Cardiology Flashcards
1
Q
Acute Treatment SVT
A
asymptomatic: usually revert spontaneously
symptomatic: attempt vagal, IV adenosine, CCB
if shocked: synchronised shock
2
Q
Adenosine
A
receptors: AV nodal tissues, vascular SM
mechanism: activates K+ channels and hyperpolarises cells
use: SVT (slows AV conduction and breaks reentry in AVRNT)
properties: short half life
SE: vasodilations, hypotension, flushing, dyspnoea, chest pain
3
Q
Allagille’s Cardiac
A
85% peripheral artery stenosis
4
Q
Anginal therapy
A
mechanisms:
- decrease oxygen consumption
- increase blood flow
drugs:
- nitrates: increase NO in vascular SM, increase cGMP and cause relaxation
- beta 1 receptor blocker: decreased ionotropy/chronotropy
- calcium channel blocker: coronary artery vasodilator
5
Q
Antiarrythmics
A
class I: Na channel blockers
class II: beta blockers
class III: K channel blockers
Class IV: calcium channel blockers
6
Q
Antihypertensive drugs
A
ACEi “prils”
- mechanism: inhibit conversion angiotension I to angiotensin II with increased bradykinin
- SE: hyperkalaemia, decrease GFR, crosses placenta, cough, oedema
Angiotension II Receptor Blockers “sartans”
- mechanism: block activation ARII receptors
- SE: hyperkalaemia, crosses placenta
Effects:
- decrease SNS
- decreased Na/Cl reabsorption
- decreased ADH secretion
7
Q
Aortic Arch anomalies
-associated disorders-
A
Marfan’s syndrome: MV prolapse, aortic aneurysm
Ehler-Danlos: aortic root dilatation
8
Q
Aortic Stenosis
A
incidence: 5% CHD
pathogenesis: failed development 3 leaflets
types: valvular 70%, supra 7%, sub 15%
physiology: high pressure LV with hypertrophy
clinical: chest pain on exertion
ECG: LVH
mumur: systolic right 2nd ICS radiation to neck
treatment: surgical (sub/supra), balloon dilation (valvular)
9
Q
Atrial Fibrillation
A
incidence: rare in children
pathogenesis: absence of SA stimulus with rapid electral discharges of atria producing fibrillation
RF: large atria, WPW, cardiac surgery
treatment: rate then rhythm control
10
Q
Atrial flutter
A
pathogenesis: reenterant rhythm from single focus in RA and circles triscuspid annulus
ECG: uniform, HR 250-300, AV node transmits every 2-4 atrial beat
RF: CHD, intra-atrial surgery
treatment: drugs to slow rate
- non-dihydropyridine CCB: verapamil, diltiazem
- beta blocker
11
Q
Atrial Septal Defect
ASD
A
incidence: 10% CHD, F>M
pathogenesis: 50% in association other CHD
types:
- ostium secundum (70%): site of FO
- ostium primum (30%): level TM/MV
- sinus venosus (10%): entry SVC into RA
- coronary sinus ASD: defect in coronary sinus
- PFO
clinical: symptomatic if large, RA/RV enlargement
ECG: RAD, RVH
mumur: widely split S2, systolic mumur
treatment:
- <3mm 100% close spontaneously
- 3-8mm 80% close by 2 years
- large closed with device
12
Q
Atrioventricular Nodal Re-entry Tachycardia
AVNRT
A
incidence: mainly adolescents
pathogenesis: 2 pathways within the AV node
clinical: syncope with exercise/stress
treatment: beta blockers, ablation
13
Q
Atrioventricular Re-entry Tachycardia
AVRT
A
incidence: 90% SVT in children
clinical: acute onset/cessation at rest or in illness
pathogenesis: normal circuit and accessory pathway
variants
- retrograde accessory
- bidirectional accessory
- antegrade accessory
14
Q
Atropine
A
mechanism: muscarinic receptor antagonist causing PNS block and increased AV node conduction
use: heart block, bradycardia
SE: dry mouth, constipation, urinary retention
15
Q
Brugada Syndrome
A
incidence: 3/1000, M>F, asians, presents in 30’s but 2-77yrs
cause: AD, mutation SCN5A gene producing sodium channel causing phase 2 reentry
diagnosis: permanent or transient ECG changes
- type 1 (20-25%): SCN5A with RBBB, ST elevation V1-V3
- type 2: GPD1L with <2mm saddleback ST elevation
- type 3: CACNA1c with type 1/2 ECG changes
clinical: recurrent syncope, arrythmia, sudden death
treatment: quinidine, defibrillation
16
Q
Calcium Channel Blockers
non-dihydropyridine vs dihydropyridine
A
dihydropyridines (amlodipine, felodipine, nifedipine)
- reduce SVR and arterial pressure
non-dihydropyridines (verapamil, diltiazem)
- myocardium selective
- decrease oxygen demand and reverse coronary vasospasm
17
Q
Cardiac Axis
A
18
Q
Cardiac Glycosides
- digitalis/digoxin-
A
use: CHF/arrhythmias
mechanisms:
- digitalis: inhibits Na/K ATPase, increased Nai and slows down Ca efflux causing increased contractility and delayed repolarisation
- digoxin: as above, slower 1/2 life
ECG: increased PR (“digitalis effect”), ST segment depression, T wave inversion
toxicity: AV block, VT/VF, nausea/diarrhoea, yellow halows
19
Q
Cardiac muscle contraction
A
20
Q
Cardiac Muscle Depolarisation
A
21
Q
Cardiac Tamponade
A
definition: inadequate cardiac output due to pericardial effusion
pathogenesis:
- acute/subacute accumulation of pericardial fluid causing pressure
- increased diastolic pressure with decreased pulmonary venous return to LA
- collapsed RA/RV
- decreased CO/BP
22
Q
Cardiomyopathies
A
definition: intrinsic disease of the heart muscle
types:
- dilated: idiopathic or secondary to infection/disease/cardiotoxic drugs/familial
- hypertrophic: familial with AD inheritance
- restrictive: idiopathic or associated with systemic disease
23
Q
Cardiomyopathy
associated disorders
A
DMD
Fabry disease
Hunter/Hurler’s syndrome
Pompe disease
24
Q
CHF therapy
A
ASPECTS
Afterload reduction: ACEo, ARBs, BNP, milrinone, nitrates
Sympathetic inhibition: beta blockers, BNP, digoxin
Preload reduction: BNP, diuretics
Enhanced contractility: digoxin
Cardiac remodelling prevention: spironolactone
Timely surgery
Systemic disease treatment
25
Class Ia antiarrhythmics
Na channel blockers
**drugs:** quinidine, procainamide
**mechanism:** moderate Na channel blockers
- non-specifically block K channels and slow repolarisation
- prolongs depolarisation/repolarisation/QRS/QT
use: atrial/ventricular arrhythmias
**SE:** agranulocytosis, thrombocytopaenia, tinnitus, torsades, hypotension, rash
26
Class Ib antiarrythmics
Fast Na channel blockers
**drugs:** phenytoin, lignocaine
**mechanism:** block fast Na channel
- decreased AP/QT duration
- no effect refractory period
**use:** VT (ischaemic arrhythmias with fast HR)
**SE:** bradycardia, HB
27
Class Ic antiarrythmic
Slow Na channel blocker
**drugs:** flecainide, encainide
**mechanism:** blocks slow Na channels
- slow phase 0 depolarisation
- prolongs QRS
**use:** suppression of PVC, last resort in normal heart
**CI:** previous MI/VT
28
Class II Antiarrhythmic
Beta blocker
**drug:** propranolol, metoprolol, atenolol
**mechanism:** decrease SNS activity to heart by beta 1 receptor
- decrease cAMP/depolarisation/repolarissation
- decreased conduction through AV
**use:** SVT, CHF
**SE:** bradycardia, AV block, CHF, impotence, bronchospasm
29
Class III antiarrhythmic
K channel blocker
**drugs:** amiodarone, sotalol
**mechanism:** K channel blocker
- normal QRS, increased QT
**use:** WPW, VT/AF, unstable VT
**SE:** torsades, pulmonary fibrosis, photodermatitis, hepatotoxicity, thyroid issues, corneal deposits
30
Class IV antiarrhythmics
Ca channel blocker
**drugs:** diltiazem, verapamil
**use:** SVTs
**mechanism:** decrease SA/AV node automaticity
- prolong depolarisation/repolarisation
- increase PR interval
**SE:** CHF, AV block, flushing, headache, gingival hyperplasia
31
Classification CHD
32
Classification Congenital Heart Disease
**Stenotic:** AS, PS, CoA
**Right to Left:** TOF, TGA, TA
**Left to Right:** ASD, VSD, PDA
**Mixing:** truncus, TAPVR, HLH
33
Coarctation of the aorta
**incidence:** 10% CHD, M\>F, 70% with bicuspid aortic arch
**pathogenesis:** constriction aorta at any point
- 98% below left SCA at origin of ductus arteriosus
**clinical:** difference pulses UL/LL, femoral-radial delay, LL hypoperfusion, BP high in UL and low in LL
- poor feeding, respiratory distress, CHF, acidosis
**CXR:** notching of inferior border of ribs by enlarged collaterals
**ECG:** RVH, cardiomegaly, pulmonary oedema
**treatment:** end to end anastomosis
**prognosis:** HTN, CVD, re-coarctation, stroke, aneurysm, endocarditis
34
Complete endocardial cushion defect
AVSD
**incidence:** 2% CHD, 70% with T21
**pathogenesis:** failured fushion of upper/lower endocardial cushions with primum ASD/inlet VSD
**associations other CHD:** TOF, DORV, TGA
**clinical:**
- shunts left to right with AV regurgitation
- hyperactive precordium, systolic thrill/mumur, mid diastolic rumble
- CHF
**ECG:** LAD, prolonged PR, RVH, LVH
**CXR:** cardiomegally, increase pulmonary markings
**treatment:** surgery at 2-4 months with patch closure
35
Complete Heart Block
**acquired:** post cardiac surgery, post myocarditis, drugs, rheumatic fever, cardiac tumour
**congenital:** AI 70% (neonatal lupus), gene mutation, complex structural disease (TGA)
**clinical:** cardiomegally, CCF
**examination:** prominent peripheral pulse, systolic mumur left sternal edge, variable 1st heart sound
**ECG:** prolonged QRS duration with slow ventricular rate as pacemaker is below the bundle of his
**treatment**: indication for pacemaker
- CCF, long QT, bradycardia, wide QRS, exercise intolerance
36
Congenital rubella
-cardiac issues-
_35% cardiac anomalies_
- PDA, PA stenosis, ASD, VSD
37
Coronary artery fistula
**incidence:** most common CA anomaly (50%)
**pathogenesis:** R\>\>L, most terminate right side of heart (40% RV, 30% TA, 20% PA)
**types:**
1. branching tributary: from CA along normal distribution 7%
2. abnormal CA system with aberant termination \>90%
**clinical:** usually asymptomatic
- CHF if left to right shunt is large
**management:** ligation
38
Cyanotic Heart Diseases
1. Tetralogy of fallot
2. Transposition of the great arteries
3. Tricuspid atresia
4. Truncus arteriosus
5. TAPVD
39
DiGeorge syndrome
-cardiac issues-
TOF
40
Diuretics
**thiazide**
_mechanism:_ inhibit NaCl reabsorption in DT
_SE:_ hypokalaemia, hyponatraemia, acidosis, hyperglycaemia, hypercalcaemia
**loop diuretics (frusemide)**
_mechanism:_ inhibit NaK2Cl transported in thick ascending LOH producing PG
_SE:_ nephritis, ototoxicity, hypokalaemia, hypocalcaemia, alkalosis, increased uric acid
**K-sparing diuretics (spironolactone, amiloride)**
_mechanism:_ aldosterone receptor antagonist OR Na channel blocker
- decreased reabsorption of Na and influx of K
_side effect:_ gynaecomastia, hyperkalaemia
41
Double outlet right ventricle
**pathogenesis:** aorta and PA both originate RV
- blood shunts across VSD to reach great arteries
- PA circulation under high pressure
**subtypes:**
1. sub-aortic VSD
2. sub-pulmonary VSD
3. doubly commited VSD
4. non-commited VSD
42
Ebstein's anomaly
**incidence:** \<1% CHD
**pathogenesis:**
- downward displacement of TV into RV causing RV hypoplasia
- TV regurg due to dilated/hypertrophic RA
- decreased CO
- required interatrial communication in ALL cases
**clinical:** cyanosis, dyspnoea, HUGE cardiomegally, CHF, HM, SVT
**mumur:** TR mumur, wide split S2
**ECG:** RAH, RBBB, 1st degree block, WPW in 20%
**CXR:** balloon shaped heart, decreased pulmonary markings
**treatment:** TV repair and fontan procedure
**prognosis:** 19% die neonatally, 30% before 10 yrs
43
Eisenmenger syndrome
**pathogenesis:** left to right cardiac shunt with subsequent pulmonary HTN
- eventual reversal of shunt causes cyanosis
**associations:** ASD, VSD, PDA
44
Fetal circulation
**drainage**
SVC: drains upper body including brain (15%CO)
IVC: drains lower body/placenta (70%CO)
**cardiac circulation**
- most SVC and 2/3 IVC goes to RA to RV to PA
- 10% to lungs and 90% to PDA
**outflow**
- 55% of CO goes to placenta (low resistance)
45
Fick's principle
amount of oxygen consumed by body is equal to the AV difference in oxygen content x blood flow (CO)
**ie.**
CO= oxygen consumption/AV difference
= oxygen consumption/(saturation difference % x oxygen content)
46
Heart block
**1st degree:** prolonged PR
**2nd degree:**
- type 1: progressive prolongation PR until QRS dropped
- type 2: prolonged PR with intermittent QRS dropped
**3rd degree:** no relationship A/V activity
47
HOCM
**incidence:** 0.2%
**genetics:** AD, 12 genes encoding sarcomere proteins
**pathogenesis:** disorganised LV architecture
- septal/LV hypertrophy causing dynamic outflow obstruction (30%) and abnormal electrical activity
**clinical:** syncope, chest pain, palpatations, dyspnoea
**examination:** LV impulse/lift, systolic mumur, S3/S4, MR mid-diastolic rumble
**ECG:** deep narrow Q waves in lateral/inferior leads, LAH with p wave changes
**CXR:** cardiomegally
**treatment:** medications (beta blockers, CCB), myectomy, ventricular pacing
**prognosis:** survival 10yrs w/o surgery 61%, with 83%
48
Hyperlipidaemia drugs
**statins (rosuvastatin/atrovastatin/simvastatin)**
_mechanism:_ HMG-CoA reductase inhibitor, increased production LDL receptors
_SE:_ myositis, increased LFTs, photosensitivity
**fibrates (gemfibrozil/fenofibrate)**
_mechanism:_ upregulation lipoprotein lipase and increased clearance TG lipoprotein
_SE:_ myositis, ATN, increased LFTs, cholelithiasis
**Niacin:**
_mechanism:_ lipolysis inhibition/TG synthesis in adipose tissue
_SE:_ flushing, hyper glycaemia, hyperuricaemia
**resins (cholecystyramine, colestipol, colesevalam)**
_mechanism:_ bile acid sequesterant preventing intestinal absorption
_SE:_ GI upset, malabsorption, pruritis
**Ezetimibe**
_mechanism:_ selective inhibitor of dietary cholesterol in small bowel
49
Hypoplastic Left Heart Syndrome
incidence: 1% CHD, 40% neonatal cardiac deaths
RFs: Turner's, T13, T18, Jacobsen's syndrome
pathogenesis: LV and aorta are hypoplastic and unable to support circulation
- RV supplies both pulmonary and systemic circulation
- survival depends on PDA/ASD or mixing
**clinical:** ill early, cyanosis, resp distress, CCF, HM
**examination:** NO mumur, single S2, weak pulses, low CO
**ECG:** RAH/RVH
**CXR:** pulmonary oedema, right sided cardiomegally
**management:** PGE1 infusion, surgery
**surgery:** 1st Norwood (RV to PA), 2nd 3-6 months bidirectional Glenn (SVC to right PA), 3rd 18-30 months Fontann (IVC to PA)
50
Indications intervention Aortic Stenosis
**refer:**
- chest pain, SOB, syncope
- asymptomatic but LVH on ECG or ECHO gradient \>50mmHg
**intervention:**
- symptoms or LVH strain or cathether gradient \>50mmHg
51
Indications VSD intervention
**1.** CHF
**2.** FTT
**3.** Aortic regurgitation into VSD
**4.** Qp/Qs \> 2
52
Interrupted aortic arch
**pathogenesis:** part of aorta absent causing obstruction blood flow to lower body
**clinical:** symptoms post PDA closure
**treatment:** PGE1, end to end anastomosis
53
Junctional ectopic tachycardia
**pathogenesis:** abnormal automaticity AV node
- junctional rate\>sinus rate and AV dissociation occurs
**causes:** cardiac surgery, congenital
**ECG:** narrow QRS, p waves not seen
**treatment:** difficult
54
Left atrial hypertrophy
-causes-
1. mitral valve disease
2. cardiomyopathy
3. large PDA/VSD
55
Long QT syndrome
**pathogenesis:** prolongation myocardial repolarisation causing refractory areas of myocardium with reentry and VT
**causes**
**_congenital (50%): defective ion channels_**
_romano-ward syndrome (AD):_ syncope with exercise/stress
- KCN/SCN genes coding Na/K channel
_jervell and lange-nielson syndrome (AR)_: bilateral SNHL, syncope with exercise/stress
- KCNQ1/KCNE1 genes encoding K channels
**_acquired_**
- antiA (Arrhythmics): amiodarone, sotalol, quinidine
- antiB (AB): erythromycin, clarithromycin, azithromycin, bactrim
- antiC (psyChotics): haloperidol, risperidonse, chlorpromazine
- antiD (Depressant): TCA
- LowEL kiw Ca/K/Mg/thyroid
- AntiF (fungal): fluconazol
- AntiH (Histamine)
- neurological/nutritional/cardiac
**clinical:** syncope 26%, seizures 10%, palpatations, arrhythmias, cardiac arrest
**diagnosis:** Schwarz score
**treatment:** if score \<4 or QT\>0.47
**prognosis:** SCD in 50% untreated
56
Longterm treatment SVT
**1st line:** beta blockers +/- digoxin
DON'T USE DIGOXIN/VERAPAMIL WPW
**2nd line:** flecainide (structurally normal), amiodarone (neonates), sotalol, ablation
57
Magnesium
**mechanism:** prevents influx Ca and prevents early depolarisation
**use:** torsades
58
Management TOF
**early:** PGE1
**late:** surgery in 1st year if life
- initial shunt procedure: Blalock-Taussig with right SCA linked to PA
- patch closure of VSD
- enlargement RVOT
59
Maternal conditions
associated CHD
_diabetes mellitus:_ TGA 5%
_rubella:_ PDA, PA stenosis, ASD, VSD
_alcohol:_ septal defects 30%
_phenylketonuria:_ TOF 25-50%
_SLE:_ CHB 40%
_lithium:_ TV defect 20%
60
Multifocal atrial tachycardia
**definition:** \>3 ectopic p waves with varying PR intervals
**incidence:** \<1yr, usually resolves by 3 years
**associations:** Noonan's, hypertrophic CM
61
Myocarditis
**pathogenesis:** cell mediated immunologic reaction causing myocardial inflammation and necrosis leading to fibrosis/dilation/cardiomyopathy
**causes**
_viral_: coxsackie B, adenovirus, CMV, echovirus, EBV, Hep C, herpes, HIV, influenza, measles, mump, rubella, varicella
_bacterial:_ mycoplasma, staph
_toxins:_ cocaine, EtOH, diptheria
_immune_: rheumatic fever, kawasaki, SLE, thyrotoxicosis, IBD
**clinical:** fever, chest pain, palpatations, syncope, shock
**ECG:** low voltage QRS, ST-T changes, PR/QT prolongation, arrythmias
**XR:** cardiomegally
**bloods:** troponin, CK, viral serology
**prognosis:** 75% mortality in neonates
**treatment:** CHF drugs, IVIg
62
Non-cardiac syncope
**behavioural:** breath holding spells
**metabolic/endocrine:** DM, DI, adrenal insufficiency
**neurological:** seizures, vertobasilar migraine
**psychiatric:** conversion
**vasovagal:** diagnosis of exclusion
63
Noonan's
cardiac issues
pulmonary stenosis 65%
- also associated with hypertrophic cardiomyopathy
64
Pacemaker AP
65
Patent Ductus Arteriosus
PDA
**incidence:** 5-10% CHD, F\>M
**pathogenesis:** failure of DA to close in early weeks of life
- large PDA causes increased pulmonary pressure
**clinical:** tachypnoea, CO2 retention, apnoeas, CHF
**examination:** bounding pulses, wide PP, palpable thrill
**mumur:** continuous machine like
**ECG:** LVH
**CXR:** increased pulmonary vascular markings, cardiomegally
**treatment:**
- _medical:_ PGE1 inhibitors, diuretics
- _surgical:_ \<2mm coil/plug, \>2mm surgical
66
Pericarditis
**pathogenesis:** inflammation of parietal and visceral surfaces of the pericardium
**causes**
- _viral:_ coxsackie, echovirus, mumps, influenza, epstein-barr, CMV
- _bacterial:_ staph aureus, strep pneumo, pneumococcus, meningococcus, HiB, TB
_other:_ fungal, collagen vascular disease, metabolic, neoplasm
**CXR:** cardiomegally
**ECG:** tachycardia, elevated ST, reduced QRS
**treatment:** pericardiocentesis, anti-inflammatory medications
67
Peripheral pulmonary hypertension
**incidence:** 1/1500
**diagnosis:** PA\>25mmHg
**_pathogenesis_**
_pulmonary vasoconstriction:_ hypoxia
_increased pulmonary SM hypertrophy:_ chronic asphyxia, maternal PGE inhibitors
_decreased area vascular bed_: diaphragmatic hernia, pulmonary hypoplasia, fibrosis, inflammation
_other:_ excess endothelin, deficit NO/prostacyclin
**ECG:** normal
**CXR:** cardiomegally
**treatment:** reverse cause, 100% oxygen, inhaled NO
68
Peripheral vascular resistance
**PVR:** (mean PA pressure-mean LA pressure)/Flow
69
Persistent Truncus Arteriosus
**pathogenesis:** single origin of PA and aorta from the heart
- large VSD always present
- blood from both ventricles passes across VSD to single trunk
- lung exposed to high pressure circulation
**associations:** Di George, maternal DM
**treatment:** surgery (\<6m) closure VSD and conduit to connect RV to PA
70
Premature atrial contractions
**incidence:** common in childhood
**pathogenesis:** premature beat arising from an ectopic focus within the atria
**ECG:** may have normal, prolonged or absent QRS
- premature p wave may be superimposed on t wave
- p waves usually different axis
- long pause after premature atrial contraction
71
Premature ventricular contractions
**definition:** premature, widened bizarre QRS complexes not preceded by p wave
**types**
- bigeminy: 1 PVC for each QRS
- trigeminy: 1 PVC for 2 normal QRS
**pathological:** 2 or more PVCs in a row, multiform PVCs, increased PVCs with exercise, R on T phenomenon, underlying heart disease
**treatment:** none, lidocaine, procainamide
72
Pulmonary atresia with intact VS
**pathogenesis:** PA valves fused and triscupid valves are hypoplastic so blood shunts via FO to LA and entire volume flows into LV to the aorta
**clinical:** cyanosis, respiratory distress
**examination:** single S2, harsh systolic mumur
**ECG**: LAD, tall p waves
**treatment:** PGE1, surgery (pulmonary valvotomy, A-P shunt)
73
Pulmonary Shunt Fraction
**Qp:Qs**= (SatA-SatSVC)/(SatPV-SatPA)
74
Pulmonary stenosis
**incidence:** 10% CHD
**pathogenesis:**
- _valvular PS:_ PV thickened with small orifice and hypoplastic RV
- _isolated infundibular PS:_ rare, associated large VSD
- _supravalvular PS:_ 3% CHD, stenosis of single or multiple branches PA, associated PV stenosis/VSD/TOF
**associations:** rubella, William's, Noonan's, Allagille, Ehler-Danlos, Silver-Russell
**clinical:** SOB, tachypnoea, poor feeding, cyanosis
**examination:** split S2, ejection click, RV thrill, ESM left 2nd ICS
**ECG:** RVH
**CXR:** normal
**treatment:** PGE1, surgery (balloon valvuloplasty, valvotomy)
75
Pulsus paradoxus
**definition:** drop BP\>10mmHg during inspiration
**pathogenesis:** inspiration causes negative thoracic pressure and increased venous return
- increased pulmonary blood capacity decreasing left sided return
76
Restrictive cardiomyopathy
**incidence:** rare
**causes:**
- _infiltration_: amyloidosis, sarcoidosis
- _non-infiltrative_: idiopathic, familial
- _storage diseases_: haemochromatosis, Fabry
- endomyocardial disease
pathogenesis: massive atrial dilatation
**clinical:** dyspnoea, respiratory illness, syncope, hepatomegally
**examination:** S4
**ECG:** atrial enlargement
77
Right Atrial Hypertrophy
**causes:**
1. tricuspid atresia
2. hypoplastic right heart
3. ebstein's anomaly
4. pulmonary atresia
78
Schwartz long QT diagnostic criteria
79
Sick sinus syndrome
**pathogenesis:** dysfunction of SA node secondary to dysgenesis of SA node and surround atrial myocardium
**incidence:** older people
**clinical:** fatigue, lightheadedness, palpitations
**ECG:** bradycardia with sinus pauses and sinus arrest
**treatment:** PACEMAKER
80
Single S2
**cause:** loss of A2 or P2
**differentials:** severe AS/PS, severe AR, absent pulmonary valve, TOF, Ebstein's anomaly, pericardial effusion
81
Sinus arrhythmias
**phase sinus arrhythmia:** impulse discharge related to respiration
- increases with inspiration, decreases with expiration
**sinus bradycardia:** fitness, anorexia, beta blockers, high vagal tone, sleep, hypothyroidism
**extrasystoles:** isolated extrasystoles unsignificant
82
Spontaneous Bacterial Endocarditis
**risk factors**
1. Multiple interventions ie. CVC
2. Immunocompromised
3. Unrepaired cyanotic heart defect
4. Prosthetic material
**investigations:** 3 blood cultures in 48 hours prior ot AB
**prophylaxis:** PO amoxycillin 1 hr prior to procedure or IV if with anaesthetic
83
Sudden cardiac death
**CAD (30%):** abberant origin left coronary artery, acquired (Kawasaki, atherosclerosis), coronary arteritis
**primary arrythmia (22%):** WPW, long QT, brugada, torsades, myopathies, pre-excitation syndromes, CHB
**cardiomyopathies (20%):** dilated, hypertrophic, restrictive, myocarditis, arrythmogenic RV cardiomyopathy
**CHD (15%):** HLHS, TGA, TOF
_other:_ obstructive lesions, tumours, Marfan's, pulmonary HTN, sarcoidosis, aortic dissection
84
SVT
**incidence:** commonest cause tachycardia in children
**pathogenesis:** all forms of tachycardia except VT
**3 types:**
1. reenterant tachycardia with accessory p/w
2. reenterant tachycardia w/o accessory p/w
3. ectopic or automatic tachycardias
**diagnosis:** HR\>220, p waves present and related to QRS
**treatment:** vagal manouvers, medications (adenosine, digoxin, CCB, beta blockers), cardioversion
85
Sympatholytics
**beta blockers:**
- _mechanism_: decreased renin release, decreased AII and blocks B1
- _SE_: asthma, bradycardia, AV block, CHF, impotence, sedation
**clonidine/methyldopa:**
- _mechanism_: central alpha 2 agonist, decreases NE release
- _SE_: sedation, dry mouth, rebound HTN
**prazosin:**
- _mechanism_: alpha 1 blocker
- _SE_: orthostatic hypotension
86
Syncope
-pathological signs-
- associated stress/exercise
- whilst supine
- in water
- palpitation prior
- family hx death before 30yrs
- odd history
87
Systemic vascular resistance
**SVR**= (mean aortic pressure-mean RA pressure)/flow
88
Tet (hyperpcyanotic) spells
**incidence:** TOF patients 2-4 months
**pathogenesis:**
- triggered decreased systemic vascular resistance
- increased R to L shunt
- decreased pulmonary blood flow
**examination:** cyanosis, no mumur, LOC
**treatment:** knee-chest position to increased venous return, oxygen, morphine, propranolol for prevention
89
Total Anomylous Pulmonary Venous Return
TAPVR
**definition:** pulmonary veins return to the venous system with hypoplasia of the left heart causing mixing of systemic and pulmonary blood
- all have ASD or incompatible
**pathogenesis:** abnormal development pulmonary veins week 3 gestation
**types:**
1. supracardiac 50%
2. cardiac (usually RAD) 20%
3. infracardiac (portal vein, ductus venosus, hepatic vein, IVC) 20%
4. mixed 10%
**clinical:** poor growth
**examination:** mild cyanosis, hyperactive RV impulse, S2 widely split, ESM in pulmonary area, mid diastolic mumur TV
**ECG:** RVH
**CXR:** cardiomegally 'snowman', increased pulmonary markings
**management:** medications (PGE1), surgery (balloon atrial septostomy, return of PA to LA)
**prognosis:** 60% dead by 1yr if untreated
90
Transposition of the Great Arteries
TGA
**incidence:** 5% CHD but most common cyanotic lesion in newborn period
**pathogenesis:** aorta arises RV, PA arises left ventricle
- 50% have mixing defect: 40% VSD, 50% PFO/PDA
**clinical:** early cyanosis
**examination:** palpable left/right ventricular impulses, loud/single S2, pansystolic mumur (VSD)
**ECG:** RAD, RVH, Q waves in V1
**CXR:** egg on string, increased pulmonary vascularity
**treatment:** PGE1 infusion, surgery (enlarged FO via balloon septostomy, arterial switch operation at week 2)
91
Tricuspid Atresia
**incidence:** 1-3% CHD
**definition:** absent connection between right atrium and ventricle with hypoplastic right ventricle
- blood diverted from RA to LA via ASD/FO
- then from LV to RV
**clinical:** cyanosis, poor feeding, TET spells
**examination:** single S2, increased LV impulse, mumur, CHF, clubbing
**ECG:** LAD, LVH
**CXR:** cardiomegally, decreased pulmonary markings
**treatment:** early (PGE1, Blalock-Taussig procedure), late 2yrs (Fontan operation connecting SVC to PA with VSD patch)
**prognosis:** LVH causes cardiomyopathy
92
Tricuspid Stenosis
**incidence:** rare
**clinical:** mid diastolic mumur, right heart failure
**ECG:** left axis deviation, RAH, peaked p waves
93
Trisomy 21
cardiac issues
**50% have cardiac anomalies**
- AVSD 40%
- AVSD\>VSD\>ASD\>PDA
- TOF
94
Truncus Arteriosus
**incidence:** 1% CHD
**definition:** single arterial trunk from the heart with a large VSD below the truncal valve
**pathogenesis:** failure of separation of the truncus at 3-4 weeks gestation
**clinical:** cyanosis, CHF, bounding pulses
**examination:** systolic ejection click and mumur, single S2
**treatment:** surgery (VSD closure, conduit between arteries)
95
Turner's Cardiac
**left heart lesions**
- aortic stenosis 10%
- biscuspid aortic valves
- coarctations
- dilated aortic arch
96
Vascular Ring
**incidence:** 1-3% all CHD
**definition:** congenital anomaly of aortic arch with abnormal formation of aorta/surrounding vessels
- complete encircling of the trachea and oesophagus
- incomplete: PA sling (trache + eso), innominate artery compression (trache), abberant right subclavian artery (eso)
**associations:** VSD, TOF, coarctation, PDA, cleft palate, CHARGE, subglottic stenosis
**clinical:** stridor, wheeze, dysphagia, feeding issues
**diagnosis:** CXR, barium swallow, bronchoscopy, MRI/CT
97
Vasoactive Factors
**endothelin-1: released endothelium**
- endothelin A: vasocontriction
- endothelin B: stimulates NO release
**prostacyclin (PG12)**
- released endothelium from COW p/w causing vasodilation
**PGH2**
- precursor prostcyclin, thromboxane, PGEs
**thromboxane A2**
- released platelets and causes vasocontriction and platelet aggregation
98
Velocardial facial syndrome
-cardiac issues-
**right sided cardiac issues**
- truncus arteriosus, TOF, pulmonary atresia
99
Ventricular Fibrillation
**definition:** uncoordinated contraction ventriles
**cause:** underlying cardiac disease/damage
**clinical:** significantly decreased CO
**ECG:** non-distinct QRS/T waves, irregular undulations
**treatment:** cardioversion
100
Ventricular Septal Defect
VSD
**incidence:** 15% CHD
**types:**
1. perimembranous 70%: membranous septum under aortic arch
2. outlet 7%: rim formed by aortic/pulmonary annulus
3. inlet 8%: AV canal
4. trabecular 10%: muscular
**clinical:** pulmonary HTN, CHF
**examination:** systolic mumur, systolic thrill, loud P2, enlarged left heart, increased pulmonary flow
**ECG:** LVH
**treatment:** 1/3 close spontaneously, surgery if Qp:Qs 2:1, pulmonary HTN
**prognosis:** RBBB 10%, CHB 2%
101
Ventricular Tachycardia
**definition:** \>3 premature ventricular beats sustained for \>30 secs with HR 120-240
**pathogenesis:** AV dissociation
**clinical:** impaired CO
**treatment:** lidocaine, amiodarone, procainamide, propranolol, cardioversion
102
William's Cardiac
supravalvular AS
PA stenosis
103
Wolf-Parkinson White Syndrome
**incidence:** 1/1000
**pathogenesis:** pre-excitation via accessory pathway (Bundle of Kent) formed during cardiac development
- can conduct retrograde/antegrade or both
**clinical:** SVT
**ECG:** delta wave, long QRS, ST/T wave changes
treatment: flecainide, procainamide, radioablation
**AVOID:** AV nodal blockers (adenosine, diltiazem, verapamil, beta blockers, amiodarone)
104
LEFT TO RIGHT SHUNT
**causes:**
- _VSD_ (LAH/LVH)
- _ASD_ (RAH/RVH)
- _PDA_ (LAH/LVH)
- _PAPVD_ (partial anomalous pulmonary venous return) (RAH/RVH/PAH)
105
LEFT CARDIAC OBSTRUCTIVE LESIONS
**1.** coarctation
**2.** aortic stenosis (supra/valvular/subvalvular)
**3.** LV restriction
**4.** mitral stenosis (supra/valvular/subvalvular)
**5.** Cor triatriatum
**6.** PV stenosis
106
Scimitar syndrome
**definition:** pulmonary hypoplasia and PAPVR on right side
**CXR:** small lung with inspilateral mediastinal shift and tubular structure on right heart border
107
Long QT
108
Long QT
109
Fontan procedure
**procedure:** right atrum connected to the pulmonary artery directly
- pulmonary resistance must be low
**prognosis:** associated atrial flutter in 50% by 18yrs
