Cardio Block Week 1 (2) Flashcards
Where is the SA node located?
At the junction of the R. atrium and the SVC
Retinal artery occlusion is an important cause of ?
Painless, monocular vision loss.
The most common cause of retinal artery occlusion is?
Thromboembolic complications of atherosclerosis in the internal carotid.
The retinal artery is a branch of the ____ artery?
Ophthalmic artery
What does the retinal artery travel within?
What does the retinal artery supply?
The retinal nerve
The inner retina and and the surface of the optic nerve.
Dystrophic calcification is considered to be a hallmark of ___?
Cell injury and death, occurring in all types of necrosis.
How do calcium deposits in dystrophic calcification stain?
dark-purple shard edged aggregates.
*With lamellated outer layers are described as psammoma bodies.
How do dystrophic calcifications occur?
Chronic hemodynamic stress -> Endothelial fibroblast death ->
Release of cellular degradation products into valvular interstitium ->calcification.
In HOCM, left ventricular outflow obstruction is due to ?
Abnormal systolic anterior motion of the anterior leaflet of the mitral vlave toward the hypertrophied interventricular septum.
Patients with SLE have accelerated levels of____?
This leads to an increased risk of?
Atherosclerosis
MI
Other cardiac features of SLE include?
SLE (verrucous endocarditis) on both surfaces of the mitral or aortic valves.
- Pericarditis
- Small vessel necrotizing vasculitis
Vegetations in SLE are made up of?
Sterile platelets + fibrin, immune complexes and mononuclear cells
Renal involvement in SLE manifests as?
Diffuse proliferative glomerulonephritis (necrotizing lesion with crescent formation)
**Light microscopy shows glomerular capillary walls with wire loop structures.
Why does increased physical activity lead to anginal symptoms in stable angina?
Mismatch of oxygen supply and demand.
Dobutamine can be used in diagnosis of ?
Atherosclerotic CAD via pharmacological stress testing.
How will a positive stress test for CAD present?
Transient decrease in contractility (wall motion defect) -> reduced ejection fraction.
How would Concentric hypertrophy px:
Uniformly thickened LV and a small LV cavity (impaired diastolic filling) -> HF with preserved ejection fraction.
Can Dilated cardiomyopathy be inherited?
Gene affected?
Yes - familial DCM is transmitted in an AD pattern.
TTN (codes for sarcomere protein - titin)
Patient with dilated Cardiomyopathy also develop this their LV?
Mural thrombus.
** increased risk for sudden death due to ventricular arrhythmia.
What liver enzymes metabolize statin?
CYP3A4
What are some adverse effects of statin use?
Statin myopathy
**can be triggered when levels are increased.
Macrolide antibiotics inhibit this liver enzyme.
CYP3A4
Other drugs that inhibit: ketoconazole, NOn-dihydropyridine CCB.
Which of the macrolides does not significantly inhibit CYP3A4 levels?
Azithromycin
What medication should be avoided in HOCM?
Why?
Vasodilators (decrease afterload & LV volumes) and Diuretics (decrease venous filling)
Lessened LV volume (caused by reduction in cardiac preload and/or afterload)
-> leads to greater flow obstruction due.
A tricuspid regurgitation will increase with?
Inspiration (due to increased preload).
Mitral regurge or VSD would either decrease or remain unchanged during inspiration.
What type of arrythmias does lidocaine treat?
Why?
Ischemia induced ventricular tachy.
Binds to inactivated Na channels and rapidly dissociates.
Ischemic myocardium has higher than normal membrane potential which delays voltage dependant recovery of sodium channels from inactivated resting state.
What is beta blocker withdrawal syndrome?
Px will px with tachy, palpitations, and anginal pain.
Due to upregulation of B-receptor after long time use of B-blockers (increasing sensitivity). Abrupt cessation of B-blockers -> Increased HR & contractility.
How can paroxysmal supraventricular tachy px?
anxiety provoked episodes of sudden onset palpitation asx with SOB & lightheadness.
What organ does Polyateritis Nodosa spare?
Lungs
What artery involvement is often prominent in PAN?
Renal Artery
What is a relatively uncommon cause of cardiomyopathy in postpartum women?
What type of cardiomyopathy is this?
What is it due to?
Peripartum cardiomyopathy.
Dilated
Impaired function of angiogenic growth factors during peripartum period.
What features would you see in a 3rd degree AV block?
Atrium and ventricle beat independently of each other. P-P (SA node) and R-R (His bundle) distances are regular.
What can cause AV 3rd degree block.
AV node dysfunction Ischemia Infiltrative dz (sarcoidosis) Lyme dz Age related fibrosis with cellular degeneration
How does sodium nitroprusside work?
Decreases LV preload and afterload but unchanged stroke volume via direct release of NO in vascular smooth muscle.
(Balanced vasodilation - this is what allows for maintenance of stroke volume).
What are the 2 medications that can help in hypertensive emergency?
Nitroprusside
Fenoldopam
What is the subclavian steal syndrome?
Due to hemodynamically significant stenosis of the subclavian artery proximal to the origin of the vertebral artery -> reversal of flow from contra Vertebral artery to the ipsi artery
How will patients with subclavian steal syndrome present?
Arm ischemia in the affected extremity
Vertebrobasilar insufficiency (dizziness, vertigo, drop attacks).
What would you see in physical examination for Subclavian Steal syndrome?
How would you diagnose it?
Significant difference in systolic BP between arms.
Doppler US
How does cardiogenic pulmonary edema present in the lungs?
Alveolar capillaries become engorged and there is transudation of fluid plasma across the alveolar capillary membrane, which shows up as pink, acellular material within the alveoli.
What are the medications that lower BP by reducing systemic vascular resistance?
Hydralazine
Minoxidil
What are the adverse effects Hydralazine and minoxidil?
Stimulate baroreceptor -> reflex sympathetic activation -> Increase HR, contractility and CO -> activation of RAAS -> Na and water retention.
*This limits their long term use
To counteract their effects, what is typically given along with direct arteriolar vasodilators?
Diuretics and sympatholytics.
In unilateral renal artery stenosis, the hyper-perfused kidney will show?
Arteriolar wall thickening due to hyaline of hyperplastic arteriosclerosis.
**due to High BP
How does ischemic damage in the kidney present?
Cortical thinning, Tubular atrophy, interstitial ischemia/fibrosis, glomerular crowding.
Vascular endothelium synthesizes NO from what amino acid?
Arginine
**enzyme is Nitric oxide synthase
What is the MOA of NO released from vascular endothelium?
NO release -> activated guanylyl cyclase -> increase formation of cyclic GMP -> activation of protein kinase G -> reduction of cytosolic calcium levels -> relaxation of smooth m.
How can pulmonary HTN be recognized on physical examination?
Loud pulmonic component (P2) of S2 (forceful pulmonic closure) & accentuated palpable impulse at the L. sternal border (*due to R. ventricular heave).
How would you differentiate Pulm HTN and Pulmonic stenosis on PE?
Pulm HTN will have a loud pulmonic component of S2 while in pulm stenosis, there will be a delayed P2.
S. bovis is associated which condition?
Colon cancer
What type of infection does S. bovis cause?
Subacute bacterial endocarditis
What role does cortisol play in vasculature?
What is this phenomenon called?
Cortisol has no direct vasoactive properties. But it augments the vasoconstrictive effects of catecholamines and angiotensin II.
This is called permissiveness.
When is this cortisol role in vasculature most prominent?
In adrenal insufficiency, low cortisol levels contribute to hypotensive crisis by decreasing vascular responsiveness to NE & angiotensin II.
In which other locations, does cortisol exert its permissive effect?
Glucagon to increase glucose release from liver.
Where do nitrates primarily act on?
Nitrates are primarily venodilators that increase peripheral venous capacitance.
They also have a modest effect on arteriolar dilation. (decrease in systemic vascular resistance).
Staph. Epidermis has a _____ catalase test and ____ coagulase test?
+ve catalase
-ve coagulase
**Catalase test separates Strepto (-ve catalase) from staph.
S. epidermis is susceptible to_____?
Novobiocin
Alpha 1 uses ____ as its second messenger?
IP3
What receptors does NE stimulate?
B1 adrenoreceptors - ↑cAMP
A1 adrenoreceptors via ↑IP3
What is the preferred treatment for septic shock?
Norepinephrine