23rd lecture (cardiology) Flashcards
Topics of cardiology that you need to know (6)
- congenital malformation
- ischemic heart disease
- endocardial diseases
- myocardium diseases
- pericardium diseases
- cardiac tumors
Describe congenital malformation of the heart? what should mothers avoid.
heart development occurs in the 3rd and 8th week.
pregnant women should avoid: rubella infection, alcohol, smoking. Most congenital problems can be corrected by surgery. In patients where the heart is corrected by surgery, the patient will not be healthy and will need followup for the lifetime since they are prone to other heart diseases, arrhythmias caused by surgery. altered blood flow can predispose to endocarditits. The altered blood blood flow can make ischemia of the heart chambers as they dilate and hypertrophy.
Name the 3 groups of congenital malformations?
A/ left to right shunt (this causes no cyanosis at birth)
B/ Right to left shunt (blue baby syndrome)
C/ obstruction (narrow outflow)
Describe Left to right shunts.
oxygenated blood from the left side goes to the right side into the pulmonary circulation. There will be an increased pressure in the right side, thus pulmonary circulation experiences a higher pressure as the systemic pressure takes over (pulmonary hypertension). Pulmonary edema could develop and be lethal.
The pulmonary arteries are not designed for such high pressure. The arteries undergo vasoconstriction, but if the pressure is maintained for a while there may be a proliferation of the smooth muscle cells and a narrowing of the lumen. This change is IRREVERSIBLE. The resistance of the lungs increases and the shunt turns around into a right-to-left shunt. this is called:
Eisenmenger syndrome
In this syndrome the right side is hypertrophy as well.
Why is timely surgery important for left-to-right shunts?
Once the Eisenmenger syndrome has developed the patient will die since the high pulmonary resistance is not compatible with life.
ALL left-to-right shunts should be corrected before the syndrome takes place.
If the surgery is performed too early the scar tissue will not grow with the baby. So they have to wait for the baby to grow to a certain size before the surgery, but if you wait too long then the syndrome may take effect.
Name the malformations that can cause a left-to-right shunt? (3)
- Atrial septal defects: (septum primum and septum secundum is involved) Normally the higher pressure in the left atrium closes the osteum foreman. When the 1st or 2nd septum development is diseased, there will be communication.
A/Osteum secundum type: secundum is not properly developed and the foramen ovale persists (foramen ovale apertum). 90%
B/Osteum primum type: no secunudm development at all, little communication between the 2 atria. 10%
Size of the communication determines the tolerance (less then 1cm). If larger then surgery is needed.
- Ventricular septal defect: (pars muscularis, pars membranosa). When there is a absence of the pars membranosa = upper septal defect, if isolated its called: Rogers disease. This makes a jet stream on the right ventricle and makes endothelial damage, and this predisposes it to endocarditis. This can also cause hypertrophy of the right ventricle and Eisenmenger syndrome. defects in the muscular part is rare but small holes can form between the muscles like holes in cheese. upper septal defect could be part of a complex problem called tetrology fallot.
- Patent ductus arteriosus:
- IRDS (infantile respiratory syndrome) The resistance of the lung is still high and thus the ductus arteriosus remains open.
- lack of prostaglandin E2 which is needed to close the ductus may leave it open. In this case the blood flows through the shunt in the other direction as the systemic resistance is much higher then pulmonary. (left-to-right shunt).
Name the malformations that can cause a Right-to-left shunt? (3)
1. Fallot tetrology: congenital heart malformation.
Right to left Hypoxic low oxygenated blood mixing with the systemic circulation. low oxygenation causes problems due to the 2 body compensations:
hyper-viscosity and Polycythemia: increase in the number of RBC’s. They also cause hypertrophy of the bone marrow. This causes hypertrophic osteoarthropathy; the fingertips look like drumsticks.
There is also a chance for paradox embolism. (venous thrombosis)
- absence of pars membranosa (upper ventricular septal defect)
- Dextra position of the aorta (aorta moves to the right) a.k.a. riding aorta.
- pulmonary stenosis (the clinical performance of the disease depends on the degree of pulmonary stenosis)
- hypertrophy of right ventricle
mild stenosis of the pulmonary will cause a left-to-right shunt this is called pink tetrology; because of no cyanosis. If the stenosis medium then its a bi-directional shunt. If sever stenosis then its a right to left shunt (blue baby syndrome).
The pulmonary stenosis being fibrotic means that it does not grow with the heart. As the patient grows the stenosis gets worse and worse.
Name all the Left-to-right and Right-to-left shunts and obstructions in heart defects?
A/Left to right shunt: (no cyanosis at birth): -Atrial septal defect -Ventricular septal defect -Patent ductus arteriosus B/Right to left shunt: (blue baby syndrome) -Fallot tetrology -Transpositon of great arteries -Truncus arteriosus C/Obstruction diseases -Cartacio aortae
Obstructive diseases of the heart?
Tricuspidal and bicuspidal stenosis, but most important is:
Cortacio aortae: 2 forms:
A/ preductal/infantile: the ascending aorta is narrowed until the left area. It called preductual because the fibrous band it before the joining of the botallo duct. Thus the very little blood goes through the aorta into the systemic circulation and most goes from the pulmonary into the aorta through the duct. This is severe malformation that needs to be fixed fast.
B/ postductal/adult: More frequent alteration when the ductus arteriosum turns into the ligamentum arteriosum it could leave a fibrous band behind that makes a narrowing of the lumen of the aorta. The increased resistance to the lower part of the body occurs. To compensate it, the heart has left sided hypertrophy. The patient in the upper body and the lower body has different pressures. The patient may have a claudication intermittente; the lower limbs may become ischemic after a certain distance and the patient has to wait for the legs to fill up with blood and start walking again. The blood pressure in the upper limbs is higher.
The patient has high risk for apoplexia do to hyper pressure, high risk for endocarditis due to the jet stream, the patient has Chronic ischemic heart disease due to the hypertrophy of the left ventricle.
what are adults with cardiac malformation, even with correction has high risk for?
- arrhythmia
- polycythemia
- endocarditis
- heart failure
Thus the patient has to be followed up fro a lifetime for cardiac control.
Describe the ischemic heart disease?
It is due to a dis-balance between the blood supply and the cardiac demand. 90% of the cases its a shortage of blood supply. 10% the problem is the increased demand.
- Ischemia may generate different diseases depending on how severe the shortage of the blood supply is.
- The rate of development of the disease may vary.
- What is the myocardial response to ischemia.
what are the 4 different disease due to ischemic heart disease?
- Angina pectoris: infraction causes angina.
- acute myocardial infraction: (fixed coronary, critical stenosis, advanced plaques)
- Chronic ischemic heart disease
- sudden cardiac death.
Chest pain (angina) less then 10 seconds its angina, if it lasts longer then 10 minutes its acute myocardial infraction.
describe the different types of angina?
- stable angina: fixed coronary critical stenosis (no consequences) the stenosis still provides enough blood in rest but if the patient is exerted then ischemia could develop with angina, this goes away after the exercise stops. Can be caused by emotional stress can cause it. It shows up as an ST depression.
- Prinzmetal angina: vasospasm can occur with or without sclerotic plaque. well treatable with Nitroglycerine.
- Unstable angina: (crescendo angina) may occur in rest or physical activity. This gets worse over time and can lead to myocardial infraction. could be causes by fissuring of a plaque, thrombosis, and immediate thrombolysis of the plaque.
The normal pathway for angina:
stable angina _ unstable angina _ acute myocardial infarction. This allows for early warning and reconstruction for the patient.
Describe chronic ischemic heart disease?
This is when the patient has progressive heart failure as a consequence of ischemia. The patient has a shortage of blood supply but the time is extended and does not happen suddenly: what are circumstances that cause chronic ischemic heart disease?
A/ hypertension (hypertrophy of the left ventricle with the same coronaries causing ischemia due to the increased demand with no change in supply, micro-infractions occur and replaced with fibrotic tissue. Fibrosis is severe in the subendocardium.
B/ coronary atherosclerosis: This may affect all coronaries with no critical stenosis but all of them are narrowed to some extend and thus the sum of the blood supply is not enough for the heart leading to ischemic heart disease.
C/ acute myocardial infraction: an area of tissue that is necrotic and regenerated by fibrous tissue will not contract. To maintain the circulation the remaining heart has to hypertrophy (adaption). But if the hypertrophy has a coronary blood supply problem because of the infraction will cause a discrepancy between the supply/demand.
The chronic ischemic heart disease can lead to arrhythmia or progressive heart failure. As the necrotic and fibrotic areas increase, the patient will have heart failure eventually.
Describe Sudden cardiac death? Name the 5 conditions.
Patient had no clinical symptoms for ischemia or other cardiac problems. This is an unexpected death related to lethal arrhythmia.
A/ acute myocardial infraction (arrhythmia could develop, the area that cannot contract is very large.
B/ Cardiac malformation (malformation may cause arrhythmias)
C/ Myocarditis (caused by viruses)
D/ Mitral prolapse
E/ cardiomyopathies: group of diseases that affect the myocardium (genetic), that ends up in dysfunction of the cardiac elements.
