CVS204 Exam 1

Location of the heart

Central thoracic cavity, slightly left of midline, between 3rd-5th intercostal spaces, anterior to vertebrae, posterior to sternum and lungs.

Pericardium

Fibroserous sac surrounding the heart and proximal great vessels.

Fluid in the pericardial sac

10-50 mL of serous fluid.

Functions of the pericardium

Protects from infection, trauma, friction; aids free pumping; anchors heart in position.

Two main layers of pericardium

Fibrous pericardium (outer) and serous pericardium (inner).

Layers of the serous pericardium

Parietal layer (lines fibrous pericardium) and visceral layer/epicardium (covers heart surface).

Function of pericardial space

Reduces friction during contraction/relaxation.

Number of heart chambers

Four — right atrium, right ventricle, left atrium, left ventricle.

Pulmonary circulation

Right side — low pressure, pumps deoxygenated blood to lungs.

Systemic circulation

Left side — high pressure, pumps oxygenated blood to body.

Two "rules" of cardiac anatomy

Right-sided structures are anterior to left-sided; atria lie to the right of their ventricles.

Four heart valves

Tricuspid, mitral, pulmonic, aortic.

Atrioventricular valves

Tricuspid and mitral.

Semilunar valves

Pulmonic and aortic.

Blood enters right atrium from

Superior/inferior venae cavae and coronary sinus.

Separator of right and left atria

Interatrial septum.

Tricuspid valve location

Between right atrium and right ventricle.

Shape of right ventricle

Roughly triangular, outflow tract cone-shaped.

Trabeculae carneae

Irregular muscular ridges lining ventricles.

Moderator band location

Right ventricle.

Papillary muscles in right ventricle

Three; connect via chordae tendineae to tricuspid valve.

Function of papillary muscles/chordae tendineae

Prevent valve prolapse and regurgitation during ventricular contraction.

Pulmonic valve structure

Three cusps attached to fibrous ring.

Pulmonic valve function

Prevents backflow into right ventricle after contraction.

Blood enters left atrium from

Four pulmonary veins.

Wall thickness of left atrium

~2 mm.

Mitral valve location

Between left atrium and left ventricle.

Shape of left ventricle

Cone-shaped, longer than right.

Left ventricle wall thickness

9-11 mm (3× thicker than right).

Trabeculae carneae in left ventricle

Finer and more numerous than right ventricle.

Papillary muscles in left ventricle

Two large; chordae thicker but less numerous.

Function of mitral valve chordae tendineae

Maintain valve closure during contraction.

Aortic valve location

Between left ventricle and aorta.

Number of aortic valve cusps

Three.

Coronary artery origins

Just above right and left aortic valve cusps.

Interventricular septum parts

Large muscular portion (bulges toward right ventricle) and small membranous portion (just under aortic cusps).

Path of blood through the heart

Venae cavae → right atrium → tricuspid → right ventricle → pulmonic valve → pulmonary arteries → lungs → pulmonary veins → left atrium → mitral valve → left ventricle → aortic valve → aorta → body.

Order of impulse conduction

SA node → AV node → Bundle of His → right/left bundle branches → Purkinje fibers.

Bundle of His location

Distal to AV node, perforates septum, bifurcates.

Right bundle branch pathway

Thick in septal muscle → apex → subendocardial near anterior RV wall → splits via moderator band and ventricular tip → plexus.

Left bundle branch pathway

Divides into anterior fascicle (to anterior papillary muscle), posterior fascicle (to posterior papillary muscle), and small septal branch → plexus to whole LV.

Purkinje fiber function

Activate papillary muscles before ventricular walls to prevent AV valve regurgitation.

What supplies blood to heart muscle?

Right and left coronary arteries.

Where do coronary arteries originate?

Root of aorta above aortic cusps.

Cardiac vessels include

Coronary arteries and coronary veins.

a wave

atrial kick in late diastole

c wave

MV and TV close bulging into the atrias

v wave

result of passing filling of the atria during systole

s1

av valves closing in early systole

s2

closure of pv and aov, end of ventricular systole

accenuated s1

-short pr interval

-mild mv stenosis

-high output rate or tachycardia

intensity factors of s1

-rate of rise of ventricular pressure

-mobility of av valves

-distance separating the leaflets of the valve during ventricular contraction

diminished s1

-long pr interval; first degree av heart block

-mv regurgitation

-severe mv stenosis

-stiff left ventricle

physiological splitting

1 expiration + 2 inspiration

a2+p2

-closure of the aov and pv

-a2 earlier in inspiration

-delayed p2 during inspiration

widened splitting

s2 sounds are father apart in timing, delayed closure of the pulmonic valve

what causes widened splitting?

right bundle branch block and pulmonary stenosis

fixed splitting

wide splitting that does not vary with respiration

what causes fixed splitting?

atrial septal defect

paradoxical splitting

reversed splitting, separation during expiration into one inspiration

what causes paradoxical splitting?

left bundle branch block, aortic stenosis

ejection clicks after s1

-aov or pv stenosis

-dilation of pulmonary artery or aorta

mid to late systolic clicks

mv or tv prolapse or regurgitation

opening snap

opening of stenotic mv or tv

s3

tensing of ct during filling called ventricular gallop

s4

atrial gallop during late diastole

s3+s4

summation gallop

pericardial knock

constrictive pericarditis

murmur

when laminar flow becomes disturbed

murmur timing

systolic, diastolic, continuous

murmur pitch

high, medium, low

murmur intensity

systolic: 1=barely audible 6=heard without stethoscope

diastolic: 1=barely audible 4=very loud

murmur shape

crescendo-decrescendo, uniform, decrescendo

murmur location

valve/space it is heard at

radiate

direction of turbulent flow

bedside maneuver

standing, valsalva, clenching fists effects intensity

systolic ejection murmur

aortic or pulmonary stenosis, heard at 2nd to 3rd intercostal space after s1

pan systolic murmur

caused by mitral or tricuspid regurgitation or vsd, uniform in intensity

mitral regurgitation;psm

heard at cardiac apex and radiates towards left axilla uniform in intensity

tricuspid regurgitation; psm

heard at lower left sternal border, radiates towards right sternum, intensity increases with inspiration

vsd;psm

4th-6th intercostal space, smaller =louder

late systolic murmurs

Occur mid to late systole, common is MR from MVP, Preceded by a mid-systolic click

Early decrescendo murmurs

Aortic valve regurge: Murmurs begins at A2

Pulmonic valve regurgiation

due to pulmonary hypertension, intensity increases with inspiration

Mid-to-late diastolic murmurs

a stenotic mitral or tricuspid valve, Preceded by an opening snap (OS)

Continuous murmurs

PDA, begins in early systole crescendo to its max at s2 then decrescendo until next s1.

to and fro murmurs

Patient must have both aortic stenosis and aortic regurgitation, during systole diamond shaped ejection murmur, during diastole decrescendo murmur

Bauchmans bundle

carries sa node impulse to the left atria

intrinsic rates

SA Node: 60-100

AV Node: 40-60

Purkinje Fibers: 20-40

abnormality of the p wave

when the p wave is taller than 2.5 mm this means the RA is enlarged

abnormalities of the qrs complex

indicative of problems in ventricular conduction; ventricular hypertrophy or bundle branch blocks

st segment and t wave abnormalities

Transient Myocardial Ischemia

Acute ST- segments elevation of myocardial infarction

Acute non- ST- segments elevation of myocardial infarction