Blood Supply of the Heart
acute coronary occlusion
** usually due to atherosclerosis can occur due to: 1) Thrombus (local blood clot) or Embolus ( occlusion of distal artery) 2) Muscular spasm in the coronary arteries (usually occurs in people with existing cardiovascular disorders)
Where does the left coronary artery run?
-- Arises from L posterior sinus of aorta -- Runs posterior to pulmonary trunk and turns forward between trunk and the L auricle -- Divides into anterior interventricular and circumflex arteries
Where does the right coronary artery run?
-- Arises in anterior aortic sinus -- Passes between RV infundibulum and right auricle -- Runs downwards in atrioventricular groove -- Turns backwards at inferior border and runs posteriorly
Where does the atrioventricular nodal artery run?
-- Arises near to origin of posterior interventricular artery -- Runs upwards in interatrial septum to supply AV node
Where does the coronary sinus run?
-- Lies in posterior atriventricular groove -- Opens into posterior R atrial wall to L of IVC opening
Where does the great cardiac vein run?
-- Runs alongside the anterior interventricular artery and circumflex artery. -- Enters L end of coronary sinus -- Receives L ventricular tributaries
Where does the circumflex artery run?
-- Runs around in atrioventricular groove to end in anastomosis with termination of R coronary artery -- Gives off the L marginal artery which runs down along L border of heart and supplies L ventricle -- Gives off SA nodal artery in 30-40% of hearts. Runs posterior to root of aorta to supply AV node
small cardiac vein
-- Vein that travels along side the right marginal artery. -- Enters coronary sinus near its termination
Where does the middle cardiac vein run
-- alongside posterior interventricular artery -- Enters coronary sinus near its termination
Left posterior ventricular vein
-- runs near the circumflex artery -- enters coronary sinus to L of middle cardiac vein -drains posterior and L side of heart
Tributaries of coronary sinus
1. Great Cardiac Vein 2. Small Cardiac Vein 3. Middle Cardiac Vein 4. the left posterior ventricular vein 5. Oblique Vein of the Left atrium
Abnormalities of the Coronary artery
1. May arise from single origin 2. Abnormal aortic origin 3. Origin from pulmonary trunk gives rise to myocardial infarction of infancy - this blood is deoxygenated 4. Anterior Interventricular branch is the artery most often affected by atheroma
Where does the left coronary artery supply?
1. Most of left ventricle 2. Most of left atrium 3. Anterior interventricular branch is main supply to interventricular septum including the atrioventricular bundle and its branches in the septum 4. May help to supply or be sole supply to SA and AV nodes
Where does the anterior interventricular artery run?
1. Runs down anterior interventricular groove to anastomose with posterior interventricular branch of R coronary 2. Gives off conus branch near its origin (anastomoses with conus branch of R coronary artery) 3. Gives off several small branches to L ventricle and anterior part of interventricular septum
Where does the right coronary artery supply?
1. right atrium and interatrial septum 2. right ventricle 3. posterior part of L ventricle and interventricular septum 4. SA and AV nodes
What is the sinoatrial (SA) node
A specialized area of cardiac tissue, located in the right atrium of the heart, which initiates the electrical impulses that determine the heart rate; often termed the pacemaker for the heart.
right marginal vein
Accompanies right marginal artery and drains into Small Cardiac vein or directly into the Right Atrium
Where does the right marginal artery run?
Along inferior border of the heart
What is another name for the anterior interventricular artery?
Also called the left anterior descending artery
conus artery
Branch of the right coronary artery that supplies blood to the upper right ventricle; conus arteriousus
Where are the major named arterial branches found?
Deep to epicardium
Coronary sinus
Enlarged vessel on the posterior aspect of the heart that empties blood into the right atrium. Has a single "valve cusp" - Thebesian valve - probable nonfunctional. Has 5 major tributaries.
How does the right coronary artery terminate?
It terminates by anastomosing with termination of circumflex branch of L coronary - gives off R posterolateral branches to L ventricle before it anastomoses
The great cardiac vein drains:
Most of the left side of the heart
In a co-dominant heart, where would the posterior intervetricular artery arise from?
Origin from junction of circumflex and R coronary
In a right dominant heart, where would the posterior intervetricular artery arise from?
Posterior Descending artery arises from Right Coronary Artery (85%)
In a left dominant heart, where would the posterior intervetricular artery arise from?
Posterior descending artery arises from the left circumflex artery (8%)
Arterial supply of the heart
RCA → Marginal a. and PIVA/RPDA LCA → AIVA/LADA and Circumflex a.
Where does the circumflex artery supply?
Supplies blood to the left atrium and posterior walls of the left ventricle
The anterior cardiac veins drains:
The right ventricle and open directly into the right atrium
Where does the sinoatrial nodal artery run?
Usually (about 60% of time), the SA nodal artery is a branch off an atrial artery that arises from the initial part of the right coronary artery, passing between the right auricle and the base of the aorta. The sinuatrial nodal artery then encircles the superior vena cava to end in the SA node.
atrioventricular bundle
a bundle of modified heart muscle that transmits the cardiac impulse from the atrioventricular node to the ventricles causing them to contract
What is antheroma?
a deposit of plaque on or within the arterial wall
atrioventricular (AV) node
a node of specialized heart muscle located in the septal wall of the right atrium; receives impulses from the sinoatrial node and transmits them to the atrioventricular bundle
branches of the left coronary artery
anterior interventricular artery and circumflex artery
Which arteries supply the heart with blood
coronary arteries
Venous drainage of the heart
coronary sinus, great cardiac vein, middle cardiac vein, small cardiac vein
Where does the left coronary artery originate?
left posterior aortic sinus
Lymphatic drainage of heart
lymphatic vessels - subendocardial and subepicardial plexuses - follow the coronary arteries, drainage empties into the brachiocephalic and tracheobronchial nodes
Where does anastomoses between terminal branches occur?
myocardium
venae cordis minimae
numerous small veins that drain the myocardium itself and empty separately into all 4 chambers of the heart
What determines dominance of heart?
origin of posterior interventricular artery can be left or right
The left posterior ventricular vein drains:
posterior and L side of heart
Where does the right coronary artery originate?
right anterior aortic sinus
Where does the coronary sinus drain?
right atrium
The small cardiac vein drains:
right atrium and right ventricle
branches of right coronary artery
right marginal artery and posterior interventricular artery
oblique vein of left atrium
runs downwards to enter coronary sinus near its L end It's seen on the left atrium and drains into the great cardiac vein.
Where does the posterior interventricular artery run?
runs to the apex of the heart
Where does the right marginal artery supply?
serves the myocardium of the lateral right side of the heart
Where does the anterior interventricular artery supply?
supplies blood to the interventricular septum and anterior walls of both ventricles
Where does the posterior interventricular artery supply?
supplies the posterior surface of the left and right ventricles
What is a myocardial infarction?
the occlusion of one or more coronary arteries caused by plaque buildup (heart attack)
The oblique vein of the left atrium drains:
the posterior wall of the left atrium directly into the coronary sinus
conus arteriosus (infundibulum)
the upper smooth-walled portion of the right ventricle, which leads to the pulmonary trunk