chap. 21 - heart, neck vessels

heart location

in mediastinum, between the lungs, behind sternum

• heavier in males than females

superior + inferior vena cava

returns deoxygenated blood to right atrium

pulmonary artery

carries deoxygenated blood from right ventricle to lungs

pulmonary veins (4)

returns oxygenated blood to left atrium

aorta

carries oxygenated blood from left ventricle to body

cardiac cells

spontaneously generates electrical impulses

conduction

controls the cardiac cycle (filling + emptying of heart chambers)

SA node (pacemaker)

located in right atrium, fires 60-100 bpm, sends impulses across atria for atrial contraction

• if node fails → other areas take over but at a slower rate of 40-60 bpm

AV node

sends impulses to bundle of his, slows impulse allowing ventricles to fill

P wave

atrial depolarization = atria contracts

QRS complex

ventricular depolarization = ventricles contract

• much larger than P wave bc ventricles have more muscle mass

• atrial repolarization occurs but hidden by QRS

T wave

ventricular repolarization = ventricles recover/relax

during diastole

• AV valves open (mitral + tricuspid)

• blood flows from atria to ventricles bc of higher atrial pressure

  • early filling = fast, passive flow

  • slow filling = mid-diastole

during systole

ventricles fill, pressure rises, and AV valves CLOSE — produces S1 “lub” sounds

• ventricular pressure rises and semilunar valves open (aortic + pulmonic)

• blood pumped out to body + lungs

ventricles empty, pressure drops, and semilunar vales close — produces S2 “dub” sounds

• cycle restarts as AV valves open again

S1 “lub”

closure of AV valves (mitral + tricuspid)

• marks the start of systole

• heard loudest at APEX

S2 “dub”

closure of SEMILUNAR valves (aortic + pulmonic)

• marks start of diastole

• heard loudest at BASE

cardiac output

how much blood the heart pumps in 1 min

• CO = HR x SV

• changes based on body needs:

  • higher CO → exercise, stress, fever

  • lower CO → heart failure, shock

CO nervous system control

1. sympathetic (fight or flight) → increases HR → increases CO

2. parasympathetic (rest and digest) → decreases HR → lowers CO

stroke volume

amount of blood pumped from heart w/ each contraction

• influenced by → stretch of heart muscle before contraction, pressure against which it has to eject blood during contraction, synergy of contraction, compliance or distensibility of ventricles, contractibility of myocardium

aortic area

2nd ICS at the right sternal border → base of heart

pulmonic area

2nd or 3rd ICS at left sternal border → base of heart

Erb’s point

3rd ICS at left sternal border

tricuspid area

4th or 5th ICS at left lower sternal border

mitral (apical)

5th ICS near left MCL → apex of heart

murmur

swooshing or blowing sound caused by turbulent, messy blood flow

murmurs happen due to …

• fast blood flow (fever, growth spurts, anemia)

• valve problems (too tight = stenosis, leaky = regurgitation)

• valve malfunction

• openings in the heart that shoudn’t be there (septal defects)

physiologic murmur

innocent murmur

pathologic murmur

congenital or acquired structural heart disease

regurgitation

valve doesn’t close tightly/properly, so blood leaks backward instead of moving forward

systolic murmur

mitral/tricuspid REGURGITATION, aortic/pulmonic STENOSIS

diastolic murmur

mitral/tricuspid STENOSIS, aortic/pulmonic REGURGITATION

DIASTOLIC = ALWAYS BAD

murmur symptoms

heart has to pump extra blood, leading to overload — chambers stretched (dilated)

• lead to → fatigue, shortness of breath, decreased cardiac output

S3 - ventricular gallop

caused by rapid filling of the ventricles that are already stretched or overloaded

• happens right AFTER S2 (lub-dub-ta) — “kentucky” (S1, S2, S3)

• commonly seen in → heart failure, fluid overload, dilated ventricles

• NORMAL → children, young adults, pregnancy

• NOT normal → older adults

S4 - atrial gallop

caused by atria pushing blood into a stiff, non-compliant ventricle

• happens right BEFORE S1 (ta-lub-dub) — “tennessee“ (S4, S1, S2)

• common causes → long-standing hypertension, left ventricular hypertrophy, aortic stenosis

• NOT normal → any age group

ejection clicks

high-pitched, short sounds during early systole

• ex: mid-systole click — often linked to mitral valve prolapse

friction rub

grating or scratchy sound

• occurs when inflamed pericardial layers RUB together

• may be heard during systole, diastole, or both

heave or lift

visible or palpable movement of chest wall caused by heart pushing strongly against it

• occur when heart is working harder than normal

pulse deficit

difference between the apical pulse + a peripheral/radial pulse

• indicates heart is beating, but not all beats are generating a strong enough pulse to reach the extremities

• seen in → atrial fibrillation, atrial flutter, PVCs, heart blocks

ALWAYS measure apical + radial pulse at the same time

bradycardia

HR <60 bpm → may decrease CO

tachycardia

HR >100 bpm → may decrease filling time + decrease CO

atrial fibrilation

quivering right atrium

atrial flutter

extra rhythmic beats in right atrium

ventricular fibrilation

quivering left ventricle

ventricular tachycardia

extra rhythmic beats in left ventricle

heart rates/rhythms can lead to…

1. decreased cardiac output

2. heart failure

3. risk for emboli (clots)

coronary heart disease

narrowing of the blood vessels that supply blood + oxygen to the heart

• causing heart attack, chest pain, stroke, affecting heart muscles, valves, or rhythm

• screening for risk → cholesterol + glucose level, C-reactive protein presence, BP, health history, PAD

  • screening starts at 20 for BP, fasting lipoprotein profile, body weight

  • screening at age 45 for blood glucose every 3 years

coronary heart disease inherited risks

increasing age, heredity (race), diabetes (type 1)

coronary heart disease factors

• modifiable → smoking, high cholesterol/triglycerides, hypertension, physical inactivity, obesity, diabetes mellitus (type 2)

• contributing → stress, excessive alcohol consumption, diet + nutrition, diabetes mellitus

coronary heart disease s/s

chest pain, shortness of breath, arrhythmia, nausea, dizziness, palpations, fatigue, weakness

coronary heart disease education

prevention, smoking secession, physical activity, weight/BP/cholesterol, alcohol, stress, nutrition

diaphragm of stethoscope

for HIGH-pitched sounds (S1, S2, most murmurs)

bell of stethoscope

for LOW-pitched sounds (S3, S4, some murmurs)

carotid arteries location

in the groove beside the trachea and under the sternocleidomastoid muscle

internal carotid artery

supplies the brain

external carotid artery

supplies the face + neck

normal carotid pulse feels …

• smooth, rapid upstroke during early systole

• gradual, smooth downstroke

• strong + equal on both sides

internal jugular vein location

deep, next to sternocleidomastoid muscle

• best for assessing right atrial pressure

jugular venous pressure (JVP)

gives clues about the right side of the heart

• right atrial pressure

• right ventricular filling

• fluid status (volume overload or deficit)

bruit = hear

abnormal whooshing sound HEARD w/ stethoscope

• happens when blood is flowing through a narrowed or partially blocked artery

• water rushing through a pinched hose (gets noisy)

• common causes → atherosclerosis (plaque buildup), narrowed carotid artery, AV fistulas (dialysis access)

thrill = feel

vibration FELT w/ fingertips

• cat purring under skin

• indicates very turbulent blood flow due to …

  • severe valve disease (murmurs strong enough to feel)

  • significant arterial narrowing

  • AV fistulas with high flow

jugular venous distention

the jugular veins look enlarged or bulging in the neck

• common cause → right-sided heart failure

• other causes → fluid overload, pulmonary hypertension, tricuspid valve problems, pericardial tamponade (pressure around the heart)

older adult considerations in neck

• atherosclerosis may have caused obstruction and compression may easily block circulation

• apical impulse may be difficult to palpate due to increased anteroposterior chest diameter