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Pathophysiology Exam 4 (Modified) (
Questions With Answers) 2024 Latest
Updated Graded A+.
normal metabolism requires _____ supply - Answer oxygen myocardial ischemia is defined as - Answer insufficient oxygen supply what are contibutors to myocardial oxygen supply - Answer -patency of coronary arteries -hemoglobin -fraction of inspired oxygen in the blood what are the etiologies of decreased myocardial oxygen supply - Answer - atherosclerosis (#1) -vasospasm -emboli -anemia -hypoxia what is the formula for expression of myocardial oxygen demand - Answer expression of demand = (MVO2) Myocardial oxygen consumption what are the factors of myocardial oxygen consuption - Answer -HR (cronotropy) -ventricular contractility (inotropy) -wall stress (preload and afterload) what are some etiologies of increased myocardial oxygen demand - Answer -tachycardia -thickened LV wall (LVH) -increased systemic activity where do the coronary arteries originate - Answer root of the aorta near the aortic valve
perfusion (filling) of the coronary arteries occurs during which phase of the cardiac cycle - Answer diastole the myocardium uses which percentage of the oxygen delivered to the muscle - Answer 70% (very high O2 extraction) describe coronary venous drainage - Answer coronary sinus drains coronary veins to the right atrium where is the coronary sinus located - Answer posterior to the AV groove describe the location of the coronary arteries - Answer they lie on the surface of the heart what are the two main coronary arteries - Answer left main and right coronary artery what arteries does the left main artery give rise to - Answer left anterior descending and left circumflex what does the right coronary artery give rise to - Answer posterior descending artery what structures does the left anterior descending artery supply - Answer - anterior wall of LV (60% of contractility) -LA (>50%) -anterior 2/3 of interventricular septum -apex -papillary muscle what does the left circumflex artery supply - Answer posterior-lateral walls of the left ventricle and atrium what does the right coronary artery supply - Answer -most of right atrium and right ventricle -SA node -AV node -bundle of His
5.) fibroatheroma formation 6.) lesion exposure / rupture describe fibroatheroma creation - Answer fibrotic/calcific layer (cap) forms over extracellular lipid core describe the lesion exposure / rupture step of atherosclerotic lesion development - Answer -rupture -platelets activated -thrombosis may occlude partially or totally; can also break off and embolize what are the different types of atherosclerotic plaques - Answer stable (fixed obstruction of blood flow) and unstable (can rupture and become emboli) what are the risk factors for coronary artery disease - Answer -gender (M:F 3:2) -hypertension (BP > 130/90) -diabetes -heredity -high cholesterol -smoking -obesity -physical inactivity describe gendered risks for coronary artery disease - Answer -men > 40 -post menopausal women describe how diabetes can put you at risk for coronary artery disease - Answer -increased LDL and triglycerides -decreased uptake of LDLs by the liver -increased inflammatory chemokines describe hereditary risks for coronary artery diease - Answer positive for first generation family member
describe how high cholesterol can be a risk factor for coronary artery disease - Answer -total cholesterol > -high LDL describe how smoking can increase risk of coronary artery disease - Answer -increases LDL -damages endothelium of coronary vessels -vasoconstricts coronary arteries what is the mnemonic for risk factors of atherosclerosis - Answer Bmi > 30 Age > 65 DM Hypertension Etoh A bad lipoprotein profile Relatives Tobacco what is angina - Answer chest pain associated with myocardial ischemia or infarction what is ischemia - Answer transient, reduced/inadequate blood flow that does not cause cell death what is infarction - Answer permanent, no blood flow, causes cell death what are the different types of angina - Answer -stable -unstable -variant/prinzmetal -silent ischemia what is stable angina - Answer occurs with exertion & relieved by rest what is unstable angina - Answer chest pain unrelieved with nitroglycerine or rest; may crescendo (increase) what is variant/prinzmetal angina - Answer caused by coronary artery vasospasm; occurs at rest with or without precipitating factors
-fibrous caps that have not ruptures describe the presentation of chronic stable angina - Answer -intermittent anginal episodes brought on by exertion -brief duration (<10 min) chest pain -may recover over a long period with same pattern of exertion onset, duration, and intensity -resolves with rest why does chronic stable angina resolve with rest - Answer fixed flow-limit allows adequate supply when at rest people with chronic stable angina only experience symptoms when? - Answer in the setting of exertion is chronic stale angina an ischemic or infarction condition? - Answer ischemic describe the EKG of a chronic stable angina patient - Answer -little or no EKG changes -minimal ST segment depression or T wave inversion -EKG returns to baseline when the pain is relieved what are the cardiac markers for chronic stable angina - Answer none! trick question! is chronic stable angina a true acute coronary syndrome emergency? - Answer nope describe the plaques found in unstable angina - Answer -unstable plaques with fibrous caps that rupture -90% occlusion (but still sub-total); without infarction describe the presentation of unstable angina - Answer -can experience it at rest -cannot tolerate much or any exertion -episodic chest pain secondary to plaque rupture and ischemia but for durations <30 minutes
describe the flow of unstable angina - Answer -fixed-flow is barely adequate at rest due to rupture and thrombus formation -severely decreased supply, but not zero is unstable angina ischemia or infarction - Answer ischemia describe the EKG changes in unstable angina - Answer -ST segment depression and/or T wave inversion -no ST elevation -EKG usually returns to baseline if pain is relieved describe cardiac markers of unstable angina - Answer little to no cardiac marker elevation is unstable angina an emergency? - Answer considered an urgent event that has the potential to become emergent what is NSTEMI - Answer non ST segment elevation myocardial infarction; platelet aggregation and thrombus formation at rupture site describe the presentation of NSTEMI - Answer -near-total (100%) occlusion (but still sub total) -experience angina at rest; intolerant of exertion -episodic chest pain from unstable plaque rupture with infarction -influenced by blood flow characteristics -lasting longer than 30 minutes describe some causes in blood flow changes that can cause NSTEMI - Answer sudden surge of SNS activity or hemodynamic stress is NSTEMI ischemia or infarction? - Answer ischemia at rest that has progressed to infarction .. infarction is non transmural what are the EKG changes of NSTEMI - Answer -ST segment depression and/or T wave inversion -no ST elevation -returns to baseline if pain is relieved what are the cardiac markers of NSTEMI - Answer positive "spill" of cardiac markers
myocardial cells can withstand ischemic conditions for approximately how long? - Answer 20 minutes describe infarction changes - Answer -irreversible cell death and impaired contractility -physical changes begin to occur in the heart 3-6 hours after infarction what stimulates MI - Answer catecholamine release, which stimulates the SNS stimulation of the SNS during MI causes - Answer -diaphoresis -vasoconstriction or peripheral blood vessels -skin appears ashen, clammy, and cool to the touch MI can rapidly progress to - Answer heart failure describe the pathogenesis of MI over 24 hours - Answer -within 24 hours, leukocytes infiltrate the area of cell death -fever -systemic inflammatory process caused by myocardial cell death describe day 4 of MI pathogenesis - Answer proteolytic enzymes of neutrophils and macrophages remove necrotic tissue, making a thinner wall describe what happens past day 4 of MI - Answer -collagen matrix laid down and cardiac remodeling occurs -repair NOT regeneration does repaired heart tissue have functionality? - Answer no... it has little to no compliance or recoil describe Q waves seen in MI - Answer -develop within 2 hours of onset of MI, thought can take 12-24 hours to appear -remain forever and will show in the pattern of infarct distribution -sign of old MIs STEMI are commonly referred to as - Answer Q wave MIs NSTEMI are commonly referred to as - Answer Non-Q MIs
describe the potential dysrhythmias that can occur in the first 24 hours of MI - Answer -PVC can progress to Vtach and Vfib -most common complication in sudden death -life-threatening dysrhythmias seen most often with anterior MI dysrhythmias are present in ______% of patients with MI - Answer 80% besides dysrhythmias, what else can occur within the firsdt 24 hours of an MI - Answer cardiogenic shock from acute LV failure describe cardiogenic shock - Answer -hypotension (from cardiac tissue ischemia to end-organ tissue ischemia) -flash pulmonary edema (acute RHF) -reflexive tachycardia what are complications of MI that can occur days 1-31 - Answer - ventricular septal defects -free wall rupture -papillary muscle rupture describe ventricular septal defect complications of MI - Answer -rupture through interventricular septum -L to R shunt of blood causes a murmur -likely death describe free wall rupture complication of MI - Answer -blood escapes to pericardial space -leads to cardiac tamponade -death without intervention describe papillary muscle rupture complication of MI - Answer -makes mitral valve incompetent -mitral regurgitation -holosystolic murmur what are the complications that can occur on days 3-14 after MI - Answer acute pericarditis describe acute pericarditis complication of MI - Answer -inflammation of pericardium
kinda dated, but oxygen and aspirin remain at first line why are morphine and nitroglycerine not used as much for MI? - Answer can induce hemodynamic alterations that can worsen conditions what are treatments for MI and ischemia of the heart - Answer -aspirin -thrombolytic therapy delivered via IV nor direct cardiac cath administered -interventional cardiac catheterization -coronary artery bypass grafting what are some way interventional cardiac catheterization can happen - Answer -balloon dilation -atherectomy -stenting describe a coronary artery bypass graft - Answer -open heart surgery -requires cardiac cath to define disease and determine viability -cardiac catheter interventions always preferred if amenable what are cardiomyopathies - Answer disease of the myocardium that can lead to ventricular hypertrophy or dilation ... associated with electrical and/or mechanical dysfunction what are the different classifications of cardiomyopathies - Answer primary and secondary describe primary cardiomyopathies - Answer -confined to the myocardium -usually genetic disorder, but may take years to present describe secondary cardiomyopathies - Answer -myocardial changes that occur with multisystem dysfunction -often associated with recreational drug use -consequence of cancer treatments -associated with ischemia describe hypetrophic cardiomyopathy - Answer -unexplained engagement of the LV -disproportionate thickening of the inter-ventricular septum -myocyte hypertrrophy and increased cardiac fibrosis
-may contribute to an outflow tract obstruction describe the physiology of hypertrophic cardiomyopathy - Answer -reduced LV cavity size -potential outflow obstruction -angina in chest in the absence of CAD describe dilated cardiomyopathy - Answer -common cause of heart failure -leading indication for cardiac transplant what are some causes of dilated cardiomyopathy - Answer -genetics -infection -alcohol -chemo describe the physiology of dilated cardiomyopathy - Answer -ventricular cavity enlargement bu thin ventricle wall muscle -impaired systolic dysfunction (ejection fraction <25%) and abnormal wall motion what are manifestations of dilated cardiomyopathy - Answer -dyspnea -orthopnea -reduced exercise capacity -ventricular thrombus formation what is peripartum cardiomyopathy - Answer -heart failure in last month of pregnancy to 5 months post-delivery -no identifiable cause of heart failure -evidence of systolic dysfunction what are the risks of peripartum cardiomyopathy - Answer -african american women -multiple pregnancies -maternal age > 35 -multiple fetuses what is Takotsubo cardiomyopathy - Answer -stress cardiomyopathy -occurs in response to profound psychological stressors -AKA broken heart
where is the AV node located - Answer lower portion of the RA what is the function of the AV node - Answer -delays passage of electrical impulse to the ventricle -passes impulses through the bundle of His what is the delay in the AV node responsible for - Answer coordinated contracting of both atrium first to prime the filling of the ventricles before they pump describe the bundle of His - Answer -separate into R and L bundle branches -conducts impulse toward the apex of heart -bundle branches pass impulses to purkinje fibers the left bundle branch sends impulses to - Answer left ventricular contraction the right bundle sends impulses for - Answer right ventricular contraction describe purkinje fibers - Answer -initiates ventricular conduction -once impulse enters this system, it spreads immediately to the ventricle -APs move upward from apex what is an action potential - Answer brief reversal of electric polarity ACROSS the cell membrane how does an action potential occur - Answer movement of ions in and out of the cells what are the main ions involved in an action potential - Answer sodium, potassium, calcium describe depolarization in an action potential - Answer moving from negative to less negative (positive) ... causing contraction describe repolarization in an action potential - Answer moving towards more negative ... relaxation
describe the threshold for action potentials - Answer polarity must depolarize to a threshold level for contraction of occur what does the P wave represent in an EKG - Answer atrial depolarization ... not the SA node firing what does the QRS complex represent in an EKG - Answer depolarization of ventricles what does the T wave represent in an EKG - Answer repolarization of ventricles describe the PR interval - Answer impulse arrives in AV node, impulse passes bundle of his, impulse passes bundle branches, impulse passes Purkinje fibers describe the ST interval in an EKG - Answer ventricular ejection what waves are involved in ventricular filling / diastole - Answer P wave, PR interval, half of ST interval what waves are involved in systole - Answer QRS complex, part of ST interval what are different types of disorders that can occur in the cardiac conduction system - Answer -disorders of rhythm -disorders of impulse conduciton what are the potential causes of disorders of the cardiac conduction system
- Answer -congenital defects -degenerative changes in system -myocardial ischemia and MI -fluid and electrolyte imbalances -effects of drug ingestion what are the different types of sinus node dysrhythmias - Answer -sinus bradycardia (HR < 60) -sinua tachycardia (HR > 100) -sinus dysrhythmia/sick sinus
describe sick sinus syndrome - Answer disorder of SA node caused by impaired pacemaking ability what are some causes of sick sinus syndrome - Answer -fibrotic changes with age -damage from ischemia -atrial dilation from valvular or heart failure what does sick sinus syndrome produce - Answer -constellation of abnormal rythms -atrial bradyarrythmia -atrial tachyarrythmia -altering with tachycardia often referred to as tachy-brady syndrome what are the symptoms of sick sinus syndrome - Answer palpitations and tissue under-perfusion leading to fatigue, lightheadedness, pre-syncope, and syncope what is treatment for sick sinus syndrome - Answer when truly symptomatic (especially bradycardia), often requires a pacemaker what are ectopic beats - Answer PACs (premature atrial contractions) and PVCs (premature ventricular contractions) describe ectopic beats - Answer if isolated and infrequent, can help be benign and most only produce palpitations describe a premature atrial contraction - Answer normal rate and rhythm, but an extra premature impulse initiated in the atrium but NOT by the SA node since the SA node is not the initiator in a PAC, what can be seen in an EKG
- Answer slightly different P wave morphology (peaked, larger, smaller) what is bigeminy in terms of PACs - Answer occurring every other complex what is trigeminy in terms of PACs - Answer occurring every third complex describe PVCs - Answer -overall normal rate and rhythm
-extra premature impulse initiated by purkinje fibers in ventricles -P wave absent -QRS dysmorphic (widened/bizarre) what do PVCs cause - Answer since they occur early before a regular heart beat, it causes a compensatory pause before the next normal beat can initiate what are the different patterns of PVCs - Answer -bigeminy: every other complex -trigeminy: every third complex -couplets: two in a tow -triplets: three in a row if PVCs are limited in frequency and asymptomatic, they are usually considered - Answer benign describe uni-focal PVCs - Answer when all PVCs look alike, they are monomorphic and usually initiated by the same focus area of the ventricle describe multifocal PVCs - Answer stimulus occurring from different foci in the ventricle area ... typically more concerning than monomorphic occasional, random, scattered ectopy without symptoms are almost always considered - Answer benign ... usually caused by heightened sympathetic tone what are common treatments for PVCs or PACs - Answer -usually none -stope caffeine -reduce stress -treat sleep apnea -low dose beta blocker (last resort) describe atrial fibrillation - Answer -supraventricular rhythm -multiple uncoordinated ectopic sites firing atrial contractions -SA node not managing HR describe the EKG presentation of Afib - Answer -no discernable P wave -baseline appears jagged and random -irregularly irregular heart beat (seen as variable R to R)
