Cardiovascular System Flashcards
Function of Cardiovascular System
Delivers O to organs and tissues, removes carbon dioxide and other by-products from body & assists reg of core body temperature
Heart Tissue (4 Layers)
Pericardium (outer, fibrous layer enclosing heart), Epicardium (inner layer of peri), Epicardium (heart muscle, major portion of the heart), Endocardium (smooth lining of inner surface and heart cavities)
Heart Chambers
R Atrium: Receives blood from systemic circulation during systole (contraction) blood is sent to right vent; R Vent: pumps blood via pulmonary artery to lungs for O; L Artium: receives O blood from lungs and 4 pulmonary veins during systole (contraction) blood sent to left vent; L Vent: pumps blood via aorta thru out entire systemic circulation. *Walls of vent are thicker/stronger than left
Flow of Blood
Systemic circulation from R Atrium > R Vent oxygenation > L Atrium > L Vent
Atriventricular & Semilunar Valves
A= prevents blood back flow into atria during vent systole - tricuspid= right heart valve/bicuspid= left heart vlalve - S= Prevents blood back flow from aorta & pulmonary arteries
Systole vs Diastole
S= period of vent contraction; D= period of vent relax and filling of blood
RCA vs LCA
R Coronary Artery: supplies R atrium, most of R vent, inf wall of L vent; Left Coronary Artery: supplies most of L vent & has 2 main divisions
Sinoatrial Node
Main pacemaker of heart, indicates sinus rhythm - affects both HR and strength of contraction. Where hear beat begins
Arteries
Transport oxygenated blood from areas of high pressure to low in body tissues.
Hyperkalemia
Increased K ions; increases rate/force of contraction & produces EKG changes
Hypokalemia
Decreased K ions; EKG changes, arrhythmias > may progress to ventricular fib
Hypercalcemia vs Hypocalcemia
Increased Ca concentration; increases HR vs Decreased Ca concentration; decreases HR
Increased vs Decreased peripheral resistance
I= increases arterial blood vL & pressure while D= decreases arterial blood vL & pressure
Coronary Artery Disease (CAD)
Atherosclerotic (plaque build up in arteries) disease process that narrows lumen of coronary arteries resulting in ischemia (decreased blood supply) to myocardium; Lipid-laden plaques affecting mod/large arteries - results in thickening of intimal layer
CAD risk factors
Age, gender, race, fam hx, smoking, high BP, hich cholesterol & low density lipoprotein (LDL), elevated homocystine, stress, DM, obesity, sedentary lifestyle
Angina Pectoris
Clinical manifestation of ischemia characterized by mild-mod substernal chest discomfort (most commonly pressure/dull ache in chest & L arm>but can be felt anywhere in UE). Usually lasts 20min-increased heart demands
Angina Types
Stable: classic, occurring during exercise/activity -relieved w rest and/or subling nitroglycerin; Unstable (preinfarction): coronary insuff at rest w/o any precipitating factor - pain diff to control, can lead to lethal arrhythmia; Variant (Prinzmetal’s): vasospasm of coronary arteries w absence of occlusive disease - responds well w nitroglycerin or Ca channel blocker LT
Myocardial Infarction (MI)
Prolonged ischemia, injury and death of an area of myocardium caused by occlusion of one(+) coronary arteries - results in necrosis of heart tissue
MI Precipitating Factors and Symptoms
Atherosclerotic heart disease w thrombus formation, coronary vasospasm/embolism; coke toxicity. Severe sternal pain for20(+)min that may radiate up, dyspena, indigestion, pain unrelieved by rest/sibling nitroglycerin
3 Infarction Sites
Transmural (Q wave)= full thick of myocardium; Nontransmural (non-Q wave) & Coronary Artery Occlusion= Inf MI: R Vent infarct (R coronary artery); Lat MI: ventricular ectopy (circumflex artery); Ant MI: (L ant descending artery)
Heart Failure
Heart is unable to maintain adequate circulation of blood to meet metabolic needs of body; Decreased cardiac output, elevated end diastolic pressure, increased HR, impaired vent contractibility > variety of causes (CAD, congenital heart disease, valvular disease, HTN, infection)
L-side HF (CHF)
Blood not adequate pumped into systemic circulation; Characterized by pulmonary congestion, edema, low cardiac output d/t back up of LV to LA and lungs > occurs w insult to LV from myocardial disease, excessive workload of heart, arrhythmias or damage
R-Side HF
Blood not adequately returned from systemic circulation to heart. Characterized by increased pressure load on RV > occurs w insult to RV from LV failure, mitral valve disease, chronic lung disease
Biventricular Failure
Sever LV pathology producing back up into lungs, increased PA pressure, and RV signs of HF
LV Failure: Signs of Pulmonary Congestion
Dyspena, dry cough, orthopena, paraxysmal nocturnal dyspena (PND), pulmonary rales, wheezing
LV Failure: Sings of Low Cardiac Output
Lightheaded, dizzy, hypotension, tachycardia, cerebral hypoxia (confusion, restlessness, impaired mem), fatigue, poor exercise tolerance, enlarged heart, murmurs
RV Failure: Signs of Pulmonary Congestion
Dependent edema, weight gain, ascites (abdom swelling d/t fluid build up), liver enlargement (hepatomegaly)
RV Failure: Sings of Low Cardiac Output
Anorexia, nausea, bloating, cyanosis of nailbeds, R upper quadrant pain, jugular vein distension, murmurs
Angioplasty
Relieves obstructed blood flow in acute angina or MI> results in improved coronary blood flow, improved L vent fx and anginal relief
Intravascular Stents
Prevents occlusion in coronary or peripheral arteries
CABG
Revascularization surgery: multiple grafts may be needed> results in improved coronary blood flow & LV fx, anginal relief, surgery results in deconditioning
Transplantation
Used w end stage myocardial disease. Heterotopic involves leaving natural heart and piggybacking donor; Orthotopic replacement heart. (Probs: rejection, infection)
