Cardiac Anatomy Flashcards
What structure occupies the central portiono fhte heat and is wedged between all 3 other valves
Aortic valve
Which AV cusp has fibrous continuity with the anterio leaflet of the mitral valve
Non-coronary cusp
Anatomic orientation of the AV groove
Obliquely oriented closer to vertical than horizontal
Two pericardial recesses
- Transverse sinus
- Anterior boarder: posterior surface of aorta/PA
- Posterior boarder: interatrial groove
- Oblique sinus
- Behind LA (between IVC and Pulmonary veins)
Location of phrenic nerve in mediastinum
- Descends anterior to anterior scalne muscle (posterior to IMA)
- Passes anterior to the pulmonary hilum
- Left phrenic: attached to lateral aspect of persistent Left SVC
- Right phrneic: attached to lateral aspect of SVC
Anatomy of vagus nerve in mediastinum
- Courses along carotid arteries and enters thorax posterior to phrenic.
- Descends posterior to pulmonary hilum (phrenic is anterior)
- Left vagus: descends btw LCA and LSC (posterior to Ao Arch), left RLN hooks anterior around ligamentum arteriosum and ascends in TE groove.
- Right vagus: right RLN hooks under RSC artery anteriorly and ascends in TE groove
Coronary arteries arise from what structures
Sinuses of Valsalva
Coronary artery dominance defined by what?
Supply of PDA
(RCA 85% of cases)
Anatomy of LMCA
- Arises from left Sinus of Valsalva
- Courses behind PA and anterior to LA appendage
- Bifurcates into: LAD and LCx
- Trifurcates: LAD, Ramus and OM
Anatomy of LAD
- Courses along interventricular groove towards cardiac apex
- Branches:
- Septal perforators (dive perpendicularly into septum)
- Diagonals (course over LV anterior wall)
- RV branches (course to the RV anterior wall)
Anatomy of Circumflex Artery
- Travels in left AV groove (ends near obtuse margin of LV)
- In Left Dominant circulation, continues in AV groove to supply PDA (10-15%)
- Branches:
- Obtuse marginals (OM): supply lateral wall of LV and posteromedial PM
- Sinoatrial (SA) node branch: 50% of population
Anatomy of RCA
- Arises from right Sinus of Valsalva
- Course: anterior to Ao and descends in right AV groove
- Branches:
- Conal branch: 1st branch, courses left of infundibulum
- Acute marginals: supply anterior RV free wall
- May continue across diaphragmatic surface to supply distal interventricular septum (10-15% pop)
- Bifucates:
- Posterior Descending Artery (PDA)
- Right posterolateral artery (a.k.a. posterolateral ventricular branch [PLVB])
Anatomy of PDA
- Courses along interventricular groove towards apex
- Septal perforators (posteror 1/3 of septum)
Anatomy of PLVB
Provides branches to posterior wall of LV
Venous drainage of heart
- Coronary sinus: 85% of coronary blood flow
- Thebesian veins: 15% of coronary blood flow (directly into RA/RV)
- Anterior interventricular vein: analog to LAD
- Great cardiac vein: travels in AV groove and turns into coronary sinus
- Posterior interventricular vein: analog to PDA
- Last tributary and drains near the coronary sinus orifice
- Explains why RV protection from retrograde cardioplegia can be marginal as cannula is usually inserted beyond entry point of vein.
- Last tributary and drains near the coronary sinus orifice
- Anterior RV veins: form small cardiac vein (right AV groove); drain into CS or RA
Anatomy of Persistent Left SVC
- Usually drains into coronary sinus
- Ineffective to adminster retrograde cardioplegia unless LSVC is occluded and flow diverted.
Anatomy of SA Node
- Junction of RA and SVC (between RA appendage and SVC)
- Horeshoe SA node: draped along SVC/RA junction (10% of patients)
Anatomy of fossa ovalis
- True intra-atrial septum
- Location where LA should be entered for transseptal approach
- Location of PFO
Thebesian valve
Valve of coronary sinus
Eustachian valve
Valve of IVC
Tendon of Todaro
Continuation of Thebesian valve to the Eustacian valve
Important structure lying within Triangle of Koch
AV node
Boundaries of Triangle Koch
- Tendon of Todaro
- Orifice of Coronary Sinus
- Septal leaflet of TV
Anatomic structure located at apex of Triangle of Koch
Bundle of His (prior to branching on the interventricular septum)
Crista terminalis
Confluence of trabeculated RA muscle into a well defined muscle band.
Anatomy of Tricuspid Valve
- Leaflets:
- Anterior
- Septal
- Inferior
- Continutiy with fibrous skelaton of heart
- Does not have true fibrous annulus circumferentially
Important anatomic relationships with Tricuspid Valve
- AV node located at base of septal leaflet
- Aortic valve near junction of septal and anterior leaflets
Surgical access to Left Atrium
- Anterior to right pulmonary veins (Sondargaard’s groove)
- Incision in LA dome
- Transseptal approach via RA (fossa ovalis)
Anatomy of Mitral Valve
- Leaflets:
- Anterior (A1, A2, A3)
- Fibrous continuity with non-coronary cusp of AV
- Anterior in surgeons view
- Covers 1/2 of annular circumference
- Longer leaflet
- Posterior (P1, P2, P3)
- Covers 2/3 of annulus but is short with respect to dept of orifice coverage
- Carpentier segments:
- A1 and P1 most medial (to left in surgeons view)
- Anterior (A1, A2, A3)
Important anatomic relationships to the mitral annulus/valve
- Left side of posterior annulus (P1): circumflex artery
- Right side of posterior annulus (P2/P3): coronary sinus
- A3 segment: AV node
Anatomy of right and left fibrous trigones
- Dense collagenous tissue
- Locations: 10 o-clock and 2 o-clock positions on the annulus
- Anteror to the valve commisures
Anatomy of RVOT
- Infundibulum
- Pulmonic valve (tricuspid)
- No fibrous annulus (suspended in muscle)
- Only valve not connected to fibrous skelaton of heart
RV papillary muscle anatomy
- Anteror PPM
- Medial PPM
- Suspend the Tricuspid Valve
Anatomy of LV
- Inflow: Mitral valve and subvalvular apparatus
- LVOT:
- Mitral-Aortic curtain:
- fibrous sheet extending from the anterior leaflet of MV to mitral-aortic continutiy supporting the left and non-coronary leaflets of the AV
- Mitral-Aortic curtain:
- Left bundle branch:
- enters LVOT posterior to membranous septum (between right and non-coronary AV cusps)
Anatomy of Aortic Valve
- Sinuses of Valsalva/AV Leaflets:
- Right
- Left
- Non-coronary
- Nodule of Arantius: thickened nodule, centrally located on each leaflet at point of coaptation.
Definition of Aortic Root
- Aortic annulus
- AV leaflets
- Sinus of Valsalva
- Sinotubular junction
- Junction at top of commissures
- Point where the sinuses neck down to form the tubular Asc Ao.
Posteromedial papillary muscle blood supply
RCA (90%)
Anterolateral papillary muscle blood supply
LAD and Cx
Average distance from the tips of each papillary muscle to the nearest trigone
~ 23 mm