Cardio Flashcards
What is an aneurysm and how are they categorised
A localised permanent abnormal dilation of a blood vessel
Catergories:
True- due to weak vessel wall
False- Caused by trauma- haematoma mainly in femoral artery
What are the different types of true aneurysms
- Saccular and diffuse- atherosclerosis and inflammatory- aorta & cerebral artery
- Dissecting aneurysm- Marfans- Aorta and branches
- Capillary micro- HTN, diabetes- Cerebral and retinal capillaries
- Mycotic- Infection and sepsis- anywhere
What is myocarditis ?
What is it caused by
Inflammation of the myocardium
Caused by infection Viral- Coxsaxkie, adenoids, ECHO, chicken pox, influenza Bacterial- Diptheria, menuungococcus Parasites ionising radiation Drugs- adriamycin
What is pericarditis and what causes it?
An inflammatory reaction involving the visceral or parietal layers of the pericardium
Causes -Non specific -viral -bacterial -TB -Post MI -Post surgery
-Dressler’s syndrome -Carcinomatous -Uraemic
Name the different types of shock
- End results = hypotension, impaired tissue perfusion and cell hypoxia
1. Cardiogenic - acute HF
2. Hypovolaemic- haemorrhage or fluid shock
3. Septic- gram neg bacterial infection
4. Anaphylactic
5. Neurogenic
Define heart failure
Typical symptoms (breathlessness) and signs caused by structural and functional cardiac abnormality causing a reduced cardiac output and or elevated intracardiac pressures at rest or during stress
How do you calculated ejection fraction
ejection fraction = stroke volume
end diastolic volume
Normal Left ventricle EF= >50% reduced= <40%
What is the classification heart failure symptoms
- No limits to physical exercise
- Mild limitation- comfy at rest but normal activity gives fatigue, sob and palp
- Comfortable at rest but gentle activity gives symptoms
- Symptoms at rest
Discuss the Frank Starling Mechanism
There is increased blood left behind after systole but not all of it is ejected which increases diastolic volume stretches myocardial fibres and enhances contractility and stroke volume
How is the RAAS system activated in heart failure
Reduced cardiac output leads to decreased renal perfusion
This activates the RAA system
This leads to enhanced salt and water retention
Which further increases venous pressure leads to direct toxic effects on myocardial cells
How is the sympathetic nervous system activated in HF
Cardiac output= stroke volume x heart rate
- Stroke volume is reduced caused by myocardial impairment and is compensated for by increased heart rate
- Chronic sympathetic nervous system activation has effects causing myocyte apoptosis - this explains the effectiveness of b- blockers
How are natriuretic peptides activated in heart failure
ANP and BNP- help to mark HF in bloods
- Counter regulatory system for the RAAS system
- Decreases blood volume, arterial pressure , central venous pressure and cardiac output
Explain left sided HF
- Pooling of blood in pulmonary circulation causing dyspnoea, orthopnoea, PND
- Leads to inadequate perfusion of downstream tissues causing renal and cerebral hypoxia
- Also causes stasis of blood in left sided chambers causes dilation of the left atrium leading to atrial fibrillation and increased risk of stroke
Explain the causes of right sided heart failure
Most commonly caused by left sided heart failure -May occur with pulmonary HTN Right ventricular infarction Right ventricular cardiomyopathy Adult congenital heart disease
Cor pulmonale= only when the right side of the heart is affected
How does right sided heart failure affect other parts of the body
- Systemic venous congestion causes spleen and bowel enlargement
- Liver and Portal system affected by congestive hepatomegaly
- Kidney and brain affected
- Hepatic necrosis when left side of heart is also involved
- Fluid accumulation in pleural, pericardial and peritoneal spaces
What is arterial blood pressure
Measure of the force exerted onto the arterial walls by circulating blood
Systolic diagnostic threshold= 140mmHg
Diatolic 90mmHg
What are the primary and secondary causes of hypertension
Primary -No single cause but a number of risk factors
- age, gamily history, African or Carribean, high salt diet, no exercise , overweight , smoking , alcohol, stress , urban dwelling
Secondary - specific cause can be identified
- Renal- parenchymal and renovascular disease
- Endocrine- Phaechromocytoma, Cushing’s , Juperaldosteronism
- Coarctation of aorta
- Medications- NSAIDs, OCP, Steroids
- Pregnancy
What are the renal parenchymal diseases
- Diabetic nephropathy
- Chronic glomerulonephritis (autoimmune)
- PCKD
- Chronic tunulointerstital nephritis
- Hypertensive renal disease
Explain renovascular disease
- Renal artery stenosis due to atherosclerosis or fibromuscular dysplasia (younger females- pathological thickening of artery wall) causes decreased blood flow through main renal arteries or branches
- This causes refractory hypertension and may lead to chronic kidney disease
What are the endocrine causes of hypertension
- Elevated aldosterone due to a benign tumour of the adrenal gland
- Elevated noradrenaline and adrenaline due to phaeochromocytoma
- Cushings syndrome- high cortisol
- Ectopic ACTH from lung cancer
- Steroid medication
Explain coarctation of the aorta
Congenital narrowing of the aorta causing reduced blood flow to the lower half of the body so blood pressure is lower than normal in the legs and higher than normal in the arms
What is the difference between atherosclerosis and arteriosclerosis
Atherosclerosis - Asymmetrical narrowing of the lumen of larger vessels by lipid accumulation in the intimate
Arteriosclerosis- Symmetrical narrowing of lumen of smaller vessels by deposition of protein in the wall of the blood vessel
What is a haemorrhagic stroke
Stroke resulting from ruputure of small cerebral micro-aneurysms that have been weakened usually by chronic arterial hypertension
What is hypertensive nephrosclerosis
- Progressive renal impairment caused by chronic poorly controlled HTN due to damage of small blood vessels, glomeruli, renal tubules and interstitial fluids
- Progressive chronic kidney disease can develop
