Cardiac Disorders Flashcards
Define vasovagal syncope
Vasovagal syncope (vay-zoh-VAY-gul SING-kuh-pee) occurs when you faint because your body overreacts to certain triggers, such as the sight of blood or extreme emotional distress.
What are the clinical features of vasovagal syncope?
• Precipitated by pain, emotion or prolonged standing • Blurred vision, light-headedness, sweating, nausea • Resolves on lying down
What are the investigations of vasovagal syncope?
What is the management of vasovagal syncope?
• Patient education is main treatment – teaching how to spot warning symptoms, avoid triggers and learn how to abort attacks
• Physical techniques such as physical counter-pressure manoeuvres and tilt training stop the faint when warning signs appear
• Increase volume – increase dietary salt and electrolyte rich sports drinks
o May give fludrocortisone
What is the most common congenital abnormality?
Congenital Heart Disease
What is the incidence of cardiac malformations?
8/1000 live born infants have significant cardiac malformation
53.2/1000 - minor abnormalities
1/10 still borns - cardiac anomalies
Name the common cardiac lesions.
Common congenital heart lesions
o Left-to-right shunts (breathless)
▪ Ventricular septal defect 30%
▪ Persistent arterial duct 12%
▪ Atrial septal defect 7%
o Right-to-left shunts(blue)
▪ Tetralogy of Fallot 5%
▪ Transposition of the great arteries 5%
o Common mixing (breathless and blue)
▪ Atrioventricular septal defect (complete) 2%
o Outflow obstruction in a well child (asymptomatic with a murmur)
▪ Pulmonary stenosis 7%
▪ Aortic stenosis 5%
o Outflow obstruction in a sick neonate (collapsed with shock)
▪ Coarctation of the aorta 5%
What are the causes of congenital heart disease?
What circulatory changes at birth occur?
In the fetus, left atrial pressure is low, as relatively little blood returns from the lungs. The pressure in the right atrium is higher than in the left, as it receives all the systemic venous return including blood from the placenta.
The flap valve of the foramen ovale is held open, blood flows across the atrial septum into the left atrium, and then into the left ventricle, which in turn pumps it to the upper body
After birth two key changes occur
o Removal of placenta
o Lungs take in air
Oxygen levels in alveoli rise→arterioles dilate in response→resistance reduces in lungs
Right side of heart now working under lower pressures and more blood can enter lungs which can be oxygenated and then travel to left side of heart
Reduced pressure on R side of heart→foramen ovale closes off as pressure on L > pressure on R
o This occurs in first few minutes of birth
• Ductus arteriosus no longer needed as blood can now travel through pulmonary artery
o Smooth muscles in ductus arteriosus sense higher levels of O2 and fall in prostaglandins→contract in response
o Eventually, ductus arteriosus closes within a few days of birth
o Some babies with congenital heart lesions rely on blood flow through the duct (duct-dependent circulation) → they will deteriorate dramatically when duct closes at day 1-2 of birth
How do congenital heart diseases present?
o Antenatal cardiac ultrasound diagnosis
o Detection of a heart murmur
o Heart failure
o Shock
o Cyanosis
What are the left to right shunts? How do they present?
Acyanotic defects cause LEFT-TO-RIGHT shunting and include: o Ventricular septal defect
o Atrial septal defect
o Patent ductus arteriosus
o Coarctation
What are the right to left shunts? How do they present?
Cyanotic defects cause RIGHT-TO-LEFT shunting and include
o Tetralogy of Fallot
o Transposition
o Truncus arteriosus
o Total anomalous pulmonary venous return
o Hypoplastic left heart syndrome
What does antenatal diagnosis entail?
• Checking the foetal heart is a routine part of the foetal anomaly scan
o Performed between 18-20 weeks’ gestation
o Leads to diagnosis of 70% of infants requiring surgery in the first 6 months
If an abnormality is detected, a paediatric cardiology will perform detailed foetal echocardiography
Children at increased risk (e.g. Down’s syndrome, previous congenital heart conditions in the family) are also checked
Depending on the diagnosis, some choose termination
What are the hallmarks of innocent murmurs?
Hallmarks of an innocent ejection murmur: (all have an ‘S’ = innoSent)
o ASymptomatic
o Soft blowing murmur
o Systolic murmur only, not diastolic
o Left Sternal edge
o Standing/sitting–vary
• Other features of innocent murmurs:
o Normal heart sounds with no added sounds
o No parasternal thrill
o No radiation
