Week 1 - Cardio, Respiratory, GIT Flashcards
The normal heart weighs how much?
~350g
What are the 2 layers of the Pericardium?
Parietal and Visceral
What types of cells can be found in the Myocardium?
Cardiac muscle cells and cardiocytes
The endothelium can be found in which layer of the heart?
Endocardium
Pulmonary circulation overload, pulmonary hypertension and RV hypertrophy are symptoms of which cardiac defect?
Left to right shunts
What is the problem in an atrial septal defect?
There is a failure of the foramen ovale to close after birth.
What is the most common cardiac defect?
Ventricular septal defect.
A ventricular septal defect is a right to left shunt. True or false?
False.
What is the problem in a Patent ductus arteriosus?
It is a failure of the closure of ductus arteriosus after birth.
Is a patent ductus arteriosus a left to right shunt or a right to left shunt?
Left to right shunt
What is a pulmonary stenotic lesion?
Narrowing of the pulmonary artery/valve.
What is a symptoms of a pulmonary stenotic lesion?
Cyanosis due to decreased oxygenation of the blood.
What are the four signs of Fallot’s tetralogy?
- Pulmonary stenosis
- High ventricular septal defect
- Overriding of the septum by the aorta
- RV hypertrophy
What is a coarctation of the aorta?
Narrowing or blockage of the aorta.
What are some of the symptoms of a coarctation of the aorta?
Headaches and dizziness
What is Situs Inversus?
Organs are on opposite sides of the body.
What is Dextrocardia?
The apex of the heart is pointing towards the right.
What are the two classifications of disorders of the pericardium?
Inflammatory and non-inflammatory
What are the two classifications of Inflammatory pericardial disorders?
Acute pericarditis and chronic peridcarditis
What is the aetiology of acute pericarditis?
Due to bacterial/viral infections, rheumatic fever, uraemia, SLE, tumours, MI and trauma.
What are the morphological manifestations of acute pericarditis?
Serous, fibrinous, suppurative or haemorrhagic
How does rheumatic fever cause acute pericarditis?
Cross reactivity by antibodies due to Group A strep infection causes inflammation.
How does ureamia cause acute pericarditis?
High levels of urea cause toxins to build up in the blood causing pericarditis.
How does SLE cause acute pericarditis?
Autoantibodies cause inflammation.
How does MI cause acute pericarditis?
Inflammation to pericardium due to muscle death.
What causes suppurative change to the pericardial fluid?
Pyogenic infection.
What causes serous change to the pericardial fluid?
SLE
What causes fibrinous change to the pericardial fluid?
Increase in urea in blood.
What causes haemorrhagic change to the pericardial fluid?
Tumours in the pericardium.
What are some of the causes of chronic pericarditis?
Organised acute pericarditis, TB, Syphilis, SLE, radiation therapy, cardiac surgery
How do TB and syphilis cause chronic pericarditis?
Granulomatous or gummatous inflammation.
How does radiation therapy cause chronic pericarditis?
Damage to the pericardium and scar tissue formation.
What is Pick’ disease of the pericardium?
progression of acute viral/bacterial pericarditis leading to formation of a rigid fibrous capsule which restricts diastolic filling of the heart leading to cardiac tamponade.
What is a classic sign of impedance of venous return?
Impedance of venous return causes increased central venous pressure which causes neck vein distention.
What causes impedance of venous return?
Formation of dense fibrous bands forming a rigid fibrous capsule around the heart.
What are some on the non-inflammatory disorders of the pericardium?
Hydropericardium, haemopericardium, pneumopericardium.
What is hydropericardium?
Too much fluid in the pericardium.
What is Haemopericardium?
Blood in the pericardium due to trauma e.g. vessel rupture.
What is pneumopericardium?
Air collection in the pericardium e.g. during surgery.
Hydropericardium, haemopericardium, pneumopericardium can all lead to _________ __________.
Cardiac tamponade
What are some of the primary tumours of the pericardium?
Mesothelioma, fibrosarcoma (both very rare).
What is an example of a secondary tumour of the pericardium?
Bronchogenic carcinoma (more common than primary tumour)
What are some examples of a disorders of the myocardium?
Coronary artery insufficiency due to atherosclerosis, amyloidosis, cardiomyopathies, myocarditis, rheumatic heart disease, cor bovinum, cor pulmonale
What are the two manifestations of coronary artery insufficiency?
Gradual occlusion of coronary artery and sudden occlusion of coronary artery.
Gradual occlusion of a coronary artery can lead to _______ ________.
Angina pectoris
What is the cause of angina?
Ano2 metabolites build up in the myocardial tissue due to partial occlusion of the coronary arteries.
A sudden occlusion of a coronary artery leads to a _________ ______.
Myocardial infarction.
What are the four types of MI?
Transmural infarct
Subendocaridal infarct
Septal infarct
Subpericaridal infarct
Which coronary artery is the most common to be blocked causing MI?
Left anterior descending coronary artery (50%)
A blockage in the Left anterior descending coronary artery causes infarction in which area of the heart?
Anterior wall of the left ventricle, anterior part of the septum and the apex.
A right coronary artery occlusion causes what percentage of MI?
~30%
A right coronary artery occlusion causes an infarct in which area of the heart?
Posterior wall of the LV and posterior part of the septum.
An occlusion in the left circumflex coronary artery causes what percentage of MI?
~20%
An occlusion in the left circumflex coronary artery causes an infarct in which area of the heart?
Lateral wall of LV
What are some of the investigations done on a person suspected of an MI?
Troponins, cardiac enzymes, blood lipids, FBE, chest x-ray, nuclear scans
What are some of the methods of management of an MI?
Defibrillation Fluid replacement Morphine Frusemide (allows diuresis) O2 therapy Inotropic agents Antiarrhythmics Antithrombotics Analgesics Rehabilitation
What are some of the sequelae of an MI?
Sudden death Cardiogenic shock Heart failure Pericarditis Fibrosis Thromboembolism Cerebral infarct Aneurysm (cardiac aneuryms, burst apex) Arrhythmias
How does amyloidosis affect the myocardium?
Deposits the two types of amyloid, amyloid light chain protein and amyloid associated protein, in the heart tissue.
What is the cause of primary amyloidosis?
Idiopathic
What body systems does primary amyloidosis affect?
Skeletal muscles, heart, skin, spleen, kidney, lungs.
What is the cause of secondary amylodisosis?
Pre-existing diseases such as RA, multiple myeloma, chronic inflammatory diseases.
What body systems does secondary amyloidosis affect?
Spleen, liver, adrenals
Amyloid is stained ______ by iodine, _____ by Congo red and you can see ______ _______ birefringence of Congo red stained tissue under polarised light.
Brown, red, apple green
What do deposits of amyloid in the myocardium do to cardiac function?
The waxy deposits in the myocardium causes the walls of the heart to become inflexible and interfere with cardiac function.
What is the definition of cardiomyopathy?
A myocardial disorder diagnosed by exclusion i.e. not due to hypertension, CHD, RHD.
What are some of the symptoms of cardiomyopathy?
Chest pain, palpitations, heart failure.
What are the three types of cardiomyopathy?
Congestive/Dilated, Hypertrophic, Restrictive
What happens to the ventricles in congestive/dilated CMP?
Ventricles enlarge/dilate and become “congested” with blood.
What are the causes of congestive/dilated CMP?
Idiopathic, viral, alcohol causes.
What happens to the ventricles in hypertrophic CMP?
They becomes enlarged/thickened.
What are the causes of hypertrophic CMP?
Idiopathic, genetic causes.
What happens to the ventricles in restrictive CMP?
Deposits of proteins in ventricular wall inhibit diastolic filing of ventricles.
What are the causes of restrictive CMP?
Idiopathic, amyloidosis.
What are the two classifications of myocarditis?
Infective and Aseptic.
What are some of the causes of infective myocarditis?
Group B Coxackievirus
Type 8 Echoviruses
Toxoplasma gondii
Staphylococcus aureus
In western countries ______ infective myocarditis is more common whereas in developing countries __________ or ________ infective myocarditis is more common.
Viral, protozoa, bacterial
What are some of the causes of aseptic myocarditis?
Alcoholic, toxic, drug-related, autoimmune, idiopathic
What are some of the effects on the heart tissue due to RHD?
Polyarthritis
Pancarditis
Aschoff nodules (Aschoff body)
Heart valve lesions (mitral, aortic)
What causes RHD?
Infection with Group A strep leads to excess antibody formation in genetically predisposed individuals, react with and destroy cardiac tissue.
What can happen to the heart valves in RHD?
They develop lesions which cause fibrosis and calcification leading to the thickening of the cusps.
What is Cor bovinum?
LV hypertrophy due to systemic hypertension. It starts with concentric hypertorphy but eccentric may supervene.
What is Cor pulmonale?
RV hypertorphy due to various lung or valve disorders. It is an enlargement of the right ventricle due to high blood pressure in the arteries of the lungs usually caused by chronic lung disease. It starts with concentric hypertrophy but eccentric may supervene.