Chapter 8 Flashcards
anatomy of the heart
- 4 chambers
- two circulations (pulmonary, systemic)
- valves (function, location)
right ventricle only pumps blood to..
lungs
left ventricle only pumps blood to..
rest of the body, significantly larger due to hypertrophy
the left and right sides of the heart pump what kind of blood?
- right is deoxygenated
- left is oxygenated
coronary circulation
- main blood supply of the heart
- myocardium is too thick for the diffusion of nutrients
- venous blood collected by cardiac veins
- empties blood into right atrium
normal sinus rhythm
sinus node -> atrioventricular node -> bundle of his -> right bundle branch -> left bundle branch
most frequent and serious problems of the heart
- atherosclerosis
- hypertensive heart disease
- aortic stenosis
- atrial fibrillation
- heart failure
myocardial infarct
- death of myocardial tissue
- severe and persistent chest pain
- often presents atypically
- may be asymptomatic
congestive heart failure
- fluid build up in lungs and other tissues
- shortness of breath due to pulmonary edema
- edema in extremities
tests for heart problems
- chest x ray
- echocardiogram
- electrocardiogram
- serum enzyme levels
- cardiac catheterization
- stress test
echocardiogram
- sound waves (ultrasound) to visualize chambers of the heart
- used to look for valve abnormalities
electrocardiogram
- sinus rhythm
- HR
- look for arrhythmias
- abnormal contraction between the QRS and T complex
serum enzyme levels
blood enzyme levels from heart
cardiac catheterization
needle in femoral artery to the heart
stress test
put patient on treadmill and hook up to a machine to make the heart work
congenital heart disease
atrial and ventricular septal defects (areas between the ventricles and atria)
congenital heart disease manifestations
- murmur (turbulent blood flow)
- easily fatigued
- heart failure because heart is working harder
tetralogy of fallot
- rare: 5 in 10,000 infants
- 4 heart defects
what are the four heart defects of tetralogy of fallot?
- VSD (opening between ventricles)
- pulmonary stenosis (valve is narrow)
- right ventricle hypertrophy (right ventricle works harder)
- overriding aorta (aorta is between left and right ventricles, over VSD, blood can’t fully oxygenize)
tetralogy of fallot manifestations
- cyanosis (tissues are blue)
- slow growth
- heart failure
- variable life expectancy
treatment of tetralogy of fallot
surgery soon after birth
myocardial infarction leads to..
necrosis of heart muscle from severe ischemia
basic mechanisms that trigger ischemia
- sudden blockage of a coronary artery from a thrombus
- blockage from atherosclerotic plaque
- sudden greatly increased myocardial oxygen requirements (vigorous physical activities)
heart attack and ______ are the same thing
myocardial infarction (ischemia leads to infarct)
symptoms of acute myocardial infarction
- angina
- sympathetic nervous system response
- hypotension and shock
- may be asymptomatic
angina
chest pain, severe, crushing, constrictive OR like heart burn
what involves the sympathetic nervous system response in an acute myocardial infarction?
- GI distress, nausea, vomiting
- tachycardia and vasoconstriction
- anxiety, restlessness, feeling of impending doom
- increased HR
manifestations of hypotension and shock during a myocardial infarction
weakness in arms and legs because unable to pump as much blood
features of MI
- 50% occur without warning
- 50% preceded by episodes of angina
- 80-90% MI patients arrive alive
why do patients die before arriving at the hospital with a MI?
cardiac arrhythmia, heart doesn’t contract like it should
- minority recover without complications
- most develop clinical complications
diagnosis of MI
- medical history (inconclusive)
- physical exam (usually not abnormal unless patient exhibits evidence of shock, heart failure, or murmur)
- lab data (EKG, enzyme tests, larger infarct = longer time for elevated levels to return normal)
cardiac enzymes
- creatine kinase
- lactate dehydrogenase
- troponin
diagnosis by angiogram involves..
locate and determine degree of obstruction
treatment for CAD
- destroy clot through angioplasty (bust through thrombus)
- cardiac bypass (taking vein from leg and moving downstream to remove blockage)
- stent = brace lumen open
myocardial infarction treatment
- control or eliminate risk factors
- cessation of smoking
- control of hypertension
- anti-coronary diet (low cholesterol and fat)
- weight reduction
- exercise
long term complications of MI
- arrhythmias (most common)
- heart failure
- cardiogenic shock
- pericarditis (enzymes damage pericardium, sack inflamed, cannot fill with blood)
- thromboemboli
- cardiac rupture
- ventricular aneruysm
hypertensive heart disease
hypertension leads to increased workload for heart, which leads to structural and functional changes
manifestations of hypertensive heart disease
- enlarged heart
- heart failure
- ischemia
- change in left ventricle
valvular heart disease
valvular dysfunctions
valvular stenosis
- aortic or mitral stenosis
- narrow valves
valvular regurgitation
- valves are leaky and open
- aortic, mitral, and tricuspid regurgitation
aortic stenosis
- most common
- calcifies and forms scar tissue, cannot move as well
- leaflets undergo degenerative changes -> fibrotic, calcified, rigid -> restricts valve mobility
clinical outcomes of aortic stenosis
increase strain leads to left ventricular hypertrophy which then leads to heart failure
diagnosis of aortic stenosis
echocardiogram or hear murmur with stethoscope, common with aging
rheumatic fever (scarlet fever)
- encounter in children due too streptococcal bacteria
- not due to bacterial infection but molecular mimicry
- scarring of heart valves
clinical outcome of rheumatic fever
valve stenosis -> increases strain on heart, eventually leads to heart failure
prevention of rheumatic fever
treat early with antibiotics, more common in rural areas
cardiac arrhythmias
- disturbance of the heart rhythm
- can be “missed” or rapid beats to severe disturbances that affect pumping ability
cause of cardiac arrhythmias
abnormal rate of impulse generation or abnormal impulse conduction
types of cardiac arrhythmias
- tachycardia (100+ bpm at rest)
- bradycardia ( < 60 bpm at rest)
atrial fibrillation
- disorganized electrical impulse
- atria quiver instead of contract (incomplete emptying, increased risk of thrombus)
- common with age
- can lead to stroke
- most common
ventricular fibrillation
- not pumping blood to organs
- life threatening
- use shock to get rhythm back
- heart attack is death cause
cardiomyopathy
pathology of heart muscle
cardiomyopathy is caused by..
- genetic mutations
- environment
dilated cardiomyopathy
- weakened
- enlarged
- poor pumping
- affects systoly (contraction)
hypertrophic cardiomyopathy
- can lead to sudden cardiac arrest
- leading cause of death in young athletes
- diminished outflow
- genetic mutation of myosin, abnormal contractions leads to arrhythmia
- diastoly is affected
restrictive cardiomyopathy
- heart is rigid, restricted from stretching
- diastoly affected
complications of cardiomyopathy
- heart failure
- blood clot (pulmonary embolism)
- valve problems
- cardiac arrest
- sudden death
