Medsurg Cardio Ana&Physio

8/8/2019 Medsurg Cardio Ana&Physio

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Right Side

- to pulmonary System thruPulmonary Artery

Left Side

- to Systemic Circulation thruAorta

Tricuspid Valves = connects the

RA to the RV; 3 cusps Bicuspid/Mitral Valves =

connects the LA to the LV;

2 cusps

Semilunar Valve = Pulmonary

Artery carries deO2 blood from

RV to Lungs for oxygenation

Pulmonary Vein carries O2

blood from Lungs to LA

Superior & Inferior Vena Cava =

carries deO2 blood from the bodyto the RA

Semilunar Valve = Aorta

carries O2 blood from LV tosystemic circulation

In between your parietal and

visceral pericardium is a

serous fluid-filled pericardial

cavity which allows the heartto beat easily without friction.

LUB

(S1 - 1ST heart s

ound)

DUB

(S2- 2ND heart sound)

1. Closure of the AV

valves (atrioventricular

Tricuspid side

Mitral side

2. Closure of the

semilunar valves

(pulmonic and

aortic valves)

Arteries = carries O2blood

Veins = caries deO2 blood

Except for:

Pulmonary Artery

= carries deO2blood

Pulmonary Veins= carries O2blood

Pericarditis inflammation of

the pericardium results in a

decrease in the amount ofserous fluid which causes the

pericardial layers to rub

formin ainful adhesions.

CARDIOVASCULAR SYSTEM

THE HEART (The Pump)

HEART:

Location: Thorax,

mediastinum

Thus: Heart surgery alsocalled thoracic surgery

The Apex is pointed towards

yourleft hip and rests on thediaphragm, approximately at the level

of the fifth intercostal space. (This is

exactly where one would place astethoscope to count the heart rate for

an apical pulse)

The size of your heart is as big as yourfist

Coverings/layers:

Pericardium (covers the heart)

1. Parietal outer part, hard and fibrous2. Visceral inner part or heart wall, consist of:

a) epicardiumprotective layer, serous membrane

with connective tissue covered by epithelium

b) Myocardium - thickcardiac muscle which contractsc) Endocardium is a thin, glistening sheet of endothelium

that lines the 4 chambers; it contains elastic and

collagenous fibers as well as Purkinje fibers whichare specialized muscle fibers that conduct cardiac

impulses

Chambers:

2 Atria = Receiving blood

2 Ventricles = Discharging

blood

Septum = Wall Divisions

The heart valves open and close passively because of pressure

differences on either side of the valve. When pressure is greater behindthe valve, the leaflets are blown open and the blood flows through the

valve. However, when pressure is greater in front of the valve, the

leaflets snap shut and blood flow is stopped. The motion of a heart valve

is analogous to the motion of the front door of your house. The door,which only opens in one direction, opens and closes due to pressure on

the door.

Apex


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Although a tremendous amount of blood flows

through the chambers of the heart, this blood does

not nourish the heart. The heart is nourished byblood from the coronary circulation, a system of

arteries, capillaries and veins that brings blood to all

of the tissues of the heart. The graphic aboveidentifies arteries (red) supplying oxygenated blood

to the heart tissue, and veins (blue) removing

deoxygenated blood. Coronary artery disease is

associated with reduced blood flow to these vessels.

Normal heart sounds are caused by the closing of

heart valves. As valves snap shut, the walls of the

chambers and major arteries vibrate. We hear thesevibrations as two distinct sounds; LUB-DUB.

Left coronary artery:

anterior interventricular

artery - supplies blood to theinterventricular septum andanterior walls of both

ventricles

circumflex artery -

supplies blood to the leftatrium and the posterior

In valvular stenosis the valve flaps becomeincompetent, they become stiff, often because ofendocarditis (bacterial infection of the

endocardium). This forces the heart to contract more

vigorously than normal. The hearts workloadincreases, and ultimately the heart weakens and may

fail. Under such conditions the faulty valve is

replaced with a synthetic valve or a valve taken froma pig heart.

Are responsible for the unidirectional flow of blood (one direction)

Also responsible for yourheart sounds

BLOOD SUPPLY of the heart is via(coronary circulation):

1. First 2 branches of the aorta,

2. left and right coronary arteries

These arteries arise

from the base of the aorta

and encircle the heart inthe atrioventricular

groove.

From thearteries it

will

goto yourcapillary

networks

capilla

ry veins

coronary sinusdrains to atrium of the

heart.

Right coronary artery:

Posterior interventricular

artery - runs to the apex andsupplies blood to the posterior

ventricular walls

Marginal artery - suppliesblood to the myocardium of

the right side of the heart

Veins: Small, middle, and great cardiac veins

leading to coronary sinus

The myocardium needs a constant supply of

oxygen in order for the heart to continually

pump. Myocardium capillaries are branchesof cardiac veins which join to form the

coronary sinus, an enlarged vein which

empties into the right atrium.

* If any part of the heart muscle is

deprived of its blood supply

through interruption of bloodflow through the coronary

arteries and their branches, the

muscle tissue deprived of bloodcannot function and will die.

This is called myocardial

infarction (MI).


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NERVE SUPPLY of the heart: Medulla (cardiac center)

Vagus nerve help regulate heart activity; it lowers heart rate (parasympathetic)

o In contrast Sympathetic Nerve will increase HR and cardiac output

Conduction System: to electrical impulses it will create a contraction.SA Node

PHYSIOLOGY OF THE HEART

CARDIAC OUTPUT

The volume of blood ejected by each ventricle in one minute

CO = Stroke Volume (SV) X Heart Rate (HR)

Stroke Volume the amount of blood ejected by the left ventricle with each heartbeat

Preload the end diastolic filling volume of the ventricle, increases by increased returning volume to

the ventricle

Afterload the resistance to left ventricle ejection; increases by increased systemic arterial pressure

Heart Rate the number of heartbeats per minute; normal heart rate is 60 to 100 bpm

CARDIAC CYCLE

Each complete heartbeat consists of two phases; N = 0.8 Seconds

Systole the contraction phase; it is triggered by depolarization of cardiac muscle cells

Diastole the relaxation phase; immediately after depolarization is completed, the process reverses

itself, resulting in repolarization & a return to the resting state

LAB/DIAG TEST:

1. BLOOD CHEMISTRY

Cardiac Isoenzymes

Troponin T and I

These are contractile proteins of the myofibril

The cardiac isoforms are very specific for cardiac injury and are not present in serum from healthy

people

Current guidelines from the American College of Cardiology Committee state that cardiac troponins

are the preferred markers for detecting myocardial cell injury

Troponin I (cTnI) or T (cTnT) are the forms frequently assessed.

Rises 2 - 6 hours after injury

Peaks in 12 - 16 hours

cTnI stays elevated for 5-10 days, cTnT for 5-14 days

Creatine

Kinase (creatine phosphokinase)

This enzyme is found in heart muscle (CK-MB),

skeletal muscle (CK-MM), and brain (CK-BB).

Creatine kinase is increased in over 90% of

myocardial infarctions

However, it can be increased in muscle trauma,

physical exertion, postoperatively, convulsions,

delirium tremens and other conditions.

Time sequence after myocardial infarctionbegins to rise 4-6 hours

peaks 24 hours

returns to normal in 3-4 days

Myoglobin

Found in striated muscle

Damage to skeletal or cardiac muscle releases myoglobin into circulation


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Have false positives with skeletal muscle injury and renal failure.

Time sequence after myocardial infarction

Rises fast (2 hours) after myocardial infarction

Peaks at 6 - 8 hours

Returns to normal in 20 - 36 hours

Lactic Dehydrogenase

This enzyme is no longer used to diagnose myocardial infarction

Elevates after 24-48 hours

2. LIPID PROFILE:

A group of tests that are often ordered together to determine risk ofcoronary heart disease

They are tests that have been shown to be good indicators of whether someone is likely to have a heart attack

orstroke caused by blockage of blood vessels or hardening of the arteries (atherosclerois)

The lipid profile typically includes:

3. HEMATOLOGIC STUDIES

CBC

Coagulation Time

Prothrombin Time (PT) Partial Thromboplastin Time (PTT)

ESR

4. ELECTRO CARDIOGRAM (ECG) gives a graphic picture of your heart

5. STRESS TEST:

Could be exercise (treadmill or bicycle), or chemical

(Persantine, dobutamine)

Stress testing provides the doctor with information about

how the heart works during physical stress

During a stress test, you exercise (walk or run on atreadmill or pedal a bicycle) or are given a medicine to

make your heart work harder while heart tests are

performed

During these tests, your heart is monitored using images or

through dime-sized electrodes attached to your chest,

arms, or legs. You may be asked to breathe into a

special tube during the test. This will allow your doctor tosee how well youre breathing.

6. ECHOCARDIOGRAM:

Non-invasive recording of the cardiac structures using an ultrasound

Total Cholesterol Less than 200 mg/dL desirable

High density lipoprotein (HDL)- good cholesterol 30 - 75 mg/dL

Low density lipoprotein (LDL)

- bad cholesterolLess than 130 mg/dL desirable

Triglycerides (Male) Greater than 40 - 170 mg/dL

Triglycerides (Female) Greater than 35 - 135 mg/dL
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7. PHONOCARDIOGRAM noninvasive device to amplify & record heart sounds and murmurs

8. CARDIAC CATHETERIZATION

Invasive but most definitive test for diagnosis ofcardiac disease

Purpose:

oTo measure intracardic pressures & oxygen

levels in various parts of the heart

oWith injection of a dye, allows visualization ofthe heart chambers, blood vessels & course ofblood flow (angiography)

Procedure:

Right-Sided Catheterization

The catheter is inserted into an antecubital

vein & advanced into the vena cava, right

atrium, & right ventricle with furtherinsertion into the pulmonary artery

Left-Sided Catheterization

The catheter is inserted into a brachial orfemoral artery; the catheter is passed

retrograde up the aorta & into the left

ventricle

Pretest Nsg. Care:

Confirm that informed consent has been signed

Ask about allergies particularly to iodine if dyeis being used

Keep client NPO for 8-12 hours prior to test

Take baseline VS & monitor peripheral pulses

Inform client that a feeling of warmth &

fluttering sensation as catheter is passed is common Posttest Nsg. Care:

Assess circulation to the extremity used for catheter insertion

Post-procedure Position: Maintain the patient in a supine position for a

minimum of 4 hours this prevents hip flexion thereby limiting injury & promoting healing of the

catheter insertion site; HOB should be elevated but it should not exceed 20degrees

Check peripheral pulses, color, sensation of affected extremity every 15 minutes for 4 hours

If protocol requires, keep affected extremity straight for approximately 8 hours

Observe catheter insertion for swelling & bleeding; a sandbag or pressure dressing may be placed over

insertion site

Assess VS & report significant changes from baseline

9. AORTOGRAPHY

Injection of a radiopaque contrast medium into the aorta to visualize the aorta, valve

leaflets & major vessels on a movie film

Purpose: To determine & diagnose aortic valve incompetence, aneurysms

of the ascending aorta, abnormalities of major branches of the aorta

PreTest & PostTest Nsg Care similar to Cardiac Catheterization


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10. CORONARY ARTERIOGRAPHY

Visualization of coronary arteries by injection of radiopaque contrast dye &

recording on a movie film

Purpose: To evaluate heart disease & angina, location of areas of infarction &

extent of lesions, ruling out coronary artery disease in clients with myocardialdisease

Nursing Care similar to Cardiac Catheterization

11. CENTRAL VENOUS PRESSURE (CVP)

Obtained by inserting a catheter into the external jugular,antecubital or femoral vein & threading it into the vena cava

The catheter is attached to an IV infusion & water manometer by a

three way stopcock

Purposes:

Reveals right atrial pressure, reflecting alterations in the right

ventricular pressure

Provides information concerning blood volume & adequacy of

central venous return Provides IV route for drawing blood samples, administering

fluids or medication, & possibly inserting a pacing catheter

Normal Range: 4-10 cm H20; elevation indicates hypervolemia &

decreased level indicates hypovolemia

Nursing Care:

Ensure client is relaxed

Maintain zero point of manometer always at the level of right

atrium (midaxillary line)

Determine patency of catheter by opening IV line

Turn stopcock to allow IV solution to run into manometer to a level of 10-20 cm above expected pressure

reading Turn stopcock to allow IV solution to flow from manometer into catheter; fluid level in manometer

fluctuates with respiration; where water flow stops that is the CVP reading

Stop ventilatory assistance during measurement of CVP

After VP reading, return stopcock to IV infusion position (KVO rate)

Medsurg Cardio Ana&Physio

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