Card Set Information
alterations in cardiac function
coronary artery disease
coronary heart disease
what is CHD
characterized by insufficient delivery of oxygenated blood to the myocardium due to atherosclerotic coronary arteries
sequelae of CHD:
-sudden cardiac death
etiology of CHD
atherosclerosis causes narrowing of arterial lumen that can lead to cardiac ischemia thru:
-endothelial cell dysfunction
mechanisms of coronary atherosclerosis
lipids are transported via apoproteins
-lipoproteins associated with a greater risk of atherosclerosis
-high-density lipoproteins transport cholesterol from peripheral tissue back to the liver, clearing atheromatous plaque
mechanisms of coronary atherosclerosis
atherosclerotic plaque formation initiated by injury to coronary artery endothelium
-endothelium becomes permeable and recreuits leukocytes
-LDL insudation occurs with oxidation by endothelial cells and macrophages
-oxidized lipids are damaging to endothelia and smooth muscle cells, and stimulate recruitment of macrophages to vessel
-macrophages engulf the lipids; foam cells release inflammatory mediators and growth factors, attracting more leukocytes and stimulate smooth muscle proliferation
-excess lipid and debris accumulate w/in vessel wall and coalesce into lipid core
vulnerable plaques may rupture/become eroded, which stimulates clot formation on plaque
what does vulnerable plaques have?
-large lipid core
-high shear stress
what is the pathophysiology of ischemia
occurs when oxygen supply is insufficient to meet metabolic demands
what critical factors in meeting cellular demands for oxygen include?
rate of coronary perfusion
How can coronary perfusion be altered?
-acute platelet aggregation and thrombosis
-failure of autoregulation by microcirculation
-poor perfusion pressure
-can be reversible if short-lived or treated appropriately
What are the clinical features and management of coronary syndromes
Chronic syndromes with slow progression due to chronic obstruction from stable atherosclerotic plaques
-Acute coronary syndrome associated with acute changes in plaque morphology and thrombosis
ACS stands for?
Acute coronary syndrome
Acute coronary syndrome means...
Chronic syndromes with slow progression means...
stable angina pectoris
what is angina pectoris?
chest pain associated with intermittent myocardial ischemia
-may result in inefficient cardiac pumping w/ resultant pulmonary congestion and shortness of breath
What are the 3 patterns of angina pectoris
-unstable or crescendo angina
What is Acute Coronary Syndrome?
Chest pain usually more severe and lasts long than typical angina
-plaque rupture w/ acute thrombus development
-unstable angina - occlusion is partial
- MI - occlusion is complete
-ECG and bio markers used for diagnosis
what does a MI in acute coronary syndrome do to the CO?
leads to drop in CO, triggers compensatory responses including sympathetic activation, which increased myocardial workload by increasing the following:
in acute coronary syndrome, sympathetic NS activation leads to an increase or decrease myocardial, and what increases it?
1) heart rate
What is sudden cardiac death
unexpected death from cardiac causes w/in 1 hr of symptom onset
-use of external defibrillators and CPR increases survival
what is usually the primary cause of sudden cardiac death?
What is chronic ischemic cardiomyopathy?
heart failure develops insidiously due to progressive ischemic myocardial damage
-typically have history of angina or MI
-commong in older adults
What causes damage to the endocardial and valvular structures?
-inflammation and scarring
(cause altered hemodynamics of heart and ^myocardial workload)
What is stenosis? An example?
failure of the valve to open completely results in extra pressure work for heart
: IHSS - Idiopathic Hypertrophic Sub-aortic Stenosis
What is regurgitation?
inability of a valve to close completely results in extra volume work for the heart
What is mitral stenosis?
blood flow from L atrium to L ventricle is impaired during ventricular diastole
-^pressure of L atrium leads to atrial chamber enlargement and hypertrophy
-low-pitched, rumbling diastolic murmur
What can mitral stenosis lead to?
chronic pulmonary hypertension
-R ventricular hypertrophy
-R sided heart failure
what is Mitral Regurgitation
backflow of blood from the L ventricle to L atrium during ventricular systole
-L atrium and ventricle dilate and hypertrophy due to extra volume
-high-pitched, pansystolic, blowing murmur
What can mitral regurgitation lead to?
L-sided heart failure
What is mitral valve prolapse?
displacement of mitral valve leaflets into L atrium during ventricular systole
-midsystolic click or systolic murmur
What kind of complications involved with mitral valve prolapse
sudden cardiac death,
cerebral embolic events
progression to mitral regurgitation
What is aortic stenosis?
results in obstruction of aortic outflow from L ventricle to aorta during systole
-crescendo-decrescendo murmur during ventricular systole with prominent S
What is the predominant cause of aortic stenosis? and what may result from it?
age related calcium deposits on aortic cusps
-may result in ischemia and L-sided HF
what are the disease of endocardium?
rheumatic heart disease
what is rheumatic heart disease?
acute inflammatory disease that follows infection with groups A β-hemolytic streptococci
-antibodies against this antigen damages the connective tissue in joints, heart and skin
-mainly in children
what is infective endocarditis
invasion and colonization of endocardial structures by microogranisms w/ resulting inflmaation-vegetations
-predisposing risk factors present
what bacteria commonly causes infective endocarditis
what is myocarditis
inflammatory disorder of heart muscle characterized by necrosis and degeneration of myocytes
-cardiomyopathy may be genetic OR acquired and is noninflamatory
What causes myocarditis and what is characterized by it?
causes + microbial agents, immune-mediated disease, physical agents
-viral etiology - common
-characterized by L ventricular dysfunction and general dilation of all 4 chambers
How is cardiomyopathy classified? How many types and name it.
by cause/functional impairment
: dysfunction of unknown cause
: known cause
dilated, hypertrophic, restrictive
What is dilated cardiomyopathy? what relates to it?
cardiac failure associated with dilation of one or both ventricular chambers
-slow progression of biventricular HF with low ejection fraction
: alcohol toxicity, pregnancy, postviral myocarditis, genetic abnormality
What is hypertrophic cardiomyopathy?
thickened, hyperkinetic ventricular muscle mass
-septum my be affected
what might hypertrophic cardiomyopathy lead to?
IHSS - idiopathic hypertrophic subaortic stenosis
What is restrictive cardiomyopathy?
-rare form of cardiomyopathy
-stiff, fibrotic ventricle with impaired diastolic filing
-associated with amyloidosis
-decreased CO and L-side HF can result