Dunedin-Cardiology Flashcards
How does a vagal manoeuvre help with SVT?
Block the AV node
What is the MOA of adenosine?
ultimately causes AV node block
Acts on A1 receptors on heart- SA and AV nodes
A2 coronary vasodilation
What is a relative contraindication for adenosine?
asthma
What are short RP tachycardia vs long RP tachycardia?
short RP tachycardia: AVRT, AVNRT
Long RP tachycardia: sinus tachycardia, focal atrial tachycardia
What type of circuit is atrial flutter?
macro re-entrant circuit
typically in right atrium around tricuspid annulus
90% counter-clockwise
10% clockwise
Why should you avoid flecainide in atrial flutter?
slows conduction velocity within flutter circuit, relatively minimal effect on AV nodal conduction
if using it, should use with AV nodal blocking agent such as b-blocker to prevent 1:1 conduction
Describe the CHA2DS2-VA score
note, new score has taken out the sex guidelines
List DOACS and their target
Dabigatran- thrombin inhibitor (reversible idarucizumab), renal cleared, p-glycoprotein substrate
Rivaroxoban- Factor Xa inhibitor (reversible andexanet alfa, prothrombin complex partial reversal), primarily hepatic clearance, some renal, metabolised CYP3A4, p-glycoprotein substrate
Apixaban- Factor Xa inhibitor (reversible adexanet alpha), primarily hepatic/biliary clearance, metabolised by CYP3A4, p-glycoprotein substrate
DOAC metabolism interactions
What did the LEGACY Trial suggest?
BMI >27 should loose weight (10% of body weight) if have AF
Also managing sleep apnoea
What are some complications for ablation of AF?
tamponade > CVA/TIA > PV stenosis > phrenic palsy >atrial oesophageal fistula
What is a bifascicular block?
RBBB + block of anterior (LAD) or posterior (RAD) fascicle of left bundle; or LBBB
What is a trifascicular block?
bifascicular block + PR prolongation (ie. AV node)
What are indications for CRT?
Heart failure
ideally SR
LBBB QRS >150ms
LVEF <35%
What is left bundle branch area (deep septal) pacing?
pacing in the left bundle region
thought to be superior
How to treat fascicular VT? “Normal heart” VT Of left ventricle
verapamil, ablation
ECG- tachy, ‘narrow’ RBBB mimicry and LAD
What is the most common cause of sudden cardiac death in athletes?
hypertrophic cardiomyopathy
What are indications for ICD?
Resuscitated VT/VF cardiac arrest not due to reversible cause
Ventricular tachycardia - sustained or symptomatic , not ablatable, associated with:
- severe compromise or
- failed anti-arrhythmias, or
- LVEF <40%
Hereditary cardiac conditions at high risk of sudden cardiac death: hypertrophic cardiomyopathy, long QT syndrome, arrhythmogenic cardiomyopathy, brigade syndrome
What gene gives highest risk in dilated cardiomyopathy?
LMNA gene mutation
Describe congenital long QT syndromes
Describe arrhythmias and their type of circuit
Focal atrial tachycardia –> ectopic atrial focus
Atrial flutter –> intra-atrial macro re-entry circuit
Atrial fibrillation –> multiple small atrial re-entry circuits pulmonary veins
VT –> macro re-entry around myocardial infarct
AVNRT –> re-entrant circuit within or around AV node
WPW –> re-entrant circuit within accessory pathway
What is ejection fraction?
stroke volume/ end-diastolic volume
Stroke volume: end diastolic- end systolic
On echocardiography what is a normal global strain?
More negative is better
abnormal if > -16%
usual < -18%
young people < -20%
What is the indication for cardiac MRI?
infiltrative disease
fairy disease
inflammatory disease (myocarditis)
LV non-compaction
amyloid
sarcoidosis
iron overload/haemochromatosis
How to treat cardiac amyloid?
CyBorDex chemotherapy x3
What are the types of amyloid that affect the heart?
AL amyloid, TTR (transthyretin amyloidosis)
What are investigations in cardiac amyloidosis?
free light chain ratio 51
IgG free kappa light chain paraprotein 6g/L
bone marrow- 8% plasma cells with amyloid infiltration
What is E/A reversal?
Indicates diastolic dysfunction
What is a normal LV wall thickness?
<11mm
What are some factors that indicate HEFpEF
When to do bone scintigraphy in heart failure?
in patients with suspected ATTR-related cardiac amyloidosis
What investigations for cardiac amyloid?
*serum free light-chain assay
*serum and urine protein electrophoresis with immunofixation
* 99mTc-PYP, DPD, or HMDP scintigraphy with SPECT
Who should be investigated for cardiac amyloid?
Heart failure and wall thickness >12mm
AND Age >65 OR “red flag”
Red flag:
- polyneuropathy
- dysautonomia
- skin bruising
- macroglossia
- deafness
- bilateral carpal tunnel
- ruptured biceps tendon
- lumbar spinal stenosis
- vitreous deposits
- family history
- renal insufficiency/proteinuria
What is high-gradient AS?
VMax >4m/s
pressure gradient >40mmHg
valve area <1
What is a high CT aortic valve calcium score?
Men: >3000
Women: >1600
What is a simplified Bernoulli pressure for RV pressure?
4xV^2
What tricuspid regurgitation suggests PH?
Tricuspid regurgitation velocity >2.9m/s
What is normal, intermediate, or high right atrial pressure?
Normal <5mmHg
Intermediate 5-10mmHg
high >10mmgHg
Indication for aortic valve replacement in asymptomatic patients?
1) Severe aortic stenosis
2) systolic LV dysfunction (LVEF <50%)
3) demonstrable symptoms on exercise testing
4) Very severe, progression, elevated BNP
TAVI vs surgical?
TAVI recommended in >75 years or high risk or unsuitable for surgery
SAVR if younger and low risk for surgery
Severity of mitral stenosis
Management of mitral stenosis?
percutaneous mitral comissurotomy or mitral valve surgery in symptomatic patients
Management of mitral regurgitation
PRIMARY MITRAL REGURGITATION
1) surgery for symptomatic patients
2) surgery is ASYMPTOMATIC patients with LV dysfunction (LVESD >40 and /or LVEF <60%)
SECONDARY MR
1) Medical therapy: angiotensin receptor blocker/neprilysin inhibitor, CRT, SGLT2
2) if no improvement, workup to valve intervention eg transcatheter edge-to- edge repair (TEER)
In heart failure with reduced systolic function, which has least mortality benefit?
angiotensin receptor blocker
In acute heart failure, what is the role of continuous infusion furosemide?
continuous infusion Frusemide same outcome as 12hr bolus IV dose.
High Dose (2.5 x usual dose) not significantly different to low dose (usual oral dose).
What is the MOA of ARNI?
Degrades vasoactive peptides, including natriuretic peptides,
bradykinin, and adrenomedullin
What happens to eGFR when starting SGLT2?
Initially eGFR falls by 5ml/min, albuminuria falls 30-40% but then improved
How does spironolactone cause gynaecomastia?
Spironolactone – inhibits testosterone binding to androgren receptor in breast tissue, less common with Eplerenone, not with Finerenone
Which agents in heart failure improve all cause mortality?
1) BB, MRA, ARNI
2) ACEI, SGLT2
3) ARB, vericguat
What is the MOA of digoxin?
Inhibition of Na+-K+ATPase, –> increase in contractility, benefit thought to be positive ionotropic action
What are the symptoms of digoxin toxicity?
life threatening arrhythmias, end organ dysfunction, hyperkalaemia
What electrolytes can contribute towards digoxin toxicity?
hypokalaemia, hypomagnesaemia, hypothyroidism
What drugs increase serum levels of digoxin toxicity?
– Clarithromycin, erythromycin,
Itraconazole
– Amiodarone, Verapamil, Quinidine
– Cyclosporine
What is the MOA of ivabradine?
Inhibition of If channel in the sinus node
slows heart rate in sinus rhythm
Describe LV pressure volume loops in systolic and diastolic dysfunction
note in diastolic dysfunction end systolic pressure is high
What are echo signs of HFpEF?
E/E’ >13
left atrial volume index (LAVI) >30ml/m
If someone has mildly reduced-preserved ejection fraction, what drugs should you use?
SGLT2 + ARNI + BB + MRA
BB less important
What is the role for semaglutide in heart failure?
use in BMI >30, improves outcomes and also improved BNP
When to use fenerenone in HF?
When EF <60%
What is the role of plasminogen activator inhibitor-1 in predicting cardiovascular disease?
it predicts cardiovascular disease
Lipid management to improve cardiovascular risk
simvastatin +/- ezetimibe
What is Incilsiran?
interferes with production of PCSK9, interferes with double-strand RNA- not enough evidence
What can reduce lipoprotein (a)?
PCSK9
note that statins will increase Lp(a) but due to reduction in LDL-C improve outcomes
First line investigations for suspected coronary cardiac syndromes?
What to do in a patient with LBBB and possible coronary artery disease?
LDL targets in someone with coronary disease
<1.4 and a >50% reduction in LDL.C baseline
What is the role of revascularisation in stable angina?
dont do it
In someone with stable coronary disease, with AF, what should you do?
stop anti platelet and start anti-thrombotic agent.
Anti-platlets vs anti-thrombotics in Coronary syndromes
Aspirin is enough
clopidogrel is the same
warfarin is as good as aspirin but more bleeds
rivaroxoban 5mg BD as effective as aspirin (but more bleeds)
Management of pain syndromes with normal coronary arteries?
CCB
What is the best timing for PPCI?
within 120min
if its going to take >90 min, give fibrinolysis and then send to intervention
What is the most preferred fibrinolytic in STEMI?
*tenecteplase
*Alteplase is good but needs infusion
*reteplase is double bolus
*streptokinase is least effective
What is the MOA of several anti-platelet therapy
Ticagrelor: REVERSIBLY binds to P2Y12 receptors. NOT a pro-drug.
Clopidogrel: IRREVERSIBLY binds to P2Y12 receptors. is a pro-drug and needs to go through the liver.
Tirofiban, eptifibatide: GP IIb-IIIa inhibitors
Aspirin: IRREVERSIBLY inhibits cyclooxygenase-1 (COX-1), blocking thromboxane A2 (TXA2) production, reducing platelet aggregation.
What is the most common type of atrial septal defects?
Secundum ASDs
Types of atrial septal defects?
What are some post-repair complications for coarctation of the aorta
Post surgical repair dilation / risk of dissection
What is the clinical signs of a coarctation of the aorta
*Loud continuous murmur, especially over L chest
*Quiet ‘hum’ due to collateral flow
How does an ECHO for coarctation of the aorta look?
What are risk factors for tetralogy of Fallott?
maternal alcohol consumption, smoking, and DM
What is the main complication after a tetralogy of fallot
progressive pulmonary regurgitation, RV dilation and impairment and arrhythmias
Echo flow for tetralogy of fallot
What characterises tetrology of fallot
How common is transposition of the great arteries?
3% of congenital heart disease
What is the optimal treatment of D-TGA?
arterial switch operation at birth
What is the difference between D-TGA and L-TGA?
D-TGA is where the aorta arises from RV and the PA from the LV but the ventricles are in the usual position
L-TGA is rarer and more complex with the aorta arising from the RV and the PA from the LV with the ventricles also reverses
What is a Mustard repair?
repair previously with an atrial baffle
What is Fontan circulation?
Its a palliative procedure used in HLHS (hypo plastic left heart syndrome), tricuspid/pulmonary atresia/ mitral atresia
Which of the following is most suggestive of a non-cardiogenic cause of pulmonary oedema?
A) Normal left ventricular function on echocardiogram
B) Normal pulmonary capillary wedge pressure
C) Normal troponin
D) Clinical signs of sepsis
E) Evidence of pulmonary oedema on CXR
B) Normal pulmonary capillary wedge pressure
Describe the cardiac electrical potential
Describe the inheritance of hypertrophic cardiomyopathy
autosomal dominant
mutations of genes of the thick and thin contractile myofilaments of the sarcomere
What is involved in the diagnosis of hypertrophic cardiomyopathy?
*Increased LV thickness
*one or more LV regional walls
* >15mm
* ASH
* SAM- lengthened MV leaflets
*LVOT gradient: dynamic
*histology
- hypertrophic cardiac myocyte
- chaotic and disordered architecture
* abnormal intramural arteries- medial thickness
Describe HCM and its relation to Valsalva
Gets louder with valsalva
Management of HOCM
ICD for secondary prevention
ICD for primary prevention if
- family history of SCD, <50 years close relative
- wall thickness equal or more than 30mm
- unexplained syncope
- LVEF < 50%
- LV apical aneurysm
- extensive LGE. equal or more than 15%
- NSVT on 24-48 hours of amb monitoring
- NSVT more than 3, more than 10 beats, or more than 200bpm
NO ROLE FOR ANTI-ARRHYTMIC agents
Drugs: B-blockers, verapamil, disopyramide with AV block, myosin inhibitors (mavecamten)
Surgical myectomy
Alcohol spatial ablation
dual chamber pacing
treat AF regardless of CHADSVASC
With the histology of arrhythmogenic RV cardiomyopathy (ARVC)?
fibrofatty replacement of myocytes
50% biventricular
Describe genetics of arrhythmogenic RV cardiomyopathy (ARVC)
mutation in desmosomal gene
significant allelic heterogeneity
Management of ARVC
- avoid strenuous activity
- anti-arrhythmic (won’t prevent sudden cardiac death)
- B-blockers
- ICD
- Catheter ablation
- treat heart failure
What is LV non-compaction?
morphological trait shared by cardiomyopathies, channelopathies and congenital heart disease
Ratio of trabeculated to compact myocardium >2.3 on echo or CMR in end diastole
Ratio of mass of non-computed to compact myocardium >20%
note: increased risk of thromboembolism
What is tachycardia induced cardiomyopathy?
due to incessant or increased frequency of
- atrial tachycardia- AF, SVT
- junctional tachycardia
- very frequent VEBs
- recurrent NSVT
What are risk factors for peripartum cardiomyopathy?
older women
multiple fetuses
genetic
uncover underlying CM
Describe the management of peripartum cardiomyopathy
pre-partum: ACEI, ARB, eplerenone contraindicated
metoprolol rather than carvedilol
spironolactone later in pregnancy
loop diuretics with caution
Describe the pattern of heart failure depending on the type of cardiac amyloidosis
AL- rapidly progressive HF, biventricular, predominately RHF
Angina- amyloid infiltration of small coronary vessels
Postural syncope: autonomic dysfunction, mutant TTR
Describe keys in physical exam that point towards cardiac amyloidosis
Absence of S4- despite stiff ventricle due to atrial systolic dysfunction from infiltration
Periorbital purpura- pathognomic of AL
Peripheral and autonomic neuropathy- mutant TTR
macroglossia
cachexia
heavy proteinuria
What is the ECG and echo findings in cardiac amyloidosis
ECG: low voltage, first degree and higher degree heart block, Q waves V1-3
Echo: small LV size, increased RV and LV wall thickness, increased echogenicity, increased LV filling pressure, severely increased regional longitudinal dysfunction
How to investigate cardiac amyloidosis?
Cardiac MRI- biventricular thickening with normal cavity size, atrial septal thickening, late gadolinium enhancement
DPP (technetium pyro phosphate) scan
- TTR amyloidosis
Monoclonal gammopathy (free kappa and lambda light chain)- AL
Subcutaneous fat pad aspiration
endomyocardial biopsy
What is the management of amyloid cardiomyopathy?
Treat heart failure: ACEI and diuretics, NOT b-blockers or CCB
AL –> chemotherapy
ATTR –> Tafamidis
Liver and cardiac transplation for mutant TTE
steroids, methotrexate, anti-TNF antibodies, manage arrhythmias
What is the mechanism of hypercalcaemia in sarcoid?
activation of Vitamin D by macrophages
