Cardiovascular imported Flashcards
Drug given to close PDA
Indomethacin
increased LV diastolic pressure in patient with mitral stenosis indicates what other pathologic condition in this patient’s heart?
dysfunctional aortic valve
isolated Mitral stenosis causes changes in vascular pressure in what anatomical location
pulmonary artery pressure (pulmonary hypertension)
Effect of long standing pulmonary hypertension
results in reduced pulmonary compliance due to endothelial-mediated pulmonary vasoconstriction, reactive hypertrophy of arterial muscle layer, and partial obliteration of pulmonary capillary bed.
isolated mitral stenosis causes elevated pressure in what heart chamber
left atrium, which is then transmitted to pulmonary veins and capillaries (increase pulmonary wedge cap pressure)
Diastolic pressure in left ventricle in patient with severe mitral stenosis
usually normal or even decreased
absence of peripheral edema is best explained by which compensatory mechanism
tissue lymphatic drainage
chronic hypoxia in COPD leads to…
pulmonary vasoconstriction, increased pulmonary artery pressure, and right heart failure
Right heart failure causes what changes in systemic vascular pressure
increased CVP and excessive hydrostatic pressure, predisposing to peripheral edema
factors that favor development of peripheral edema (4)
- elevated capillary hydrostatic pressure2. decreased plasma oncotic pressure3. sodium and water retention 4. lymphatic obstruction
peripheral edema is accumulation of fluid in what compartment
interstitial space
holosystolic murmur best heard at apex of heart that radiates to axilla
MITRAL REGURGITATION; generated by regurgitant blood flow from LV back to LA during diastole; produces audible S3
Why is audible S3 heard in mitral regurgitation?
elevated pressure and blood volume in LA, increased the amount of blood reentering LV during DIASTOLE;
mechanism behind audible s3 gallop
generated by the sudden cessation of blood flow into LV during passive filling phase of diastole. LV is unable to accommodate excess blood flow
when you see S3, think..
classically associated with heart failure
Absence of S3…
used to exclude severe chronic MR
S4
low-frequency diastolic sound that occurs during the atrial kick of ventricular diastole, reflects blood colliding with stiff ventricular wall
S4 pathology
indicated hypertrophic caridiomyopathy or concentric left ventricular hypertrophy (due to hypertension or aortic stenosis)
mid-systolic click
characteristic or mitral valve prolapse; occurs earlier in systole with physical maneuvers that decrease left ventricular volume
opening snap
early diastolic sound after S2 in patients with mitral or tricuspid stenosis; decrease interval between S2 and opening snap correlates with increase severity (more stenotic mitral valve)
hypertrophic cardiomyopathy inheritance
typically autosomal dominant; patients often have family history of HCM or unexplained sudden cardiac death
ECG findings of HCM
- overall increase in LV mass2. reduced LV cavity size –>impairing diastolic function3. asymmetric increase in LV wall thickness, predominantly affecting septum4. normal/increased LV ejection fraction5. left atrial enlargement (secondary to increased LV end-diastolic pressure)
coronary capillary situation in hypertrophic cardiomyopathy
poorly developed coronary capillary network; evidence of chronic ischemia in hypertrophied regions (ie fibrosis, scarring)
Difference between athlete’s heart (cardiac adaption) and pathologic hypertrophic cardiomyopathy
athlete’s heart does not have reduced LV cavity size and localized septal wall thickening
severe coronary artery disease associated cardiomyopathy
ischemic cardiomyopathy that typically manifests as dilated cardiomyopathy with enlarged LV cavity and thin LV walls with impaired systolic fxn
viruses (5) that can cause viral myocarditis
adenoviruscoxsackie bparvovirus B19HIVHHV-6viral myocarditis may sometimes lead to dilated cardiomyopathy with eccentric hypertrophy and impaired LV systolic function
meiotic nondisjunction
when chromosomes fail to separate, allowing one or more daughter cells to pass on extra copy of a chromosome. most common consequences of maternal nondisjunction=trisomies 21 (down syndrome), 18 (edwards syndrome), and 13 (patau syndrome)
compensation of chronic aortic regurgitation to maintain cardiac output
increase LV stroke volume; due to increase in LV end-diastolic volume (volume overload)
type of hypertrophy that occurs in aortic regurgitation
eccentric hypertrophy due to volume overload
principle behind pharmacologic stress tests with coronary vasodilators
pharmacologic stress agents (ie, adenosine, dipyridamole) are used during myocardial perfusion imaging to simulate the generalized coronary arteriole dilation caused by exercise to assist in identifying areas of ischemic myocardium
coronary steal syndrome
redistribution of blood flow directed toward newly vasodilated areas of nonischemic myocardium
Change in cardiac cycle regarding mitral regurgitation
increased LA atrial pressure (normal is approx. 10 mm Hg); results in early and large V wave
best time to hear mumur throughout cardiac cycle
when the difference in pressure between the two areas (ie LV and aorta) are at largest difference (when LV pressure is highest compared to aortic valve pressure)
holosystolic murmur found in…
- VSD2. tricuspid regurgitation3. mitral regurgitation
holosystolic mumur best heard where (anatomic location)?
lower left sternal border
bifid carotid pulse with brisk upstroke found in what pathology?
characteristic of hypertrophic cardiomyopathy, a condition with dynamic LV outflow tract obstruction during systole.
decreased femoral-to-brachial blood pressure ratio is found in …
coarctation of aorta
fixed splitting of S2 found in
atrial septal defect, causes increased SpO2 in RA compared with vena cava
eisenmenger syndrome caused by
uncorrected left-to-right shunt (VSD, ASD, PDA)
Down syndrome CV abnormalities
endocardial cushion defects (ostium primum atrial septal defects, regurgitant AV valves)
DiGeorge syndrome CV abnormalities
- tetralogy of fallot2. interrupted aortic arch (complete form of coarctation)
Friedreich ataxia CV abnormalities
hypertrophic cardiomyopathy
Kartegener syndrome CV abnormalities
situs inversus
Marfan syndrome CV abnormalities
- cystic medial necrosis (eg aortic dissection and aneurysm)
- mitral valve prolapse
Tuberous sclerosis CV abnormalities
valvular obstruction due to cardiac rhabdomyomas
turner syndrome CV abnormalities
- aortic coarctation2. bicuspid aortic valve
change in pulse pressure seen in aortic regurgitation
widened pulse pressure due to compensatory increase in SV + reduced diastolic pressure in AR
characteristic physical findings in Aortic Regurgitaton
head bobbing and ‘pistol-shot’ femoral pulses
aortic root dilation is one of the most common causes of ? in developing countries?
chronic aortic regurgitation
Aortic arch derivatives
1st root: part of maxillary artery (branch of external carotid artery)
2nd root: stapedial artery and hyoid artery
3rd root: common carotid and proximal part of internal carotid
4th root: on left, aortic arch; on right, proximal part of subclavian artery
6th root: proximal part of pulmonary arteries and (on left only) ductus arteriosus
coarctation of aorta associations
bicuspid aortic valve, other heart defects, and Turner syndrome
bicuspid aortic valve sound/location
associated with aortic ejection sound; early systolic, high-frequency click heard over the right second interspace
rheumatic heart disease and affect on valve
affects mitral valve; early lesion=mitral valve regurgitation , late lesion=mitral stenosis
TTN gene
encodes for sarcomere protein titin; most common cause of familial DCM –absence of titin proteins leads to myocardial dysfunction
fxn: connects Z-line to M-line
arrhythmogenic right ventricular cardiomyopathy
characterized by fibrosis and scarring of right ventricular myocardium, which predisposes to ventricular arrhythmias and sudden cardiac death. the disease results from impaired desmosome function due to mutations in genes encoding desmosomal proteins (ie plakoglobin, desmoplakin)
Hemosiderin-laden macrophages in lungs are usually result of …
chronic passive lung congestion in the setting of heart failure (ie left ventricular systolic dysfunction)
most common etiologic agent in subacute bacterial endocarditis following dental work
Streptococcus viridans
etiologic agent that causes bacteremia or endocarditis that is associated with colon cancer
Streptococcus gallolyticus (aka S. bovis)
mechanism of increased serum creatine kinase
cells within heart, brain, or skeletal muscle are injured, the enzyme creatine kinase leaks across the damaged cell membrane and into circulation
typical right-sided heart failure physical findings
- distended jugular veins
- pulsatile and tender hepatomegaly
- abdominal distension with ascites
- lower extremity edema
Etiology of Acute pericarditis
- viral or idiopathic (most common cause)
- autoimmune disease
- uremia
- post MI: early–peri-infarction pericarditis, late–dressler syndrome
acute pericarditis clinical feautures
- pleuritic chest pain
- pericardial friction rub
- ECG: diffuse ST elevation (due to inflammation of ventricular myocardium)
- pericardial effusion on ECG
Pericarditis typically presents with…
substernal pleuritic chest pain that may radiate to bilateral scapulae posteriorly
free wall rupture (MI)
typically occurs within first 5-14 days post MI due to weakening area of infarcted myocardium via: coagulative necrosis, neutrophil and macrophage infiltration, and enzymatic lysis of connective tissue
common pathology that occurs due to free wall rupture (MI)
cardiac tamponade (presented with sudden onset of chest pain and profound shock and rapid progression to death)
wide and fixed splitting seen in…
atrial septal defects with left to right shunting
Decreased CO (CHF) and RAAS
RAAS system increases activity in CHF, leading to to mechanisms being activated via Angiotensin II:
- potent vasoconstrictor
- stimulation of aldosterone
how to assess degree of mitral stenosis?
measure A2 to opening snap time interval. Shorter interval=more severe. the OS occurs due to abrupt tensing of the valve leaflets as the mitral valve reaches its maximum diameter during forceful opening. AS-OS interval becomes shorter as left atrial pressure increases.
How much time is needed for myocardium to stop contracting?
loss of myocyte contractility occurs within 60 seconds after the onset of total ischemia. Ischemia lasting less than 30 min, restoration of blood flow leads to reversible contractile dysfunction. After 30 minutes of total ischemia, ischemic injury becomes irreversible.
how is brain natriuretic peptide released/activated?
released from ventricular myocytes in response to increase tension (increased in ventricular wall stress).
ANP is released from atrial myocytes in response to increase blood volume and atrial pressure
fxn:
1. natriuretic peptides stimulate both venous and arterial VASODILATION to decrease cardiac preload and afterload and reduce strain on myocardium
- stimulate salt and water excretion by kidneys to facilitate diuresis
when and where is left-sided S4 best heard?
cardiac apex with patient in left lateral decubitus position; will intensify during expiration due to increased blood flow from lungs to left atrium
Pathology behind abnormal S4
reduced ventricular compliance; atrial kick
S4 is a diastolic dysfunction
pathology behind abnormal S3
rapid ventricular filling; associated with increase filling pressures
notable changes to pressure tracings that occur in Aortic regurgitation
- loss of aortic dicrotic notch
- steep diastolic decline of aortic pressure
- high peaking left ventricular and aortic systolic pressure; combined with low aortic diastolic pressure leads to wide pulse pressure
myocardial infarction leading to mitral regurgitation due to papillary muscle dysfunction
MI leading to ischemia of papillary muscle results in hypokinesis and outward displacement of papillary muscle, creating increased tension on attached chordae tendinae and preventing complete closure of corresponding mitral valve cusp.
prolonged systemic hypertension leads to..
Concentric LV hypertrophy via addition of myocardial contractile fibers in parallel
negative changes that occur with concentric hypertrophy
thickening of LV walls–>reduces LV compliance–>impaired diastolic filling and heart failure with preserved ejection fraction
isolated diastolic heart failure diagnostic findings
- increased LV end-diastolic pressure
- normal LV end-diastolic volume
- normal LV ejection fraction (preserved)
- elevated LV filling pressures
diastolic dysfunction can be due to conditions that decrease LV compliance such as impaired myocardial relaxation or increased intrinsic ventricular wall stiffness
jugular venous pulse ‘a wave’
generated by atrial contraction; ABSENT IN ATRIAL FIBRILLATION
jugular venous pulse ‘c wave’
RV contraction (closed tricuspid valve bulging into atrium)
jugular venous pulse ‘x wave’
relaxation of right atrium
jugular venous pulse ‘y wave’
abrupt decrease in right atrial pressure during early diastole after tricuspid valve opens and RV begins to fill passively
renin secretion occurs from what cells?
juxtaglomerular cells of kidney
Process of RAAS
Renin secretion (juxtaglomerular cells of kidney)–> converts angiotensinogen (produced by liver) into angiotensin I in systemic circulation –> Angiotensin I converted to Angiotensin II by ACE in the small pulmonary vessels. Angiotensin II will reach kidney and release aldosterone.
Prostaglandin E1 (2 fxns)
- keep PDA open
- causes afferent arteriolar vasodilation in kidneys
produced in multiple types of cells: endothelial, mast cells, and macrophages
Ruptured Left ventricular free wall
- due to MI
- mechanical compliation that occurs within the first 5-14 days post MI
- abrupt rupture leads to hemopericardium and cardiac tamponade
- patients present with sudden onset of chest pain and profound hypotension and shock
acute pericarditis physical findings
- decreases when patient sits and leans forward
- pericardial friction rub=most specific physical finding
- may be caused by myocardial infarction, rheumatologic disease, uremia, or viral infection
Kussmaul sign
paradoxical increase in jugular venous pressure on inspiration; occurs because of impaired right-sided diastolic filling in conditions such as constrictive pericarditis, restrictive cardiomyopathy, and tricuspid stenosis.
what is precordial knock
brief, high frequency, precordial sound heard in early diastole (shortly after S2) in patients with constrictive pericarditis
aortic stenosis causes what pathologic change in the myocardium of the heart (and in what location)?
hypertrophy of LV
compartment of heart that contributes significantly in concentric hypertrophy?
LA
Effect of atrial fibrillation in LA
decreased filling in LV; decreased emptying in LA; back up of fluid to pulmonary veins, leading to acute pulmonary edema
what organism synthesizes dextrans from sucrose
Streptococcus sanguinis (viridans streptococci); dextrans bind to fibrin-platelet aggregates on damaged heart valves, causing subacute bacterial endocarditis
dextran is a extracellular polysaccharide
viridans streptococci adhere to affected valve in patients with pre-existing valvular lesions.
what do Neutrophils bind to on endothelial cells during inflammatory response
endothelial surface glycoproteins mediate binding of immune cells to endothelium, facilitated by expression of cell adhesion molecules on surface of inflamed endothelium
physical findings of constrictive pericarditis
- slowly progressive dyspnea
- chronic edema
- ascities
- *rapid y-descent during inspiration observed on jugular venous pressure tracing (not unique to constrictive pericarditis)
aortic dissection key findings
- sudden chest pain that radiates to the back
- double aortic lumen seen on CT of chest
classic presentation of ischemic heart disease
causes pressure (substernal chest pain) that radiates to left shoulder calcifications in coronary arteries and aorta are usually seen on CT
normal LV ejection fraction
55%
diastolic heart failure is caused by
decreased ventricular compliance and is characterized by normal LV ejection fraction, normal LV end-diastolic volume, and elevated filling pressures
S4 heart sound
- ‘atrial kick’ working against still LV wall (hypertrophy)
- considered abnormal regardless of age
- often associated with restrictive cardiomyopathy and LV hypertrophy
most common cause of dilated cardiomyopathy in young patients who develop heart failure
viral myocarditis
buldging of interventricular septum into LV side is usually due to
venous blood increasing during inspiration in patient with cardiac tamponade
systolic anterior motion of mitral valve found in
hypertrophic cardiomyopathy that causes dynamic outflow obstruction
auscultation change in patient with elevated pulmonary artery pressure (pulmonary hypertension)
increased intensity of the pulmonic closure sound (P2)
noturnal dyspnea usually caused by
impaired LV function
patient with mitral regurgitation, how do you increase ratio of forward to regurgitant blood flow?
reduction in systemic vascular resistance
final stage of MI healing process involves what collagen type
collagen type I
type I found mostly in interstitial connective tissues and bone
cartilage and nucleus pulposus are composed of what types of collagen?
type II
basement membrane is composed of what type of collagen
type IV
granulation tissue is composed of what type of collagen
type III; granulation tissue lasts approximately 7 days and eventually replace by type I; forms reticular fibers in organs such as spleen, lymph node, and bone marrow
primary collagen found in mature scars
type I
familial hypercholesterolemia is what type of inheritance
autosomal dominant
LDL receptor defect leads to..
high LDL levels; increases risk of premature atherosclerosis
*Homozygous familial hypercholesterolemia (a rarer and more severe form of the disease due to inheritance of 2 defective LDL receptor alleles) –often presents with coronary heart disease in [childhood/adolescence]
pulsus paradoxus
exaggerated drop in systolic blood pressure (>10mmHg) during inspiration; usually seen in cardiac tamponade
unlike S3 sound, S4 sound is always pathologic in ______ patients
younger
classic characteristics of cardiac tamponade (3)
- muffled heart sounds
- jugular venous distension
- hypotension
breath sounds heard in tension pneumothorax
absent; hyperresonance to percussion on affected side
aortic rupture causes ________ shock
hypovolemic
cardiac tamponade leads to decreased ______ pressure during _______
systolic pulse pressure; inspiration
_______ is beat-to-beat variation in pulse amplitude due to change in systolic blood pressure
pulsus alternans
a dicrotic pulse is a pulse with 2 distinct peaks. when do these peaks occur
one during systole; one during diastole
____________ pulse is a rapidly rising pulse with high amplitude due to rapid ejection of a large stroke volume against a decreased afterload.
hyperkinetic; occurs with aortic regurgitation and high-output conditions (ie thyrotoxicosis, arterio-venous fistula)
______________ aka slow-rising low amplitude pulse
pulsus parvus et tardus; occurs during fixed LV outflow tract obstruction due to diminished stroke volume and prolonged ejection time
Left ventricular gallops (S3/S4) will be best heard at cardiac apex in Left lateral decubitus position. At what point in the breathing cycle are they best heard?
End of expiration; lungs are decreased in volume and brings the heart closer to chest wall
straining phase (phase 2) of valsalva maneuver increases/decreases venous return to heart?
decreases; just like standing does
molecule that is important for excitation-contraction coupling in smooth muscle cells, which lack troponin, unlike cardiac and skeletal muscles
calmodulin
calcium efflux from cardiac cells prior to relaxation due to
Na/Ca exchange pump
intracellular calcium moved from cytosol into sarcoplasmic reticulum
SERCA pump; decreases calcium concentration within cytosol
isolated systolic hypertension usually caused by..
age-related stiffness and decrease in compliance of the aorta and major peripheral arteries
mechanism behind plaque rupture
activated macrophages infiltrate thin-cap fibroatheromas (characterized by large necrotic core covered by thin fibrous cap) and secrete metalloproteinases which break down ECM proteins (ie collagen), destabilizing the mechanical integrity of the plaque, leading to plaque rupture.
what strengthens extracellular collagen fibers by mediating cross-link formation?
lysyl oxidase; cross-links between lysine and hydroxylysine residues (requires copper)
mechanism behind decreased pulse on palpitation during inspiration in cardiac tamponade
due to impaired expansion into the pericardial space, the increased RV volume that occurs with inspiration leads to bowing of interventricular septum towards LV. This leads to decrease in LV end-diastolic volume and forward stroke volume, with a decrease in systolic pressure during inspiration
most common site for aortic injury during blunt trauma?
aorta close to left subclavian artery (aka aortic isthmus) which is close to ligamentum arteriosum
Name the 2 areas where baroreceptors are found what nerve innervates these areas
Carotid sinus: hering nerve (branch of glossopharyngeal nerve); afferent limb; travels to medullary center
Aortic body: parasympathetic fibers via vagus nerve travel down to aortic arch
