Coronary & Conductance Systems

Name the anterior sulci of the heart

Coronary sulcus

Anterior interventricular sulcus

Name the posterior sulci of the heart

Coronary sulcus

Posterior interventricular sulcus

What runs through the anterior interventricular sulcus

Great cardiac vein

Anterior interventricular branch of the left coronary artery

What runs through the coronary sulcus

Right coronary artery

Coronary sinus (with great & small cardiac vein)

Circumflex branch of the left coronary artery

(coronary sulcus runs almost completely around top of heart) (2 arteries, 2 veins & a sinus)

What runs through the posterior interventricular sulcus

Posterior interventricular branch of the right coronary artery

Middle cardiac vein

What decides if a heart is right/left side dominant

Whether the posterior interventricular artery branches from the right coronary artery (right side dominant) or the circumflex branch of the left coronary artery (left side dominant)

Are right or left side dominant hearts more common - what percentages

Right side are more common (90%)

Blood supply to SA node

Sinu-atrial nodal branch of the right coronary artery

What is the typical branching pattern of the major coronary arteries

Generally 2 marginal & 1 diagonal

• Right marginal branch of right coronary artery

• Left marginal branch of circumflex branch

• Diagonal branch of anterior interventricular branch

Branches of the right coronary artery

Branches of the left coronary artery

What does the right coronary artery supply

What does the left coronary artery supply

Which branch would be most detrimental to stop working

anterior interventricular branch of the left coronary artery (Left anterior descending LAD)

The LAD supplies blood to:

Most of the left ventricle, which is the heart's main pumping chamber.

The anterior 2/3 of the interventricular septum, including the bundle branches, which are crucial for electrical conduction.

Parts of the right ventricle.

What do the arrows point towards

stenosis

treatment for stenosis of the coronary arteries.

percutaneous intervention (stent)

Through what vessel is a stent fed to get to a coronary artery

Femoral artery

myocardial infarction

heart attack

Occlusion of what causes an anterior infarct

left anterior descending branch aka anterior interventricular branch of the coronary artery

What does an anterior infarct affect

Left ventricular wall & interventricular septum without blood

Occlusion of what causes an anterolateral infarct

left circumflex coronary artery

marginal branch of the left circumflex artery

or

Diagonal branch of the left anterior descending artery

What does an anterolateral infarct impact

Lateral wall of the left ventricle

The posterior wall (if the left is dominant)

Occlusion of what causes a true posterior infarct

Distal circumflex artery

&

Inferior interventricular branch of the coronary artery

(all arteries on the post. surface of the heart)

What does a true posterior infarct affect

Posterior left ventricle

Occlusion of what causes a diaphragmatic / inferior infarct

Right coronary artery

What does a diaphragmatic / inferior infarct affect

Posterior wall of the left ventricle

The interventricular septum (if the right is dominant)

What are the 3 most common artery occlusions that cause a myocardial infarction. What is their percentage occurrence in a myocardial infarction

Left circumflex: 15-20%

Right coronary: 30-40%

Left anterior descending (LAD): 40-50%

What vessels are used to create a coronary artery bypass graft (main & 2 alternative)

Superficial veins of lower limb - e.g. short saphenous vein (from great saphenous vein) (or internal thoracic/radial artery)

Alternative treatment to coronary artery bypass graft

Stent placement using Coronary angioplasty

What are the small coronary veins called

Anterior cardiac veins

Thesbian veins

Where do the anterior cardiac veins drain into

Directly into the right atrium

Thesbian veins are aka

venae cordis minimae

What do thesbian veins drain

drain blood directly from the myocardium into the atria and ventricles.

The anterior interventricular vein along its course becomes what

The great cardiac vein

What veins run in the posterior interventricular sulcus

The middle cardiac veins

The great, middle & small cardiac veins drain their blood into _________ which drains into _______

The coronary sinus

The right atrium

What are the components of the conducting system

Where in the heart does the AV bundle run

The interventricular septum

What conductor does the septomarginal trabeculum come off

Atrioventricular node → Atrioventricular bundle → Right bundle branch → Septomarginal trabecula

What are the steps of impulse conduction through the heart

SA node activity and atrial activation begin

Stimulus spreads across the atrial surfaces and reaches the AV node (takes 50 msec)

There is a 100 msec delay at the AV node. Atrial contraction begins.

The impulse travels along the interventricular septum within the AV bundle and the bundle branches to the Purkinje fibres (takes 25 msec)

The impulse is distributed by Purkinje fibres and relayed throughout the ventricular myocardium. Atrial contraction is completed and ventricular contraction begins. (50 msec)

What activities in the heart cause what parts of the ECG

How do endocardial leads of a pacemaker reach the heart

Introduced via the subclavian(/brachiocephalic) vein, through the vena cava to the right atrium

Where is the pulse generator placed in a pacemaker

What fibres of the ANS are involve in cardiac innervation

Post-ganglionic fibres

What nerves are associated with preganglionic & postganglionic fibres

the sympathetic trunk provides sympathetic innervation

the vagus nerves provide parasympathetic innervation

What in the cardiac system is the ANS responsible for

The Autonomic Nervous System is directly responsible for regulating heart rate, force of contraction and cardiac output

Effect of parasympathetic stimulation on heart

Parasympathetic decrease heart rates, reduces force of contraction and constricts Coronary Arteries

Effect of sympathetic stimulation on heart

Sympathetic increase heart rate and increase force of contraction

Branches from parasympathetic (Vagus) and sympathetic (Trunk) systems contribute to the cardiac plexus. The plexus has how many parts

Cardiac plexus has two parts – Superficial and Deep

Visceral Afferents travel from the _____ to the ______ carrying what

Visceral Afferents travel from the heart to the CNS carrying information regarding Cardiac Homeostasis (Blood Pressure / Biochemistry) and Pain

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