cardio uworld Flashcards
isolated systolic HTN
an age related decrease in compliance (increased stiffness) of the aorta and its proximal major branches can cause isolate systolic HTN
Constrictive pericarditis
etiology:
idiopathic or viral pericarditis
-cardia surgery or radiation therapy
-tb
PAthogenesis:
thickened, rigid pericardium forms a noncompliant casing surrounding the heart, limiting ventricular expansion during diastolic filling
hemodynamic signs:
- increased JVP
- Kussmaul sign
- pulses paradoxus
- pericardial knock
statins
-inhibit HMG coa reductase, the rate limiting enzyme of hepatic cholesterol synthesis.
in response to these changes, hepatocytes increase their surface expression of the LDL receptor to increase uptake of circulating LDL therefore increase LDL receptor density
amlodipine
peripheral calcium channel blocker!
flushing and peripheral edema
stenotic mitral valve
increase pressure gradient between LA and LV, increase L A Pressure and volume
promotes atrial fibrillation and mural thrombus formation
Normal adult pressures right side
RA 0/8
RV 4/25
PA 9/25
Normal adult pressures left side
LA 2/12
9.130
aorta 70/130
verapamil
cardio selective, side effects constipation and gingival hyperplasia and sometimes bradycardia at first then second or third degree AV node block in 1-2% of patients
atropine
competitive antagoinst at post junctional muscarin receptors in the heart M2, increases the HR by blocking vagal influences
epinephrine
a1,b1 increase systolic blood pressure
b1 increase HR
low does B2>a1 and decreases diastolic bp
at high does a1>b2 and increases diastolic blood pressure
NE on B1
increase cAMP increase contractility,conduction, HR.
however, NE increases peripheral resistance via a1, baroreceptor-mediated reflex bradycardia that occurs
-this combine result keeps the HR unchanged or even a bit decreased after NE administration
NE
a1 increased IP3 –> peripheral vasoconstriction
a2 - decrease cAMP –> decrease release of NE and insulin
b1: increase cAMP –> increased contractility
b2: very little effect, but increase cAMP resulting in bronchodialtion and vasodilation
renal artery stenosis and ACE inhibitors
patients with renal artery stenosis are dependent on ACE mediated efferent arteriole constriction to maintain renal perfusion and GFR (via ATII)
use of ACE inhibitors will block this effect and reduce renal perfusion potentially leading to acute renal failure
vitamin k-dependent clotting factors
ii, Vii, Ix, X
2,7,9,10
dobutamine
relatively selective B1 agonist
increases HR, contractility, conduction velocity and myocardial oxygen consumption!
Carcinoid heart disease of carcinoid syndrom
caricinoid syndrome: skin flushing, abdominal cramping, nausea, vomiting, and diarrhea and it thought to be due to production of 5HT, kallikrein, bradykinin, histamine and PG and or tachykinins by carcinoid tumors
-endocardial fibrosis seen in this syndrome correlates with plasma levels of serotonin and urinary excretion of the serotonin metabolite:
5-hydroxyindoleacetic acid
fibrosis is genrally limited to the right heart because both serotonin and bradykinin get inactivated distally by pulmonary vascular endothelial monoamine oxidase
B1 receptors are found in?
cardiac tissue and on renal juxtaglomerular cells
lethal acute rheumatic fever cause?
heart failure due to severe myocarditis!
MS after acute rheumatic fever requires years of decades to develop
patients with adult type coarctation of the aorta commonly dies of HTN associated complications?
- LV failure
- rupture dissecting AA
- intracranial hemorrhage
- increased risk for ruptured intracranial aneurysms because of the increased incidence of congenital berry aneurisms of the circle of willis as well as aortic arch HTN
Left sided heart failure–> pulmonary arterial HTN –> Right-sided heart failure
- chronic HTN–>concentric LV hypertrophy and decreased LV diastolic compliance
- steady state LV filling pressures rise to maintain SV and CO.
- LA pressures rise, and pulmonary venous congestion ensures, causing hydrostatic pressures in the lung to rise dramatically.–> leak..> edema
- Edema causes alveolar collapse and results in decreased ventilation, which in turn causes hypoxemia.
- Reactive vasoconstriction occurs in order to shunt blood toward areas where ventilation is less compromised
- pulmonary arterial HTN –> increased pulmonary afterload then causies right sided heart failure
Atrial fibb occurs due to irregular, chaotic electrical activity within the atria. While some of the atrial impulses are transmitted to the ventricles, most are not due the AV nodal REFRACTORY PERIOD
each time the AV node is excited it enters a refractory period. Durring this period, additional atrial umpurses cannot be transmitted to the ventricles; consequently the majority of atrial uimpuses never reach the ventricles,
ebsteins anomoly
-characterized by:
apical displacement of the tricuspid valve leaflets, decreased volume of the RV, and atrialization of the right ventricle
cause?
lithium use during pregnancy
NO drugs and metabolism
-nitroglycerin and isosibide dinitrate undergo considerable first pass metabolism in the liver when taken by oral route.
Isosorbide mononitrate is nearly 100% bioavailable when taken by the oral route!
sodium nitroprusside, IV? sublingual or ingested?
IV, notable for ability to cause CN toxicity
AR in developed countries
normally best heard at L sternal border
developed most caused by aortic root dilation– best heard at right sternal border. or caused by a bicuspid aortic valve
What is the drug of choice for PSVT paroxysmal supraventricular tachycardia?
ADENOSINE!
t1/2 10 seconds
-slows conduction through the AV node by hyperpolarixing the nodal pacemaker and conudcting cells.
side ffects: flushing, chest burning (due to bronchospasm), hypotension and high grade AV block
effect method for preventing doxorubicin cardiomyopathy is?
Dexrazoxane
Fe-chelating agent that decreases formation of oxygen free radicals by doxorubicin and other anthracyclines
biventricular pacemakers
first two leads in the RA
the L ventricular leads course through the coronary sinus, which resides in the atrioventricular groove
Best ausculatory indicator of the severity of mitral stenosis?
length of the interval between A2 and the opening snap OS
The shorter the interval the more severe the stenosis.
The OS occurs due to tensing of the mitral valve leaflets after the valve cusps have completed their opening excursion. The more thickened and fibrotic the MV, the earlier this tensing occurs.
turner syndrome
bicuspid aortic valve
A fibrinous of serofibrinous early onset pericarditis develops in about 10-20% of patients between days 2 and 4 folloing transumural MI
- the pericarditis is a rxn to the transmural necrosis
- the inflammation affects the adjacent visceral and parietal pericardium
- generally short lived and disappears with 1-3 days of aspirin therapy
organ susceptibility to infarction?
CNS> myocardium> kindey> spleen> liver
liver has dual and or collateral blood supply
S. aureus biding to heart valve
following bacterial binding, tissue factor expression results in platelet and fibrin deposition and the formation of vavlular vegetation
skeletal manifestations of marfans?
upper body is disproportionately short compared to leg length
- spinal scoliosis and kyphosis
- long arms
- long tapering fingers
autosomal dominant defect in gylcoprotein fibrillin-1
marfan cardio
-MVP
-cystic medial degeneration of the aorta:
may lead to aortic dilation and dissection
AR leading cause of death, followed by cardiac failure due to MS and or AR.
most important factors for coronary blood flow
large arteries and pre-arteriolar - NO
small coronary arterioles - adenosine ( a product of ATP metabolism)
both vasodilatory
postive FTA-ABS
syphillis
-vasa vasorum endarteritis and obliteration, resulting in inflammation, ischemia and weakening of the adventitia
digoxin
block na/k/atpase –> increased ca intracellular –> inotropy
stimulates vagus nerve –> parasympathetic tone –> decreases AV nodal conduction –> decreased HR
Dopamine dosage
- low doses of DA stimulate D1 receptors in the renal and mesenteric vasculature resulting in vasodilation and increased blood flow to these sites.
- higher doses of DA increase cardiac contractility by stimulation of B1 adrenergic receptors
- even higher doses produce generalized vasoconstriction by alpha 1
statin + fibrate =
risk for myopathy rhabdoooo
fibrate + bile acid-binding resins =
risk for cholesterol gallstones
digoxin toxicity
fatigure, blurry vision, changes in color perception, nausea and vomiting, diarrhea, abdominal pain, headache, dizziness, confusion and delirium.
-bradycardia from increased AV nodal block occurs then junctional escape beats–> sustaing escape –> v tach –> v fibb
angioedema
swelling of tongue, lips, or eye lids maybe even a lil laryngeal edema and difficulty breathing
ACE inhibitor indusced angioedema is more than likely due to increased bradykinin levels as a result of ACE inhibition
normally ACE breaks down bradykinin
transmural inflammation of the arterial wall with fibrinoid necrosis is
polyarteritis nodosa!
-segmental, transmural, necrotizing inflammation of medium to small sized arteries. any organ, especially the lung
asoc with Hep B sooooo LIVER!
Libman-Sacks endocarditis
SLE!!!!
recall SLE has IC and a hypercoagulable antiphospholipid antibody syndrome
verrucous endocarditis occurs 25%
-small (1-4mm) cardiac valvular vegetations on either side of the valve, consisting of sterile, finely granular, fibrinous eosinophilic material. These veggies may result from IC deposition.
total flow =
total flow = flow velocity X cross sectional area = constant
what joins together to make the portal vein?
splenic + SMV
myxomatous changes in the media of large arteries
- cystic medial degeneration
- medial degeneration is characterized by fragmentation of elastic tissue (basket weave patter of separated elastic fibers - compared to normal elastic tissue) and by separation of the elastic and fibromuscular components of tunica media by small, cleft like spaces that become filled with amorphous extracellular matrix
Marfan syndrome is a frequent cause of cystic medial degeneration – AD with a defect in extracellular glycoprotein fibrillin-1 a major component of extracellular matrix myofibrils, which form the scaffolding for elastic fibers.
A high intraplaque activity of which enzyme would predispose a patient to myocardial infarction?
Metalloproteinases
The balance of collagen synthesis and degradation determine the mechanical strength of the fibrous cap of a plaque. Activated macrophages in the atheroma contribute to collage degradation by secreting metalloproteinases
hypertrophic cadiomyopathies and increasing the murmur
- ASYMMETRIC centricular SEPTAL hypertrophy and variable dynamic left ventricular OUTFLOW OBSTRUCTION which may produce a systolic ejection murmer.
- decrease in the LV end diastolic volume (via decreased preload) inreases the obstruction, causing the murmer of HCM to be enhanced
so suddenly standing from supine and the valsalva maneuver would decrease venous return
ED50
The potency of different agents can be compared by determining the dose of drug that is required to produce 1/2 50% of the maximum biological response.
the lower the ED50 (log) of a drug the more POTENT
potency of a drug:
primarily affected by the affinity of the drug for its receptor and the amount of drug that is able to reach the target tissues.
