Heart Flashcards
coronary angiography
catheter passed into ascending aorta through some artery (often femoral) and injection of radioplaque allows examination of coronary arteries with angiograms
echocardiography
method of graphically recording ultrasound results of the position of heart and motion of the heart
doppler echocardiography
demonstrates and records the flow of blood through the heart and great valves–used for diagnosing septal defects
coronary artery disease
One of leading causes of death. Also know as coronary heart disease and results in reduced blood supply to the vital myocardial tissue. Has many causes including myocardial infarction, coronary atherosclerosis, and slowly progressive coronary artery disease
myocardial infartion
Sudden occlusion of a major artery by an embolus. Region of myocardium supplied by occluded vessel becomes infarcted (rendered bloodless) and undergoes necrosis.
The area of myocardium that has undergone necrosis constitutes the “myocardial infraction”
most common areas of occlusion for MI
- anterior IV (LAD) branch of the LAD (40-50%)
- RCA (30-40%)
- Circumflex branch of the LCA (15-20%)
coronary atherosclerosis
Lipid deposits in intima (lining layer) of coronary arteries and results in stenosis of the lumina in the arteries
-may be compensated for by collateral channels expanding, but myocardium may still not receive enough blood and myocardial ischemia may result in MI
slowly progressive coronary artery disease
The slow occlusion of a coronary artery. Effects may be lessened by increased collateral branches and anastomosis that are beneficial for CAD, but may not be able to prevent a sudden artery occlusion
Angina pectoris
Pain that originates in the heart. Brief but mod. severe constricting pain deep to the sternum such as tightness in the thorax. Result of ischemia that falls short of necrosis.
- often caused by periods of anaerobic metabolism and lactic acid in myocardium
- relieved by rest or sublingual nitroglycerin (dilation of arteries)
coronary bypass surgury
Segment of artery or vein connected to ascending aorta and anastomosed with cardiac artery distal to stenosis. Often use great saphenous vein or radial artery
percutaneous transluminal angioplasty
Pass a catheter with small inflatable balloon attached to its tip into obstructed artery and inflate to flatten atherosclerotic plaque, increasing circulation
thrombokinase
enzymes injected via catheter to dissolve a blood clot.
intravascular stent
Maintain dilation of artery. composed of rigid or semirigid tubular meshes collapsed during introduction.
collateral circulation of smallest cardiac veins
reversal of flow may bring luminal blood to capillary beds improving circulation, but not likely able to prevent MI
electrocardiogram
ECG or EKG. Recording of passage of electrical impulses over the heart from the SA node
heart block
Branches supplying AV bundle (LAD), or SA and AV nodes (RCA), are affected by an occlusion leading to damage to parts of conduction system.
-ventricles begin to contract independently at their own rate (25-30 times per minute)
bundle branch block
Damage to one branch bundle will result in excitation continuing in unaffected branch, with normal contraction rate that then spreads to other ventricle via myogenic contraction producing a late asynchronous contraction.
Artificial cardiac pacemaker
A pulse generator (battery pack), a wire and an electrode are implanted and the wire is inserted through a vein followed with a fluoroscope. The terminal electrode passed through SVC to right atrium and through the tricuspid valve into right ventricle and fixed to trabeculae carneae
Fibrillation
Multiple, rapid, circuitous contractions or twitching or muscular fibers including cardiac muscle.
- atrial fibrillation: uncoordinated twitching of different parts of atrial walls with ventricles responding at irregular intervals. circulation usually satisfactory.
- ventricular circulation: rapid twitching movements that do not pump. fatal if allowed to persist
defibrillation
electric shock to heart given through thoracic wall via large electrodes ceases all of the cardiac movements and a few seconds later the heart may restart
cardiac referred pain
Anginal pain is felt as radiating from the substernal and left pectoral regions to the left shoulder and the medial aspect of the left upper limb (innervated by medial cut. n.).
Visceral afferent nerves coming from the heart, and which follow the sympathetic nerves, synapse with somatic afferent neurons (say from the arm) in the spinal chord, often through T1-T5.
