Cardiology notes Flashcards
Give some ddx for chest pain, SOB, heart failure signs?
- ACS (can cause heart block causing acute heart failure and acute pulmonary edema)
- Aortic stenosis
- Cardiomyopathies (4 types: HOCM, restrictive cardiomyopathy, dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy)
- Aortic dissection (medical emergency)
How may pulmonary embolism present with chest pain, SOB, heart failure symptoms?
What CXR features may be seen?
- There is decreased perfusion causing V/Q mismatch
- Acts on right heart which causes right heart failure –> obstructive shock
- CXR is mostly normal as hard to find oligemic fields
- May have Hamptons hump, wedge infarct
- Dilated pulmonary trunk, enlarged hilum
How may aortic dissection result in acute heart failure and acute pulmonary edema?
- Type A ascending aortic dissection may extend into the aortic root and detach the aortic valve leaflets causing aortic regurgitation (severe)
- Can extend into the main coronary arteries (RCA affected more commonly –> presents with ST elevation in inferior leads)
What symptoms of aortic stenosis are relevant to the patients prognosis?
What portion of the heart is affected in Takotsubo cardiomyopathy?
Takotsubo = octopus in japanese
* Mid and apical contraction impaired
* Basal has normal contraction
What are the Ix and why are they done for chest pain, SOB, heart failure symptoms?
What would you expect?
- CBC: anemia (CKD, anemia of chronic disease, post gastrectomy (Fe def anemia patient)), leukocytosis (common triggering factor of exacerbation), reactive thrombocytosis (chronic Fe iron deficiency)
- LRFT: if CKD will ahve high creatinine, urea and low eGFR
- Clotting profile (may need anticoagulants if undergoing operation): INR, aPTT
- Cardiac profile: myoglobin, CKMB, cTnT, cTnI
- BNP, anti pro BNP (end terminal peptide so more specific. BNP is an atrial neutritic peptide (released when there is atrial stretch –> indicates volume status. When there is increase in BNP means there is high volume overload). Good prognostic indicator if low anti pro BNP level
- Lactate levels: elevated (as less oxygen and patient in shock so in lactic acidosis)
- ABG: suspect hypoxia, or CO2 retention (if fatigued) if acidotic more stress on the heart
In patient with chest pain, SOB, heart failure symptoms what are the main 2 types of MI that can occur?
What are the 5 types of MI?
In critical illness, it is most likely type 2 MI
Type 2 MI: MI due to oxygen supply. demand mismatch without acute coronary obstruction)
Increased demand causes: thyrotoxicosis, pregnancy, large AVN shunt
Decreased supply: systemic hypoperfusion = common cause (aortic stenosis), coronary artery vasospasm, coronary artery dissection
Type 1: MI due to coronary artery plaque rupture/erosion
Type 2: MI due to imbalance in oxygen supply/demand without evidence of coronary plaque rupture
Type 3: cardiac death with symptoms suggestive of myocardial ischemia (death before biomarkers could be obtained), or mycoardial ischemia detected by autopsy exam
Type 4: MI related to previous coronary interventin. 4a: after PCI, 4b: due to stent/scaffold thrombosis, 4c: due to restenosis (where CKMB is used as cTnI stays elevated for up 10 days)
Type 5: MI associated with CABG
What is the managent of patient with chest pain, SOB and heart failure symptoms with aortic stenosis?
ABCDE (always resuscitation and stabilize first)
Decongest the patient first prior to any surgical consideration
Management of acute pulmonary edema: fluid and salt restriction, IV lasix, acetozolamide, check urine sodium (check natriuresis)
Haemodynamically sunstable: inotropes are not ideal but used as bridging therapy as it increases myocardial oxygen demand (use IV dobutamine/dopamine)
Surgical management
Balloon aortic valvuloplasty (briding to definitive surgery) as it will improve the AVA (aortic valve area). However complications include acute aortic regurgitation (cannot control where the crack occurs and valve already impaired in AS). Contraindications to BAV when patient already has baseline AR (has high chance of progressing to severe AR which is much worse than AS)
Valvular replacement (definitive): surgical AVR for low/intermediate surgical risk (young patients) however transcatheter AV implantation (TAVI) originally only for high surgical patietns is being slowly phased into medium and low risk patients.
What is surgical management of MR?
Transcatheter repair clip of mitral valve (clip the leaflets together)
TMVR: transapical approach (done by surgery), percutaneous= more common (femoral vein, RA than transeptal puncture –> left atrium). Normally the ASD is well tolerated so iatrogenic ASD is left behind.
What are the indications for closure of ASD?
Concept: if it will lead to right heart failure (right atrial/ ventricular dilatation) –> must operate before it progresses to Eisenmenger syndrome
What are the ix that must be done prior to doing TAVI in aortic stenosis?
- CT scan of aorta, iliac and femoral arteries (vascular insuffciency that prevents catheter access)
- CT angiogram (done with contrast even with renal impairment as it is urgent
- After doing repair there will be increased blood supply to the kidneys improving renal outcome
What can be causes of anemia in post gastrectomy, CKD, aortic stenosis patient?
- CKD (reduced EPO)
- Anemia of chronic disease
- Heyde disease: triad of aortic stenosis, GI angiodysplasia (postulated that AS changes vasculature of the gut), acquired type 2a vWF –> once AS is fixed –> angiodysplasia disappears
- MAHA (if prosthetic)
What simple test can be done to confirm AR?
- Measure BP –> wide pulse pressure (low diastolic pressure due to blood run off)
What are the surgical options for aortic stenosis?
Old school: balloon valvuloplasty (disadv: can crack the calcified valve and cause aortic regurgitation –> can only use small balloon)
TAVI/TAVR preferred (but can only be used for degenerative causes of AS as the calcification causes better adherence of valve to the wall): lasts for 10-15 years (bioprosthetic valve)
Out of pocket payment (300k) but can apply for funding via HA.
If younger patient: can do mechanical heart valve replacement (lasts longer but requires lifelong anticoagulant) –> open heart surgery that is fully funded by HA.
What are the options for TAVR (transcatheter aortic valve replacement)?
Self expanding valve: navitor (abott) TAVI system, Evolut Pro
Balloon expanding valve: Sapien XT (Edwards lifesciences)
Who are the younger individuals who may be affected by aortic stenosis?
- Bicuspid aortic valve
- Rheumatic heart disease (however more commonly affecting mitral valve)
How to manage symptomatic ASD?
What must be given after procedure?
Transcatheter closure of atrial septal defect: goes from IVC –> RA –> LA
Fill up balloon in the LA side than pull out through ASD which covers the defect. Then inflate the other balloon in the RA which closes defect.
* Takes 3 months for epitheliazation
Given antiplatelets for 6 months (given SD) to prevent clot formation for turbulent flow
How can ASD present?
Mostly will be congenital and will be left to right shunt (due to higher left heart pressure over the right side) –> will present with leg swelling
Rarer: eisenmenger syndrome (as it takes a long time to develop) –> pulmonary hypertension, volume overload causing right to left shunt –> will present with pulmonary edema
What is the management of moderate to severe MR?
- Mitraclip (2nd most common valvular replacement after TAVI)
- Clips the posterior and anterior leaflet which forms 2 orifices. This is considered repair. (cannot do replacement with current technology as attachment sites is not firm enough)
consideration: more clips inserted (restrict forward flow) which may induce mitral stenosis
Real time USG to measure gradient (try to adust clip)
What can mitraclip be used for?
- Degenerative prolapse
- Secondary MR/functional MR in the setting of normal mitral leaflet morphology (annulus keeps enlarging, pulling the valves apart) which is normally due to atrial (left atrial dilatation) or ventricular dilatation (cardiomyopathic diseases)
What is the gold standard treatment for moderate/severe MS?
Why is TMVR not feasible (such as in TAVR) with current technology?
Balloon valvuloplasty (improves pressure gradient but can cause MR)
If concomitant MS and MR: dont do balloon valvuloplasty (can induce severe MR)
TMVR cannot be done as in TAVR as the annulus in mitral valve is very compliant. Valve cant be held well in comparison to aortic valve which is rigid.
Mx of severe tricuspid regurgitation?
Tric valve: transcatheter bicaval valves system
What is the role of ventricular pacing (VC) and ventricular sensing (VS) in pacemaker?
Used to monitor how much ventricular control is self regulated vs pacemaker regulated. Will dictate consumption of battery.
Can you have 40 year old presenting with symptoms of ASD?
Can be symptomatic from childhood to adulthood –> then due to aging there is degeneration and heart starts to dilate manifesting the symptoms
What are the rare causes of acquired ASD?
What commonly causes VSD in adults?
Acquired ASD: endocarditis, MI, iatrogenic ASD (from valve replacement procedures)
If there is acquired septal defect: most common is VSD from MI
Benefits of self expandible valves over balloon expanding valves for TAVR?
If calcified valve balloon expanding valve places more stress on the calcification and has higher risk of plaque rupture
Self expandible has lower risk of plaque rupture. It partially blocks the coronary vessels (longer valve): harder to manipulate if there is CAD requiring intervention.
What devices for left atrial appendage occlusion?
What drugs must be used after operation?
What alternative is there and why is it not done?
- Watchman Boston
- Amulet abott
After operation: can stop warfarin after 3 months, can stop aspirin after 6 months (unless indicated)
USG, TEE to decide what shape and configuration to plug the hole.
Anticoagulants has same efficacy as LAAO (but with more side effects)
These methods reduces chance of thromboembolic stroke (removes local effect of producing thrombus) but does not reduce chance of ischemic stroke.
What drug coverage after TAVI needed?
DAPT 3 months post TAVI
Than aspirin monotherapy
What is the anticoagulants given for valvular and non valvular AF?
AF should be given NOAC 1st line
Other valvular issues with AF can give NOAC
Only medium/severe MS with AF –> requires warfarin. Doing LAAO would not help in patient with severe MS with AF as thrombus formation is from the whole left atrium.
What drugs may be needed for heart failure patient?
- Eplerenone (K+ sparing diuretic): same MOA as spironolactone but less AE but also more expensive
- Furosemide is an extra (if patient has foot edema)
- Entresto (ACEI and ARB): newer generation drug
- Dapagliflozin (heart failure: SGLT2 inhibitor)
What needs to be counselled when using warfarin as an anticoagulant?
What is the target INR?
- Warfarin requires monitoring of INR, diet control (antagonizes vit K (downstream clotting factors) –> requires a stable vit K intake so that INR will not fluctuate due to diet. Dosage changes all the time -> will adjust if INR is too low or high
- Target INR is 2-3
What anticoagulant for non valvular AF?
- 1st line is NOAC (superior to warfarin: less stroke, less bleeding. But higher risk of GI bleed): rivaroxaban (highest GI bleed risk) –> can take etoxiban
- 2nd line is warfarn
- Alternative is left atrial appendage occlusion if non valvular AF (most thrombus formation is here due to stasis of blood). It is non inferior to warfarin. Currently undergoing trial to see if efficacy is comparible to NOAC. If it is in the future LAAO may be 1st line as no associated bleeding risk and decreased risk of ischemic stroke.
What is done for Mx of AF?
Rate control for everyone
Rhythm control (improve overall cardiovascular mortality): K channel blockers: amiodarone (cardioversion and maintenance), dronedarone (maintenance)
When is ablation done for AF?
What are the 2 types available?
- Catheter pulmonary vein isolation: indicated in patients wit symptomatic paroxysmal/ persistent/long standing persistent AF who are refractory or intolerant to 1 class I or class 3 antiarrhythmic drugs when a rhythm control strategy is desired.
Primary trigger for most episodes of AF involves electrical discarhge within 1 or pulmonary veins. Principle goal is to isolate the pulmonary veins so that these discharges do not activate the atrial tissue.
2 main types of energy source for catheter ablation include RFA and cryoballoon (cryothermal) ablation.
Most common pulmonary vein isolation is circumferential pulmonary vein isolation. - Surgical ablation (open heart surgery): indicated in select patients underoing cardiac surgery for another indication such as valvular replacement or CABG. Aim to create a maze of functional myocardium within the atrium that allows for propogatation of atrial depolarization while reducing the likelihood that the wavefront would promote microentry
Theoretically can do pulmonary vein isolation and ablation at the same time.
Indications for repair of MR?
Dilated LV and AF
Impaired systolic dysfunction
What are structural and functional tests for cardiac function?
Structural tests
* Coronary CT angiogram (non invasive)
* Coronary angiography (invasive: requires catheterization)
Functional tests
* Thallium scan (huge radiation risk)
* MRI scan (more time consuming)
What are the causes of bradycardia?
Drug:
Parasympathomimetics - acetylcholine, acetylcholineesterase inhibitors
Sympatholytics - beta-blockers, methyldopa
Opioids and sedatives
Cimetidine (H2 antagonist)
Digitalis
Non-DHP CCB (diltiazem, verapamil)
Ivabradine
Amiodarone
Lithium
Chemotherapeutic agents - thalidomide, lenalidomide, paclitaxel
Intrinsic Cardiac causes :
Sick sinus syndrome
AV block (e.g. from AMI)
Electrolytes (e.g. HyperK)
Endocrine (e.g. Hypothyroid)
Others - increased ICP, anorexia nervosa, certain infections (e.g. typhoid fever)
What cardiac device used in severe HF?
How to differentiate betwen pacemaker and ICD on CXR?
In implantable cardioverter defibrillator a lead is only present in right ventricle. Also has radiodense coil to deliver shock for life threatening arrhythmia.
In heart failure cardiac resynchronization therapy (CRT)/pacing is biventricular to coordinate both the right ventricle and left ventricle contraction –> lead present in both LV and RV. (there is no radiodense coil) Can also be biventricular in RA and RV instead.
