Paediatric Cardiology 2 Flashcards
What do the genes often involved in hypertrophic cardiomyopathy encode?
Mutations of the genes encoding cardiac β-myosin heavy-chain (MYH7) and myosin-binding protein C (MYBPC3)
Approximate prevalence of dilated cardiomyopathy:
50/100,000 = 1/2000
How is hypertrophic cardiomyopathy inherited?
Autosomal dominant
What cardiac issue is associated with Duchenne and Becker Muscular Dystrophy?
Dilated Cardiomyopathy
What % of dilated cardiomyopathy is genetic?
20-50%
Describe presentation of dilated cardiomyopathy (common and uncommon features)
- often presents in congestive heart failure (rarer: palpitations, syncope or sudden death)
- cough, dyspnoea and wheeze on exertion
- abdominal pain, nausea
- irritable/lethargic
- may have creps/wheeze on examination
- hepatomegaly
- increased precordial impulse
- increased cardiac size
- tachycardia, gallop rhythm (kentucky, S3), MV insufficiency
- narrow pulse pressure
- uncommon: pallor, hypotension, altered mentation, shock
- also may have signs of underlying issue (e.g. Gower sign for DMD)
ECG signs of dilated cardiomyopathy
Non-specific: atrial/ventricular hypertrophy, T-wave anomalies, atrial/ventricular arrhythmias
Commonest cause of dilated cardiomyopathy?
Idiopathic
Which chemotherapy agent is most likely to cause cardiomyopathy? (Bonus: what additional treatment makes it worse?)
Doxorubicin
Radiotherapy concurrently makes it worse
What metabolic issues are associated with dilated cardiomyopathy?
- Mitochondrial myopathies e.g muscular dystrophies
- Disorders of fatty acid oxidation.
- Phospholipid disorders
What is the commonest cause for cardiac transplantation?
Dilated cardiomyopathy
Risk factors at DCM diagnosis for subsequent death or transplantation:
- Older
- congestive heart failure
- low left ventricular fractional shortening z score
- underlying etiology
Which syndrome is associated with hypertrophic cardiomyopathy?
Noonan
Describe the characteristic ECG in Pompe disease:
Prominent P waves, a short P-R interval, and massive QRS voltages
What is the cardiac issue associated with mumps?
Endocardial fibroelastosis (EFE)
What viruses can cause myocarditis?
Most common:
- Coxsackievirus and other enteroviruses, CMV, Hep C
- Adenovirus
- Parvovirus, parechovirus
- Influenza
- EBV, Enteroviruses
(Hep C - mainly in Asia)
Describe the variety of signs/symptoms of myocarditis.
Infants and young children specifically - fulminant presentation with fever, respiratory distress, tachycardia, hypotension, gallop rhythm, murmur.
Can also have rash, end organ involvement such as hepatitis or aseptic meningitis.
Generally: chest discomfort, fever, palpitations, easy fatigability, or syncope/near syncope. Cardiac findings include overactive precordial impulse, gallop rhythm, apical systolic murmur of mitral insufficiency. In patients with associated pericardial disease, a rub may be noted. If cardiac failure: hepatic enlargement, peripheral oedema, and creps/wheeze
Describe the possible ECG changes in myocarditis.
Nonspecific
- sinus tachycardia
- atrial or ventricular arrhythmia
- heart block
- decreased QRS voltages
- nonspecific ST and T-wave changes, often suggestive of acute ischemia
What is the mortality of acute myocarditis in newborns?
Up to 75%
What % of patients with myocarditis are reported to recover LV function?
10-50%
Viral agents causing pericarditis are:
Parvovirus
Enteroviruses
Respiratory syncytial virus
Influenza
Adenovirus
Bacterial agents causing pericarditis are:
Haemophilus influenza
Pneumococcus
Tb if you have HIV
Can also get immune complex mediated following haemophilus or meningococcus - this is sterile rather than purulent
Describe the manifestations and treatment of post-pericardotomy syndrome:
1-2/52 post open cardiac surgery
Seems to be common post ASD repair
Fever, lethargy, anorexia, irritability, and chest/abdominal discomfort beginning 7-14 days postoperatively
Treat with aspirin, NSAIDs and steroids (+drainage if tamponades)
Non infectious causes of pericarditis are:
Rheumatological: JIA, lupus
Post-infectious: acute rheumatic fever, haemophilus, meningococcus
Organ dysfunction: renal failure, hypothyroidism
Oncological: Hodgkin, other lymphoma/leukaemia
How common are benign vs. malignant cardiac tumours? What is the commonest paediatric cardiac tumour and what is it associated with?
75% benign, 25% malignant
Rhabdomyomas are the most common, natural history is resolution.
In 70-95% of cases, associated with tuberous sclerosis.
Malignant tumours are more often mets (Wilms, lymphoma or leukaemia), however primariess are angiosarcomas, rhabdosarcomas, or fibrosarcomas.
What syndrome and what gene is associated with cardiac fibroma?
Syndrome: Gorlin syndrome (3% of sufferers have fibroma)
Gene: Loss of tumour suppressor PTCH1
Describe myxoma and name the associated syndrome/gene.
Intra-atrial, pedunculated and mobile causing murmur, CHF, syncope (as obstructive).
Carney complex
Gene - PRKAR1A (some families)
Frusemide: dosing, mechanism of action, cautions.
Dose: 1-2mg/kg daily in divided doses, up to 1mg TDS then think about IV
Mechanism of action: Loop diuretic, binds to Cl transport channel and inhibits the luminal Na-K-Cl cotransporter (NKCC) in the thick ascending limb of the loop of Henle. Distal tubule effects.
Cautions: Low potassium/sodium mostly!
Spironolactone: dosing, mechanism of action, cautions
Dose: 1-2mg/kg daily usually given as mane dose but sometimes BD
Mechanism of action: Aldosterone inhibitor. Cortical collecting duct, decreases the reabsorption of sodium and water but limits potassium loss.
Cautions: Hyperkalemia.
Captopril: dosing, mechanism of action, cautions
NB: can change to enalapril when older.
Dose: 0.3-6mg/kg/day in 3 divided doses
Mechanism of action: ACE inhibitor, blocks angiotensin II. Significant afterload reduction, decreased resistance. Venodilation and consequent preload reduction reported. Decreases aldosterone production.
Cautions: Observe for uptitration of dose due to big drop in BP (+symptoms of same). Hyperkalemia due to aldosterone effect. Rash (not allergy-can disappear with time) Neutropenia, renal toxicity, chronic cough.
Enalapril dose: 0.05-0.5mg/kg BD
How common is congenital heart disease?
0.8% of live births overall
2% preemies
3-4% stillbirths
10-25% miscarriage
How long does a PDA take to close normally?
Normal neonate - functional closure 15hr of life, true closure 2-3/52
Preterm infants take longer as less response to oxygen, thought to metabolise prostaglandin poorly.
Abnormal after 3/12
Spontaneous closure - 72-75% of preterm infants <3/12 age.
Can give indomethacin in first 10-14/7
Describe the clinical presentation of small PDA and examination findings:
Small PDA - usually asymptomatic. Normal pulses, normal cardiac size, machinery-like continuous murmur which is maximal at end of systole and waning in late diastole - may be 2nd L intercostal space or radiate to L clavicle/down LSE.
What does CHARGE association stand for?
Coloboma Heart (VSD, ASD, PDA, ToF, endocardial cushion defect) choanal Atresia Retardation Genital issues Ear
What syndromes are associated with pulmonary stenosis? (bonus points: name that gene)
Noonan syndrome - 50% of cases with PS have a mutation in the gene PTPN11 which encodes the protein tyrosine phosphatase SHP-2 on chromosome 12.
LEOPARD syndrome (lentigines, electrocardiographic abnormalities, ocular hypertelorism, pulmonary stenosis, abnormalities of genitalia, retardation of growth, deafness syndrome) PTPN11, RAF1 and BRAF
Arteriohepatic dysplasia aka Alagille syndrome
Jagged1 gene. Peripheral PS
Describe the presentation, examination and investigation findings of mild pulmonary stenosis:
Mild (RV-PA gradient ≤30 mmHg) - asymptomatic
Exam - normal heart size, pulse. Pulmonic ejection click at LUSE after 1st HS in expiration, short ESM at LUSE with some radiation to lung fields, split S2 (may be slightly wide), not a loud P2.
ECG - normal or mild RVH
CXR - often normal, may see post stenotic PA dilatation
What is critical pulmonary stenosis?
It’s when you have a neonate with REALLY BAD PS.
What happens is because it’s so bad, you get R -> L shunting across the PFO and a blue baby.
When does the T-wave in V1 become upright?
At birth due to RV dominance, then inverts by 7 days of age. Should not be positive again until age 6-8, sometimes continues into adolescence…
What conditions are associated with peripheral pulmonary stenosis?
- Alagille (big forehead, pointed chin)
- Congenital rubella syndrome (microcephaly)
- Williams syndrome (elfin facies, more likely supravalvular AS)
What are the features of Williams syndrome and what genetic anomaly is associated with it?
- Supravalvular aortic stenosis (care with coronaries!)
- Pulmonary arterial branch stenosis
- Idiopathic hypercalcemia of infancy
- Elfin facies
- Intellectual disability
Also:
- loquacious personality
- hypersensitivity to sound
- spasticity
- hypoplastic nails
- dental anomalies (partial anodontia, microdontia enamel hypoplasia)
- joint hypermobility
- nephrocalcinosis
- hypothyroidism
- poor weight gain
Associated with deletion of the elastin gene in region 7q11.23 on chromosome 7
What does LEOPARD syndrome stand for?
Lentigines Electrocardiographic abnormalities Ocular hypertelorism Pulmonary stenosis Abnormalities of genitalia Retardation of growth Deafness
Describe the murmur of non-pathological peripheral PS in infancy.
- Neonatal-infancy. Soft systolic ejection murmur, which can be heard over either or both lung fields.
- Absent: (right ventricular lift, soft pulmonic 2nd sound, systolic ejection click, murmur loudest at the upper left sternal border)
This murmur usually disappears by 1-2/12
What ECG and CXR findings would you expect with severe branch PS?
Probably the same as severe PS!!
ECG - gross RVH + tall, spiked P wave.
CXR - R sided cardiomegaly. Prominence of MPA.
What syndrome is sub-aortic stenosis associated with?
Shone’s syndrome
Complete form has 4 anomalies of the L side of the heart
- Supravalvular mitral membrane
- Parachute mitral valve
- Subaortic stenosis (membranous or muscular)
- Coarctation of the aorta
What are signs/symptoms of mild/moderate aortic stenosis?
Mild-Mod AS
- no symptoms
Exam - normal pulse, heart size, impulse
Early systolic ejection click, present throughout respiration, heard apically/LSE.
Murmur - ESM loudest at RUSE radiating to neck + L midsternal area, thrill in suprasternal notch.
If subvalvular, maximal along the LSE/apex.
What percentage of people with AS have other associated cardiac lesions?
20% - MV, arch, VSD, PDA
What are signs/symptoms of severe/critical aortic stenosis?
Severe AS
- fatigue
- angina
- dizziness
- exertional syncope
Exam - decreased pulses, no click, quiet S1.
- Murmur louder, harsher (higher pitch), and longer.
- Paradoxical split S2 wider in expiration
- S4 due to decreased LV compliance
Critical AS
- neonatal period - breathless, grey, failing to feed/thrive
- LV failure (weak pulses, pulmonary oedema, pallor or grey skin)
- Possibly decreased U.O.
Diastolic murmurs:
Aortic regurg in subvalvular/bicuspid AV
Mitral stenosis
Describe the ECG and CXR findings of PDA:
Normal ECG, CXR.
ECG LVH or biVH. CXR prominent PA, increased pulmonary markings, cardiomegaly with LAH/LVH
Describe the presentation, examination and investigation findings of moderate pulmonary stenosis:
Mod (30-60 mm Hg) - may also be asymptomatic
Exam - elevated JVP + a wave. RV lift at LLSE, louder longer ESM with more radiation, split S2 with quiet P2. May not have ejection click or P2!
ECG - RVH, may have spiked P wave
CXR - normal but could find enlarged RV (uptilted apex), and pulmonary vascularity may be slightly decreased
Describe the presentation, examination and investigation findings of severe pulmonary stenosis:
Severe (>60mmHg) - RV failure e.g. hepatomegaly, peripheral edema, exercise intolerance may be present. Cyanosis with ASD/PFO. Prominent venous pressure waves.
Exam - parasternal RV heave, enlarged heart. Loud, long, and harsh ESM + thrill maximal in pulmonic area with radiation everywhere. No click.
ECG - gross RVH + tall, spiked P wave.
CXR - R sided cardiomegaly. Prominence of the main pulmonary artery segment may be seen due to poststenotic dilation and intrapulmonary vascularity is decreased.
What are the features of Carney Complex?
Carney complex is an autosomal dominant disorder with multiple neoplasias
- Endocrine: pituitary adenoma, thyroid, testis, ovarian
- Lentiginosis
- Cardiac myxomas can occur at a young age in any or all cardiac chambers
Describe the presentation and symptoms of large PDA:
Large PDA - heart failure. FTT, bounding peripheral arterial pulses and wide pulse pressure
Cardiomegaly with prominent apical impulse, heave.
Systolic thrill maximal in the 2nd left intercostal space radiating to L clavicle, down LSE, or apex.
May get less diastolic murmur if increased PVR or mitral flow murmur in diastole.
