Cardiovascular pathology Flashcards
What is a normal heart systolic ejection fraction?
60%
Until what week of gestation does the foetus have 1 single chamber?
5th week of gestation
What percentage of live births are affected by congenital heart disease?
1%
What is the most common congenital heart disease?
Ventricular septal defects (25-30%)
What is a patent ductus arteriosus?
Duct between pulmonary artery and aorta which persists after birth causing ongoing cardiac failure issues if not fixed.
What is the second most common congenital heart disease?
Atrial septal defect (10-15%)
What percentage of congenital heart disease are fallots?
4-10%
What are the risk factors for atheroma & atherosclerosis?
Hypertension Tobacco smoking DM Elevated cholesterol Age, obesity, male, family history, OCP, sedentary life style
How does atheroma initiate?
Endothelial dysfunction and injury occurs (smoking, HTN, etc.)
Lipids accumulate at site of impaired endothelial barrier
Local cellular proliferation and incorporation of oxidised lipoproteins
Thrombi on the surface with subsequent
What are the complications of plaque rupture in atherosclerosis?
Complete occlusion due to thrombosis
Chronic narrowing of lumen with healing of local thrombus
Aneurysm change
Embolism of thrombus which can impact downstream smaller arteries
Dissection where the blood seeps into the plaque wall and blood leaks into intima
What are the common presentations of atherosclerosis?
Angina
Myocardial infarction
Chronic congestive cardiac failure
Sudden death
How can ischaemic heart disease cause angina, MI, congestive cardiac failure and sudden death?
Angina - too little blood flowing through coronary arteries causing chest pain (particularly worse on exertion)
MI - death of tissue downstream of area of narrowing causing significant damage to heart muscle and loss of heart pumping function
Chronic congestive cardiac failure - 75% of patients with cccf with dilated or failing hearts reflect ischaemic heart disease
Sudden death - failing heart will not carry electrical impulses as effectively and can lead to arrhythmias and sudden death. Sudden death typically occurs when lumen is >70% occluded.
The complications of infarction differ depending on what area of the heart has been affected.
What area of the heart is usually affected in arrhythmias?
Arrhythmias usually occur when the supra and ventricular areas of the heart have been affected.
What are some reasons for imperfect blood supply to the heart?
Atherosclerosis Thrombosis Thromboemboli Artery spasm Collateral blood vessels Poor blood pressure, cardiac output and heart rate Arteritis
What is the risk of suddenly replenishing oxygen to tissues after an infarction?
Can cause significant haemorrhage and reperfusion injury where delivery of oxygen causes a further degree of injury as superoxide radicals are generated.