Cardio 2 Flashcards
Define heart block
- Atrioventricular (AV) block is a cardiac electrical disorder defined as impaired (delayed or absent) conduction from the atria to the ventricles.
- The severity of the conduction abnormality is described in degrees: first-degree; second-degree, type I (Wenckebach or Mobitz I) or type II (Mobitz II); and third-degree (complete) AV block.
Describe epidemiology of heart block
- More prevalent in African American patients
- More common over age 50
- 3rd degree incidence is 0.04%
- More common in men
Describe aetiology of heart block
- Fibrosis and calcification of the conduction system
- CAD (including patients with a chronic disease and/or an acute coronary syndrome, right coronary artery)
- Medication such as AV-nodal blocking agents (i.e., beta-blockers, calcium-channel blockers, digitalis, adenosine), anti-arrhythmic medications such as sodium-channel blockers, and some class III agents (i.e., sotalol and amiodarone).
- High vagal tone; cardiomyopathy (e.g., hypertrophic, sarcoid, amyloid, haemochromatosis); calcification from adjacent valvular calcification; post catheter ablation for arrhythmias
- Post-surgical causes (i.e., valve repair or replacement myectomy, septal ethanol ablation); blunt cardiac injury;[10]and some indigenous medicines.
- Severe electrolyte disturbance, acidosis, or hypoxaemia may result in AV block as well as neuromuscular disorders (myotonic dystrophy, Kearns-Sayre syndrome, Erb dystrophy, peroneal muscular atrophy), myocarditis, infective endocarditis, and Lyme disease.
- AV block may be congenital as well
List risk factors for heart block
- Age-related degenerative changes in the conduction system
- Increased vagal tone
- AV-nodal blocking agents
- Chronic stable CAD
- Acute coronary syndrome
- CHF
- Hypertension
- Cardiomyopathy
- Left ventricular hypertrophy
- Recent cardiac surgery
- Acid-base or electrolyte disturbance
- Neuromuscular disorders
- Sarcoidosis
- Myocarditis
- Infective endocarditis
- Hypoxemia
- Blunt cardiac injury
- Some indigenous medicines
List symptoms of heart block
Mobitz 2 and 3rd degree only
- Fatigue
- Dyspnoea
- Chest pain, palpitations, and nausea or vomiting
List signs of heart block
- Hypertension
- Cannon A waves (3rd degree heart block, irregular large wave of the JVP)
- Hypoxaemia
Describe diagnosis of heart block
- ECG
- First degree increased PR interval
- Mobitz 1 increasing PR interval then dropping a QRS complex
- Mobitz 2 PR the same with randomly dropped QRS
- Third degree P and QRS dissociated
- Troponin may be elevated, measure potassium, calcium, pH
Describe treatment of heart block
First degree or Mobitz 1
- Monitor for development
- Discontinue AV-nodal blocking medications including beta-blockers, non-dihydropyridine calcium-channel blockers, and digitalis.
- Pacemaker if symptoms continue
Mobitz II or third degree
- Discontinue AV blocking drugs
- Give atropine
- Pacemaker insertion with or without ICD
List complications of heart block
Pacemaker insertion 2-3% risk of
- Bleeding, infection, vascular trauma, pneumothorax, cardiac tamponade, lead dislodgement, and pocket haematoma development.
- The risk of MI, stroke, and death is <1%.
- Long-term complications include pulse generator or lead malfunction and infection, requiring replacement or extraction
Describe prognosis of heart block
- First-degree AV block 2-fold increase in the probability of atrial fibrillation, a 3-fold increase in the probability of pacemaker implantation, and an increase in all-cause mortality.
- In symptomatic patients with irreversible AV block, symptoms are likely to persist or potentially worsen.
- Patients with irreversible advanced AV block (type II second-degree or third-degree) are at high risk for progression to third-degree AV block or ventricular asystole.
- Low rate of pacemaker complications
Describe prognosis of ACS and angina
- Stable angina 58% of patients free of symptoms within 1 year following lifestyle modification and medical therapy
- non-ST ACS patient mortality after 6 months 4.8%
- At 12 months, rates of adverse cardiovascular events (MI and death) 10%
- NSTEMI high risk of morbidity and death, sudden death rate 4-6 times higher than general population
- STEMI in hospital mortality 4-12% and 1 year mortality 10%
List risk factors for myocarditis
- Infection (non-HIV)
- HIV infection
- Smallpox vaccination
- Autoimmune/immune-mediated diseases
- Peripartum and postnatal periods
- Drugs and toxins
Describe diagnosis of myocarditis
- 12-lead ECG (ST and T wave abnormalities, commonly ST elevation/depression)
- CXR (bilateral pulmonary infiltrates)
- Serum CK (mildly high)
- Serum CK-MB (mildly high)
- Serum troponin (I or T - elevated)
- Serum B-type natriuretic peptide (elevated in ventricular distention)
- Two-dimensional echocardiogram (global and regional left ventricular motion abnormalities and dilatation)
- Endomyocardial biopsy (EMB - myocardial cellular infiltrated and or necrosis)
- Coronary angiography (normal)
- Cardiac MRI (early enhancement myocarditis)
Define constrictive pericarditis
- A type of chronic pericarditis (lasts more than 3 months)
- Characterized by thickening and rigidity of the pericardium, resulting in both backward and forward failure. There is a characteristic pericardial knock on auscultation, which is caused by a sudden stop in ventricular diastolic filling.
- Effusive-constrictive pericarditis (the other type of chronic pericarditis) is characterized by a thickened pericardium with an effusion; this can lead to cardiac tamponade
.
Describe aetiology of constrictive pericarditis
- Idiopathic
- Infectious (most commonly viral e.g., coxsackie B virus), bacterial e.g., Staphylococcus spp., Streptococcus spp., or M. tuberculosis, fungal or toxoplasmosis)
- Myocardial infarction (Postinfarction fibrinous pericarditis within 1–3 days as an immediate reaction or dressler syndrome within weeks to months following an acute myocardial infarction)
- Postoperative (postpericardiotomy syndrome): blunt or sharp trauma to the pericardium
- Uremia (e.g., due to acute or chronic renal failure)
- Radiation
- Neoplasm (e.g., Hodgkin lymphoma)
- Autoimmune connective tissue diseases (e.g., rheumatoid arthritis, systemic lupus, scleroderma)
List risks for constrictive pericarditis
- Low if idiopathic or viral pericarditis
- Intermediate risk for autoimmune and neoplastic aetiologies
- High risk for bacterial aetiologies, especially with TB and purulent pericarditis
Describe epidemiology of constrictive pericarditis
- 9% of patients with acute pericarditis
- 0.76 cases per 1,000 person-years after acute idiopathic/viral pericarditis
- 31.7 cases per 1,000 person-years for acute tuberculous pericarditis
- 52.7 cases per 1,000 person-years for purulent pericarditis
List symptoms and signs of constrictive pericarditis
Symptoms of fluid overload (i.e., backward failure)
- Jugular vein distention
- Kussmaul sign
- Hepatic vein congestion: hepatomegaly, painful liver capsule distention, hepatojugular reflux
- Peripheral edema; or anasarca, ascites with abdominal discomfort
Symptoms of reduced cardiac output (i.e., forward failure)
- Fatigue, dyspnea on exertion
- Tachycardia
- Pericardial knock: sudden cessation of ventricular filling during early diastole that is heard best at the left sternal border
- Pulsus paradoxus: ↓ blood pressure amplitude by at least 10 mm Hg during deep inspiration
List investigations for constrictive pericarditis and their findings
- Echocardiography (increased pericardial thickness)
- CT and cardiac MRI (pericardial thickening > 2 mm, calcifications, normal cardiac silhouette)
- Chest x-ray (heart size normal or slightly increased, pericardial calcifications, clear lung fields)
- Cardiac catheterization if noninvasive methods have failed to provide a definitive diagnosi (similar pressures in the left and right atria and right ventricle at the end of diastole (e.g., “equalization of pressures”), normal pulmonary artery systolic pressure < 40 mm Hg, mean right arterial pressure > 15 mm Hg)
- Square root sign - dip-and-plateau waveform, a sudden dip in the right and left ventricular pressure in early diastole followed by a plateau during the last stage of diastole
- ECG (no conclusive findings: generalized flat/inverted T waves, low QRS voltage, possible AF)
List signs on examination associated with intermittent claudication
- Wet gangrene
- Shiny hairless skin
- Ulcers
- Non-palpable pulses
- Buergers angle (pale limb under 20 degrees with flushing when the limb is lowered due to overcompensation)
Describe investigations of peripheral vascular disease
- Doppler ultrasound
- Ankle brachial index (systolic pressure of leg divided by systolic blood pressure of the arm - less than 0.41 is grounds for immediate surgical consultation)
- HbA1c, lipid screen, u&es, digital subtraction angiogram, cardio exam and lower limb exam
List signs on examination associated with limb ischaemia
- Paralysis
- Pallor
- Perrishingly cold
- Pain
- Pulseless
- Paraesthesia
Describe aetiology of limb ischaemia
Chronic
- Atherosclerosis (intermittent claudication)
Acute
- Embolus (eg. mural thrombus, AF, TB, IV drug users, malignant)
- Thrombotic (Vircows triad - ruptured plaque with clot on it)
- Aneurysm (eg. marfans)
- Iatrogenic (eg. air embolis)
Describe vircows triad
- Hypercoagulability (blood clotting due to liver failure, polycythaemoa vera)
- Stasis (long haul flights, recent surgery)
- Endothelial trauma (bruising, crush injury, plaque rupture)
Describe arterial ulcers
- Located distally, over bony prominences
- Severe pain, particularly at night
- Irregular edge, dry necrotic base, poor granulation tissue, round or punched out with sharp demarcation
- Trophic changes of chronic ischaemia associated with it
Describe venous ulcers
- Lower third of leg (gaiter area between malleolus and lower calf)
- Mild pain, relieved by elevation
- Shallow, irregular shape, granulating base, flat or steep elevation markings, fibrinous material at ulcer bed
List associated signs alongside venous ulcers
- Lipodermatofibrosis/ lipodermatosclerosis
- Pigmentation
- Oedema
- Atrophie blanche
- Telangiectasia
- Normal cap refill time
List associated signs alongside arterial ulcers
- Trophic changes of chronic ischaemia
- Pale
- Hair loss
- Atrophic skin
- Cool feet
- Absence of pulses
- Prolongued cap refill
- ABI less than 0.5
- Dependent rubor
Describe neurotrophic ulcers
- Under calluses or pressure points
- Punched out, deep sinus variable depth, seep sinus, may involve bone, tendon, fascia, joint capsule
- Neuropathy may be associated/ underlying osteomyelitis
List investigations for aortic stenosis
- Transthoracic echocardiogram (including Doppler - elevated aortic pressure gradient; measurement of valve area and left ventricular ejection function - diagnostic modality of choice)
- ECG (left ventricular hypertrophy and absent Q waves, atrioventricular block, hemiblock, or bundle branch block)
- Cardiac MRI
- Cardiac catheterisation
- ECG exercise stress testing
- Dobutamine stress echo
Define aortic sclerosis
Narrowing of the aorta which causes a murmur but has no functional impairment. Does not radiate to the carotids
Define mitral stenosis
A narrowing of the mitral valve orifice, usually caused by rheumatic valvulitis producing fusion of the valve commissures and thickening of the valve leaflets.
Describe aetiology of mitral stenosis
- Rheumatic fever
- congenital
- Mucopolysaccharidosis
- endocardial fibroelastosis
- Malignant carcinoid
- Prosthetic valve
List risk factors for mitral stenosis
- Streptococcal infection
- Female sex
- Ergot medications
- Serotogenic medications
- Amyloidosis
- Bronchial carcinoid syndrome
Describe epidemiology of mitral stenosis
- Mainly in developing countries as primarily caused by rheumatic fever
- Highest prevelence in Oceania, South Asia and sub-Saharan Africa
- Rheumatic heart disease more common in females
- No longer a notifiable disease in US
List symptoms of mitral stenosis
- Start at diameter below 2cm
- Pulmonary hypertension causes dyspnoea, haemoptysis chronic bronchitis-like picture
- Pressure on local structures by enlarged left atrium causes haemoptysis, dysphagia and bronchial obstruction
- Paroxysmal nocturnal dyspnoea
- Fatigue, palpatations, chest pain, emboli
List signs of mitral stenosis
- Malar flush due to decreased cardiac output
- Weak pulse
- AF
- Tapping, non-displaced apex beat
- Loud S1, then opening snap with mid diastolic rumble. Closer to S2/ longer rumble = worse disease. Louder on laying on side and expiration (pre-systolic accentuation)
- Graham steel murmur may be heard (pulmonary hypertension, high pitched decreascendo diastolic murmur on left sternal border)
List investigations for mitral stenosis
- ECG (AF, left atrial enlargement, right ventricular hypertrophy, bifid p waves ‘p-mitrale’/ no p waves)
- CXR (double right heart border indicating enarged left atrium, prominent pulmonary artery, kerley B lines, mitral valve calcification)
- Trans-thoracic echocardiography (hockey stick shaped mitral deformity - diagnostic. Stenosis significant if valve orifice <1cm2/m2 body surface area)
- Trans-oesophageal echocardiography (possible left atrial thrombus)
- Cardiac catheterisation (high left atrial pressure, low left ventricular pressure and low CO, Indicated if signs of other valve disease, pulmonary hypertension/ calcified mitral valve, angina)
- Dynamic exercise testing (pressures increase with exercise)
Describe diagnosis of ventricular septal defect
- Chest radiograph
- ECG
- Echo
- Coronary angiogram
- Swan ganz pulmonary artery catheter
Describe treatment of ventricular septal defect
- Analgesia
- Urgent transfer
- Intra-aortic balloon pump
- Ionotrophic support
Describe signs of ventricular septal defect
- Pan systolic murmur left sternal edge with heaves and thrills
- Raised JVP
- Cardiac failure
Compare pericardial effusion with cardiac tamponade
- Both involve fluid in the pericardial space
- Cardiac tamponade is a pericardial effusion which raises intrapericardial pressure, reducing ventricular filling and dropping cardiac output. Can lead to cardiac arrest
- For both treat the cause, urgent fluid drainage and send for analysis
Describe management of stable and unstable angina
- Stop smoking, increase exercise, stop alcohol, weight loss, diet modifications
- Aspirin 75mg if not contraindicated
- Statin
- GTN spray/sublingual (SE headache)
- ACEi
- B blocker
- CABG or angioplasty if necessary
Compare aetiology of STEMI and NSTEMI
- NSTEMI subendocardial ischaemia
- STEMI transmural ischaemia
Define aortic dissection
- Intimal layer of wall of the aorta separating resulting in a blood filled lumen
- Type A ascending aorta
- Type B descending aorta
List signs and symptoms of aortic dissection
- Acute onset, severe, tearing chest pain radiating from the back. Intense from the onset.
- Hypertension, dyspnoea
- Asymmetric upper and lower extremity blood pressure and pulses (absent pulse in one arm)
- New onset of aortic regurg
- Paraplegia, paraesthesia
- Limb pain, abdo pain
- Left sided decreased breath sounds/dullness
List risk factors for aortic dissection
- Hypertension
- Atherosclerotic aneurysmal disease
- Marfan syndrome
- Ehlers-Danlos syndrome
- Bicuspid aortic valve
- Annulo-aortic ectasia
- Coarctation
- Smoking
- Family history of aortic aneurysm or dissection
- Older age
- Giant cell arteritis
- Overlap connective-tissue disorders
- Vasculitis (takayasus/giant cell)
- Surgical/catheter manipulation
- Cocaine/amfetamine use
- Heavy lifting
- Infection (syphollis)
- Pregnancy
Describe epidemiology of aortic dissection
- 0.5-2.95 cases per 100000 annually
- US 0.2-0.8 per 100000 cases annually, 2000 new cases each year
- Highest rate in italy, 4.04 per 100000 per year
- Men predominantly affected, especially over 50 years
Describe aetiology of aortic dissection
- Intimal tear extending into the media of the aortic wall
- Cystic medial degeneration predisposes to intimal disruption and is characterised by elastin, collagen and smooth muscle breakdown in the lamina media
- Inherited conditions (eg. marfans and ehlers danlos)
- Aterosclerosis
List types of aortic dissection
- Type A ascending aorta (always needs surgery)
- Type B descending aorta
Describe diagnosis of aortic dissection
- ECG (look for MI)
- CXR showing widened mediastinum, possible pericardial effusion
- Cardiac enzymes usually negative
- BP in both arms, then transthoracic/oesophageal ultrasound
- CT angiography (include abdo and pelvis to see extent - shows intimal flap) GOLD STANDARD
- MRI
- Renal function tests (elevated creatinine and urea in reduced renal perfusion)
- LFTs (asparate transaminase and alanine transaminase raised in reduced hepatic perfusion)
- Lactate
- FBC
- Group and save (prepare for surgery)
Describe ECG changes in hypokalaemia
- U wave, elongated PR interval, t wave flattening and inversion and ST depression caused by hypokalaemia.
- Untreated hypokalaemia causes toursades de points, a form of ventricular tachycardia
Define aortic regurgitation
- The diastolic leakage of blood from the aorta into the left ventricle.
- It occurs due to inadequate coaptation of valve leaflets resulting from either intrinsic valve disease or dilation of the aortic root.
Describe epidemiology of aortic regurgitation
- Not as common as aortic stenosis and mitral regurgitation
- 13% prevalence in men and 8.5% in women trace or mild.
- Prevalence increases with age
Describe aetiology of aortic regurgitation
- Developing countries rheumatic heart disease is the most common cause
Acute:
- Infective endocarditis
- Ascending aortic dissection
- Chest trauma
Chronic
- Congenital
- Connective tissue disorders (eg. marfans, Ehlers Danlos)
- Rheumatic fever
- Takayasu arteritis
- Rheumatoid arteritis
- SLE
- Appetitie suppressents
- Arthritides
- Hypertension
List risks for aortic regurgitation
- Bicuspid aortic valve
- Rheumatic fever
- Endocarditis
- Marfan’s syndrome and related connective tissue disease
- Aortitis
- Systemic hypertension
- Older age
List symptoms of aortic regurg
- Exertional dyspnoea
- Orthopnoea
- Paroxysmal nocturnal dyspnoea
- Palpitations, angina, syncope
List signs of aortic regurg
- Collapsing (water hammer) pulse
- Wide pulse pressure
- Displaced, hyperdynamic apex beat
- High pitched early diastolic murmur louder on expiration when sitting up in tricuspid region
- Corrigons sign (caorid pulsation)
- De mussets sign (head nodding with each heartbeat)
- Quinckes signs (carotid pulsations in nail bed)
- Duroziezs sign (in the groin a finger compressing the femoral artery gives a diastolic murmur)
- Traubes sign (pistol shot sound over femoral arteries)
- Austin flint murmur (severe AR)
Describe investigations for aortic regurg
- ECG showing left ventricular hypertrophy
- CXR showing cardiomegaly, dilated ascending aorta, pulmonary oedema
- Echo is diagnostic
- Cardiac catheterisation to assess severity of the lesion, anatomy of the aortic root, left ventricular function, coronary artery disease and other valve disease
Define mitral regurgitation
Backflow through the mitral valve during systole
Describe aetiology/risks of mitral regurg
- Functional (LV dilation)
- Annular calcification (elderly)
- Rheumatic fever
- Infective endocarditis
- Mitral valve prolapse
- Ruptured chordae tendinae
- Papillary muscle dysfunction/rupture post MI
- Connective tissue disorders (eg. Ehlers Danlos and Marfans)
- Cardiomyopathy
- Congenital
- Anorectic/dopaminergic drugs
List symptoms of mitral regurg
- Dyspnoea
- Fatigue
- Palpitations
- Symptoms of causitive factor
List investigations for mitral regurg
- ECG showing AF, echo
- P-mitrale pn ECG if sinus rhythm
- LVH
- CXR (large LA and LV, mitral valve calcification, pulmonary oedema)
Define tricupsid regurgitation
Backflow of blood through the tricuspid valve in systole
Describe epidemiology of tricuspid regurg
- COmmon incidental finding on imaging
- 50-60% mild asymptomatic adults
- 15% moderate
- In developed countries most commonly ischaemic or degenerative mitral regurg.
- Developing rheumatic fever
Describe aetiology/risks of tricuspid regurg
- Functional eg. RV dilation eg. due to hypertension induced by LV falure or PE
- Rheumatic fever
- Infective endocarditis
- Cardinoid syndrome
- Congenital (ASD, AV canal, ebstein)
- Drugs (ergot)
- RA, marfans, tricuspid valve prolapse
List symptoms of tricuspid regurg
- Fatigue
- Hepatic pain on exertion due to congestion
- Ascites
- Oedema
- Symptoms of causative condition
List signs of tricspid regurg
- Giant v wave and prominent y descent on JVP
- RV heave
- Pansystolic murmur heard best at lower left sternal border, on inspiration
- Pulsatile hepatomegaly
- Jaundice
- Ascites
Describe investigations for tricuspid regurg
- Echocardiogram (assess left and right heart ejection fraction)
- ECG (atrial flutter/fib)
- LFT
- Serum urea and creatinine
- FBC
- CXR (cardiomegaly, pleural or pericardial effusion)
Compare osler nodes and janeway lesions
- Osler nodes are caused by immune complex deposition. Painful in the fingers and toes
- Janeway lesions are non-tender palmar or plantar nodules due to emboli
List risk factors for atrial fibrillation
- Age over 70
- Thyrotoxicosis
- Rheumatic heart disease
- Alcoholism
- Left ventricular dysfunction
Also: IHD, post op, hypokalaemia, pneumonia, caffine
Define ventricular fibrillation
An arrythmia causing the ventricles to quiver and cause uncoordinated muscle contraction
Describe aetiology/risks for ventricular fibrillation
- MI
- Increased catecholamines
- Electrolyte imbalances (torsades de pointes)
- Hypoxia
- Acid-base disturbance
- Hyper/hypothermia
- Congenital conditions (QT syndrome, Brugada)
List signs and symptoms of ventricular fibrillation
- Chest pain
- Dizzy
- SOB
- Unconscious