Cardio USMLE Flashcards
pregnant woman in 3rd trimester has normal BP when standing and sitting. When supine BP drops to 90/50.
what is the dx?
compression of the IVC
35 y/o man has high BP in arms and lowBP in his legs.
what is the dx
coarction of teh aorta
5 y/o boy presents weith a systolic murmur and a wide fixed split S2. what is the dx
ASD
During a game a young football player collapses and dies immediately. What is the most likely type of cardiac dz
hypoertrophic cardiomyopathy
pt has a stroke after incurring multiple long bone fractures in trauma stemming from a MVA. What caused the infarct
fat emboli
elderly woman presents with a headache and jaw pain. labs show elevated ESR. what is teh dx
temporal arteritis
80 y/o man presents w/ systolic crescendo-decrescendo murmur. What is the most likely cause?
aortic stenosis
Man starts a medication for hyperlipidemia. He then develops a rash, pruritis, and GI upset. What drug was it
Niacin
Pt developes a cough and must discontinue captopril. What is a good replacement drug and why doesn’t it have the same side effects?
losartan, an angiotensin II receptor antagonist, does not increase bradykinin as captopril does.
What are the 3 sx inside the carotid sheath
1) Internal jugular Vein (lateral)
2) Common carotid Artery (medial)
3) Vagus Nerve (posterior)
mneu: VAN
In the majority of cases, the SA and AV nodes are supplied by this carotid artery?
Right coronary artery
80% of the time the Right coronary artery is “dominant”, suppplying the left ventricle via the _________ branch
Posterior descending artery
cardiac output =
SVxHR
During exercise, CO ↑ initially as a result of an ↑ in ____. After prolonged exercise, CO ↑ as a result of an ↑ in ____.
SV
HR
Mean argerial Pressure (MAP)=
give 2 equasions:
1) CO, TPR
2) systolic, diastolic
1) CO x TPR
2) 1/3 systolic +2/3 diastolic
CO=
rate of O2 consumption, aa O2 content, vv O2 content
rate of O2 consumption
_______________________
aa O2 content-vv O2 content
Pulse pressure =
systolic, diastolic
systolic-diastolic
pulse pressure ≈
stroke volume
SV=
(2 equasions)
1) CO, HR
2)EDV,ESV
1) =CO/HR
2) =EDV-ESV
Coronary Artery Anatomy [pic]
1) Right Coronary aa (RCA)
2) Left main coronary aa (LCA)
3) Circumflex artery (CFX)
4) Left anterior descending aa (LAD
5) Posterior descending aa (PD)
6) Acute marginal aa
Stroke volume is affected by what 3 things
mneu: SV CAP
Contractility, Afterload, and Preload
mneu: SV CAP
↑Preload →__SV
↑
↑Afterload→ __SV
↓
↑contractility→ __SV
↑
SV ___ in anxiety, exercise, & pregnancy
↑
a failing heart has a ___ SV
↓
Contractality (and SV), ____ with catecholemines
↑
Contractality (and SV), ____ with ↑ intracellular Ca++
↑
Contractality (and SV), ____ with ↓ extracellular sodium
↑
Contractality (and SV), ____ with digitalis
↑
Contractality (and SV), ____ with β1 blockade
↓
Contractality (and SV), ____ with heart failure
↓
Contractality (and SV), ____ with acidosis
↓
Contractality (and SV), ____ with hypoxia/hypercapnea
↓
Contractality (and SV), ____ with Ca++ channel blockers
↓
Myocardial demand is ___ by ↑ afterload (diastolic BP)
↑
Myocardial demand is ___ by ↑ contractility
↑
Myocardial demand is ___ by ↑ heart rate
↑
Myocardial demand is ___ by ↑ heart size
↑
ventricular EDV
Preload
Systolic arterial pressure
afterload
proportional to peripheral resistance
afterload
venous dialators (e.g. nitroglycerine) ↓ \_\_\_\_\_\_\_ (preload or afterload)
preload
vaso dialators (e.g. hydralazine) ↓ \_\_\_\_\_\_\_ (preload or afterload)
afterload
______ ↑ w/ exercise, ↑ blood volume, exitement (sympathetics)
(preload or afterload)
Preload
Starling Curve: Force of _______ is proportional to initial length of cardiac mm fiber (preload)
contraction
contraction state of the myocardium is ____ by circulating catecholamines
(+,-)
+
contraction state of the myocardium is ____ by digitalis
+,-
+
contraction state of the myocardium is ____ by sympathetic stimulation
(+,-)
+
contraction state of the myocardium is ____ by pharmacologic depressants
(+,-)
-
contraction state of the myocardium is ____ by loss of myocardium (MI)
(+,-)
-
EF=
(give 2 equasions)
1) SV, EDV
2) EDV, ESV, EDV
1) SV/EDV
2) EDV-ESV/EDV
this is an index of ventricular contractility
EF
EF is normally > ___%
55
Place condition on the Starling curve [pic p.219]
1) exercise
2) CHF + digitalis
3) CHF
(driving Pressure)ΔP=
Q (flow) ,R (resistance)
Q x R
Resisitance (R) =
Give 2 equasions:
1)ΔP(driving pressure),flow(Q)
2)n(viscosity), length(l), radius (r)
1) =ΔP/Q
2) 8nxl/Πr(^4)
viscosity depends mostly on _______
hematocrit
increased ______ in:
1) Polycythemia
2) Hyperproteinemic states (e.g., multiple myeloma)
3) hereditary spherocytosis
viscosity
resistance is ________ to viscosity
proportional or inversely proportional
proportional
resistance is ________ to the radius to the 4th power
proportional or inversely proportional
inversely proportional
cardiac and vascular fx curves [pic p.219]
1) (+) inotropy
2) (-) inotropy
3) (↑) blood volume
4) (↓) blood volume
cardiac cycle image [p. 220]
1) isovolumetric contraction
2) aortic valve opens
3) ejection
4) aortic valve closes
5) isovolumetric relaxation
6) mitral valve opens
7) ventricular filling
8) mitral valve closes
Name the phase of the cardiac cycle:
period between mitral valve closure and aortic valve opening.
isovolumetric contraction
Name the phase of the cardiac cycle: period of highest O2 consumption
isovolumetric contraction
Name the phase of the cardiac cycle: period between aortic valve opening and closing
systolic ejection
Name the phase of the cardiac cycle: period between aortic valve closing and mitral valve opening
isovolumetric relaxation
Name the phase of the cardiac cycle: period just after mitral valve opening
rapid filling
Name the phase of the cardiac cycle: period just before mitral valve closure
slow filling
name the heart sound: mitral and tricuspid valve closure
S1
name the heart sound: aortic and pulmonary valve closure
S2
name the heart sound: at the end of rapid ventricular filling
S3
name the heart sound: high atrial pressure/stiff ventricle
S4
this heart sound is associated w/ dilated CHF
S3
this heart sound AKA “atrial kick” is associated with a hypertrophic ventricle
S4
Jugular venous pulse waves:
a wave
Atrial contraction
Jugular venous pulse waves: c wave
RV Contraction (tricuspid valve bulging into atrium)
Jugular venous pulse waves: v wave
increaseed atrial pressure due to filling against closed tricuspid Valve
jugular venous distention is seen in ___________
right heart failure
when the aortic valve closes before the pulmonic this heart sound abnormality results
S2 splitting
S2 splitting is increased upon ________
inspiration
Paradoxical splitting (S2 split increasd upon expiration is associated with what?
aortic stenosis
cardiac mm contraction is dependent on extracellular ________, which enters the cells during plateau of action potential and stimulates ______ release from the cardiac mm sarcoplasm reticulum.
calcium
calcium
calcium induced calcium release
In contrast to skeletal mm, cardiac mm action potential has a plateau, which is due to ____ influx.
Ca+
In contrast to skeletal mm, cardiac nodal cells ________ depolarize, resulting in automaticity
spontaneously
In contrast to skeletal mm, cardiac myocytes are electrically coupled to each other by ________
gap junctions
myocardial action potential occurs in atrial and ventricular myocytes and ________
perkinje fibers
In a myocardial action potential, this phase is the rapid upstroke, when voltage gated Na+ channels open
phase 0
In a myocardial action potential, this phase is the initial repolarization-inactivation of voltage0gated Na+ channels. Voltage gated K+ channels begin to open
Phase 1
In a myocardial action potential, this phase is the plateu–Ca++ influx through voltage-gated Ca++ channels balances K+ efflux. Ca++ influx triggers another Ca++ release from sarcoplasmic reticulum and myocyte contraction.
phase 2
In a myocardial action potential, this phase is the rapid repolarization–massive K+ efflux due to opening of voltage-gated slow K_ channels and closure of voltage gated Ca++ channels.
Phase 3
In a myocardial action potential, this phase is the resting potential–high K+ permeability through K+ channels.
phase 4
Pacemaker action potentials occur where
SA & AV nodes
In a pacemaker action potential this phase is the upstroke phase–it involves opening of voltage-gated Ca++ channels. These cells lack fast voltage-gated Na+ channels. Results in a slow conduction velocity that is used by the AV node to prolong transmission from the atria to ventricles.
phase 0
In a pacemaker action potential this phase, the plateau is absent.
phase 2
In a pacemaker action potential this phase, the slow diastolic depololarization results in membrane potential spontaneously depolarizing as Na+ conductance increases. This accounts for automaticity of SA and AV nodes. The slope of this phase in the SA node determines the heart rate. ACh decreases and catecholamines increasee the rate of diastolic depolarization decreasing or increasing heart rate respectively.
phase 4
electrocardiogram: atrial depolarization
P wave
electrocardiogram: conduction delay through AV node (normally <200 msec)
PR segment
electrocardiogram: vetricular depolarization (normally < 120 msec)
QRS complex
electrocardiogram: mechanical contraction of the ventricles
QT interval
electrocardiogram: ventricular repolarization
T wave
electrocardiogram:
atrial repolarization is masked by _______
QRS complex
electrocardiogram: isoelectric, ventricles depolarized
ST segment
electrocardiogram: These waves caused by hypokalemia
U wave
this syndrome is caused by an accessory conduction pathway from atria to vetricle (bundle of kent), bypassing AV node. As a result, ventricles begin to partially depolarize earlier, giving rise to characteristic delta wave on ECG. May result in reentry current leading to supraventricular tachycardia [image p.223]
Wolff-Parkinson-White syndrome
This ECG tracing has a chaotic and erratic baseline (irregularly irregular) with no discrete P waves in between irregularly spaced QRS complexes (pic. p 224)
Atrial fibrillation
This ECG tracing has a rapid succession of identical, back to back atrial depolarization waves. The identical appearance accounts for the “sawtooth” appearance of the flutter waves. (pic. p 224)
Atrial flutter
In this condition PR interval is prolonged (>200 msec). Asymptomatic.
(pic. p 224)
1st degree AV block.
Progressive lenthening of the PR interval until a beat is “dropped” (a P wave not followed by a QRS complex). Usually asymptomatic. (pic. p 224)
2nd degree AV block
Mobitz type I (Wenckebach)
On ECG shows dropped beats that are not preceded by a change in the length of the PR interval. These abrupt, nonconducted P waves result in a pathologic condition. It is often found as a 2:1 block, where there are 2 P waves to 1 QRS response. May progress to 3rd degree block.(pic. p 225)
Mobitz type II AV block
In this condition, the atria and ventricles beat independently of each other. Both P waves and QRS complexes are present, although the P waves bear no relation to the QRS complexes. The atrial rate is faster than the ventricular rate. Usually treat with pacemaker.
3rd degree AV block (complete)
completely erratic rhythm with no identifiable waves. Fatal arrhythmia without immediate CPR and defibrillation. (pic. p 225)
Ventricular Fibrillation
________receptor transmits via vagus nn to medulla (responds only to increase blood pressure)
aortic arch receptor
________ receptor transmits via glossopharyngeal nn to medulla
carotid sinus
decreased firing by aroreceptors during hypotension results in an increase in efferent ________ firing
sympathetic
In a carotid massage, the increased pressure on carotid aa results in increased stretch and ____ in heart rate
decrease
Peripheral chemoreceptors in the carotid and aortic bodies respond to (3 things)
decreased PO2 (<60mmHg), increased PCO2 and decreased pH of blood
Central chemoreceptors respond to what changes (2)
changes in pH and Pco2 (not Po2)
This chemoreceptor is responsible for Cushing reaction, response to cerebral ischemia, response to increase intracranial pressure leads to hypertension (sympathetic response) and bradycardia (parasympathetic response)
Central chemoreceptor
This orgen gets the largest share of systemic cardiac output
liver
this organ gets the highest blood flow per gram of tissue
kidney
this orgen has a large arteriovenous O2 differnece. Increased O2 demand is met by increased coronary blood flow, not by increased extraction of O2.
heart
this is a good approximation of L atrial pressure and measured with a Swan-Ganz catheter
Pulmonary capillary wedge pressure
blood flow is altered to meet demands of tissue
autoregulation
Name the organ regulated by the local metabolites:
O2 adenosine, NO
heart
Name the organ regulated by the local metabolites:
CO2 (pH)
brain
Name the organ regulated by the local metabolites: Myogenic and tubuloglomerular feedback
kidneys
Name the organ regulated by the local metabolites: hypoxia causes vasoconstriction
lungs
_______ vasculature is unique in that hypoxia causes vasoconstriction (in other organs hypoxia causes vasodilation)
pulmonary
Name the organ regulated by the local metabolites: lactate, adenosine, K+
skeletal mm
Name the organ regulated by the local metabolites: sympathetic stimulation most important mechanism–temp control
skin
______ forces determine fluid movement by osmosis throug capillary membranes
starling
moves fluid out of capillary
P(c) capillary pressure
moves fluid into capillary
P(i) interstitial fluid pressue
moves fluid into capillary
π(c) plasma colloid osmotic pressure
moves fluid out of capillary
π(i) interstitial fluid colloid osmotic pressure
net filtration pressure=Pnet=
[Pc-Pi)-(πc-πi)]
capillary pressure -interstitial pressure
-
plasma colloid osmotic presure - interstitual fluid colloid osmotic pressures
Kf=
filtration constant (capillary permeability)
excess fluid outflow into interstitium
edema
edema is commonly caued by ___ capillary pressure (give example)
↑ P(c)
Heart failure
edema is commonly caued by ___ plasma protiens(give example)
↓π(c) plasma proteins
nephrotic syndrome, liver failure
edema is commonly caused by ___ capillary permeability (give example)
↑Kf
infections, burns
edema is commonly caued by ___ interstitial fluid colloid osmotic pressure
(give example)
↑ πi
lymphatic blockage
right-to-left shunts (early cyanoisis) “blue babies”
3 Ts
Tetrology
Transposition
Truncus
Children with this type of shunt may squat to increase venous return
right to left shunts
Right-to Left shunts (early cyanosis) - “blue babies”
1) Tetrology of fallot
2) Transposition of great vessels
3) Truncus arteriosis
The 3 Ts
children with this type of shunt may squat to increase venous return.
right to left shunt
Left to right shunts (late cyanosis) - “blue kids”
1) VSD
2) ASD
3) PDA
