)
North West Axis (extreme) qrs in v1 & avF - Answers - ✔✔ neg / neg (thumb down /
thumb down)
two parts of left bb - Answers - ✔✔ left anterior fascicle & Left posterior fascicle
right ventricular hypertrophy signs + right axis deviation = - Answers - ✔✔ likelihood of
right axis deviation
LVH on an ecg - Answers - ✔✔ sum of S wave in v1 + v2 and the R wave in v5 or v6 is
greater than or equal to >35mm
if pt has LVH (s wave + R wave = >35mm), and pt has RAD (neg/ pos) + - Answers -
✔✔ Biventricular Hypertrophy
deflection of a impulse toward a lead - Answers - ✔✔ positive
deflection of an impulse moving away from lead - Answers - ✔✔ negative
,deflection of an impulse moving 90 deg to a lead - Answers - ✔✔ same pos/neg
deflection (equiphasic)
easy 7 steps to finding axis on ecg - Answers - ✔✔ 1. find the most equiphasic limb
lead
2. look at lead running 90 deg to this
3. impulse mainly +Ve? axis is towards this lead
4. impulse mainly -Ve? axis is away from this lead
5. truly equiphasic? yes- you found cardiac axis
6. slightly more +Ve ; move axis 15 deg towards equiphasic lead
7. Slightly more -Ve? Move axis 15 deg away from equiphasic lead
right ventricular hypertrophy (causes) - Answers - ✔✔ -pulmonary hypertension
-mitral stenosis
-pulmonary embolism
-chronic lung disease
-congenital heart disease
right ventricular hypertrophy (leads) - Answers - ✔✔ - right axis deviation
- dominant R wave in V1 (>7mm tall or R/S ratio >1)
- dominant S wave in V5 or V6 (>7mm deep or R/S ratio <1)
-QRS duration <120ms (changes not due to rbbb)
Right Atrial Hypertrophy (causes) - Answers - ✔✔ - chronic lung disease
- tricuspid stenosis
-congenital heart disease
- primary pulmonary hypertension
-anything that increase size in cell size
Right Atrial Hypertrophy (leads) - Answers - ✔✔ - p wave is >2.5mm in the inferior
leads (II,III, avF)
->1.5mm in V1&V2
-Think 3 P's
-Pointed, prominent, pulmonary
Left Atrial Hypertrophy (causes) - Answers - ✔✔ - mitral stenosis
- systemic hypertension
- aortic stenosis
- hypertension cardiomyopathy
Left Atrial Hypertrophy (leads) - Answers - ✔✔ Lead 2 P wave
- bifid p wave >40ms between 2 peaks
- total p wave duration >110 ms
- p mitrale
Lead V1
,- Biphasic P wave w terminal negative portion >40ms duration
- Biphasic p wave w terminal negative portion >1 mm deep
left ventricular hypertrophy (causes) - Answers - ✔✔ -a thickening of the wall of the
heart's main pumping chamber
Left ventricular hypertrophy ( leads) - Answers - ✔✔ -most common used criteria is the
sokolov- lyon
- S wave depth in v1 + tallest R wave height in V5- V6 >35mm
enlargement VS hypertrophy - Answers - ✔✔ enlargement is increase in chamber size
Hypertrophy is an increase in chamber wall thickness
atrial enlargement - Answers - ✔✔ p wave axis is normally +30 deg- +75deg
- if axis shifts right +75deg suggests RAE
- if axis shifts right +30deg, suggests LAE
- look at lead 2 , its a good lead to look at for atrial enlargement
LAE left atrial enlargement - Answers - ✔✔ - effects the second part of the pwave
-p wave is 2 parts, right atrial depolarization represents the first half
RAE Right Atrial Enlargement - Answers - ✔✔ -effects the first part of p wave
secondary repolarization abnormalities - Answers - ✔✔ - consists of downsloping ST
seg & T wave inversion
- mostly seen in leads over hypertrophied ventricle
- formerly known as a "strain pattern"
Intrinsicoid Deflection - Answers - ✔✔ - the duration of time from the beginning of the
qrs complex to the peak of the R wave
- it is typically not measured in the precordial leads
- normal <35ms in V1, <45ms in
- usually a sign of Ventricular Hypertrophy (usually left)
tall R waves +/- secondary repolarization abnormalities are found in ___ leads for RVH
and ___ leads for LVH - Answers - ✔✔ v1-v2 RVH / I, avL,v5,v6 LV
usually deep S waves are found in ___ leads for RVH and ___ leads for LVH - Answers
- ✔✔ I, avL,v5,v6 RVH / v1, v2 LVH
axis deviation for RVH & LVH - Answers - ✔✔ rightward of +90deg RVH / leftward of -
30deg LVH
atrial abnormalities for RVH & LVH - Answers - ✔✔ RAE for RVH&LAE for LVH
, conduction abnormalities for RVH & LVH - Answers - ✔✔ Rbbb(complete or not) RVH
& Lbbb (complete or not) LVH
other abnormalities for RVH&LVH - Answers - ✔✔ poor r wave progression for RVH &
delayed intrinsicoid deflection for LVH
3 types of diagnostic criteria for LVH - Answers - ✔✔ 1. sokolow-lyon criteria
2. Cornell Criteria
3. Romhilt-Estes Point system
sokolow-lyon criteria (diagnosing LVH) - Answers - ✔✔ -s wave in v1 + R wave in v5 or
v6 > or eq to 3.5mV (35mm)
- R wave in v5 or v6 >2.6mV (26mm)
cornell criteria (diagnosing LVH) - Answers - ✔✔ for men ; R in avL + S in v3 >2.8mV
(28mm)
for women; R in avL + S in v3 >2.0mV (20mm)
blood pressure measures in - Answers - ✔✔ mmHg milimeters of mercury in blood
blood pressure is made up of two parts, ___ & ____ - Answers - ✔✔ systolic (top) /
diastolic (bottom)
systolic pressure - Answers - ✔✔ -ventricles contracting
- normally 120mmHg
- listen for first sound w stethoscope
-pressure caused by ventricular contraction
- av valves ; closed
- semilunar valves ; open
- blood headed out of heart, to body, lungs
- THIN heart walls are a sign of systolic failure
diastolic pressure - Answers - ✔✔ - ventricles relaxed / filling
- normally 70-80mmHg
- heart is relaxed & filled w blood
- Av valves; open
- semilunar valves; closed
- pressure is highest in arteries closest to heart
- THICK heart walls are a sign of diagnostic failure
cardiac blood flow on hand (to remember main arteries) on left hand - Answers - ✔✔
av node on lower right palm/ Right Coronary Artery on pinky (feeds av node and inferior
wall)
L shape = Left Main Artery = branches into
finger- left anterior descending
DETAILED ANSWERS WITH
RATIONALES (VERIFIED ANSWERS)
What is a vector in the heart? - Answers - ✔✔ The purpose of electrocardiographic
investigation is to find out something about the heart itself by means of an accurate
knowledge of its electric action. This may be repre- sented by the so-called heart-vector,
a directed quantity, indicating in which direction elec- tricity is propagated by the heart.
Left Axis Deviation (LAD) - Answers - ✔✔ 30-90 degrees
Right Axis Deviation (RAD) - Answers - ✔✔ +90 to +180
normal axis - Answers - ✔✔ -30 to +90
Extreme Axis Deviation - Answers - ✔✔ -90, 180
normal axis qrs in v1 & v2 - Answers - ✔✔ pos / pos (thumbs up / thumbs up)
LAD qrs in v1 & v2 - Answers - ✔✔ pos / neg (thumb up / thumb down)
RAD qrs in v1 & AvF - Answers - ✔✔ neg / pos (thumb down / thumb up)
North West Axis (extreme) qrs in v1 & avF - Answers - ✔✔ neg / neg (thumb down /
thumb down)
two parts of left bb - Answers - ✔✔ left anterior fascicle & Left posterior fascicle
right ventricular hypertrophy signs + right axis deviation = - Answers - ✔✔ likelihood of
right axis deviation
LVH on an ecg - Answers - ✔✔ sum of S wave in v1 + v2 and the R wave in v5 or v6 is
greater than or equal to >35mm
if pt has LVH (s wave + R wave = >35mm), and pt has RAD (neg/ pos) + - Answers -
✔✔ Biventricular Hypertrophy
deflection of a impulse toward a lead - Answers - ✔✔ positive
deflection of an impulse moving away from lead - Answers - ✔✔ negative
,deflection of an impulse moving 90 deg to a lead - Answers - ✔✔ same pos/neg
deflection (equiphasic)
easy 7 steps to finding axis on ecg - Answers - ✔✔ 1. find the most equiphasic limb
lead
2. look at lead running 90 deg to this
3. impulse mainly +Ve? axis is towards this lead
4. impulse mainly -Ve? axis is away from this lead
5. truly equiphasic? yes- you found cardiac axis
6. slightly more +Ve ; move axis 15 deg towards equiphasic lead
7. Slightly more -Ve? Move axis 15 deg away from equiphasic lead
right ventricular hypertrophy (causes) - Answers - ✔✔ -pulmonary hypertension
-mitral stenosis
-pulmonary embolism
-chronic lung disease
-congenital heart disease
right ventricular hypertrophy (leads) - Answers - ✔✔ - right axis deviation
- dominant R wave in V1 (>7mm tall or R/S ratio >1)
- dominant S wave in V5 or V6 (>7mm deep or R/S ratio <1)
-QRS duration <120ms (changes not due to rbbb)
Right Atrial Hypertrophy (causes) - Answers - ✔✔ - chronic lung disease
- tricuspid stenosis
-congenital heart disease
- primary pulmonary hypertension
-anything that increase size in cell size
Right Atrial Hypertrophy (leads) - Answers - ✔✔ - p wave is >2.5mm in the inferior
leads (II,III, avF)
->1.5mm in V1&V2
-Think 3 P's
-Pointed, prominent, pulmonary
Left Atrial Hypertrophy (causes) - Answers - ✔✔ - mitral stenosis
- systemic hypertension
- aortic stenosis
- hypertension cardiomyopathy
Left Atrial Hypertrophy (leads) - Answers - ✔✔ Lead 2 P wave
- bifid p wave >40ms between 2 peaks
- total p wave duration >110 ms
- p mitrale
Lead V1
,- Biphasic P wave w terminal negative portion >40ms duration
- Biphasic p wave w terminal negative portion >1 mm deep
left ventricular hypertrophy (causes) - Answers - ✔✔ -a thickening of the wall of the
heart's main pumping chamber
Left ventricular hypertrophy ( leads) - Answers - ✔✔ -most common used criteria is the
sokolov- lyon
- S wave depth in v1 + tallest R wave height in V5- V6 >35mm
enlargement VS hypertrophy - Answers - ✔✔ enlargement is increase in chamber size
Hypertrophy is an increase in chamber wall thickness
atrial enlargement - Answers - ✔✔ p wave axis is normally +30 deg- +75deg
- if axis shifts right +75deg suggests RAE
- if axis shifts right +30deg, suggests LAE
- look at lead 2 , its a good lead to look at for atrial enlargement
LAE left atrial enlargement - Answers - ✔✔ - effects the second part of the pwave
-p wave is 2 parts, right atrial depolarization represents the first half
RAE Right Atrial Enlargement - Answers - ✔✔ -effects the first part of p wave
secondary repolarization abnormalities - Answers - ✔✔ - consists of downsloping ST
seg & T wave inversion
- mostly seen in leads over hypertrophied ventricle
- formerly known as a "strain pattern"
Intrinsicoid Deflection - Answers - ✔✔ - the duration of time from the beginning of the
qrs complex to the peak of the R wave
- it is typically not measured in the precordial leads
- normal <35ms in V1, <45ms in
- usually a sign of Ventricular Hypertrophy (usually left)
tall R waves +/- secondary repolarization abnormalities are found in ___ leads for RVH
and ___ leads for LVH - Answers - ✔✔ v1-v2 RVH / I, avL,v5,v6 LV
usually deep S waves are found in ___ leads for RVH and ___ leads for LVH - Answers
- ✔✔ I, avL,v5,v6 RVH / v1, v2 LVH
axis deviation for RVH & LVH - Answers - ✔✔ rightward of +90deg RVH / leftward of -
30deg LVH
atrial abnormalities for RVH & LVH - Answers - ✔✔ RAE for RVH&LAE for LVH
, conduction abnormalities for RVH & LVH - Answers - ✔✔ Rbbb(complete or not) RVH
& Lbbb (complete or not) LVH
other abnormalities for RVH&LVH - Answers - ✔✔ poor r wave progression for RVH &
delayed intrinsicoid deflection for LVH
3 types of diagnostic criteria for LVH - Answers - ✔✔ 1. sokolow-lyon criteria
2. Cornell Criteria
3. Romhilt-Estes Point system
sokolow-lyon criteria (diagnosing LVH) - Answers - ✔✔ -s wave in v1 + R wave in v5 or
v6 > or eq to 3.5mV (35mm)
- R wave in v5 or v6 >2.6mV (26mm)
cornell criteria (diagnosing LVH) - Answers - ✔✔ for men ; R in avL + S in v3 >2.8mV
(28mm)
for women; R in avL + S in v3 >2.0mV (20mm)
blood pressure measures in - Answers - ✔✔ mmHg milimeters of mercury in blood
blood pressure is made up of two parts, ___ & ____ - Answers - ✔✔ systolic (top) /
diastolic (bottom)
systolic pressure - Answers - ✔✔ -ventricles contracting
- normally 120mmHg
- listen for first sound w stethoscope
-pressure caused by ventricular contraction
- av valves ; closed
- semilunar valves ; open
- blood headed out of heart, to body, lungs
- THIN heart walls are a sign of systolic failure
diastolic pressure - Answers - ✔✔ - ventricles relaxed / filling
- normally 70-80mmHg
- heart is relaxed & filled w blood
- Av valves; open
- semilunar valves; closed
- pressure is highest in arteries closest to heart
- THICK heart walls are a sign of diagnostic failure
cardiac blood flow on hand (to remember main arteries) on left hand - Answers - ✔✔
av node on lower right palm/ Right Coronary Artery on pinky (feeds av node and inferior
wall)
L shape = Left Main Artery = branches into
finger- left anterior descending
