Physio ECG

TRUE OR FALSE: The heart is positioned in such a way that the left atrium and ventricle are anterior to their counterparts.

FALSE - The heart is positioned in such a way that the RIGHT atrium and ventricle are anterior to their counterparts.

carries deoxygenated blood away from the heart in the lungs

Pulmonary Circulation (Right Heart)

carries oxygenated blood away from the heart and into the different tissues of the body

Systemic Circulation (Left Heart)

WHAT IS THE CORRECT ORDER: Pulmonary Circulation

1. right ventricle

2. lungs

3. superior and inferior vena cava

4. right atrium

5. pulmonary artery

3-4-1-5-2

WHAT IS THE CORRECT ORDER: Systemic Circulation

1. capillaries

2. tissues

3. aorta

4. pulmonary vein

5. left ventricle

6. left atrium

4-6-5-3-1-2

WHICH IS NOT TRUE: Conduction System of the Heart

a. contains the specialized excitatory and conducting muscles of the heart

b. allows for automacity and rhythmicity

c. begins at the cavo-atrial junction

d. action potentials begin in the atrioventricular node

d. - action potentials begin in the SINOATRIAL node

WHAT IS THE CORRECT ORDER: Conduction System of the Heart

1. SA node

2. left and right bundle branches

3. Bundle of His

4. Purkinje system

5. internodal pathways

6. atrioventricular node

1-5-6-3-2-4

WHICH IS NOT TRUE: Depolarization Pathway

a. In the heart, what depolarizes last repolarizes first.

b. The mean vector for depolarization is left downward posterior.

c. The mean vector for repolarization is right upward posterior.

d. Repolarization begins at the pulmonary artery conus.

c. - The mean vector for repolarization is right upward ANTERIOR.

Atrial depolarization

a. parts of the heart involved

b. depolarization vector direction

a. SA node - Left atrium

b. left downward posterior (LDP)

Septal depolarization

a. parts of the heart involved

b. depolarization vector direction

a. left atrium - AV node at the septum

b. right horizontal anterior (RHA)

apical depolarization

a. parts of the heart involved

b. depolarization vector direction

a. AV node at septum - apex

b. left downward anterior (LDA)

ventricular depolarization

a. parts of the heart involved

b. depolarization vector direction

a. apex - free wall (left ventricle)

b. left downward posterior (LDP)

pulmonary artery conus depolarization

a. parts of the heart involved

b. depolarization vector direction

a. free wall to pulmonary artery conus

b. right upward anterior (RUA)

WHICH IS NOT TRUE:

a. The left ventricle free wall is composed of the area of the left ventricular wall not in contact with the interventricular septum and is not part of the apex.

b. The vector courses through the left ventricle because it is relatively thinner than the right ventricle.

c. Pacemakers of the heart are specialized excitatory cardiac cells that can undergo spontaneous depolarization to create action potentials.

d. Failure of a pacemaker allows a subsidiary pacemaker to take over.

b. - The vector courses through the left ventricle because it is relatively THICKER than the right ventricle.

WHICH IS NOT TRUE: Heart block

a. Heart block is a blockage of impulses coming from the SA node.

b. AV Node takes over pacemaker resulting to a slower heart rhythm.

c. Heart block tends to lead to tachycardia.

d. Compromises to the SA Node and AV Node allows the Purkinje system or ventricular muscles to take over, hence a slower rhythm.

c. - Heart block tends to lead to BRADYCHARDIA.

PART OF THE ECG: atrial depolarization

P wave

PART OF THE ECG: beginning of the P wave until the beginning of the QRS complex

PR Interval

PART OF THE ECG: time it takes for an impulse to travel from the SA Node to AV Node

PR Interval

PART OF THE ECG: atrial repolarization

atrial T wave

PART OF THE ECG: ventricular depolarization

QRS complex

PART OF THE ECG: between the end of QRS complex up to the beginning of the T wave

ST segment

PART OF THE ECG: transition between ventricular depolarization and repolarization

ST Segment

PART OF THE ECG: ventricular repolarization

T Wave

PART OF THE ECG: between the beginning of the QRS complex up to the end of the T wave

QT interval

PART OF THE ECG: time it takes for the ventricles to depolarize and repolarize

QT Interval

WHICH IS NOT TRUE: Leads in ECG

a. In a 12-lead ECG, there are 12 leads calculated using 10 electrodes.

b. Six leads are considered as the limb leads and the other six leads are termed precordial or chest leads.

c. Limb leads can either be bipolar or unipolar

d. Three electrodes are used in limb leads.

d. - FOUR electrodes are used in limb leads, one is used for grounding.

WHICH IS NOT TRUE: Leads

a. In standard limb leads, 3 electrodes create the Einthoven's triangle where each electrode is equidistant from the umbilicus.

b. Augmented limb leads are unipolar as composed of a single positive lead and reference point at the center.

c. Precordial unipolar leads are recorded by placing an electrode on the anterior surface of the chest.

d. If the lead direction is toward the same direction as the mean vector, it records a positive deflection or upward QRS complex wave.

a. - In standard limb leads, 3 electrodes create the Einthoven's triangle where each electrode is equidistant from the HEART.

PLACEMENT OF ELECTRODE: Lead I

negative on right arm and positive on left arm

PLACEMENT OF ELECTRODE: Lead II

negative on right arm and positive on left leg

PLACEMENT OF ELECTRODE: Lead III

negative on left arm and positive on left leg

PLACEMENT OF ELECTRODE: aVF

from center to foot

PLACEMENT OF ELECTRODE: aVL

from center to left hand

PLACEMENT OF ELECTRODE: aVR

from center to right hand

PLACEMENT OF ELECTRODE: V1

4th intercostal space on right sternum

PLACEMENT OF ELECTRODE: V2

4th intercostal space at the left sternum

PLACEMENT OF ELECTRODE: V3

midway between placement of V2 and V4

PLACEMENT OF ELECTRODE: V4

5th intercostal space at the midclavicular line

PLACEMENT OF ELECTRODE: V5

anterior axillary line on the same horizontal line as V4

PLACEMENT OF ELECTRODE: V6

mid-axillary line on the same horizontal level as V4 and V5

DEFLECTION OF QRS COMPLEX:

a. Lead 1

b. Lead 2

c. Lead 3

a. positive / upward with some negative

b. positive / upward