Cardio Phys: aSection I: Introduction to Cardiology
Blood from the coronary sinus drains into the right atrium → right ventricle → pulmonary arteries → pulmonary veins → left atrium → left ventricle → aortic root → coronary arteries → coronary sinus.
Describe the coronary circulation.
Blood from the inferior and superior vena cava drains into the right atrium → right ventricle → pulmonary arteries → pulmonary veins → left atrium → left ventricle → aorta → systemic circulation (arteries, arterioles, capillaries, venules, veins) → vena cava.
Describe the pathway of the systemic and pulmonary circulation
The esophagus sits posterior to the left atrium. So dilation of the left atrium would compress the esophagus and compromise swallowing.
PQ: Dilation of what part of the heart can cause dysphagia?
An AV shunt is an abnormal connection between an artery and a vein. This allows blood to go directly from the artery to the vein, bypassing the tissues. This means the oxygen content in the veins would be increased be the capillaries would not be able to carry out gas exchange.
PQ: How would an arteriovenous (AV) shunt alter the oxygen content in the tissues?
The stenosis of the pulmonary artery causes increased blood volume in the right ventricle. This causes regurgitation of blood and increased blood volume in the right atrium as well as increased blood in the coronary sinus. Overall t e pressure would be greater in these areas: CS < RA < RV.
PQ: How would stenosis of the pulmonary artery alter the pressure in the right ventricle, right atrium, and coronary sinus?
An echocardiogram is an ultrasound of the heart to assess how the heart is contracting. RCA supplies a majority of the posterior portion of the right and left ventricles as well as the posterior part of the intraventricular septum. Stenosis would cause decreased activity of the posterior portion of the right ventricle on echocardiogram.
PQ: How would the right ventricle appear on an echocardiogram in a patient with stenosis of the right coronary artery?
Arterioles
PQ: What part of the systemic circulation contributes the most to total peripheral resistance?
The coronary sinus. The large vein on the posterior aspect of the heart. It is not the pulmonary artery because the cardiac muscle is so metabolically active that is pulls oxygen from the blood more efficiently, leaving the venous blood highly deoxygenated.
PQ: What vessel in the body contains the most deoxygenated blood?
Left circumflex artery (LCX) Left anterior descending artery (LAD)
What are the branches of the left coronary artery?
Right (acute) marginal artery Posterior descending artery (PDA) [80% of the time]
What are the branches of the right coronary artery?
Right coronary artery (RCA) Left coronary artery (LCA)
What are the main arteries of the heart that branch from the aorta?
Left circumflex artery
What artery lies underneath the coronary sinus ?
When the patient's right coronary artery branches into the posterior descending artery (this occurs 80% of the time)
What does it mean to have a right dominate circulation?
Anterior wall of the left ventricle Part of the intraventricular septum
What does the LAD supply?
Lateral and posterior walls of the left ventricle
What does the LCX supply?
Right atrium/ventricle Papillary mm of the right ventricle Posterior wall of the heart
What does the right coronary artery supply?
Capillaries
Where does oxygen exchange occur in the tissues?
The PDA can be a branch of the LEFT CIRCUMFLEX ARTERY (occurs 10% of the time)
Where else can the PDA branch from (aside form the right coronary artery)?
