Download Dr.Yoused Aljeesh Dr. Motasem Salah The Heartbeat

Chapter 26
Assessment of Cardiovascular Function
Medical Surgical- Part B
By
Dr. Yousef Aljeesh
Associated Professor
Islamic University
Dr. Motasem Salah
PhD Nursing Administration
Palestinian College
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Objectives:
On completion of this chapter, the learner will be able to:
1. Explain cardiac physiology in relation to cardiac anatomy
and the conduction system of the heart.
2. Incorporate assessment of functional health patterns and
cardiac risk factors into the health.
3. Identify the clinical significance and related nursing
implications of the various tests and procedures used for
diagnostic assessment of cardiac function.
4. Compare central venous pressure monitoring, pulmonary
artery pressure monitoring, and systemic intra-arterial
monitoring
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Overview of Anatomy and Physiology of
the Heart
 Three layers of the heart
 Four chambers
 Heart valves
 Coronary arteries
 Cardiac conduction system
 Diagnostic test
 Hemodynamic monitoring
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The Heart
 The heart is a cone-shaped, muscular organ
located between the lungs behind the
sternum.
 The heart muscle forms the myocardium, the
inner lining of the myocardium is called
Endocardium and the outer layer cells is
called the Epicardium.
 The pericardium (visceral) is the outer
membranous sac with lubricating fluid.
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 The heart has four chambers: two upper, thin-
walled atria, and two lower, thick-walled
ventricles.
 The ventricle are, the chambers that eject
blood in to arteries. The functions of the
atrium are to receive the incoming blood from
the vein.
 The septum is a wall dividing the right and left
sides.
 Coronary arteries: the vessels that supply blood
to theDr.Yoused
heartAljeesh
muscle.
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Structure of the Heart
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Cardiac Valves:
Cardiac valves permit blood to flow in only one directions
through
I. Atrioventricular Valves:
1] Tricuspid valve: separates the Rt atrium from the
Rt ventricle
2] Bicuspid valve [Mitral valve]: lies Lt atrium and
Lt ventricle.
II. Semilunar valves:
1] Pulmonic valve: the valve between the Rt ventricle
and the pulmonary artery.
2] Aortic valve: the valve between the Lt ventricle and
the aorta.
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Internal view of the heart
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The Heartbeat
 Each heartbeat is called a cardiac cycle.
 When the heart beats occur, the two atria
contract together, then the two ventricles
contract; then the whole heart relaxes.
 Systole is the contraction of heart chambers;
diastole is their relaxation.
 The heart sounds, lub-dup, are due to the
closing of the atrioventricular valves, followed
by the closing of the semilunar valves.
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Conducting system of the heart
Intrinsic Control of Heartbeat
 The SA (sinoatrial) node, or pacemaker, initiates the
heartbeat approximately 60-100 impulses/min.
 The AV (atrioventricular) node conveys the stimulus
and initiates contraction of the ventricles, located
right Atrial wall, similar to S.A node but with impulses
about 40-60/ min..
 The signal for the ventricles to contract travels from
the AV node through the atrioventricular bundle to the
smaller Purkinje fibers.
 Purkinje fiber: heart muscle fibers that help carry the
electrical signals that control heart contraction.
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Conduction system of the heart
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Cardiac Conduction System
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Extrinsic Control of Heartbeat
 A cardiac control center in the medulla
oblongata speeds up or slows down the
heart rate by way of the autonomic
nervous
system
branches:
parasympathetic system (slows heart
rate) and the sympathetic system
(increases heart rate).
 Hormones
epinephrine
and
norepinephrine from the adrenal medulla
also stimulate faster heart rate.
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The Pulmonary Circuit
 The pulmonary circuit begins with the
pulmonary trunk from the right ventricle
which branches into two pulmonary
arteries that take oxygen-poor blood to
the lungs.
 In the lungs, oxygen diffuses into the
blood, and carbon dioxide diffuses out of
the blood to be expelled by the lungs.
 Four pulmonary veins return oxygen-rich
blood
to
the
left
atrium.
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The Systemic Circuit
 The systemic circuit starts with the aorta carrying
O2-rich blood from the left ventricle.
 The aorta branches with an artery going to each
specific organ.
 The vein that takes blood to the vena cava often
has the same name as the artery that delivered
blood to the organ.
Note:
 Stroke volume: the amount of blood ejected per
heart beat. (Cardiac output) CO = SV X HR
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Passage of Blood
Through the Heart
 Blood follows this sequence
through the heart: superior
and inferior vena cava →
right atrium → tricuspid
valve → right ventricle →
pulmonary semilunar valve
→ pulmonary trunk and
arteries to the lungs →
pulmonary veins leaving the
lungs → left atrium →
bicuspid
valve
→
left
ventricle → aortic semilunar
valve → aorta
→ to the body.
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External heart anatomy
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Diagnostic Test
1] Cardiac enzyme:
 CK & CK-MB: (Creatinine
kinase 50-350) CK
and in its isoenzyme CKMB are most specific enzymes analyzed in acute MI, and they
are the first enzyme levels to increase (enzymes are released
from injured cell when the cell membrane rupture).
Note: CK-MM (skeletal muscle), CK-BB (brain tissue), CK-MB
(heart muscle).
 LDH: lactic dehydrogenase (analyzed only in select patients
who have delayed seeking medical attention, because the blood
levels of these substances peak in 2 to 3 days). 100-135
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Diagnostic Test
 SGOT: Serum glutamic oxalocetic transminase ,
found in heart, liver & muscle (0-40).
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2] Lipid profile: Total cholesterol, Triglycerides and
lipoproteins to evaluate atherosclerotic disease.
3] Serum electrolyte:
 Na : ↓ Na : hyponatremia.
↑ Na : hypernatremia.
 Ca: ↑ Ca : causes ECG changes or dysrhythmias
 K: ↓ K cause cardiac irritability.
 Glucose: many cardiac patients also have serum glucose
level will ↑ with stress.
4] Chest x-ray:
Usually used to determine size and position of the heart.
E.g CHF, placement of cardiac catheters.
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5] Angiography:
x-ray examination of blood vessels.
6] Echocardiography:
Non invasive procedure ultrasound test used to
examine the size + shape, useful in diagnosis of the
heart murmur (turbulent flow of blood + the cause
is narrowed valve, which allow regurgitation blood
flow, can be heard at the apex or chest).
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7. Cardiac Catheterization
 Invasive procedure used to measure cardiac
chamber pressures and assess patency of the
coronary arteries
 Requires ECG and hemodynamic monitoring;
emergency equipment must be available
 Assessment prior to test; allergies, blood work
 Assessment of patient after procedure: circulation,
potential for bleeding, potential for dysrhythmias
 Activity restrictions
 Patient education before &
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after procedure
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 Rt heart catheterization:
Involve passing a catheter from femoral vein- Rt atrium → Rt .ventricular
→ tricuspid valve.
 Lt heart catheterization:
The same but passing a catheter through femoral artery.
Cardiac catheterization
Pre – operative :
1- fasting 8-12 hrs.
Post – operative :
1- observe puncture sites, hematoma, peripheral pulses, every 15 minutes for
1 hr. then every 1-2 hrs until stable.
2- color of exterimities, pain, numbness.
3- observe cardiac monitor for dysrhythmias
4- nausea + vomiting , ↓ Bp.
5- supine position 2 head 30 degrees with leg straight.
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6- analgesic medication, and report any chest pain.
Hemodynamic Monitoring
 CVP
 Intra-arterial BP monitoring
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Arterial Pressure Monitoring System
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