Cardiology 2 Flashcards
What is Anemia?
Anemia is a simply a reduction in haem and/ or globin
Properties to Hb
- Consists of haem and globin
- 4 polypeptide globin chains
- Each chain is complexed to a haem molecule
- Haem is an iron containing compound
2 beta chains and 2 alpha chains
Classification of Anemia
- Anaemia is classified as:
- Men: Hb <130/L
- Women: Hb <120/L
- Further classification based on mean corpuscular volume (MCV) – what is this?
- In simple terms, the average size of the total red blood cells.
Examples of Microcytic anaemia?
Iron Deficiency
Thalassaemia
Anemia of Chronic disease
Sideroblastic anemia
Lead poisoning
Examples of Normocytic anaemia?
Acute blood loss
Haemolytic anaemia
Anaemia of Chronic disease
Chronic Kidney Disease
Aplastic anaemia
Examples of Macrocytic anaemia?
B12 deficiency
Folate deficiency
alcohol
Liver dosease
Hypothyroidism
Signs and symptoms of anaemia?
Fatigue
Tachycardia
SOB on exertion
Tachypnoea
Chest pain
Hypotension
Palpitations
Pallor
Red flags for Anaemia?
•Weight loss, anorexia, night sweats, lymphadenopathy
What is iron deficiency Anaemia?
Reduced intake, increased requirement or increased loss of iron
Features of iron deficiency?
Glossitis
Angular stomatisits/chelitis
Koilonychia
Pica
Ix for Iron deficiency Anaemia
What is Thalassemia?
Prevalent in what areas?
Definition: Autosomal recessive haemoglobinopathy. Inherited blood disorder causing the body to make fewer healthy red blood cells with les hb
•Haemoglobinopathy: Impaired globin chain synthesis
Prevalent in areas of malaria
- Alpha: Asia and Africa
- Beta: Asia, Mediterranean and Middle East
Clinical features of thalassaemia?
Patho of thalassemia
Alpha: 4 alleles on chromosome 16 that code for alpha globin – the more deletions, the worse the anaemia.
•4 deletions = hydrops fetalis- not compatible with life
Beta: 2 alleles on chromosome 11 that code for beta globin. Mutated alleles can either produce less beat globin or no beta globin. The worse the mutations, the worse the anaemia.
What is anaemia of chronic disease?
What is the causes?
Anaemia due to an inflammatory mediated reduction in RBC production
Can be microcytic or normocytic
Causes:
- Autoimmune disorders: e.g. RA
- Chronic infection
- Chronic disease: e.g. CKD, HF
- Malignancy
- Major trauma
What is the difference between iron deficiency anemia and anemia of chronic disease?
In iron-deficiency anemia, the TIBC is higher than 400–450 mcg/dL because stores are low. In anemia of chronic disease, the TIBC is usually below normal because the iron stores are elevated
A total iron-binding capacity (TIBC) test measures the blood’s ability to attach itself to iron and transport it around the body. A transferrin test is similar. If you have iron deficiency (a lack of iron in your blood), your iron level will be low but your TIBC will be high.
What is sideroblastic anaemia?
Causes?
•Rare
Definition: Anaemia due to defective heam synthesis within the mitochondria.
Causes:
- Lead poisoning
- Vitamin B6 deficiency
- Congenital: X-linked recessive enzyme deficiency
- Chronic Alcoholism
Signs in normocytic anaemia
think of 3As and 2Hs
- A – Acute blood loss
- A – Anaemia of Chronic Disease
- A – Aplastic Anaemia
- H – Haemolytic Anaemia
- H – Hypothyroidism (can also be macrocytic)
What is sickle cell disease?
- Autosomal recessive mutation in the Hb beta chain at position 6 (glutamic acid to valine)
- 2 alleles code for the beta chain
- Sickle cell disease: 2 abnormal alleles
- Sickle cell trait: 1 abnormal allels
- Sickle cell crisis: Acute manifestation of sickle cell disease
What happens in normocytic anaemia?
- Normocytic anaemias: Either increased destruction of RBCs or reduced production of RBCs.
- Reticular count is used to distinguish the two
- Reduced production – reticular count is low (failure of bone marrow )
- Increased destruction – Bone marrow is working fine – compensation from haemolysis so increased reticulocytes
What is hereditary spherocytosis?
- Inherited defect in the RBC membrane proteins leading to a haemolytic anaemia
- Usually autosomal dominant
- Extra features:
- Neonatal jaundice, splenomegaly, gallstones
- Ix: Increased reticulocytes
Patho of sickle cell?
- HBS: Crystallises and is insoluble at low PaO2
- This causes sickling of the RBC
- Extra features: jaundice, failure to thrive, frontal bossing
What is G6PD deficiency?
- Inherited X-linked deficiency resulting in a haemolytic anaemia.
- Results in a reduced half-life of RBCs (<120days)
- G6PD is required by cells to prevent them from damage by oxidation.
- Red cells are under constant stress by oxidants as oxyhaemoglobin is converted to deoxyhaemoglobin
G6PD deficiency is an inherited condition. It is when the body doesn’t have enough of an enzyme called G6PD (glucose-6-phosphate dehydrogenase). This enzyme helps red blood cells work correctly. A lack of this enzyme can cause hemolytic anemia. This is when the red blood cells break down faster than they are made.
What is autoimmune haemolytic anaemia?
- Antibody mediated destruction of RBCs
- Divided into cold or warm depending on what temperature the antibodies bind to RBCs the best.
- Warm: IgG binds to RBCs; Cold: IgM binds to RBCs.
- Associated with Autoimmune conditions, infections and drugs
- Causes extravascular haemolysis (warm) and extra/intravascular haemolysis (cold)
- Warm: SLE, CLL, Drugs e.g. penicillin
- Cold: M.pneumonia, EBV
- Warm vs cold? Coombs test (normally direct)
What is the b12 deficiency?
- B12 is absorbed in the ileum bound to intrinsic factor (which made by parietal cells in the stomach)
- Pernicious anaemia is an autoimmune reaction against intrinsic factor and parietal cells causing a B12 deficiency. Most common cause in the western world.
Risk factors of b21 deficiency?
- Increased age
- Vegan Diet (11% on a vegan diet)
- Gastric surgery
- Malabsorption
- Drugs e.g. metformin
Folate deficiency
RF?
Drugs?
- Reduced levels of folic acid
- RF:
- Increasing age
- Malabsorption
- Pregnancy
- Alcohol
- Drugs: e.g. methotrexate, trimethoprim
- Folate is absorbed in the jejunum
What is Heart Failure?
Characterised by the heart’s inability to effectively fill and/or eject (pump) blood, caused by an underlying pathology commonly coronary artery disease or previous MI.
Heart Failure can be described as:
- Heart failure with reduced ejection fraction – HFrEF – where there is a pump dysfunction
- Heart failure with preserved ejection fraction – HFpEF – due to a filling dysfunction
What is the types of heart failure?
biventricular heart failure, left sided heart failure, right sided heart failure and cor pulmonale
What is left sided heart failure?
uChange in function of the left ventricle resulting in decreased cardiac output, pulmonary congestion and decreased peripheral perfusion
uCan be either with a reduced ejection fraction or preserved ejection fraction
What are the risk factors for left heart failure?
- Coronary artery disease → decreases blood supply to cardiomyocytes → decreases contractile strength
- Hypertension, aortic stenosis → ↑afterload → ↓stroke volume
- Arrhythmias decrease ventricular filling and lead to ineffective contractions
- Mitral or aortic regurgitation
- Age, Obesity, Diabetes, Smoking, Ethansol, Illicit drug
Pathology of left sided failure?
- Underlying disease results in a decrease in the cardiac output results in backup of blood into left atrium, pushed back into pulmonary circulation → ↑pulmonary capillary pressure → pulmonary oedema → ↑gas exchange
- RAAS activation due to ↓cardiac output. Angiotensin II production → systemic effects, increasing blood pressure, cardiac hypertrophy, decreased diuresis
Consequences and complications for left heart failure?
Effects of compensation: ↑afterload, ↑LV workload, LV remodelling
Pulmonary oedema
Pulmonary haemorrhage (congested capillaries bursting)
Cardiorenal syndrome
Death
Signs and symptoms for left sided heart failure
uLeft sided heart failure can present as
uExertional dyspnoea and can be on rest
uOrthopnoea
uParoxysmal nocturnal dyspnoea (PND)
uCough, restlessness
uBibasal crackles on auscultation of lungs – pulmonary oedema
uS3/S4 sound
What is righ sided heart failure
and what causes it?
- Change in function of the right ventricle leading to decreased delivery of blood to the pulmonary circulation and elevated venous pressure
- ↑venous pressure leads to systolic volume overload
- ↑Right ventricular workload → RV hypertrophy → ↓pumping ability
Caused by left sided heart failure and the associated pulmonary oedema (most common cause).
Other causes include RV infarct, bacterial endocarditis, pulmonary valve stenosis, cardiomyopathy.
Signs and symptoms of right sided heart failure?
- Peripheral pitting oedema
- Fatigue/exercise intolerance – due to poor gas exchange
- Hepatojugular reflux
- Ascites
- Hepatosplenomegaly
- S3/S4 sounds
Complications of right sided heart failure?
- Failure of left side of heart
- Tricuspid regurgitation
- Congestive hepatopathy – liver damage due to backup of blood
- Cardiac cachexia – nausea, vomiting, anorexia, abdo pain
- Eventual death
What is New York Heart Association – Classes of Heart Failure
What is Cor Pulmonale?
Pulmonary Heart Disease
- Right heart failure secondary to pulmonary arterial hypertension
- Right ventricular hypertrophy/dysfunction caused by pulmonary hypertension
- Presents with signs and symptoms of right sided heart failure
What are the Diagnostic findings in Heart Failure?
- Elevated BNP/NT-pro-BNP – raised due to stretching of ventricular wall
- Chest X-Ray
- In Left Heart Failure & biventricular failure – cardiomegaly, pulmonary vascular congestion, Kerley B lines
- Echocardiogram
- ECG abnormalities – arrhythmias, tall QRS
Management for heart failure
- Beta blockers have an evidence base to reduce mortality. (e.g. bisoprolol)
- ACE inhibitors (e.g. ramipril) and ARBs (e.g. candesartan) are also used
- In fluid overload a loop diuretic can be prescribed e.g. furosemide
What is compensated and decompensated HF?
•If the dilated ventricle (as seen in systolic left sided HF) is able to maintain cardiac output by this means, the patient is said to be in compensated heart failure.
However, ventricular dilation comes at the expense of increased wall tension and amplifies the oxygen requirements of an already-compromised myocardium. With time, the failing muscle is no longer able to propel sufficient blood to meet the needs of the body, and the patient develops decompensated heart failure.
What is cardiomyopathy?
Cardiomyopathy refers to diseases of the heart muscle. These diseases have many causes, signs and symptoms as well as treatments. In most cases, cardiomyopathy causes the heart muscle to become enlarged, thick or rigid.
Types of cardiomyopathies
- Hypertrophic Cardiomyopathy
- Dilated Cardiomyopathy
- Restrictive Cardiomyopathy
- Arrhythmogenic Right Ventricular Cardiomyopathy
- Takatsubo Cardiomyopathy
What is Primary and Secondary Cardiomyopathy?
- When cardiomyopathy develops as a way to compensate for some other underlying disease like hypertension or valve disease its called secondary cardiomyopathy.
- If it develops all by itself its called primary cardiomyopathy.
What is Hypertrophic Cardiomyopathy?
- Basics: When the walls of the heart become thick, heavy and hypercontractile, essentially the muscle grows a lot larger – and new sarcomeres are added in parallel
- Usually LV is affected + muscle growth is asymmetrical meaning that the IV septum grows larger in comparison to the free wall and this causes 2 things:
- Take up more room so less blood in the ventricle
- More stiffness and less compliant and hence it cant stretch as much – cant fill as much leading to what type of HF?
Hypertrophic Cardiomyopathy
- In some patient the LV outflow is blocked by the outgrowth of IV septum during _______– Increased blood velocity through smaller aortic valve and this pulls the _____ leaflet of the _____ valve towards the septum (VENTURI EFFECT) causing further obstruction
- This is also referred to as _________ _______ _________
- Causes a ________ _________ Murmur (like AV valve stenosis)
- Bifid Pulse from the mitral valve
- S_ Sound can be heard of atrial depolarization – pushing blood into a non-compliant ventricle during diastole
- In some patient the LV outflow is blocked by the outgrowth of IV septum during systole – Increased blood velocity through smaller aortic valve and this pulls the anterior leaflet of the mitral valve towards the septum (VENTURI EFFECT) causing further obstruction
- This is also referred to as Hypertrophic Obstructive Cardiomyopathy
- Causes a Cresendo-Decrecendo Murmur (like AV valve stenosis)
- Bifid Pulse from the mitral valve
- S4 Sound can be heard of atrial depolarization – pushing blood into a non-compliant ventricle during diastole
Causes of Hypertrophic Cardiomyopathy
- Genetic: Autosomal Dominant: Missense mutation in the Beta Myosin Gene
- Freidriches Ataxia: Autosomal Recessive
- On Histology: Myocyte Disarray aka Myocytes organization is haywire
What is Dilated Cardiomyopathy (MC type)
- Causes all 4 chambers to dilate
- New sarcomeres are added in series causes the muscles to become thin and there is less muscle present for contraction causing weak contractions
- This causes reduced stroke volume and leads to Systolic Heart Failure
- As chambers get larger they tend to stretch out the valves that separate the atrium and ventricles
- This causes valves to not close all the way leading to regurgitation (Mitral and tricuspid: Holosystolic murmur)
- Arrhythmia complication: stretching of conduction system
Dilated Cardiomyopathy : Causes
> Primary : idiopathic: the most common cause
> inherited: either a familial genetic predisposition to DCM or a specific syndrome e.g. Duchenne muscular dystrophy, or haemochromatosis, sarcoidosis
> Myocarditis: e.g. Coxsackie B, HIV, diphtheria, Chagas disease(protozoan)
> Alcohol is toxigenic
> Drugs like chemotherapy: Daunorubicin and cocaine
> Wet beriberi decreases B1
> Peripartum cardiomyopathy where DCM can develop in the 3rd trimester of pregnancy or in weeks following pregnancy probably because of of pregnancy associated hypertension.
What is Restrictive Cardiomyopathy
- Is where the heart muscle is restricted meaning it becomes stiffer and less compliant
- The muscles and size of ventricles stay about the same size or are maybe only slightly enlarged
- When blood fills into restricted ventricles, the ventricles aren’t allowed to expand.. because they cant stretch .. Less filling … less pumped out causes diastolic HF
Diagnosis of Restrictive Cardiomyopathy
using ECG: smaller QRS complexes, low amplitude signals, Echo
Restrictive Cardiomyopathy Causes
Causes include amyloidosis, sarcoidosis, hemochromatosis, endocardial fibro elastosis (children), and Loeffler syndrome (endomyocardial fibrosis with an eosinophilic infiltrate and eosinophilia).
What is an Abdominal Aortic Aneurysms (AAA)?
Causes?
■ An aneurysm is a weakening/thinning of the arterial wall leading to a localized bulging.
Definition of AAA: A permanent, localised dilatation in the wall of the abdominal aorta.
Cause: Primarily from the loss of intima with loss of elastic fibres from the media
Risk factors of AAA
o Arterial disease - atherosclerosis - hypertension - diabetes - smokers oConnective tissue disorders - Marfan’s syndrome, Ehler-Danlos syndrome
- Extracellular matrix becomes disrupted with changes in the balance of collagen and elastic fibres
o Age – over 65 years
o Male sex – 3 to 4 times more prevalent
o Family history – especially in male first degree relatives
Presentation for AAA:
1) Asymptomatic pulsatile abdominal mass (normally diagnosed incidentally)
2) Detected during USS Routine Screening in men over age 65
3) Emergency (rupture)
– Sudden onset, severe chest/abdominal pain that radiates to the back
– Collapse
– Hypotension with tachycardia
– Profound anaemia
Ix of AAA
– History and examination - examination may identify a expansile, pulsating mass.
– Ultrasound - To look at the diameter of the abdominal aorta.
– (GOLD STANDARD) CT Angiography - Used preoperatively to check for renal artery involvement and for planning surgery.
Management for AAA
o <5.5 cm on ultrasound - Continued monitoring with ultrasounds
o >5.5 cm on ultrasound - Elective surgery to prevent rupture.
o Emergency - Oxygen, 2 large-bore cannulas, fluid management (BP at 100mmHg to prevent dislodging a clot), surgical aneurysm repair
Prognosis: 80% mortality for ruptured AAA
What are the surgical management options for AAA
■ Clamping below the renal artery, then sewing a graft into the aneurysm sac
■ Endovascular Aneurysm Repair (EVAR)
- less invasive endoscopic procedure whereby stents are inserted through the femoral artery
What is an aortic dissection?
Definition: Blood escapes through the innermost tunica intima layer of the aorta wall, prising apart the media and creating a new lumen
Presentation for aortic dissection
- Acute severe tearing or ripping chest pain, radiating to the back
- Weak or absent pulses
- Systolic BP variation of >20mmHg between the arms
- Hypertension
- Aortic regurgitation
Ix for Aortic Dissection
Chest X-ray - Widened mediastinum
CT Angiograph of Chest-Abdo-Pelvis (For STABLE patients) - False lumen
What is the Debakey classification for aortic dissection?
■ DEBAKEY Classification:
- Type 1 - originates in ascending aorta, propagates to at least the aortic arch and possibly beyond it distally
- Type 2 - originates in and is confined to the ascending aorta
- Type 3 - originates in descending aorta, rarely extends proximally but will extend distally
What are the classifications for aortic dissection?
DEBAKEY
STANDFORD