ANATOMY OF THE HEART
Hallow , muscular organ about the size of a closed fist.
Located between the lungs in the mediastinum , behind and to the left of the sternum.
Heart span is from the second to fifth intercostal space.
ANATOMY OF THE HEART
Thin sac with an inner or visceral layer that forms the epicardium and an outer or parietal layer that protects the heart
It contains 10 to 20ml serous fluid, which lubicates the surface and prevents friction between the layers as the heart pumps.
LAYERS OF THE HEART
Endocardium: The thin membrane that lines the inside of the heart
Myocardium: The thickest layer of the heart, made of muscular tissue that contracts and relaxes to pump blood throughout the body
Epicardium: The protective outer layer of the heart
VESSELS OF THE HEART
Inferior vena cava
Superior vena cava,
Pulmonary arteries,
Pulmonary veins,
The aorta CARDIAC CIRCULATION
Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium.
As the atrium contracts, blood flows from your right atrium into your right ventricle through the open tricuspid valve.
When the ventricle is full, the tricuspid valve shuts. This prevents blood from flowing backward into the atria while the ventricle contracts.
As the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery, and to the lungs where it is oxygenated.
CARDIAC CIRCULATION
The now-oxygen-rich blood travels through your pulmonary vein and into your left atrium.
As the atrium contracts, blood flows from your left atrium into your left ventricle through the open mitral valve.
When the ventricle is full, the mitral valve shuts. This prevents blood from flowing backward into the atrium while the ventricle contracts.
As the ventricle contracts, blood leaves the heart through the aortic valve, into the aorta, and to the body.
This cycle is repeated with every heartbeat. The sound of your heartbeat is the sound of different heart valves closing.
PHYSIOLOGY OF THE HEART
Contractions of the heart occurs in a rhythm , called the cardiac cycle and are regulated by impulses that normally begin at the sinoatrial (SA) node. CARDIAC CONDUCTION
Conduction system begins with the heart ‘s pacemaker, the SA node.
Impulses leaves the SA node , travels through the atria along Bachmann ‘s bundle and the internodal pathways on its way to the atrioventricular (AV) node and the ventricles .
After the impulses passes through the AV node , it travels to the ventricles first down the bundle of His , then along the bundle branches and finally down the purkinje fibers CARDIAC CYCLE
ARTERIAL SYSTOLE
The atria contract, emptying blood into the ventricles as pressure within the ventricles rises, the mitral and tricuspid valves snap shut, producing the first heart sound.
VENTRICULAR SYSTOLE
After atrial systole ventricles contract , ejecting blood from the heart to the lungs and the rest the body.
DIASTOLE
Atria and ventricles relax and blood refills each chamber.
ASSESSMENT
As with assessment of other body systems , we will
Inspect
Palpate
Percuss
auscultate ASSESSING THE NECK VESSELS
INSPECTION
Carotid artery appear to have a brisk, localized pulsation
The internal jugular vein has a softer, undulating pulsation
The vein normally protrudes when the patient is lying down and lies flat when he stand.
Inspecting the neck vessels can provide information about blood volume and pressure in the right side of the heart
ASSESSING GENERAL APPEARANCE
First assess the pt’s general appearance.
Is he overly thin?
Obese?
Alert and anxious?
Note skin color , temperature, turgor and texture
Are his fingers clubbed
Clubbing is a sign of chronic hypoxia caused by lengthy cardiovascular or respiratory diseases
ASSESSING THE NECK VESSELS
INSPECTION
Carotid artery should appear to have brisk , localized pulsation
Internal jugular vein has a softer undulating pulsation.
AUSCULTATION
If you detect a blowing , swishing sound this is a bruit that result from turbulent blood flow.
bruit can occur in patients with arteriosclerotic plaque formation
Normally you should hear no vascular sounds over the carotid arteries upon auscultation using the bell of the stethoscope.
Lightly place your fingers medial to the trachea and below the angle of jaw, the pulse should be regular in rhythm and equal strength in the right and left carotid arteries.
don’t palpate both carotid arteries at the same time or press to firmly , pt may faint or become bradycardic
ASSESSING THE HEART
INSPECTION
Look for pulsation , symmetry of movement, retractions or heaves( strong outward thrusts of the chest wall that occur during systole)
Note the location of the apical impulse , should be located in the fifth intercostal space at or just medial to the midclavicular linee
PALPATION
Palpate over the precordium, note heaves or thrills, fine vibrations that feel like the purring of a cat.
AUSCULTATION
Use a zigzag pattern over the pericardium to listen the entire precordium not just the valves
Note the heart rate and rhythm.
Identify the first and second heart sound(s1 &s2)
then listen adventitious sound such as third and fourth heart sound(s3&s4)
Murmurs & pericardial friction rubs( scratchy, rubbing sounds)
Percuss at the anterior axillary line and continue towards the sternum along the fifth intercostal space.
The sound changes from resonance to dullness over the left border of the heart
ASSESSING THE VASULAR SYSYTEM
INSPECTION
Start by making general observations, arms are equal in size, legs are symmetrical.
Note the skin color
Body hair distribution, lesions scars, clubbing and edema of the extremities.
Examine the finger nails and toenails for abnormalities.
Check the sacrum if pt is bed ridden
PALPATION
Assess the capillary refill in the nail beds on the fingers and toes.
Refill time should be not more than 3 seconds.
Palpate the pt’s arms and legs for temperature and edema.
Palpate for arterial pulses by gentle pressing with the pads of your index and middle fingers, start at the top of the body at the temporal artery and work your way down, palpate on each side , comparing pulse volume symmetry and should be regular in rhythm and equal in strength
AUSCULTATION
Using the bell of the stethoscope ,follow the palpation sequence and auscultate over each artery.
Assess the upper abdomen for abnormal pulsation, which could indicate the presence of an abdominal aortic aneurysm,
Auscultate for the femoral and popliteal pulses, checking for a bruit or other abnormal sound.
GRADING PULSES
Pulses are graded on a four point scale
4+ = bounding
3+ = increased
2+ = normal
1+ = weak
0 = absent
ABNORMAL FINDINGS
SKIN AND HAIR ABNORMALITIES
Warm skin may indicate fever or increased cardiac output.
Absence of body hair on the arms or legs may indicate diminished arterial blood flow
Cyanosis , pallor or cool skin may indicate poor cardiac output and tissue perfusion.
EDEMA
Swelling or edema may indicate heart failure or venus insufficiency.
Right sided heart failure may cause swelling in lower legs.
Edema may also result from varicosities or thrombophlebitis.
Edema may b pitting or nonpitting.
Pitting edema , causing indentation that slowly fills, depth in cm 1+ 2+ 3+ 4+
Nonpitting edema , no dentation skin feels unusually tight and firm
ABNORMAL PULSATIONS
A weak arterial pulse may indicate decreased cardiac output or increased peripheral vascular resistance, both point to arterial atherosclerotic disease. Strong or bounding pulsation usually occur in a patient with a condition that causes increased cardiac output , such as hypertension hypoxia anemia , exercise or anxiety.
A thrill usually suggests a valvular dysfuction
THIRD HEART SOUND.
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