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