Unit 1 Flashcards by Ashley McNally

The P wave and QRS wave of a standard ECG represent which of the following events?

A) Atrial depolarization and ventricular depolarization
B) Atrial repolarization and ventricular repolarization
C) Atrial depolarization and ventricular repolarization
D) Atrial repolarization and ventricular depolarization

A) Atrial depolarization and ventricular depolarization

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What is the highest oxygen consumption achieved during exercise called?

A) a-vO2 difference max
B) Cardiac output max
C) VO2peak
D) Heart rate max

C) VO2peak

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When expressed in terms of milliliters of oxygen consumed per kg of body weight per minute, what does 3 METs equal?

A) 3.5 mL . kg-1 . min-1
B) 7.5 mL . kg-1 . min-1
C) 10.5 mL . kg-1 . min-1
D) 15.0 mL . kg-1 . min-1

C) 10.5 mL . kg-1 . min-1

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Which of the following statements would be true for exercise that is achieved through arm as compared to leg ergometry at the same workload?

A) Arm exercise has higher heart rate and lower blood pressure than leg exercise
B) Arm exercise has lower heart rate and higher blood pressure than leg exercise
C) Arm exercise has lower heart rate and lower blood pressure than leg exercise
D) Arm exercise has higher heart rate and higher blood pressure than leg exercise

D) Arm exercise has higher heart rate and higher blood pressure than leg exercise

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The vagus nerve is under ___ control and functions to ___ heart rate.

A) parasympathetic; slow
B) parasympathetic; increase
C) sympathetic; increase
D) sympathetic; slow

A) parasympathetic; slow

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What does a prolonged Valsalva maneuver produce?

A) A rapid & dangerous rise in blood pressure
B) Sore abdominal muscles
C) A rapid drop in blood pressure
D) Increased tidal volume

A) A rapid & dangerous rise in blood pressure

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A typical partial pressure for oxygen in the alveoli is around:

A) 40 mmHg
B) 60 mmHg
C) 104 mmHg
D) 159 mmHg

C) 104 mmHg

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Which of the following is an example of extrinsic control of heart activity?

A) The impulse from the SA node travels to the AV node, the AV bundle (bundle of His), and finally to the purkinje fibers.
B) Norepinephrine and epinephrine are released and lead to increased heart rate.
C) The purkinje fibers transmit the impulse extremely quickly through the ventricles, causing all parts of the ventricle to contract at about the same time.
D) The SA node initiates the impulse.

B) Norepinephrine and epinephrine are released and lead to increased heart rate.

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The most important variable that determines resistance to blood flow is

A) HR
B) Viscosity of blood
C) Length of blood vessels
D) Diameter of the vessel

D) Diameter of the vessel

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Carbon dioxide is transported in the blood principally as:

A) Oxyhemoglobin
B) Bicarbonate
C) Dissolved CO2 solution in the blood
D) Carbaminohemoglobin

B) Bicarbonate

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The heart’s main nutrient blood supply is provided via _____ that originate off of the _____.

A) the superior and inferior vena cavae, right ventricle
B) the right and left coronary arteries, aorta
C) the coronary veins, aorta
D) the pulmonary arteries, right ventricle

B) the right and left coronary arteries, aorta

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In healthy individuals, what provides the most important respiratory stimulus at rest?

A) Increase in potassium concentrations
B) Increase in temperature
C) Carbon dioxide pressure in arterial plasma
D) The blood’s hemoglobin content

C) Carbon dioxide pressure in arterial plasma

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Adequate gas exchange between alveoli and blood requires effective matching of alveolar ventilation to:

A) Blood perfusing the pulmonary capillaries
B) Residual volume
C) Tidal volume
D) Forced vital capacity

A) Blood perfusing the pulmonary capillaries

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The volume that describes air volume moved during either the inspiratory or expiratory phase of each breathing cycle is the:

A) Forced vital capacity
B) Inspiratory reserve volume
C) Tidal volume
D) Residual volume

C) Tidal volume

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What factors are associated with the faster dissociation of oxygen from red blood cells?

A) increased PO2 gradient, increased acidity, decreased pH, decreased temperature
B) increased PO2 gradient, decreased acidity, decreased pH, increased temperature
C) increased PO2 gradient, increased acidity, increased pH, increased temperature
D) increased PO2 gradient, increased acidity, decreased pH, increased temperature

D) increased PO2 gradient, increased acidity, decreased pH, increased temperature

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Hypertrophy of the heart occurs due to:

A) Increased resistance activity
B) Increased aerobic activity
C) Certain diseases such as hypertension
D) Increased physical activity
E) All of these are correct.

E) All of these are correct.

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What does the arteriovenous oxygen difference describe?

A) The amount of oxygen extracted from the blood by the tissues
B) The difference in oxygen content in the blood pre- and post-exercise
C) The range of oxygen content in blood from forced exhale to inhaled deep breath
D) The amount of oxygen attached to hemoglobin immediately preceding a breath

A) The amount of oxygen extracted from the blood by the tissues

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Which of the following spirometry measures can help detect pulmonary obstructive conditions like asthma or COPD?

A) Forced vital capacity
B) Tidal capacity
C) FEV1/FVC
D) Residual lung volume

C) FEV1/FVC

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Nitric oxide causes what changes in blood vessels?

A) Vasoconstriction and increased vascular resistance
B) Vasoconstriction and decreased vascular resistance
C) Vasodilation and increased vascular resistance
D) Vasodilation and decreased vascular resistance

D) Vasodilation and decreased vascular resistance

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Which is true about the oxidative capacity of myocardial tissue compared to that of skeletal tissue?

A) Skeletal muscle can use more lactate than the myocardium
B) Myocardium has a higher anaerobic capacity
C) Myocardium has lower oxidative capacity
D) Myocardium is more susceptible to injury from ischemia

D) Myocardium is more susceptible to injury from ischemia

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T/F: In a person with limited cardiac capacity like chronic heart failure, training can improve performance and oxygen utilization at the local tissue level.

True

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The blood pressure response with increased intensity during resistance training is systolic ___ and diastolic ___. During aerobic training it’s systolic ___ diastolic ___.

Increases
Increases
Increases
Stays the same

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How long does a Holter monitor record the heart?

25-48 hrs

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T/F: An EKG directly detects mechanical problems in the heart.

False

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What is the significance of the "big boxes" on the EKG tracing? A) Represents MI B) Represents V-tach C) Represents 0.2 sec D) Represents a mechanical problem

C) Represents 0.2 sec

What does the PR interval represent? A) Time it takes to depolarize the atria B) The pause at the AV node C) The pause at the SA node D) Time it takes to repolarize the artia

B) The pause at the AV node

What does the QT interval represent? A) The time to depolarize and repolarize the atria B) The time to depolarize and repolarize the ventricles

B) The time to depolarize and repolarize the ventricles

What is a wandering baseline?

Occurs when the isoelectric line is not straight Causes: - poor prep of electrode & skin - loose wires - moving clothing on leads

What is a 60 cycle interference?

Interference on the EKG due to wall current; occurs from devices such as elevators and overhead lights using 60 Hz wall current

Why is there a delay in impulse at the AV node?

It allows time for efficient blood flow

Depolarization in sequence

SA node Atria AV node Bundle of His Bundle branches Apex of the heart Base of the heart

Shapes of waves

All waves have the same fundamental shape Differences in amplitude & velocity can make waves look very different

What does the P wave represent?

Atrial depolarization

What does the Q wave represent?

First part of ventricular depolarization; may be absent or small

What does an abnormal Q look like?

Very large - it should be 1/3 of max height of QRS complex

What does the R wave represent?

First of second part of QRS; always upright by definition

What does the S wave represent?

Downward deflection that must follow R by definition

What does the T wave represent?

Repolarization of the ventricles; usually tall, symmetric, & upright

Which direction should the axis of depolarization be pointing and why?

Down and to the left toward the muscular left ventricle which the workhorse of the heart

Various P wave shape during EKG indicates:

Pathology

T/F: A T wave that is not upright and symmetric is a red flag.

True - inverted, flat or biphasic T waves indicate abnormal repolarization usually due to ischemic disease

What is the R' wave?

Second upward deflection Indicates abnormal conduction through one bundle branch Can only be seen clearly in chest leads on side of heart with abnormal conduction

What does ST segment depression indicate?

Ischemia

What does ST segment elevation indicate?

Acute MI (STEMI) "Tombstone appearance"

Which EKG wave(s) indicate(s) presence of ischemia? A) Significant Q wave B) Inverted T wave C) ST segment depression D) ST segment elevation

B) Inverted T wave - myocardial ischemia C) ST segment depression- myocardial ischemia

What is the conduction rate of the SA node?

60-100 bpm

What is the conduction rate of the AV node?

40-60 bpm

What is the conduction rate of the Bundle of His?

40-60 bpm

What are pacemaker cells?

Cell that has the fastest rate of spontaneous depolarization that becomes the pacemaker of the entire heart Normally this is SA node

What neurotransmitter slows the rate of spontaneous depolarization?

ACh released by parasympathetic nerves (vagus)

What neurotransmitter increases the rate of spontaneous depolarization?

Norepinephrine released by sympathetic nerves, or circulating epinephrine

What is the rate of a normal PR interval?

0.12 - 0.20 seconds (3-5 small boxes)

What is the rate of a normal QRS complex?

0.06 - 0.10 seconds (1.5-2.5 small boxes)

If the PR interval is too slow, what would this indicate?

Heart block

If the QRS complex is too slow, what would this indicate?

Conduction problem in ventricles

Regularly irregular rhythm

Same spacing between cycles with occasional interruption in rhythm - Usually PVCs - May be PACs

Irregularly irregular rhythm

Spacing changes from one cardiac cycle to the next - Usually AFIB, may be other cause

Sinus arrhythmia

Excessive variation in rate, normal waves Usually caused by alterations in vagal stimulation (breathing, meds, infection)

Sinus pause or block

Occurs when the SA node fails to initiate an impulse, usually only for one cycle

Sinus arrest

Sinus pause/block occurring for > 2 sec.

Wandering atrial pacemaker

More than 1 node initiating heartbeat Varying P wave Can lead to AFIB

Premature atrial contractions (PAC)

Beat occurs earlier than expected based on the prevailing rhythm, otherwise normal appearance - shape of QRST is perfectly normal P wave may be hidden or superimposed in T wave

Atrial tachycardia

3 or more PACs in a row Rapid HR present

Paroxysmal atrial tachycardia

Sudden increase in HR (> 160 bpm) with normal-looking complexes

Atrial flutter

Sawtooth appearance of F waves; 2-8 F waves between T and next QRS

AFIB

No real pacemaker Quivering/twitching of atrial muscle Risk of CVA due to mural thrombus formation Atrial kick lost

Junctional rhtyhm

AV node takes role of pacemaker of the heart Usually caused by damage to SA node May be caused by increased automacity of AV node

Junctional tachycardia

No P before QRS - retrograde P (occurs between S & T)

PVC

Increased automaticity in the ventricular conducting system Ventricular cell depolarizes prior to depolarization of SA node Wide, unbalanced QRS Absence of P wave

Bigeminy PVC

Occurs every other beat

Trigeminy PVC

Occurs every third beat

Couplet or paired PVC

2 PVCs occur together

V-tach

3 or more consecutive PVCs

Ventricular Tachycardia

3 or more PVCs in a row P waves absent HR = 100-250 bpm SV decreased & BP drops Emergent situation, even if non-sustained b/c can progress to VFIB plus BP issues

VFIB

Totally chaotic electrical activity of the ventricles No meaningful cardiac output occurs CPR or electrocardioversion is necessary