Part 17 Flashcards
3 routine therapies for heart failure and how they impact the condition
- diuretics (decrease preload, afterload, pulmonary edema, cardiac distension)
- RAAS inhibitors (promote dilation of artereioles and veins and decrease aldosterone release)
- B blockers (not understood mechanism)
DOC for patients with severe heart failure and why
Loop diuretics (furosemide), promote strong diuresis and work even when GFR is low
sacubitril/valsartan (entresto) drug class, function, and mech of action
- Angiotensin receptor neprilysin inhibitor (ARNI)
- approved for patients with class II-IV HF to be used in place of an ACEI or ARB as it is superior than elanapril alone when looking at reduced risk of CV related death
- functionally increases natriuretic peptide levels by inhibiting neprilysin that breaks them down
sacubitril/valsartan (entresto) ADR’s (4)
- hypotension by volume depletion
- cough
- hyperkalemia
- fetal harm
Aliskiren (tekturna) function
Can shut down RAAS by binding renin, should work as well as ACEI and ARB’s but is only approved for HTN and not for treatment of HF (doesn’t improve outcomes)
Ivabradine (Corlanor) drug class and indications
- SA node inhibitor (selective for funny channels slowing firing of SA node and reducing HR)
- indicated for patients with resting HR of at least 70bpm and are on max doses of B blockers or have contraindications of it, and have and LVEF equal or less than 35%
Aldosterone antagonists functions (2) and two examples
- Block receptors for aldosterone in heart and blood vessels, can prevent myocardial remodeling and delay fibrosis (aldosterone increases fibrosis of myocardium and vascular) (as well as its original function to prevent Na+ and thus H2O retention with K+ excretion)
- spironolactone and eplerenone
Ivabradine (Corlanor) ADR’s (3) and contraindications (3)
- Bradycardia
- hypertension
- afib
- Low BP
- sick sinus syndrome
- 3rd degree heart block
Dopamine (inocor) function at diff doses
Low - stimulate kidneys
Intermediate - increase inotropy and thus SV/CO
Large - stimulates a1 receptors on vascular smooth muscle producing vasoconstriction
Nitroglycerin function
Potent venodilator causing a dramatic decrease in preload on the heart, in HF used to reduce acute severe pulmonary edema but should not be taken with PDE5 inhibitors such as sildenafil
Sodium nitroprusside (nitropress) function
Agent to rapidly dilate arterioles and veins for short term therapy of severe HF
Digoxin (lanoxin, loxicaps) mech of action
- accelerates entry of Ca2+ into cardiac muscle cells
- during AP, Na+ and Ca2+ enter cardiac muscle cells and K+ exits
- Then Na/K ATPase pumps things back and Ca2+ leaves via Na/Ca transporter
- Inhibits adenosine triphophate (ATPase which energizes Na+/K+ pump
- buildup stimulates exchane of Na for Ca2+, increasing levels in cell
- greater contraction
- too much K+ will inhibit effect of digoxin
What must be monitored and kept in normal range when on digoxin?
K+
Drug for patients with bradycardia or AV block due to digoxin toxicity and why
Atropine - it is an anticholinergic that inhibits parasympathetic action on the heart, therefore reversing some of the effect of digoxin toxicity via a separate mechanism
Pericarditis signs and symptoms (3)
- sharp chest pain relieved by sitting and leaning forward
- rhythmic pericardial friction rub usually at the left lower sternal border not associated with respiratory rate
- Retrosternal pain radiating to neck, shoulders, back
Pericarditis has the potential to sequellae into ____ requiring ____
cardiac tamponade, pericardiocentesis of fluid
Becks triad for acute cardiac tamponade
- low arterial bp
- increased central venous pressure
- distant heart sounds (muffled)
Best diagnostic test for pericrditis and finding on that test indicating positive result
EKG - diffuse ST elevation across all leads except AVR (fuck AVR man it don’t do shit)
Chest x ray findings for pericarditis
“water bottle” heart (can’t tell where the pericardium ends and where the heart begins but the shape is helpful to diagnose)
Post MI pericarditis
Occurs 2-5 days*** (diff from dressler syndrome) after infarction due to inflammatory response to necrosis, will see symptoms of both post MI and pericarditis despite self resolving after period of time sometimes requiring pain management for small pericardial effusions
Dressler’s syndrome will have ___ pericardial effusions, and how often does it cause tamponade? When does it occur?
Large, rare, occurs weeks to months*** after MI or open heart surgery
Most common viral cause of myocarditis
-coxsackie virus B
When I say diffuse ST segment elevation you say ___. When I say nonspecific ST segment changes you say ____
pericarditis, myocarditis
Bed rest and myocarditis
-Not recommended to remain in bed but do not recommend exercise or exert self
Constrictive pericarditis
Thickened, fibrotic adherant pericardium due to injury (surgery) or infection that causes restricted diastolic filling
Infective endocarditis
Infection of the hearts endocardial surface, most commonly involving the valves but may also occur at a septal defect or chordae tendinae, can be acute or subacute
Risk factors associated with infective endocarditis (5)
- underlying cardiac structural abnormalities
- pacemaker infections
- prolonged surgery
- catheter related bacteremia
- IV drug abuse or piercings
3 big presenting signs and symptoms of endocarditis
- fever
- onset of new murmur
- positive blood cultures
Microorganisms associated with native valve endocarditis (3)
- S aureus (skin, iv drug use)
- viridans group streptococci (most common)
- HACEK (haemophilus, actinobacillus, cardiobacterium, eikenella, kingella: uncommon, seen in immunocompromised hosts)
Signs of embolization of vegetation from infective endocarditis in periphery (4)
- pectechiae (small hemorrhages sometimes in nailbeds [called splinter hemorrhages])
- osler’s node (painful, purple lesions on fingers and toes)
- janeway lesions (flat, painless red lesions on palms and soles)
- roth spots (retinal hemorrhages with pale or yellow centers)
Blood culturing process for infective endocarditis
- 3 sets drawn at least 1 hour apart for 3 diff mediums (aerobic, anaerobic, fungal)
- as soon as positive is obtained then starting broad spectrum antibiotic treatment
- narrow down once culture and sensitivity obtained
IV drug users will see growth of vegetation mostly on ____ sided valves
Right
Valvular dehiscence
Refers to the separating of an artificial valve from its anchor due to vegetation overgrowth resulting in rocking motion of prosthetic valve back and forth with blood flow
Infective endocarditis treatment (2)
Hospitalization and IV antibiotics:
- PCN and gentamycin IV daily for 4 weeks (most common)
- vanco or ceftriaxone IV daily 4 weeks
5 year mortality of infective endocarditis
54-87%
Procedures that put patients at elevated risk of infective endocarditis and which is most common? (5)
- endoscopy
- colonoscopy
- dental extractions
- TURP (most common)
- transesophageal echocardiography
Antibiotic prophylaxis for infective endocarditis (2)
- amoxicillin 2 g 1 hr prior to procedure***
- clindamycin 600mg if allergic
Syncope definition
Transient loss of consciousness due to global cerebral hypoperfusion characterized by rapid onset, short duration, and spontaneous complete recovery (not lethargic upon return)
Diagnosis of syncope must rule out these 2 things
head trauma and epilepsy
Syncopal recurrence is about __%
What are the 3 types of syncope and which are favorable and which are unfavorabe?
20,
- Reflex (neutrally mediated) syncope/vasovagal (favorable outcome)
- Orthostatic hypotension (favorable outcome)
- Untreated cardiac syncope (greater chance of mortality, unfavorable)
Orthostatic blood pressure measurements
A series of 3 measurements going from lying, sitting, to standing, if systolic BP drop greater than 20 mmHg or diastolic 10 mmHg then considered positive (or if HR increases 20-30bpm or if patient becomes symptomatic)
Neurally mediated (reflex) syncope/vasovagal syncope mech of action
- Baroreceptors in carotid sinus and aortic arch monitor BP and HR by innervation of CN IX and X
- Decreased firing due to lack of stretch from baroreceptors activates brain stem to respond with sympathetic innervation to raise pressure
- Increased firing due to stretch from baroreceptors inhibits brain stem from responding with sympathetic innervation causing lowering of blood pressure as well as increase in vagal tone to heart to decrease HR
Carotid sinus hypersensitivity (charcot weiss baker syndrome)
Occurs when stimulation of carotid sinus causes bradycardia and hypotension often in elderly or with tight collars, can diagnose with carotid sinus massage
Orthostatic hypotension syncope etiology
-Sudden decrease in BP after standing or during standing after exertion due to volume depletion, drugs, or autonomic dysfunction, most common in elderly and rare in those less than 40 years of age caused by autonomic failure, drugs, hypovolemia, and treated with volume replacement, avoiding precipitating factors, treatment of underlying cause
Long QT syndrome and how it relates to syncope
Problem with heart’s electrical system that is often asymptomatic until sudden syncopal episode, may be congenital or acquired, and is linked to sudden cardiac death and torsades de pointes
DOC for torsades de pointes
-IV magnesium
1 treatment for long QT syndrome (and its supplement)
- IV magnesium followed (stabilize) by B blocker
- sometimes supplementary implantable cardioverter defibrillators in those with high risk for sudden cardiac death expected to live more than a year
Brugada syndrome
Genetic condition channelopathy responsible for 4-12% of all sudden cardiac deaths, high risk, manifests with specific “saddle-like” pattern ST segment elevation in leads V1-V3 and right bundle branch block
Brugada syndrome treatment
Implantable cardioverter defibrillator (ICD)