HSCI 211L Final Exam

Where is the heart located?

Thoracic cavity

What space is the heart located in?

mediastinum

Which side does the apex point to?

left side

What side does the heart recline?

Right side

What are the four chambers of the heart?

Right atrium, right ventricle, left atrium, left ventricle

Blood flow of heart

Superior/inferior vena cava —> right atrium —> right ventricle —> pulmonary trunk —> lungs —> four pulmonary veins —> left atrium —> left ventricle —> aorta —> body

What has deoxygenated blood?

Superior/inferior vena cava, right atrium, right ventricle, pulmonary trunk

What has oxygenated blood?

four pulmonary veins, left atrium, left ventricle, aorta

What are intercalated discs?

Connect cardiac muscle cells

Conduction system of the heart

1. Sinoatrial node generates impusles

2. Impulses pause at atrioventricular node

3. Atrioventricular bundle connects the atria to the ventricles

4. Bundle branches conduct the impulses through the interventricular septum

5. Subendocardial conducting network stimulates the contractile cells of both ventricles

What is diastole?

filling

What is systole?

pumping

Electrocardiogram

a record of a person’s heartbeat produced by electrocardiography

Electrocardiography

the measurement of electrical activity in the heart using electrodes placed on the surface of the chest and limbs

Electrode

Device with conductive media placed on the skin to view the heart’s electrical activity from different angles and planes

Lead

Recording of electrical activity between electrodes

What does a electrode provide

Magnitude of electrical activity and direction of electrical acitivity

How is an electrode important?

Diagnose differently heart conditions like enlargement of heart muscle, arrhythmia, presence of ischemia, or infraction

3 bipolar limb leads

Lead I, Lead II, Lead III

If the electrical activity goes toward the + electrode,

There is an upward deflection

If the electrical activity goes toward the - electrode,

There is an downward deflection

Lead I

constructed by comparing the left arm electrode as positive to the right arm electrode as negative

Lead II

connects the left leg as positive to the right arm as negative

Lead III

connects the left leg as positive to the left arm as negative

Einthoven’s Triangle

Right arm, left arm, left leg

Right arm +, - or +/-?

always -

Left leg +, - or +/-?

always +

Right arm +, - or +/-?

+/-

What are the 3 Augmented Unipolar Leads?

aVR, aVL, aVF

If the electrical activity goes toward the electrode,

there will be an upward deflection

If the electrical activity goes away the electrode,

there will be an downward deflection

Lead aVR

Waveforms have negative deflection

Lead aVL

Waveforms have positive deflection

Lead aVF

Waveforms have a positive deflection

Where does the right atrium receive blood from?

SVC, IVC, and coronary sinus

Where does the right atrium send blood to?

right ventricle

Where does the right ventricle receive blood from?

right atrium

Where does the right ventricle send blood to?

pulmonary arteries

Where does the left atrium receive blood from?

Lungs through pulmonary veins

Where does the left atrium send blood to?

Left ventricle

Where does the left ventricle receive blood from?

left atrium

Where does the left ventricle send blood to?

Aorta

Right AV valve

tricuspid valve

Left AV valve

bicuspid valve

What happens when the semilunar valves don’t work?

Valves are working harder

Hypertrophy

an increase in mass attributable to increases in cell size (not number)

Frank-Starling Law

As a larger volume of blood flows into the chambers, the blood stretches the cardiac muscle fibers, leading to an increase in the force of contraction

Horizontal axis of ECG

Timing of electrical activity

Ventricle axis of ECG

magnitude of electrical activity

Normal P wave

less than 2.5mm high (0.25mV), and 2.5mm wide (0.1sec)

What do you use to determine Right atrial enlargement?

Lead II, Lead III, and aVF

Right Atrial Enlargement

Tall P wave

What can cause a Right Atrial Enlargement?

Tricuspid stenosis “narrow”, Tricuspid prolapse “leaky”

What do you use to determine Left atrial enlargement?

Lead II, Lead III, and aVF

Left Atrial Enlargement

Wide P wave

What causes a left atrial enlargement?

it takes longer time to reach and depolarize left atria enlarged mass

What can cause a Left Atrial Enlargement?

Bicuspid ”Mitral” stenosis “narrow”, Bicuspid ”Mitral” prolapse “leaky”

What do you use to determine Right Ventricular Hypertrophy?

V1 & V5

What occurs in Right Ventricular Hypertrophy?

the opposite deflection pattern occurs

What causes right ventricular hypertrophy?

Pulmonary valve stenosis or prolapse.

What causes left ventricular hypertrophy?

Normal adaption to exercise, diseases

What can cause heart blocks?

Age-related wear and tear to the heart muscle , Diseases and conditions that cause scarring or damage to the heart's electrical system, Scar tissue from a previous heart surgery, particularly in children, Side effect of medications (e.g. calcium channel blockers or beta blockers)

SA block

when the AV Node becomes the pacemaker

What happens when there is a SA block?

the P wave and QRS will occur at the same time

First degree AV block

There is a delay in the transmission of the impulse from the atria (that started with the SA Node and hence the P wave) to the ventricles, This delay reflects in the PR interval, 1º AV Block is identified by a prolonged PR interval (i.e. 0.20 sec or more) in all leads

Second degree AV block Type 1

increasing PR intervals, increasing until the QRS is "dropped" or missing, Usually, the P wave is seen, but the impulse does not initiate a ventricular response. Thus, the dropped complex is the QRS wave. The cycle is resumed with no set pattern.

Second degree AV block Type II

There are multiple P waves prior to the QRS complex., The number of P waves prior to the QRS wave will be consistent. For example, you may always observe two P waves prior to the QRS complex. In this case, you would interpret the EKG as Mobitz II, 2:1 (i.e. 2 P waves prior to 1 QRS complex).

Third degree AV block

there is no association between the atria and the ventricles,

What is blood pressure

the amount of force/pressure exerted against the walls of an artery and recorded as 2 numbers

What is the top number for blood pressure?

systaloic diastolic

What is the bottom number for blood pressure?

diastolic pressure

What artery do you listen to when taking blood pressure

Brachial artery

What are the two types of sphygmomanometer?

Aneroid & mercury filled

What is phase 1 of korotkoff sounds?

appearance of faint tapping “systolic pressure”

What is phase 2 of korotkoff sounds?

sound becomes louder and usually gets characterized by swishing sound

What is phase 3 of korotkoff sounds?

sound is very distinct and loud

What is phase 4 of korotkoff sounds?

Sound becomes muffled and softer diastolic pressure

What is phase 5 of korotkoff sounds?

sound disappears

What should a person do before taking blood pressure?

rest for 5 min

What happens to blood pressure after hard exercise?

Possible that the heart sound disappears

Auscultory method

taking blood pressure is considered the “gold standard” if performed by a trained healthcare provider

Too wide of cuff

underestimate BP

Too narrow of cuff

overestimate BP

Hypertension

High blood pressure is a major risk factor associated with heart disease and the primary reason why it is measured every time you visit the doctor’s office.

Normal blood pressure

Systolic: less than 120 & Diastolic: less than 80

Elevated blood pressure

Systolic: 120-129 & Diastolic: less than 80

High blood pressure stage 1

Systolic: 130-139 or Diastolic: 80-89

High blood pressure stage 2

Systolic: 140 or higher or Diastolic: 90 or higher

Hypertensive crisis

Systolic: Higher than 180 & Diastolic: Higher than 120

Treatments for high blood pressure

Healthy diet and exercise, Diuretics, ACE inhibitors “Angiotensin converting enzyme inhibitors”, Beta Blockers, Vasodilators

Normal BP responses to exercise

Systolic pressure elevates with each increase in workload due to stretch in the left ventricular wall and increased force to pump more blood.

Diastolic pressure either remains the same or may decrease with each increase in workload due to the vasodilation of the arteries from the exercise bout.

Abnormal BP Responses to Exercise

Systolic pressure fails to elevate or declines after an increase in workload due to heart diseases that affect the heart’s ability to contract.

Diastolic pressure elevates after an increase in workload due to high pressure in the blood vessels while the heart is in diastole.

Diagnosing Heart Disease

Exercise requires the heart to work harder and if there is ischemia and hypoxia, this can be identified via ST Segment Depression (downsloping and horizontal)

Accuracy of ST Segment Depression in Diagnosing Heart Disease

The amount of ST Segment Depression that would be interpreted as a positive test is 2 mm. The 2 mm is not an arbitrary number, but based upon maximizing sensitivity and specificity.

Sensitivity

The percent of individuals with heart disease that test positive for the disease

Specificity

The percent of individuals without heart disease that test negative for the disease

The percent of individuals without heart disease that test negative for the disease

Sensitivity decreases because more patients who have the disease would test negative (FN).

Specificity increases because less patients who do not have the disease would test positive (FP).

Accuracy of ST Segment Depression in Diagnosing Heart Disease

Sensitivity increases because less patients who have the disease would test negative (FN).

Specificity decreases because more patients who do not have the disease would test positive (FP).

Sensitivity & Specificity Problem

Shown in the table below are the numbers of subjects who tested + or – in a diagnostic test. The number of people who truly had the disease was confirmed with further testing.

Confirmation of Heart Disease

A physician can confirm the existence and location of coronary artery disease using a technique called Angiogram