Care Lecture 1: Perfusion I - Valve Disorders, Rheumatic Heart Disease, ECGs, & Dysrhythmias

perfusion

the flow of blood through arteries and capillaries delivering nutrients and oxygen to cells and removing wastes

sufficient cardiac output (CO) to transport blood

what does proper perfusion require?

shock

the inability of central perfusion to supply blood to peripheral tissues

blood flow to, from, and within the heart

valve disorders interfere with what functions of the heart?

1. stenosis

2. regurgitation

3. prolapse

what are the 3 types of valve disorders?

enters heart through vena cava

↓

right atrium

↓

tricuspid valve

↓

right ventricle

↓

pulmonary artery

↓

lungs

↓

pulmonary vein

↓

left atrium

↓

mitral valve

↓

left ventricle

↓

aortic valve

↓

aorta

↓

cells

what is the pathway of blood through the heart?

bring blood back to heart to get oxygenated

what do veins do?

-right and left atria contract together

-right and left ventricles contract together

which of the four chambers contract together?

systole

contraction of a heart chamber

diastole

relaxation of a heart chamber

sinoatrial (SA) node

region of the heart that serves to set the normal sinus rhythm, or pace of contraction

-veins = 2 mmHg

-arteries = 100 mmHg

what is the average pressure of veins? of the arteries?

-pulmonary veins

-left atrium

-mitral valve

-left ventricle

-aortic valve

-aorta

which parts of the heart carry oxygenated blood?

-superior/inferior vena cava

-right atrium

-tricuspid valve

-right ventricle

-pulmonary valve

-pulmonary arteries

which parts of the heart carry unoxygenated blood?

70-100

what is a normal MAP (mean arterial pressure) value?

-diuretics (ex: Furosemide, Spironolactone

-calcium channel blocker (ex: Nifedipine, Verapamil, etc.)

-ACE/ARB inhibitor (ex: Enalapril - ACE; Losartan - ARB)

-beta blockers (ex: Metoprolol)

what are some common meds for HTN?

-IV fluid bolus

-vasopressors

-catecholamines (EPI, norepinephrine)

what are some common meds for hypotension?

-APTT: 30-40

-prothrombin time (PT): 10-12 seconds

-INR: 0.9-1.2

what are the normal values for APTT, prothrombin time, and INR?

-platelets: 150,000-450,000

-RBCs: 4.5-5.5

-WBCs: 4,500-11,000

what are the normal values for platelets, RBCs, and WBCs?

-female: 11-16

-male: 13-18

what are the normal values for hemoglobin?

-female: 36-48%

-male: 39-54%

what are the normal values for hematocrit?

murmur

the sound of turbulent blood flow through a cardiac structure

1. mitral

2. tricuspid

3. aortic

4. pulmonic

what are the 4 valves in the heart?

normal murmur (AKA functional or innocent)

type of heart murmur that is characterized by an increase in blood flow through a normal valve

abnormal murmur (AKA pathologic)

type of heart murmur that is caused by a dysfunctional valve that leads to turbulent blood flow and a murmur

1. stenosis (stenotic valves)

2. regurgitation

in abnormal murmurs, the valve can be dysfunctional in what two different ways?

-stenosis = valve OPENING problem

-regurgitation = valve CLOSING problem

in simple terms, what is the main problem with valves regarding stenosis and regurgitation?

associated with connective tissue disorders

valve degeneration is often associated with what other issue in the body?

left side is more commonly affected

**left side of the heart is the workforce that pumps blood out to rest of the body at high pressures --> blood gets SMACKED up against the valves on the left side and tires them out

which side of the heart is usually affected by valvular heart conditions?

annulus

fibrous ring that supports the heart valves

papillary muscles

serve as ventricular attachments to heart valves via the chordae tendinae

"lub" --> tricuspid and mitral valves closing

what does the S1 heart sound represent?

"dub" --> aortic and pulmonic valves closing

what does the S2 heart sound represent?

cardiac output

heart rate x stroke volume; the amount of blood being pumped in 1 minute

rheumatic heart disease

a chronic scarring and deformity of the heart valves resulting from rheumatic fever; can lead to damage in the valves (calcification, vegetative growths, etc.)

60-100 bpm

what characterizes normal sinus rhythm?

< 60 bpm

what characterizes normal sinus bradycardia?

> 100 bpm

what characterizes normal sinus tachycardia?

normal sinus rhythm = no action

what are nursing interventions for a normal sinus rhythm?

-no s/s of low oxygen = no action

-cut out meds that slow down heart (ex: beta blockers, CCBs, digoxin)

-give atropine to ↑ HR

what are nursing interventions for normal sinus bradycardia?

1. P-wave

2. QRS-wave

3. T-wave

what are the components of an EKG?

-activation of atria (atrial contraction)

-sending a charge out

what happens during the P-wave?

-activation of ventricles (ventricular contraction)

-sending a charge out

what happens during the QRS-wave?

-recovery wave/repolarization of ventricles

-refilling with blood (ventricles relax)

what happens during the T-wave?

no electrical conduction is happening at all

what happens during asystole?

1. volume (blood)

2. pump system

3. blood vessels/tubes

what are the 3 things we need in order to perfuse the tissues of the body?

mitral and tricuspid

what are the 2 atrioventricular heart valves?

aortic and pulmonic

what are the 2 semilunar heart valves?

constriction or narrowing of blood vessels --> creates pressure differences

what is valvular heart stenosis characterized by?

blood backs into pulmonary artery & lungs (perfusion AND gas exchange issue)

why is it bad that blood pools in the atrium during stenotic valve disease?

incomplete closure of valve --> results in backward flow of blood

what is valvular heart regurgitation characterized by?

behind the damaged vessel

in both regurgitation and stenotic valve diseases, where can we expect blood pressure to be the highest when observed during hemodynamic monitoring?

-narrowed, hardened valves

-restricts blood flow into next chamber

-blood volume & BP ↑ behind stenotic valve

-blood not getting through valve = inadequate tissue perfusion

what happens to the heart and blood flow during valvular heart stenosis?

-valve does not close completely

-backward flow of blood

-blood volume & BP ↑ BEHIND regurgitant valve

what happens to the heart and blood flow during valvular heart regurgitation?

-leaflets bulge back into left atrium during systole

-leakage of small amount of blood back into left atrium

what happens to the heart and blood flow during valvular heart prolapse?

most patients are asymptomatic unless something aggravates it

what is true about valvular heart prolapse symptoms?

clicking sound

what can you expect to hear upon auscultation regarding prolapse valve disease?

rheumatic heart disease is most common cause

what is the most common cause of mitral valve stenosis?

mitral valve stenosis

valvular disorder characterized by narrowing of the mitral valve opening; usually caused by scarring from rheumatic fever

block blood flow

↓

create pressure difference between left atrium and LV during diastole

↓

left atrial pressure/volume ↑

how does mitral valve stenosis affect blood flow?

exertional dyspnea caused by ↓ lung compliance

what is the main symptom of mitral stenosis?

mitral valve regurgitation

valvular disorder characterized by a backflow of blood caused by failure of the heart's mitral valve to close tightly

incomplete valve closure during systole

↓

blood flows backward from LV to left atrium

↓

LV & left atrium must work harder to preserve adequate CO

how does mitral valve regurgitation affect blood flow?

-thready peripheral pulses

-cool extremities

-audible S3 heart sound (murmur)

what are the clinical manifestations of mitral valve regurgitation?

mitral valve prolapse

valvular disorder that occurs when the heart contracts and part of one or both valves collapse backward into the left atrium

-clicking murmur

-most are asymptomatic their entire lives

what are the clinical manifestations of mitral valve prolapse?

aortic valve stenosis

valvular disorder that is characterized by a narrowing of the aortic valve opening that causes obstruction of blood flow from the left ventricle to the aorta during systole

-angina

-syncope

-exertional dyspnea

what are the clinical manifestations of aortic valve stenosis?

aortic regurgitation

valvular disorder that is characterized by backward blood flow from the ascending aorta into the left ventricle during diastole, resulting in volume overload

pulmonary HTN & right ventricular failure

what often results from aortic regurgitation?

-severe dyspnea

-chest pain

-hypotension

what are the clinical manifestations of aortic regurgitation?

patients who have endocarditis

tricuspid valve disorder is almost exclusive to patients who have what disease process?

almost always congenital

pulmonic stenosis is almost always what?

-congenital

-degenerative disease (ex: cardiomyopathies, aneurysms, etc.)

-rheumatic disease

-infective endocarditis

what are some potential causes of valvular heart disease?

-treat causes of ↑ HR (fever, stress, anxiety, pain, etc.)

-vagal maneuver

-carotid massage

-beta blockers

-CCBs (ex: diltiazem, nifedipine)

what are nursing interventions for normal sinus tachycardia?

infection with group A streptococci

↓

inflammatory autoimmune response

↓

microscopic lesions develop

↓

age into scar tissue

↓

damage to heart valves

describe the pathophysiology of rheumatic heart disease

rheumatic fever

an inflammatory disease of the heart, joints, and CNS caused by Group A Beta Strep

strep throat

what is a common early sign of rheumatic heart disease?

infective endocarditis (IE)

a disease of the endocardial (innermost) layer of the heart; occurs when blood borne bacteria lodges in the endocardial layer causing infection and inflammation

-vegetative growths form on valve surface

-narrowed valves ↓ movement of blood

what often results from infective endocarditis?

almost always surgical txt

what is usually the treatment for infective endocarditis?

-depolarization = contracting

-repolarization = rest

regarding an ECG, what does depolarization and repolarization mean?

telemetry

form of continuous cardiac monitoring that involves sending electronic signals from one place to another

-monitor rhythm

-educate patient on monitoring

-clip excessive hair on chest wall

-change ECG patches each day with baths

-ALWAYS ASSESS THE PATIENT!!

what is involved in the care of a patient with telemetry monitoring?

EKG/ECG

a graphic tracing of the electrical impulses produced in the heart

electrical activity produced by movement of ions across membranes of the heart

what do waveforms represent on an EKG?

0.06-0.12 seconds

what is the normal duration of the P-wave?

P-R interval

the interval from the beginning of the P wave to the beginning of the QRS complex

time from initiation of atrial contraction to initiation of ventricular contraction

what does the P-R interval represent?

0.12-0.20 seconds

what is the normal duration of the P-R interval?

less than 0.12 seconds

what is the normal duration of the QRS complex?

big QRS waves = ventricle is affected

what do big QRS waves represent on an EKG?

measures beginning of QRS complex to end of T wave

what does the QT interval measure?

time taken for entire electrical depolarization & repolarization of ventricles

what does the QT interval represent?

0.34-0.43

what is the normal duration of the QT interval?

usually 6 seconds (half a strip is 3 seconds)

how much time is represented on an EKG strip usually?

-small box = 0.04 seconds

-large box = 0.20 seconds

what are the measurements of the small boxes and large boxes on an EKG strip?

1. determine if rate is regular or irregular

2. calculate the rate (tachy, brady, or normal)

3. is there a "p" wave for each complex?

4. what is the PR interval --> 0.12-0.20 seconds = 3-5 small boxes

5. determine QRS complex --> < 0.12 seconds = 1.5 - 3 small boxes

what are the 5 steps to interpreting an EKG strip?

1. count # of R waves in 6 second interval

2. take # of R waves and multiply by 10

what is the easiest way to calculate HR on an EKG?

precedes each QRS complex

what is the location of a P-wave?