Anatomy: Heart and Pericardium

transcript

Anatomy of the Pericardium & Heart

Karlos Noel R. Aleta, M.D.Karlos Noel R. Aleta, M.D.

Dept of SurgeryDept of Surgery

San Beda College of MedicineSan Beda College of Medicine

Outline• PericardiumPericardium• HeartHeart

• Surface anatomySurface anatomy• Internal anatomyInternal anatomy

• ValvesValves• ChambersChambers• SkeletonSkeleton

• Conduction pathwayConduction pathway• NerveNerve• Blood supplyBlood supply

• ArterialArterial• Coronary artery diseaseCoronary artery disease• VenousVenous

PERICARDIUM• fibroserous sac w/c surrounds heart & root of great fibroserous sac w/c surrounds heart & root of great

vessels vessels • Invaginate the serous sac from behind during devtInvaginate the serous sac from behind during devt

Components of the pericardium1. 1. FIBROUS PericardiumFIBROUS Pericardium

• outer layer of pericardial sacouter layer of pericardial sac~ cone shaped bag~ cone shaped bag

Boarders:Boarders:• superior: pretracheal fasciasuperior: pretracheal fascia• posterior: trachea & 1posterior: trachea & 1°° bronchi bronchi• anterior: sternumanterior: sternum• Inferior: fused w/ diaphragmInferior: fused w/ diaphragm

Structures w/c pass thru: Structures w/c pass thru: • 4 pulmonary veins4 pulmonary veins• IVC [R side]IVC [R side]

2. 2. SEROUS PericardiumSEROUS Pericardiuma. PARIETALa. PARIETAL

• lines inner surface of lines inner surface of fibrous pericardiumfibrous pericardium

b. VISCERAL b. VISCERAL • ‘‘epicardium’epicardium’• lines outer surface of lines outer surface of ♥♥• completely invests heart completely invests heart

EXCEPT POSTERIORLY EXCEPT POSTERIORLY b/w entrance of 2 vena b/w entrance of 2 vena cavae & 4 pulmonary cavae & 4 pulmonary veinsveins

Components of the pericardium

Pericardial Cavity

• space b/w parietal & visceral percardiumspace b/w parietal & visceral percardium• (+) small amt of pericardial fluid ~ prevents (+) small amt of pericardial fluid ~ prevents

friction, “lubrication”friction, “lubrication”• normal capacity ~ 50 ml normal capacity ~ 50 ml • max capacity ~ 300 mlmax capacity ~ 300 ml• Pericardial effusionPericardial effusion ~ ~ accumulation of fluid w/in accumulation of fluid w/in

sacsac

Pericardial tamponade

• ““cardiac tamponade” cardiac tamponade” • Limits Limits diastole diastole (PRELOAD)(PRELOAD)

~restricted expansion of relaxed heart~restricted expansion of relaxed heart~compromise ability to fill w/ blood properly~compromise ability to fill w/ blood properly~inadequate amount propelled to systemic circ ~inadequate amount propelled to systemic circ

• 60 ~ 100 ml 60 ~ 100 ml acuteacute accumulation of accumulation of blood/clots/fluid can produce tamponadeblood/clots/fluid can produce tamponade

Clinical pictureClinical picture• Beck’s triad (hypotension, Beck’s triad (hypotension,

distended neck veins, distended neck veins, muffled heart sounds)muffled heart sounds)

• Pulsus paradoxus Pulsus paradoxus (exaggerated fall in (exaggerated fall in systolic BP during systolic BP during inspirationinspiration

• Drain fluidDrain fluid

Cardiac tamponade

Constrictive Pericarditis• Inflammation~affects both Inflammation~affects both

parietal & visceral parietal & visceral • Thickening ~ adherence to Thickening ~ adherence to

underlying myocardiumunderlying myocardium• May initially present w/ May initially present w/

pericardial effusionpericardial effusion• Chronic constrictionChronic constriction• In PI, TB #1 etiologyIn PI, TB #1 etiology

Constrictive Pericarditis

Constrictive Pericardiectomy

Sinuses

1. 1. TransverseTransverse • Breakdown of embryonic dorsal Breakdown of embryonic dorsal

mesocardiummesocardium• passage fr L --> Rpassage fr L --> R• behind pulmonary trunk & ascending aorta behind pulmonary trunk & ascending aorta • significance:significance: ligate pulmonary trunk & ligate pulmonary trunk &

asc. aorta during cardiac transplantasc. aorta during cardiac transplant

Transverse Sinus

2. 2. ObliqueOblique• behind LV & LAbehind LV & LA• LA & 4PV enter LA in base/posteriorLA & 4PV enter LA in base/posterior• Serous p reflects onto inner surface of Serous p reflects onto inner surface of

fibrous p as parietal pfibrous p as parietal p• Reflection of serous p forms blind ending Reflection of serous p forms blind ending

sacsac

Sinuses

Oblique Sinus

Nerve supply

• Fibrous / Parietal - Somatic N [ fr phrenic N]Fibrous / Parietal - Somatic N [ fr phrenic N]

• Visceral - Autonomic N [ Visceral - Autonomic N [ fr coronary plexus] fr coronary plexus]

• insensitive to paininsensitive to pain

Blood supply of Pericardium

• Fibrous & parietal Fibrous & parietal →→ branches from: branches from:– internal thoracic [mammary] a internal thoracic [mammary] a – bronchial abronchial a– pericardiacophrenic apericardiacophrenic a– aortaaorta– arteries to diaphragmarteries to diaphragm

• Visceral Visceral →→ coronary a coronary a [ share w/ myocardium ][ share w/ myocardium ]

Pericardial pain

• felt diffusely posterior to the sternum ~ felt diffusely posterior to the sternum ~ substernal painsubsternal pain• May radiate to other areasMay radiate to other areas

• Acute inflammation of pericardial sac ~ Acute inflammation of pericardial sac ~ pericarditis pericarditis

~ Pain, +/- effusion~ Pain, +/- effusion• Auscultation ~ pericardial friction rubAuscultation ~ pericardial friction rub

• central organ of circulatory systemcentral organ of circulatory system• wall :wall :

EPICARDIUM - external surfaceEPICARDIUM - external surface MYOCARDIUM - middle, muscular, thickestMYOCARDIUM - middle, muscular, thickest ENDOCARDIUM - internal surfaceENDOCARDIUM - internal surface

• short CONEshort CONE• base: faces posteriorlybase: faces posteriorly

• formed by LAformed by LA & & part of RApart of RA

• apex: points downward, apex: points downward, to Left & forwardto Left & forward formed by LVformed by LV

• Apex beat is Point of Maximal Impulse

• located at 5th ICS, L midclavicular line

Surfaces1. Diaphragmatic or inferior 1. Diaphragmatic or inferior

• LV & part of RVLV & part of RV• rests on diaphragmrests on diaphragm

2. Left surface2. Left surface• LVLV

3. Right surface3. Right surface• RARA

4. Sternocostal 4. Sternocostal • faces anteriorlyfaces anteriorly• RV , partly by RA & LVRV , partly by RA & LV• RVRV = = most commonly most commonly

injuredinjured in penetrating in penetrating traumatrauma

Penetrating cardiac injury

• PathophysiologyPathophysiology• Injury patternInjury pattern

• Right ventricle most common (>40 %)• Left ventricle 2Left ventricle 2ndnd most common (40%) most common (40%)• Right atriumRight atrium 24%24%• Left atriumLeft atrium 3% 3%• Complex Complex 8%8%• Coronary arteriesCoronary arteries 5%5%

Cardiac Box

- Penetrating cardiac injury- Penetrating cardiac injury- In stable patients - In stable patients

~ ~ r/o (+/r/o (+/──) pericardial ) pericardial effusion effusion

~ prove if blood~ prove if blood- In unstable patients- In unstable patients

~ open/surgery to locate & ~ open/surgery to locate & repair external cardiac repair external cardiac injuryinjury

Traumatic cardiac tamponade

Traumatic Cardiac Injury

D. Internal Anatomy1. Chambers1. Chambers : R atrium : R atrium R ventricleR ventricle

L atrium L atrium L ventricleL ventricle

2. Openings/ Valves2. Openings/ ValvesFunction of valves: prevent backward flow of bloodFunction of valves: prevent backward flow of blooda. Tricuspid = R atrioventricular, valve w/ 3 cuspsa. Tricuspid = R atrioventricular, valve w/ 3 cuspsb. Mitral = L atrioventricular, valve w/ 2 cuspsb. Mitral = L atrioventricular, valve w/ 2 cuspsc. Aorticc. Aortic = bet LV & aorta = bet LV & aortad. Pulmonic = bet. RV & pulmonary trunkd. Pulmonic = bet. RV & pulmonary trunke. Aortic sinuses e. Aortic sinuses - dilated pockets bet cusps & - dilated pockets bet cusps &

aortic wall aortic wall- origin of coronary arteries- origin of coronary arteries

Internal Anatomy

Rheumatic Heart Disease• vegetationsvegetations• calcifications calcifications • affects mainly mitral valveaffects mainly mitral valve• cause stenosis or insufficiencycause stenosis or insufficiency• severity may affect other valvesseverity may affect other valves

Valvular surgery

• Closed Valve repairClosed Valve repair• Open Valve repairOpen Valve repair• Open Valve replacementOpen Valve replacement

PROSTHETIC VALVES

• Types of valvesTypes of valves• MechanicalMechanical• TissueTissue

• XenograftsXenografts• autografts/human homograftsautografts/human homografts

MECHANICAL VALVES

TISSUE VALVES

VALVE REPLACEMENT

CHAMBERS of the HEART

1. R ATRIUM

• quadrangular shapedquadrangular shaped

• receives blood fr SVC, receives blood fr SVC, IVC & coronary sinusIVC & coronary sinus

• communicates w/ RV communicates w/ RV thru R AV openingthru R AV opening

R ATRIUM

• crista terminalis = crista terminalis = smooth muscular ridge smooth muscular ridge w/c divides into 2 parts:w/c divides into 2 parts:

• 1. sinus venarum1. sinus venarum = = smooth,thin, posterior smooth,thin, posterior part where vena cava part where vena cava open, coronary sinusopen, coronary sinus

• 2. musculi pectinati = 2. musculi pectinati = rough, thick, anterior rough, thick, anterior partpart

• fossa ovalisfossa ovalis ~ depression above ~ depression above orifice of IVCorifice of IVC

• marks location of former marks location of former foramen ovaleforamen ovale [opening [opening thru w/c blood flows fr thru w/c blood flows fr RA RA →→ LA before birth] LA before birth]

R ATRIUM

Congenital Heart Disease

Atrial septal defectAtrial septal defect = incomplete closure of foramen = incomplete closure of foramen

ovale (most common)ovale (most common)

~ “patent foramen ovale” (PFO)~ “patent foramen ovale” (PFO)

= blood flows fr LA = blood flows fr LA →→ RA RA

ATRIAL SEPTAL DEFECT

• Hole in interatrial septum (IAS) of variable Hole in interatrial septum (IAS) of variable sizessizes

• Left-to-right shunting Left-to-right shunting →→ atrial level atrial level• Association with other cardiac anomaliesAssociation with other cardiac anomalies

TYPES OF ASD1. Sinus venosus

• 5-10%• PAPVR

2. Ostium primum• Partial AV canal

defects• 10-15%

3. Ostium secundum• 80%• Patent foramen ovale

ASD REPAIR

2. R VENTRICLE• CC-shaped cavity-shaped cavity

~ capacity of 85 ml~ capacity of 85 ml

• leads to Pulmonary trunkleads to Pulmonary trunk

• trabeculae carnae = fleshy trabeculae carnae = fleshy ridges on ventricular wallridges on ventricular wall

• interventricular septum = interventricular septum = partition b/w RV & LV partition b/w RV & LV

• 2 parts: 2 parts: 1] membranous = thin1] membranous = thin 2] muscular = thick2] muscular = thick

Ventricular septal defectVentricular septal defect = = affects affects membranous membranous partpart

R VENTRICLE

• septomarginal trabecula = elevated band w/c bridges interventricular septum &

anterior wall near apex = transmits right branch of conducting system

• papillary muscles = column-like projections fr trabeculae

3 sets: anterior - most constant & largestposterior

septal

R VENTRICLE

• chordae tendinae = fibrous cords attached to apices of papillary muscles fr cusps of valves

• function of papillary muscle & chordae: * prevent eversion of cusps of valves into atrium

R VENTRICLE

VENTRICULAR SEPTAL DEFECT

• Congenital or acquiredCongenital or acquired• Hole/s in interventricular septum (IVS)Hole/s in interventricular septum (IVS)• May be part of other major cardiac anomaliesMay be part of other major cardiac anomalies

VENTRICULAR SEPTAL DEFECT

VSD PATCH CLOSURE

3. L ATRIUM

• smaller but thicker smaller but thicker wall (vs. RA)wall (vs. RA)

• base base of heartof heart

• most common site of most common site of benign cardiac tumors benign cardiac tumors called myxomacalled myxoma

2 parts:2 parts: 1. Principal cavity1. Principal cavity

= contains openings of 4 = contains openings of 4

pulmonary veinspulmonary veins

=AV opening [mitral valve] =AV opening [mitral valve] is smaller than Ris smaller than R

= smooth surface= smooth surface

L ATRIUM

2. Auricle2. Auricle

= longer & narrower = longer & narrower (vs RA)(vs RA)

= interior marked by = interior marked by ridges of musculi ridges of musculi pectinatipectinati

L ATRIUM

4. L VENTRICLE

• more work than RV ~pump into systemic circulation

• longer , more conical, thicker walls than RV

• trabeculae carnae are trabeculae carnae are more numerous & more numerous & densely packeddensely packed

• papillary muscles are papillary muscles are largerlarger

• Interventricular septumInterventricular septum• > oblique position> oblique position

L VENTRICLE

SKELETON OF THE HEART

• formed by merging of fibrous formed by merging of fibrous ringsrings

• attachment for myocardiumattachment for myocardium• attachment for cusps of attachment for cusps of

valvesvalves• keep valves patent & from keep valves patent & from

overdistensionoverdistension

• ““Wringing” of blood inWringing” of blood in• Allows myocardium to contract against a rigid Allows myocardium to contract against a rigid

basebase• Provides connective tissue skeleton for Provides connective tissue skeleton for

controlled contraction of the heart controlled contraction of the heart

componentscomponents::1. 1. 4 fibrous rings4 fibrous rings = each = each

encircles a valve encircles a valve 2. 2. 2 fibrous trigones2 fibrous trigones = bet = bet

aortic ring and AV ringaortic ring and AV ring3. 3. tendon of conustendon of conus

• modified cardiac muscles w/ power of modified cardiac muscles w/ power of spontaneous rhythmicity & conductionspontaneous rhythmicity & conduction

• more highly developed than rest of the heartmore highly developed than rest of the heart

CONDUCTING SYSTEM

CONDUCTING SYSTEMParts:Parts:

1. 1. SINOATRIAL (SA) NodeSINOATRIAL (SA) Node - in crista terminalis at junction of SVC-RA- in crista terminalis at junction of SVC-RA - not visible grossly- not visible grossly - initiates contraction of heart - initiates contraction of heart

internal internal PACEMAKERPACEMAKER2. 2. Atrioventricular (AV) nodeAtrioventricular (AV) node - near orifice of coronary sinus in septal wall - near orifice of coronary sinus in septal wall

of RAof RA

3. 3. Atrioventricular bundle (Bundle of His)Atrioventricular bundle (Bundle of His)• begins at AV node & follows along membranous begins at AV node & follows along membranous

septum towards the L AV opening for a distance septum towards the L AV opening for a distance of 1-2 cmof 1-2 cm

a. Right branch a. Right branch →→ RV RV b. Left branch b. Left branch →→ LV LV

4. 4. Purkinje fibersPurkinje fibers• terminal conducting fibersterminal conducting fibers• ramify on individual fibers throughout ventricleramify on individual fibers throughout ventricle

CONDUCTING SYSTEM

Conduction pathway:• SA node ---> AV node ---> AV bundle ----> bundle SA node ---> AV node ---> AV bundle ----> bundle

branch ----> Purkinje fibersbranch ----> Purkinje fibers

Cardiac Plexus

• Controls impulse conduction for the Controls impulse conduction for the ♥♥• Enables Enables ♥♥ to respond to to respond to ΔΔ-ing physiological -ing physiological

needsneeds• located at base of located at base of ♥♥• extends fr trachea to aortic arch, pulmonary extends fr trachea to aortic arch, pulmonary

trunk & ligamentum arteriosumtrunk & ligamentum arteriosum

1. Parasympathetic – fr Vagus n1. Parasympathetic – fr Vagus n- ↓ ↓ in heart ratein heart rate- ↓ ↓ force of heartbeatforce of heartbeat- constricts CAsconstricts CAs

2. Sympathetic - fr cervical & thoracic ganglia2. Sympathetic - fr cervical & thoracic ganglia - ↑ in heart rate- ↑ in heart rate- ↑ ↑ force of heartbeatforce of heartbeat- dilates CAsdilates CAs

Cardiac Plexus

Sympathetic

Subdivisions:Subdivisions:1. Superficial cardiac plexus1. Superficial cardiac plexus

-lies in arch of aorta -lies in arch of aorta 2. Deep cardiac plexus2. Deep cardiac plexus

-deep to arch of aorta-deep to arch of aorta

Angina Pectoris & Myocardial Infarction

• Cardiac referred pain Cardiac referred pain • Commonly present as:Commonly present as:

• SubsternalSubsternal• L pectoral L pectoral • L arm medialL arm medial

• Less common Less common →→ R shoulder & arm R shoulder & arm• w/ or w/o concommitant L side painw/ or w/o concommitant L side pain

Cardiac referred pain

• Heart insensitive to touch, cutting, cold & Heart insensitive to touch, cutting, cold & heatheat

• Ischemia Ischemia + accumulated metabolic products + accumulated metabolic products ~ stimulate pain endings in myocardium~ stimulate pain endings in myocardium

• Sympathetic trunkSympathetic trunk

Blood SupplyCoronary arteries Coronary arteries

- fr aortic sinus of - fr aortic sinus of ascending aortaascending aorta1) Right 1) Right 2) Left 2) Left

Right coronary artery (RCA)branches:branches: 1. posterior interventricular 1. posterior interventricular

branch = supplies branch = supplies diaphragmatic surface of diaphragmatic surface of both ventricles, both ventricles, longestlongest

2. marginal2. marginal 3. br to SA node3. br to SA node 4. br to AV node4. br to AV node 5. br to conus 5. br to conus

Left coronary artery (LCA)• bifurcates into:bifurcates into:

1. anterior interventricular 1. anterior interventricular = both ventricles, = both ventricles, interventricular septum, interventricular septum, conusconus

2. circumflex 2. circumflex Branches :Branches :-Posterior L ventricular art-Posterior L ventricular art-Marginal-Marginal-Intermediate-Intermediate-branch to SA node & AV -branch to SA node & AV

nodenode

Coronary Angiogram

1.1. coronary sinus coronary sinus

~ main venous drainage (except ~ main venous drainage (except 2.2.))

~ opens into RA ~ opens into RA

2.2. small veins ~ drain directly into chambers small veins ~ drain directly into chambers

- - venae cordis minimae

- anterior cardiac v

Venous system

Venous Drainage

Coronary sinus tributaries:Coronary sinus tributaries:

1. Great cardiac1. Great cardiac 2. Middle cardiac2. Middle cardiac

3. Small cardiac3. Small cardiac4. Left posterior 4. Left posterior ventricular ventricular 5. Left oblique atrial5. Left oblique atrial

Myocardial ischemia

- insufficient blood supply to heart- insufficient blood supply to heart

- necrosis of an area of myocardium - necrosis of an area of myocardium

- Myocardial Infarct or MI - Myocardial Infarct or MI

Common sites of coronary occlusion: “ Triple vessel disease”

1. Anterior interventricular branch of Left coronary 1. Anterior interventricular branch of Left coronary art (LCA)art (LCA)

2. Circumflex branch of LCA2. Circumflex branch of LCA

3. Posterior interventricular branch of RCA3. Posterior interventricular branch of RCA

Most common cause of coronary occlusion :

AtherosclerosisAtherosclerosis

Heart-Lung Bypass Machine

Internal Mammary Artery Grafts

CORONARY ARTERY BYPASS GRAFTING (CABG)

THANK YOU

Anatomy: Heart and Pericardium

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