6. Thoracic Cardiology (Olinger) Flashcards
Border of mediastinum
Divisions of the Mediastinum: Superior and Inferior Mediastinum are separated by the Sternal Angle.
The Inferior Mediastinum is further divided into Anterior,
Middle and Posterior Mediastinum.
The Anterior Mediastinum is anterior to the Heart.
The Middle Mediastinum is the Heart.
The Posterior Mediastinum is posterior to the Heart.
Layers of the pericardium
Visceral serous pericardium, parietal serous pericardium, with pericardial cavity in between. The most exterior layer is the fibrous pericardium.
Transverse and oblique pericardial sinuses
The SVC, IVC and pulmonary veins are partly covered by serous pericardium as they enter the heart. This covering is the Oblique Pericardial Sinus (a wide recess posterior to the base of the Heart). The oblique sinus can be entered inferiorly and will admit several fingers, but the fingers cannot pass around the vessels because the sinus is a blind area (cul-de-sac).
A finger can be inserted through the Transverse Pericardial Sinus (transverse passage traversing the origins of the great vessels) where the aorta and the pulmonary trunk leaves heart. This is located posterior to the large vessels, and anterior to the SVC.
Heart surfaces
- Sternocostal (Right Ventricle)
- Diaphragmatic (Right and Left Ventricles)
- Pulmonary (Paired; Right Atrium and Left Ventricle, occupying the Cardiac Impression on both Lungs)
Heart borders
o Right (Right Atrium)
o Inferior (Right Ventricle)
o Left (Left Ventricle)
o Superior (Right and Left Atria and the exit point for the Aorta and Pulmonary Trunk
External grooves
- Right Atrioventricular Groove (between the Right Atrium and Right Ventricle, transmits the Right Coronary A.)
- Left Atrioventricular Groove (between the Left Atrium and Left Ventricle, houses the Coronary Sinus)
- Anterior Interventricular Groove (between Right and Left Ventricles on the anterior aspect of the Heart, transmits the Anterior Interventricular A. and Great Cardiac V.)
- Posterior Interventricular Groove (between Right and Left Ventricles on the posterior aspect of the Heart, transmits the Posterior Interventricular A. and the Middle Cardiac V.)
- Sulcus Terminalis (external vertical groove corresponding to the internal Crista Terminalis)
- Ligamentum Arteriosum (embryological remnant of the Ductus Arteriosus, communication between the Pulmonary Trunk and the Arch of the Aorta)
Right Atrium features
o Sinus Venarum (posterior, smooth, thin walled region where the Venae Cavae and Coronary Sinus empty)
o Pectinate Muscle (anterior, rough muscular wall
- Right Auricle
o Crista Terminalis (internal ridge separating smooth and rough regions)
o Opening for the Coronary Sinus
o Interatrial Septum (wall between the two Atria)
- Fossa Ovalis (embryonic remnant of the Foramen Ovalis)
Right Atrioventricular Orifice
Passage from Right Atrium to Right Ventricle, variably occluded by the Tricuspid Valve
Right Ventricle - tricuspid valve
Anterior Cusp
Posterior Cusp
Septal Cusp
Chordae Tendineae (attach free edges of the three cusps to three corresponding Papillary muscles)
Anterior Papillary M. (joined to the Anterior Cusp of the Tricuspid valve via Chordae Tendineae)
Posterior Papillary M. (joined to the Posterior Cusp of the Tricuspid valve via Chordae Tendineae)
Septal Papillary M. (joined to the Septal Cusp of the Tricuspid valve via Chordae Tendineae)
Right Ventricle - Trabecula Carnae
Septomarginal Trabeculum (Moderator Band; from the Interventricular Septum to the Base of the Anterior Papillary M., transmits the right bundle branch of Atrioventricular bundle to the Anterior Papillary M.)
Right Ventricle - Conus Arteriosus
smooth-walled, leads into the Pulmonary Trunk
Pulmonary valve
Semilunar valve possessing Right, Left and Anterior Cusps, separates Right Ventricle from the Pulmonary Trunk
Pulmonary sinuses
Around pulmonary valve. Space between the wall of the Pulmonary Trunk and the Cusps of the Pulmonary Valve
Left Atrium
thicker-walled than the Right Atrium:
o Left Auricle (contains Pectinate M.)
o Openings for the 4 Pulmonary V.
o Interatrial Septum
Left Atrioventricular Orifice
passage from Left Atrium to Left Ventricle, variably occluded by the Bicuspid Valve
Left Ventricle - valves
Bicuspid (mitral) valve, which separates the left atrium from the left ventricle
Anterior cusp
Posterior cusp
Chordae tendineae (attach free edges of the two cusps to ventricular surfaces)
Anterior papillary m. (joined to the anterior cusp of the bicuspid valve via chordae tendineae)
Posterior papillary m. (joined to the posterior cust of the bicuspid valve via chordae tendineae)
Left Ventricle - Trabecula crane
rough muscular region
Left Ventricle - aortic vestibule
smooth-walled, leads into the ascending aorta
Interventricular septum
myocardial wall separating the two ventricles, houses the Atrioventricular Bundle, Right and Left Bundle Branches and Subendocardial Branches. Described as having Membranous (Fibrous) part that belongs to the Fibrous Skeleton of the Heart and a much larger Muscular part
Interatrial septum
separating the atria, has an oval, thumbprint sized depression, the oval fossa.
Interventricular septa
is a strong, obliquely placed partition between the right and the left ventricles. The membranous part of the IV septa is thin and continuous with the fibrous skeleton of the heart. The muscular part is think and bulges into the cavity of the right ventricle d/2 higher pressure in the left ventricle.
Location of heart valves
Aortic valve: 2nd intercostal space to right of the sternal border
Pulmonary valve: 2nd intercostal space to the left of sternal border
Tricuspid valve: near left sternal border in 5th or 6th intercostal space
Mitral valve: apex of heart in 5th intercostal space in midclavicular line
Roles of the fibrous skeleton
Four bands of Connective Tissue that surround 1) base of pulmonary trunk, 2) aorta, 3) mitral, and 4) tricuspid valves
Functions:
- keeps semilunar valves patent and prevents them from being overly distended
- attachment for leaflet of cusps
- electrical insulator
- consists mainly of protein collagen; a type of glycoprotein found in CT
Electrical flow through the heart
SA node AV node Bundle of His Purkinje fibers --> right and left atrium --> then right and left ventricles contract
myocardial infarction
lack of blood flow to a specific area of the myocardium, usually the result of a blockage in a Coronary A. Coronary Atherosclerosis, or buildup of lipids on the internal walls of the Coronary arteries decreases the size of lumen of that vessel, increasing the likelihood of an embolus, or plug blocking a vessel off entirely.
angina pectoris
Pain that originates in the heart and produces a strangling pain of the chest. Angina Pectoris literally means strangling pain of the chest. The main is usually the result of narrow or obstructed coronary arteries that produces ischemia of the myocardium.
Cardiac Referred Pain
Ischemia stimulates visceral pain sensory fibers in the heart of the Autonomic Nervous system. These visceral sensory fibers often share a spinal ganglion with the somatic sensory fibers of areas such as the upper limb and superior lateral chest wall.
* Left Medial Brachial Cutaneous nerve
Ligamentum Arteriosum
Travels from the superior aspect of the Pulmonary Trunk to the inferior concave border of the Aortic Arch. The Ligamentum Arteriosum is the adult remnant of the embryological Ductus Arteriosus which shunted blood from the Pulmonary Trunk to the Aorta to bypass the nonfunctional lungs.
Cardiac Catheterization
Insertion of a catheter into the femoral vein which is then passed up to the Inferior Vena Cava allowing radiographic visualization of the Right Atrium, Right Ventricle, Pulmonary Trunk and Pulmonary arteries.
Atrial Septal Defects
Typically involves an incomplete closure of the Foramen Ovale. It is estimated that 15-20% of adults have a small patency of their Foramen Ovale which is considered clinically insignificant.
Ventricular Septal Defects
Due to the embryologically divergent tissues that make up the Interventricular Septum that structure is particularly susceptible to defects. All defects are clinically relevant as they allow the mixture of oxygen rich and oxygen depleted blood.
Artificial Cardiac Pacemaker
Produces a regular electrical impulse that is carried to the Ventricles via electrodes which are inserted through a large vein to the Superior Vena Cava, into the Right Atrium past the Tricuspid Valve into the Endocardium of the Trabecula Carnae of the Right Ventricle.
Atrial Fibrillation
Irregular twitching of the Atrial cardiac muscle fibers to which the ventricles respond at irregular intervals. Circulation usually remains satisfactory.
Ventricular Fibrillation
Rapid irregular twitching of the ventricles rendering the Heart unable to pump blood. An electric shock administered by electrodes can cease all cardiac movement (defibrillation), in the hopes that the Heart may begin beating regularly after a period of time
Pericarditis
Inflammation of the pericardium, which can make the pericardium rough and produce friction. This friction called a pericardial friction rub can be observed with a stethoscope. If left untreated the pericardium can calcify.
Pericardial Effusion
Inflammation of the pericardium can result in the accumulation of fluid or pus in the pericardial sac which can compress the heart. Heart compression is known as Cardiac Tamponade.
Pericardiocentesis
Drainage of blood, fluid or pus from the pericardial sac. This is usually done to relieve cardiac tamponade.
