PaPh Assessment 4 Review Assessment 4: Cardiology: Bold things are what teachers said in class to know for test. Resistance= dp/Q = 8ln/(π x r4 ) During diastole, elastic recoil of arteries propels blood into small vessels o Arterioles determine systemic pressure Balance of oncotic and hydrostatic pressure determines where fluid is transported S3 relates to early ventricular filling, S4 relates to early atrial filing (or a stiff ventricle) o Click= aortic pulmonary valve opening, Snap=Mitral tricuspid opening I bands=actin, A bands= thick filaments Series element contract, parallel elements prevent heart from being stretched too far dV/dP= compliance, therefore dP/dV=stiffness Cardiac output= SV x HR SV determined by size of heart, diastolic relaxation, and extent of myocardial shortening Preload, afterload, contractility determine myocardial shortening Blood pressure and ventricular size determine afterload RAAS increases effective blood volume and increases peripheral resistance Coronary blood flow and saturation levels determine oxygen supply, o HR, contractility and wall tension determine oxygen demand Ventricular performance is directly proportional to EDV Three types of coronary disease o Chronic stable angina Exertional angina Person who has a positive treadmill test Increased demand on heart (exercise) results in ischemic conditions due to narrowing of arteries Two determinants of myocardial oxygen demand: Wall Tension Heart Rate o Acute coronary syndrome Ruptured atherosclerotic plaque o ST elevation MI Complete sudden blockage of a coronary artery Zero flow of blood through the artery If someone places a swan-ganz catheter into a patient who is critically ill, what is measured? Preload S. Viridians is the number one cause of infective endocarditis, S. aureus is second Vegetation is a mixture of RBC’s, WBC’s, germs and fibrin that deposits on a valve Diastolic vs. Systolic Heart Failure Diastolic Systolic Normal Ejection fraction Stiff ventricle Elastic tissue replaced by fibrous tissue No drugs available Low ejection fraction Drugs can help PaPh Assessment 4 Review Three drugs help in systolic heart failure o ACE inhibitors o Beta blockers o Spironolactone Three neurohumeral responses in heart failure o Increased RAAS o Increased sympathetic activity (catecholamines) o Increased BNP An unrestrictive VSD in a newborn infant is likely to be associated with little to no murmur Unrestrictive VSD n a 2 month old infant with normal pulmonary resistance is likely to be associated with IV/VI systolic murmur at mid left sternal border, and a II/VI diastolic rumble at the apex Physiologic murmurs are never diastolic Mechanism for systolic murmur at left upper sternal border in a patient with ASD is relative pulmonary stenosis from increased pulmonary flow Cyanosis can be caused by: o Central Apnea o Pneumonia, Pneumothorax o Intercardiac shunting o Congenital defects Truncus arteriosus Tetralogy of Fallot Tricuspid atresia Transposition of great vessels Total analomous venous return Coronary artery disease risk factors o HTN, smoking, hyperlipidemia, lack of exercise ST depression shows myocardial ischemia ST elevation shows acute cell damage (necrosis) Electrical instability due to V. fib can cause sudden death Stary’s classification atherosclerosis o Foam cellsFatty streakintermediateatheromafibrous plaquecomplicated rupture Complications of MI o Aneurysm, thrombus o Rupture o Pericarditis o Venous thrombosis Cardiac but no coronary causes of chest pain o Aortic stenosis o Hypertrophic cardiomyopathy o Pulmonary HTN PaPh Assessment 4 Review Electrophysiology o Amplitude and direction of deflection depends on relation of electrode to polarity of field, strength of field, and distance between electrode and field o PR wave s conduction from SA node to purkinje system o Increased Q wave is ventricular hypertrophy o Lengthened QRS is bundle branch block o Negative deflection of T wave is from ischemia o Disorders of impulse formation (causes) ** Re-Entry Tissue path with slower conduction, pathways are contiguous, unidirectional block in one pathway Altered phase 4 of action potential Know the following EKG’s: PaPh Assessment 4 Review No P waves! Volume overload=eccentric hypertrophy, stenosis/HTN= concentric hypertrophy Main cause of mitral stenosis is rheumatic fever Higher the HR the more severe mitral stenosis is Types of pericardial disease o Pericarditis Gets better when patient sits forward Inflammation of pericardium Friction rub on auscultation o Pericardial Effusion o Pericardial Tamponade Mechanism of Pulsus Paradoxus o Inspiratory decrease in BP (normal) o When systolic BP decreases more than 10mmHg on inspiration it is pulsus paradoxus o RV expands on inspiration (due to decreased intrathoracic pressure and increased venous return to RA and therefore RV), encroachment on IV septum into ventricular cavity decreases volume of left ventricle which results in decreased contractility (frank starling relationship) and decreased cardiac output. When cardiac output decreases the pressure decreases resulting in decreased pulse seen on inspiration.