A&P Review Cardiovascular



A&P Review Cardiovascular

• Heart: Weighs less than 1#, about the size of

your fist.

• Systole: Blood ejected from chambers; approximately 70ml of blood per beat

• Diastole: Chambers refill with blood

Heart Anatomy

• Endocardium: Innermost layer

• Myocardium: Middle layer; muscle fibers

• Epicardium: Outermost layer

• Pericardium: Thin fibrous sac encasing the heart and root of great vessels

• Composed 2 layers:

• Visceral pericardium

• Parietal pericardium

• Pericardial space: Filled with 30 ml of fluid, allows free movement

• Four chambers: 2 atria, 2 ventricles

• Right heart:

• right atria, what receives the blood from the superior and inferior vena cave

• right ventricle that sends the blood via the pulmonary arteries

• Left heart: atria receives the oxygenated blood from the pulmonary veins and the ventricles send that oxygenated blood out into circulation

CV Heart Valves

• Atrioventricular valves (AV valves):

• Mitral valve- seperates the left atria from the left ventricle

• tricuspid valve- what seperates the right atria from the right ventricle

• Papillary muscles & chordae tendineae

• Semilunar valves (3 half moon leaflets):

Aortic & pulmonary valves

• Pulmonic valve- between the right ventricle and the pulmonary artery

• Aortic valve- between the left ventricle and the aorta

CV-Coronary Arteries

• Perfused during diastole

• LCA:

• LM: 2 bifurcations

• LAD (left anterior descending) & circumflex- feeds the left atrium and the lateral wall of the left ventricle

• Right coronary artery:

• Smaller branches and they feed both ventricles

Conduction System of Heart***

• Pacemaker cells:

• Automaticity: ability to generate electrical impulse automatically

• Conductivity: ability to pass impulse to the next cells (from one cell to the next)

• Contractility: Ability to shorten the fibers in the heart while receiving the impulse

CV-Conduction

• Sinoatrial (SA) node: Aka the “pacemaker”

• 60-100 beats/min

• Firing sends impulse to right and left atrium

• Results in atrial contraction

• AV node: Slows conduction between atria and ventricles

• 40-60 beats/min

• Bundle of His: Travels thru to Purkinje fibers

• Purkinje fibers: Causes ventricles to contract

• Ventricles: Generate impulse in event of failure of other two nodes

• 20-40 beats/min

Physiology of Cardiac Conduction

• Cardiac action potential: Response of myocardium to electrical impulse

• Depolarization: Contraction/shortening

• Na enters cell, K+ exits cell, Ca+ enters

• Repolarization: Relaxation/lengthening

Refractory Periods

• Absolute refractory period: Regardless of strength of impulse, will not contract

• Relative refractory period: May contract IF

impulse is strong enough

• Protects heart: Keep from sustained contraction

CV-Mechanical Events

• Cardiac cycle:

• Systole: AV valves close, S1

• Contraction, rapid increase pressure

• Semilunar valves open

• Diastole: Semilunar valves close, S2

• Atrial kick: portion of blood squeezed into ventricles

CV-Cardiac Output

• CO: 4-8 liters/minute (the amount of blood pumped out of the heart in 1 min)

• CO: Stroke volume (SV) times the heart rate

• SV: Amount of blood ejected/heart beat

• Can be determined by preload, contractility, and afterload

• Cardiac Index: CO divided by body mass index; adjusts for body size

• Capacity: Approximately 70ml in resting state

CV-Control of Stroke Volume***

• Preload:

• End-diastolic volume

• stretching of muscle fibers in the ventricles

• Starling’s Law of the Heart – the greater the stretch of the heart during diastole the more forcefully the heart will contract during systole (a normal heart)

• Decrease preload:

• Diuresis, vasodilating drugs (pressure is decreased), hemorrhage, loss of pressure or loss of volume in a normal heart, loss of fluid

• Increase preload:

• Fluid gain, vasoconstriction, volume related- replace the fluids they have lost

• Afterload: resistance the left ventricle has to work against to eject the blood

• SVR (systemic vascular resistance) – increase or decrease in afterload

• Increases afterload:

• Vasoconstriction (arterial)

• Decreases afterload:

• Vasodilation (arterial)

Control of Stoke Volume: Contractility

• Increased contractility:

• Causes: increase in SV, SNS (increase in contractility = increase SV)

• meds: digoxin, dopamine, dobutamine

• Decreased contractility:

• hypoxemia, acidosis, certain meds, b-blockers

• Decrease contractility = decrease SV

Ejection Fraction

• Ejection fraction:

• Fraction of total ventricular filling volume and then measured to see how much of that blood is ejected from the heart

• Normal EF: 65%

• Decreased contractility = decreased EF

Control of Heart Rate

• Vagus (parasympathetic):

• Slows the HR, stimulate the vagus nerve = slowing of the HR

• Sympathetic:

• Speeds up HR, accelerates it

• Catecholamines:

• Baroreceptors:

• Pressure sensors, sensitive to changes in BP

• Location: Aortic arch and carotid arteries

• Effect: Sensitive to changes in BP

• Elevated BP:

• Transmit impulses to medulla

• Stimulates PNS

• Resulting in lowers HR and BP

• Low BP:

• Less baroreceptor stimulation

• Increases SNS = vasoconstriction

• Resulting in increased HR and BP

• Chemoreceptors:

• Location: Aortic arch & carotid body

• Effect: Increase in heart rate

• Responsive to:

• Decreased arterial O2 pressure

• Increased arterial CO2 pressure

• pH of the blood

Peripheral Vascular

• Arteries/arterioles

• Capillaries

• Venules

• Veins

• Blood vessels composed 3 layers:

• Tunica intima

• Tunica media

• Tunica externa or adventitia

PV-Review-Blood Flow

• Unidirectional flow:

• >>left heart>>aorta>>arteries>>arterioles>> capillaries>>venules>>veins>>vena cava>>right heart

• Blood flow due to pressure gradients:

• hi to low

• Resistance: vessel radius small = >pressure

• Turbulent blood flow: bruit (listen for this)

Nursing CV Assessment

■ Three important factors:

■ Gender differences

■ Gerontologic differences

■ Ethnic differences

■ Gender differences: Women

■ Smaller heart & arteries

■ Increased risk occlusions

■ Hemodynamics are increased

■ Effects of estrogen

■ Reduces the risk of atherosclerosis

■ Increases co-agulation proteins

■ Decreased fibrinolytic protein, which puts u at a higher risk for thrombosis

■ Overall cardioprotective

■

Women & Symptoms of ACS (acute coronary syndrome)/MI

More atypical S/S:

■ shoulder & upper back pain

■ SOB & extreme fatigue

■ epigastric pain

Prodromal S/S:

■ unusual fatigue

■ sleep disturbances

■ SOB

Acute S/S: most common SOB, weakness & fatigue

■ Brunner page 795 (Nursing Research Profile)

[pic]

■ Gerontologic Considerations:

■ Adequate CO (cardiac output) under normal circumstances

■ Elderly & diabetics S/S of ACS (atypical): fatigue & SOB are predominant S/S

[pic]

Wall thickness (in the chart) ***

■ Gathering Health History:

■ Age, gender, & ethnic origin

■ Changes in weight

■ Client health history & family history

■ Cultural background/religious practice/ diet- nutrition

Cardiac S/S:

■ Chest pain (character, location, radiation, duration, ppt. events, relieving measures)

■ SOB/dyspnea

■ Edema/wt. gain

■ Palpitations

■ Fatigue/dizziness/syncope

■ 1st thing to do when someone c/o chest pain – put O2 on them at 2L/min with or without a dr order***

[pic]

■ Management-Health Perception:

■ Assess risk factors

■ Assess client’s perception of risk factors

■ Assess meds

■ Nonmodifiable risk factors and

■ Modifiable risk factors; (Chart 26-2, pp. 796 Brunner)

■ Nutrition & Metabolism:

■ Diet, exercise, wt. loss

■ Manage increased lipids

■ Pt needs to lower fat, cholesterol, sodium, less simple starches

■ Pt needs to eat a diet high in fiber, more fruits and veggies

■ Elimination:

Assess bowel and bladder habits

Ask: Do your feet or ankles swell?

■ Do you take medication to get rid of excess fluid?

■ Do you weigh daily?

■ Do you take meds for constipation?

■ Any blood in urine or stools?

■ Activity and Exercise:

■ New or change in S/S important

■ Assess for change in activity pattern

■ Fatigue, can be R/T meds

■ Sleep and Rest:

■ Determine number of pillows used

■ Where does patient sleep

■ Presence of nocturia

■ Paroxysmal nocturnal dysmia- do they have air hunger, or a sense of suffocating**

■ S/S: coughing, feel like suffocating, sweating and tachycardia

■ Cognition and Perception:

■ Determine if client has cognitive problems

■ Are there visual or hearing problems?

■ Need to be able to read and understand their meds (ex.)

■ Self-Perception & Self-Concept:

■ Type-A personality

■ Short temper – look up

■ Self-esteem problems

■ Especially younger men

Effects of Stress on the Heart

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■ Role and Relationships:

■ Assess social support system

■ Is there a change in role?

■ Sexuality and Reproduction:

■ Reluctance of patient to discuss

■ Impotence from cardiac meds

■ Coping and Stress Tolerance:

■ Adverse effects of stress & anxiety

■ Link between hostility & CV disease

■ Cardiac Physical Exam

■ Head to toe examination:

■ general appearance, cognition, skin, BP, arterial pulses, jugular venous pulsations, heart, extremities, lungs, abdomen

■ General Appearance & Cognition:

■ Level of distress

■ LOC

■ Thought process

■ Anxiety/emotional stresses

■ Temperature/moisture

■ Clubbing

■ Edema/weight

■ Wounds

■ Arterial circulation

■ Blood Pressure:

■ Systolic blood pressure

■ Diastolic blood pressure

■ Determinants of BP

■ Pulse pressure: difference b/w sys and dia – the difference should be about 1/3 of the sys

■ 189/110=79

■ 77/50=27

■ When the systemic

■ When your arteries become less elastic

■ When you have an increase in SV

Terms r/t Blood Pressure

■ Blood pressure = cardiac output x SVR

■ SVR= systemic vascular resistance

■ BP determined in part by cardiac output, SVR, blood volume, elasticity of arterial wall

■ Pulse Rate and Rhythm

■ Normal pulse

■ Rate 60-100

■ Easily palpated

■ Full and regular

■ Pulse deficit

■ Difference between apical and radial rates

■ Pulse configuration

■ Carotid is best to examine

■ Pulse wave should be smooth with rounded shape

■ Sinus arrhythmia

■ Increase in hr during inhale

■ Slowing during exhale

■ Usually young people

■ Pulse Quality Review:

■ 0: absent pulse

■ 1+: weak, thready, difficult palpate

■ 2+: normal pulse

■ 3+: slightly increased, full pulse

■ 4+: strong bounding, can’t be obliterated

■ Jugular Venous Pulsation

■ Estimate of right heart function

■ Distension when supine

■ Heart Inspection, Palpation, & Auscultation

■ Aortic

■ 2nd intercostal space, right side

■ Pulmonic

■ 2nd intercostal space, left side

■ Tricuspid

■ 4 – 5th intercostal space, left side

■ Mitral

■ 5th intercostal space, mid-clavicle line

■ Epigastric

■ 4 bowel quadrants

CV Heart Sounds

■ S1:

■ Closure tricuspid & mitral valves

■ “lub”

■ heard best at apical or mitral area

■ systole

▪ S2:

▪ Closure pulmonic and aortic valves

▪ “dub”

▪ heard best at aortic area

▪ diastole

■ Gallop Sounds: S3

■ S3 “Ken-tuck-y”

■ S1____S2_S3______S1

■ Gallops

■ So named due to sound like a horse

■ Abnormal sounds, ventricular origin

■ Low frequency – use bell & press lightly on skin

■ Heard best at apex, lying on left side

■ S3

■ Follows S2

■ R/T vibrations caused by abrupt ventricular distention & resistance to filling

■ Common in children

■ Sign of heart failure in adult

■ Gallup Sounds: S4

■ S4 “Ten-nes-see”

■ S4-S1____S2______S4_S1

■ S4

■ Atrial in origin

■ Occurs prior to S1 after atrial contraction

■ Occurs in elderly (most common), HTN, or Hx of MI

■ From vibrations caused by forceful atrial ejection of blood into the ventricles that are resistant to expansion

■ If you see in chart somewhere that they have a gallup, make sure you listen

■ Quadruple rhythm

■ May have both S3 and S4 sounds

Murmurs

■ Turbulent blood flow:

■ increased blood flow-normal area

■ valve problems

■ Related to hyperthyroidism

■ Graded: location, timing, intensity, pitch (low, med, high), quality (harsh or musical – blowing or rumbling, swish), radiation (radiates to other areas), benign (its present but there is not a problem), numerically (if there is an increase in intensity and volume, the number will go up)

Friction Rub

■ Machine-like sound

■ Pericardial friction rub, grating sound, heart through systole and diastole, heard most distinctly at the sternum and apex of the heart, heard best when the pt is sitting up and leaning foward

■ Inflamed pericardial sac

Lungs

■ Hemoptysis

■ Crackles – can indicate inflammation, congestion, heart failure, pneumonia

■ Wheezes – high pitched, musical, indicates bronchospasms or bronchoconstrictions

■ Orthopnea – difficulty breathing in supine position

■ Paroxysmal nocturnal dyspnea

Normal findings of Assessment

[pic]

Diagnostic Evaluation

■ Laboratory: Blood Chemistries

■ Electrolytes:

■ Potassium

■ Hyperkalemia = weaker heart rate

■ Hypokalemia = premature ventricular contractions

■ Calcium

■ Hypercalcemia

■ Magnesium – affects the absorption of ca and maintains K stores

■ Sodium

■ (Use norms previously given)

Cardiac Enzymes & Proteins (released after damage of heart muscle)

■ Creatine kinase (CK) & CK-MB

■ Found in heart and skeletal muscle, brain tissue, most in heart, rises in MI, elevate with an MI

■ Myoglobin

■ Not used as much anymore cause it also rises with skeletal muscle damage, found in hear and skeletal muscles

■ Troponins T & I (cTnT & cTnI): most specific to heart muscle**

■ Normally absent

■ Detectable w/i 1 hour of injury

■ Rise 4-6 hrs

■ Elevated up to from 1 to 3 weeks

■ most accurate and specific to the heart

■ Protein specific to the heart

■ Peaks w/i 14-20hrs

■ C-Reactive protein

■ Produced in the liver

■ Indicates inflammation

■ Poss link between inflammation and heart disease

■ Homocysteine

■ Amino acid

■ High levels irritate the vessels and can lead to atherosclerosis

■ Can raise LDL levels

■ If its higher you are more prone to blood clots

■ Folic acid between 6-12 to treat it

■ BNP: ................
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