Cardiovascular Learning Objectives Flashcards
Pulmonary Stenosis Pathophysiology
Narrowing of the circulature/valve/heart responsible for blood flow to the lungs.
Can be due to isolated valvular (90%), subvalvular or peripheral pbstruction.
Valvular - 2/3 have dysplastic pulmonary valve where valves are irregularly shaped with thickened leafelets, do not clsoe/seal well if at all and decrease mobility
Pulmonary Stenosis Epidemiology and Aetiology
Most common congenital heart disordr - 10% of cases
Slightly more common in females
Pulmonary Stenosis Clinical Signs
Most Asymptomatic
Exertional dyspnoea and fatigue
In rare cases -exertional angina, syncope or sudden death. Cyanosis present with significant right to left shunt via patent foramen ovale, ASD or VSD
Pulmonary Stenosis Management
Prehospital: Oxygen, Supportive cares, IV access.
Hospital: Surgery. Balloon Valve.
Aortic Stenosis Pathophysiology,
Narrowing of aortic valve.
Results in compensatory ventricular hypertrophy over time proportional to the obstruction.
Severe cases may lead to hypertrophy, valvular obstruction, MI, exercise induced syncope and death.
Severe obstruction in utero mmay cause variable heart hypoplasia, endomyocardial fibroelastosis, reduced ventricular function and significant mitral valve insufficiency
Aortic Stenosis Epidemiology and Aetiology
Approx 8 per 1,000 live births
3-5% of congenital heart defects
Male:female = 4:1
Aortic Stenosic Clinical signs
Symptoms of congestive heart failure - present when patient unable to adequately increase CO and or pulmonary or systemic fluid overload
- Infants: tachypnoea, diaphoresis during feedings, easily fatigued, irritable, decreased volume of feeds, poor weight gain
- Younger children: similar to common illness, GI symptoms (abdo pain, nausea, vomiting and poor appetite), failure to thrive, easily fatigued and recurrent or chronic cough with wheeze
- Older children: exercise intolerance, anorexia, abdominal pain, dyspnoea, wheeze, oedema, palpitations, chest pain or syncope
- Everyone: tachycardia, poor perfusion, pulmonary congestion, systemic congestion, high blood pressure, systolic murmur
Aortic Stenosis Management
Prehospital: Oxygen, IV access, supportive cares
Hospital: Surgery, balloon valve. Surgery to swap aortic and pulmonary valve and insert new valve as pulmonary valve.
Atrial Septal Defect Pathophysiology
Shunt between atria. Magnitude of shunt depends on defect size, relative compliance of ventricles and relative resistance in pulmonary and systemic circulation.
- Small - L) atrial pressure may exceed R) by some mmHg. With large atrial pressures are nearly identical.
- Shunting occurs in late ventricular systole and early diastole.
- Increased pulmonary bloodflow and diastolic overload of R) ventricle
- Altered ventrcular compliance may increase left to right shunting, exacerbating symptoms
Aortic Septal Defect Epidemiology and Aetiology
3 main types (ostium secundum, ostium primmum and sinus venousus) account for 10% of congenital heart diseases and 20-40% of congenital heart diseases presenting in adulthood
Female to male 2:1
Aortic Septal Defect Clinical signs
*May not present until adolescence or adulthood
- Heart murmur
- cyanosis
- dyspnoea
- easily fatigued
- syncope
stroke and/or heart failure
- sustained atrial arrhythmia
- palpitations
Atrial Septal Defect Management
Prehospital: Supportive, Oxygen
Hospital: surgery to close valve
Coarctation of the Aorta Pathophysiology
Narrowing of the aorta
- increases afterload on Left ventricle -> increased wall stress and compensatory ventricular hypertrophy
- Occurs after ductus arteriosus occurs. increases left ventricular pressure which elevates left atrial pressure which can open the foramen ovale leading to left to right shunting and dilation of right atrium and right ventricle
Coarctation of the Aorta Epidemiology and Aetiology
Common. 6-8% of congenital heart disease. Found most frequently in infants < 1 year
Coarctation of the Arota Clinical Signs
Poor feeding, tachypnoea, lethargy and progress to CHF and shock
Deterioratin coincides with closing of patent ductus arteriosus
Coarctation of the Aorta Management
Prehospital: Oxygen, IV access, supportive cares
Hospital: Surgery
Tetralogy of Fallot Pathophysiology
Combination of 4 defects
- Large Ventricular septal defect
- Pulmonary Stenosis - harder for blood to enter pulmonary circulation
- Right ventricular hypertrophy - harder for blood to enter pulmonary circulation
- Overriding aorta - located between left and right ventricles, directly over VSD. Blood flows into aorta instead of pulmonary artery
Tetralogy of Fallot Epidemiology and Aetiology
One of most common congenital disorder - 10%
Most common cause of cyanotic CHD
Tetralogy of Fallot Clinical Signs
Depend on severity of anatomical defects
- Cyanosis if insufficient pulmonary bloodflow
- Oxygen desaturation
- Smaller than expected
- Finger and toe clubbing
- Systolic thrill
- Haemoptysis
- Retinal engorgement
- Scoliosis
Tetralogy of Fallot Management
Prehospital: IV/IO access, Oxygen. Position knee to chest to increase systemic vascular resistance
Hospital: Palliative shunts and intracardiac repair
Hypoplastic Left Heart Syndrome
Small left ventricle and aorta. Blood flow to body suplied by ductus arteriosus. Mitral valve closed or atretic.
- Oxygenated pulmonary venous blood returns to left atrium cannot pass through mitral valve then crosses atrial septum.
- Bloodflow to systemic circulation is mixed
- Systemic circulation decreased after birth when pulmonary resistance decreased
Hypoplastic left heart syndrome Epidemiology and Aetiology
1.2-1.5 congenital heart defects
55-70% male predominance
75% survivial rate
Hypoplastic Left Heart Syndrome Clinical signs
Presentation depends on the patency of the ductus arteriosus, level of pulmonary vascular resistance and size of interarterial communication
- Cyanosis and after ductus arteriosus closes (24-48 hours) symptoms worsen and include tachypnoea, respiratory distress, pallor, lethargy, metabolic acidosis and oliguria
Hypoplastic Left heart Syndrome Management
Prehospital: Oxygen, IV access, supportive cares
Hospital: Surgery to repair defects
Patent Ductus Arteriosus Pathophysiology
Ductus arteriosus doesn’t close (Normally functional closing occurs after 15 hours)
Leads to mixing of systemic and pulmonary blood and pulmonary congestion as higher systemic pressure pushed blood into pulmonary circulation