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Cardiac NSG
Cardiac notes
49
Nursing
Undergraduate 2
03/25/2011

Additional Nursing Flashcards

 


 

Cards

Term

 

 

 

Blood flow through the heart

Right side(lungs)

Definition

Right Side: receives blood body--pumps blood to lungs

*Blood from body through IFV & SVC, to Right atrium...

*Through Tricuspid Valve to Right ventricle...

*Through pulmonary vavle, to pulmonary artery..

*Into LUNGS

 

Term

 

 

Blood flow through the heart

Left side (to body)

Definition

Left side: Pumps blood to body- receives from lungs.

*From Lungs, through pulmonary veins..

*To LEFT atrium..

*Through mitral(bicuspid) valve, to left ventricle..

*Through Aortic valve, To aorta..

*To BODY.

Term

 

 

 

Systole Cardiac Cycle

Definition

*Ventricle contraction=

Eject blood from LEFT ventricle into AORTA

Eject blood from RIGHT ventricle into PULMONARY ARTERY

 

*Emptying of atria and ventricles.

Term

 

 

 

Diastole Cardiac Cycle

Definition

*Ventricle Relaxation=

ventricles relax

Atria contract: moving blood into ventricles

*Filling of heart chambers

*2/3 of cardiac cycle

*AV valves open

*semilunar valves close

Term

 

 

 

Ventricular Contraction and Heart sounds

Definition

**S1 (lubb)

*AV valve closure

*ventricular contraction forces mitral & tricuspid valves to close.

 

**S2 (dubb)

*ventricles emptying the pressure in ventricles decreases aortic & pulmonic(semilunar) valves to close.

*Blood flows from RIGHT to LEFT ventricles to the lungs & body.

 

Term

 

 

 

Valves of the Heart

Definition

*ATRIOVENTRICULAR*

*Tricuspid (right heart)

*Mitral (left heart)

 

function to prevent backflow of blood from ventricles to atria during systole (contraction of heart). The valves keep blood flowing in a forward direction.

Term

 

 

 

Valves of heart continued

Definition

A valve that does not close tightly causes backflow of blood= insufficiency or regurgitation)

 

A valve that does not open wide enough causes a turbulent flow (secondary to obstruction or narrowing, i.e., stenosis)

Term

 

 

SEMILUNAR Heart Valves

Definition

*AORTIC (in aorta)

*PULMONIC (in pulmonary artery)

 

Open during systole and close during diastole.

 

Term

 

 

 

HEART SOUNDS REVIEW

S1 & S2

Definition

*S1= lubb

Closure of AV valves(mitral 1st)

Beginning of ventricular systole

Best heard @ 5th ICS.

 

*S2= dubb

Closure of semilunar valve(aorta 1st)

End of ventricular systole or beginning of diastole

Best heard @ 2nd ICS.

Term

 

 

 

Heart sounds Review

S3

Definition

*S3=

Right ventricle= heard @4th ICS @left sternal boarder.

Left ventricle= heard @apex

Ventricular gallop, >40yrsold=pathological (more normal in younger)

Hear a close after S2 in early diastole while ventricles relax & fill w/blood.

Commonly heard w/heart failure(ventricle has not completely emptied so blood is returning an already partially filled ventricle).

Term

 

 

 

Heart Sounds Review

S4

Definition

*S4= late diastole, pre systolic gallop before S1 sound

Heard best @apex of heart

When pathologic- produced by atrial contraction vs. stiff noncompliant ventricles

Due to or R/T scarring of MI or Ventricular hypertrophy (hypertension and pulmonic stenosis).

Term

 

 

HEART

MURMERS

Definition

Extra sounds during systole or diastole

Turbulent sounds in heart or vesssels

Occur B/T normal sounds

DUE TO or R/T valve disorders & abnormal blood flow patterns.

Term

 

 

 

CORONARY CIRCULATION

Definition

Coronary Artery blood flow to the myocardium occurs almost exclusively during DIASTOLE

Left & right arteries & their branches supply arterial blood to the heart.

Originate from aorta above aortic valve leaflets.

Arteries perfused during DIASTOLE.

Right side of heart= right coronary artery

Left side of heart= left coronary artery

Term

 

 

 

AORTIC DIASTOLIC PRESSURE

Definition

Pressure by which blood enters the coronary arteries.

IF DIASTOLE (relaxation of heart) is shortened (i.e., increased HR) so is myocardial perfusion.

DIASTOLIC B/P of @ least 60 to maintain adequate blood flow.

Term

Conduction System

 

 

AUTOMATICITY

Definition

Ability of the heart to initate impulses regularly & spontaneously.

Prominent property of SA NODE.

Term

Conduction System

 

 

 

EXCITABILITY

Definition

Ability of cardiac cells to respond to a stimulus by initating the cardiac impluse.

Term

Conduction System

 

 

 

CONDUCTIVITY

Definition

Ability of cardiac cells to respond to a cardiac impulse by transmitting the impulse along cell membranes.

Term

Conduction System

 

 

 

CONTRACTIBILITY

Definition

Ability of cardiac cells to respond to an impulse by contracting.

 

**Contractile cells compose the largest mass of the myocardium.

Term

Conduction system of Heart

 

 

 

SA NODE & AV NODE

 

Definition

SA NODE:

Near Vena Cava in right atrium

PACEMAKER OF HEART

Rate controlled @70-80 (60-100).

 

AV NODE:

Responsible for .10sec delay in conduction of impulse to ventricles

Composed of dense fibrous tissue that continues into the BUNDLE OF HIS

Term

Conduction System of the heart

 

 

 

BUNDLE OF HIS

 

Definition

Tail of AV NODE

Separates into RIGHT & LEFT BUNDLE BRANCHES which then travel into ventricles

Connects AV NODE to the BUNDLE OF HIS

Separates into RIGHT & LEFT BUNDLE BRANCHES which then travel into ventricles

Term

Conduction System of the Heart

 

 

 

PURKINJIE FIBERS

(network)

Definition

On endocardial surface of both ventricles

Aid in accelerated conduction of the impulse.

Term

 

 

 

ECTOPIC BEAT

Definition

Beat originating in area other than the SA NODE

Term

 

 

 

 

CARDIAC OUTPUT

Definition

Amount of blood ejected from the LEFT ventricle into the AORTA per min.

 

**CO= SV X HR

Term

 

 

 

 

STROKE VOLUME

Definition

Amount of blood ejected into the aorta by the LEFT ventricle per beat.

SV= end of DIASTOLIC volume- end SYSTOLIC volume

Term

 

 

 

 

EJECTION FRACTION

Definition

Ratio of stroke volume to end DIASTOLIC volume (EDV)

A measure of LEFT ventricle function

*A decrease in ejection fraction means left ventricular failure

* SV divided by EDV= EJECTION FRACTION

Term

 

 

 

 

Control of Cardiac Output

Definition

Compensatory adjustments to HR or Stroke Volume occur to stabilize Cardiac Output in the normal healthy heart.

Term

MECHANISMA REGULATING STROKE VOLUME

 

 

 

PRELOAD

Definition

Refers to the degree of myocardial fiber stretch at the end of DIASTOLE and just before contraction.

 

*STARLINGS LAW OF THE HEART*

Myocardial fibers respond with a more forceful contraction when stretched.

Term

MECHANISMS REGULATING STROKE VOLUME

 

 

 

AFTERLOAD

Definition

Refers to resistance

As AFTERLOAD increases so does the CARDIAC work and O2 consumption.

Term

MECHANISMS REGULATING STROKE VOLUME

 

 

 

CONTRACTILITY

Definition

Refers to the FORCE of contraction that myocardial muscle generates

 

*Inotropic State*

Postive= increased contractility

Negative= decreased contractility

 

Increased contractility improves ventricular emptying so-- increased STROKE VOLUME.

Term

Control of Heart Rate--ANS

 

 

 

SYMPATHETIC

Definition

Increases rate (positive chronotropic)

Increases force (positive inotropic)

Neurotransmitter is NOREPINEPHRINE

Term

Control of Heart Rate--ANS

 

 

 

PARASYMPATHETIC

Definition

decreases rate (neg chronotropic)

decreases force of contraction (neg. inotropic)

neurotransmitter is ACETYLCHOLINE

Term

Control of Heat Rate

 

 

 

BARORECEPTORS

Definition

specialized nerve cells in aortic and carotid arteries

Sensitive to changes in BP

Hypertension= transmit to medulla to initate a PARASYMPATHETIC RESPONSE

Hypotension= less baroreceptor stimulation-allows for enhances of SYMPATHETIC ACTIVITY.

Term

 

 

 

 

GERONTOLOGIC CONSIDERATIONS

Definition

General aging can result in:

Changes in LEFT ventricle

Decreased elasticity & widening of AORTA

Thickening & rigid cardiac valves

Increased connective tissue in SA & AV NODES & BUNDLE BRANCHES

 

Term

 

 

 

ELECTROPHYSIOLOGY

of the

HEART

Definition

The heart has RHYTHMIC pumping b/c of electrical impulses generated & passed along the conduction system of the heart.

 

ECG= complexes that make up an electrocradiography image. 

Term

 

 

 

 

CARDIAC ACTION POTENTIAL

Definition

Changes in cell membrane potential is described in terms of polarization

 

POLARIZED= resting state

*Na- extracellualr

*Ka-intracelluar

Term

 

 

 

 

DEPOLARIZATION

Definition

When cell responds to electrical stimulus.

Mechanical contraction of cardiac muscle cell follows depolarization (SYSTOLE)

Term

 

 

 

 

REPOLARIZATION

Definition

When cell is going back into the resting state (polarized)

Corresponds to mechanical relaxation of myocardial muscle (DIASTOLE)

Term

 

 

 

 

RESTING MEMBRANE POTENTIAL

Definition

Cell is at rest

Inside the cell is more neg. charged than outside the cell

Cell is polarized-not participating in electrical events.

Term

 

 

 

 

Phases of Cardiac Action Potential

(phases 0-4)

Definition

PHASE 0= DEPOLARIZATION

The cell responds to an impulse due to rapid entry of Na & Ca, lasts a few millisecs

 

P wave= atrial depolarization

 

QRS Complex= ventricular depolarization

 

Term

Phases of Cardiac Action Potential

 

 

PHASE 1= short period of repolarization/early rapid   repolarization

 

Begins @ ST segment

Definition

Phases of Cardiac Action Potential

 

PHASE 2= PLATEAU

allows completion of contraction

asst. w/slow entry of Ca into cells

longer lasting- 100 millisecs

 

ST segment

 

Term

PHASES of Cardiac Action Potential

 

PHASE 3= RAPID repolarization

electrical recovery of cells

cells regain neg. charge

 

T WAVE

Definition

PHASES of Cardiac Action Potential

 

PHASE 4= Resting membrane potential

cell prepared for next electrical impulse

Term

 

 

REFRACTORINESS

 

The ability of Cardiac cells to respond

to

sucessive stimuli

Definition

ABSOULTE REFRACTORY PERIOD=

No stimulus will produce a response

 

 

RELATIVE REFRACTORY PERIOD=

During final stage of repolarization a strong stimulus will produce a response.

Term

EFFECTS OF Ca+ & K+

 

Hypercalcemia                                  Hypocalemia

increased                                             decreased

contractility                                          contractility

ventricular                                            decreased 

dysrhytmias                                          sensitivity to Dig

                                                          Cardiac

                                                           insufficiencies

Definition

Hyperkalemia                              hypokalemia

slowed conduction of impulses          Prolonged cardiac

                                                  repolarization

                                                  decreased strength in

                                                  muscle contraction

                                                  Potentiates Dig

                                                  toxicity

Term

 

 

 

ECG Assessment

 

 

Definition

HEART RATE=

Count # of complexes in a 6 sec strip & multiply by 10

Count # of large boxes b/t 2 complexes & divide by 300

Count # of small squares b/t complexes & divide that # into1500

 

RHYTHM & REGULARITY=

Atrial- measure P to P waves w/caliper= <1-3 small boxes (0.8-0.12 secs)

Ventricular- measure R to R intervals

Term

ECG Assessment

 

Examine P waves-

should be present & look the same in size & shape throughout Sinus Rhythm (SR)

 

If not the impulse is generated from a focus different from the SA NODE, may be ectopic.

Definition

ECG Assessment

 

P to QRS relationship-

There should be one P for every QRS

Term

ECG- Interval durations

 

P to R

Measures the time for ATRIAL depolarization & impulse delay & travel through the PURKENJIE FIBERS (0.12-0.20 secs)

Measure beginning of P wave to beginning of QRS

Definition

ECG- Interval durations

 

QRS complex-

Ventricular depolarization

Shape of this complex will depend on the lead selected

Check that ea. is preceded by a P wave

Is it consistant in duration & form?

Duration: 0.06-0.10 secs, normally less than 3 small boxes.

Term

ECG Assessment

 

S T segment

A flat line having no voltage from end of S wave to beginning of T wave (isoelectic)

Early ventricular repolarization- PHASE 1 & 2.

Definition

ECG Assessment

 

Q  T interval

Represents total ventricular repolarization & depolarization

Less than .4 sec (0.32-0.44) or 8-11 sm boxes

Onset of QRS complex to end of T wave

Term

ECG Assessment

 

T wave

ventricular repolarization

If an ectopic stimulus excites the ventricles at this time it may cause irritabilty

Look @shape- smooth, round, same direction as QRS

 

U wave sometimes follows T wave: may represent hypokalemia.

Definition
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