cardiovascular anatomy and physiology afams residency orientation april 16, 2012 armed forces...
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Cardiovascular Anatomy and Physiology
AFAMS Residency OrientationApril 16, 2012
ARMED FORCES ACADEMY OF MEDICAL SCIENCES
Heart Facts• Human heart is 13 x 9 cm• Weighs about 1 kg• Beats 100, 000 times a day• Pumps 7600 L of blood
daily• Circulates blood
completely about 1000 x a day
• Pumps blood through 100,000 km of vessels
• Cardiovascular Death is most common cause of death worldwide
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Purpose of Cardiovascular System
• Deliver blood to tissues and organs– Nutrients– Oxygen
• Remove used blood from organs and tissues– Deoxygenated
hemoglobin• Deliver deoxygenated
blood to lungs for re-oxygenation
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Cardiac Anatomy: Chambers
• Right Atrium (RA)– Receives deoxygenated blood from
venous circulation– Pumps blood to RV
• Right Ventricle (RV)– Receives deoxygenated blood from
RA– Pumps deoxygenated blood to
lungs• Left Atrium (LA)
– Receives oxygenated blood from pulmonary vein
– Pumps blood to LV• Left Ventricle (LV)
– Receives oxygenated blood from LA
– Pumps oxygenated through aorta to body
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Cardiac Anatomy: Valves
• Classification– A-V valves
• Tricuspid– Separates RA and RV
• Mitral– Separates LA and LV
– Systemic Valves• Aortic
– Separates LV and Aorta
• Pulmonic– Separates RV and
Pulmonary artery
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Aortic Valve Mitral Valve
Cardiac Anatomy: Outflow
• Pulmonary Artery– Arising from Right
Ventricle (RV)– Blood from RV to lungs
• Aortic Arch– Arising from Left Ventricle
(LV)– Blood from LV to body
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Cardiac Anatomy: Coronary Arteries
• Left Main (LM)• Left Anterior Descending
(LAD)– Septal Perforating Branches– Diagonal Branches
• Left Circumflex (LCx)– Obtuse Marginals
• Right Coronary Artery (RCA)– Acute Marginals– Posterior Descending– Posterior Lateral Branch
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Coronary Anatomy
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LAO Caudal View LAO Cranial View
OM1
LM
RCA
D1LCx
LADLM
PLB
PDA
Left Ventricular Volumes
• End Diastolic Volume (EDV)– Volume of blood in LV
and end diastole– Directly proportional to
venous return• End Systolic Volume
(ESV)– Volume of blood in LV at
the end of systole (contraction)
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Left Ventricular Volumes
• Stroke Volume (SV)– EDV - ESV
• Ejection Fraction (EF)– SV/EDV– Normal resting EF: 60%
• Best predictor of heart performance and heart disease prognosis
– Normal exercising EF: 80%
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Cardiology Physiology• Cardiac Output (CO)
– HR x SV• Cardiac Index (CI)
– CO / BSA• Preload
– Volume of blood in the left ventricle at end diastole
– Dependent upon venous return and compliance of left ventricle
• Afterload– Amount of resistance the heart
has to overcome to pump blood forward
• Mean Arterial PressureARMED FORCES ACADEMY OF MEDICAL
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Cardiology Physiology
• Myocardial Contractility – Amount of force with
which the heart contracts at a given preload
– Dependent upon• Sympathetic Nerve activity• Catecholamines• Myocardial mass• Drugs
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Contractility
• Increased Cardiac Contractility– Exercise: increased sympathetic tone– Catecholamines: epinephrine and norephinephrine– Excitement / Fear: Fight of flight response– Drugs: Digitalis and sympathomimetics
• Decreased Cardiac Contractility– Loss of Contractile Mass: Secondary to myocardial
infarction– Myocardial muscle disease: Cardiomyopathy– Drugs: anesthetics and barbituates
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Starling Curve• In a normal heart
– Increasing preload (EDV or EDV) increases SV
– Increasing contractility increases stroke volume at a constant preload
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Definitions• Systolic Blood Pressure (SBP):
blood pressure in brachial artery during systole
• Diastolic Blood Pressure (DBP): blood pressure in brachial artery during diastole
• Mean Arterial Pressure (MAP): average blood pressure against the walls of the aorta throughout a complete cardiac cycle– MAP = [(2 x DBP) + SBP] / 3
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Abdominal Blood Supply
Importance:• Surgical Procedures• Renal Artery Stenosis• Embolic Events to the
GI tract• Watershed areas• Differential diagnosis of
abdominal organ failure• Nutritional Implications
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Vascular Anatomy of the Neck
Importance:• Central Venous Access
– Internal Jugular Vein– Subclavian Vein
• Stroke– Carotid artery
arteriosclerosis
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Arteries of the Brain
Importance:• Localizing site of stroke• Watershed areas• Localizing site of
aneurysm• Importance of
understanding cerebral perfusion
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Arteries of the Brain
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3D MRI with Gadolinium
Gross Anatomy of Circle of Wilis
Arm Vasculature
Importance:• Placement of peripheral
IVs• Central Venous
Catheters– Brachial vein
• Placement of radial arterial line
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Lower Extremity Vascular Anatomy
• Importance:• Central Venous
Catheter– Femoral Vein
• Arterial Line– Femoral Arterial
• Localizing Peripheral Arterial Disease
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Lower Extremity Vascular Anatomy
• Angiogram of Peripheral arterialDisease
CFA: Common femoral arteryDFA: Deep Femoral ArterySFA: Superficial Femoral Artery
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