Myocardial and Endocardial diseases Flashcards
What is hypertrophic cardiomyopathy?
Defined as the occurrence of inappropriate (abnormally distributed) ventricular hypertrophy. The chief feature is massive LV hypertrophy, usually most marked in the interventricular septum close to the aortic outflow tract. It is the most common cause of sudden cardiac death.
What is thought to be the cause of hypertrophic cardiomyopathy?
Genetic - familial autosomal dominant, due to mutations in the genes encoding sarcomeric proteins
What are symptoms of hypertrophic cardiomyopathy?
Asymptomatic
If symptomatic:
- Chest pain
- Dyspnoea
- Syncope/pre-syncope on exertion
- Palpitations
- Sudden death
What are signs of hypertrophic cardiomyopathy?
- Double apical pulsation
- Jerky carotid pulsation
- Systolic thrill at LLSE
- A-wave in JVP
- ESM at LLSE, does not radiate to carotids
- Pansystolic murmur over mitral valve, radiating to axilla
- 4th heart sound
Why do you get double/triple apical pulsation in hypertrophic cardiomyopathy?
A combination of a stiff, thickened myocardium +/- LV outflow tract obstruction leads to higher left ventricular and left atrial end diastolic pressures. A forceful atrial contraction can be felt (one ripple), a sensation of outward systolic thrust with rapid ejection early in systole is then palpated (second ripple), then a sustained late slow ejection of blood from the ventricle can be sensed (third ripple).
What causes a jerky carotid pulse in hypertrophic cardiomyopathy?
Pulsus bisiferans - there is a sharp rapid upstroke of the carotid pulse in systole, owing to a hyperdynamic contraction due to hypertrophy, followed by rapid decline due to left ventricular outflow obstruction. The Venturi effect may also draw the anterior mitral valve leaflet towards the interventricular septum, exacerbating the outflow tract obstruction and producing a more significant ‘notch’. The second pulse peak is thought to be related to the reflected wave
What causes the ejection systolic murmur at the LLSE heard in hypertrophic cardiomyopathy?
Left ventricular outflow tract obstruction - The obstruction and murmur is significantly contributed to by systolic anterior motion of the anterior leaflet of the mitral valve. That is, in systole the anterior leaflet of mitral valve is dragged into the left ventricular outflow tract towards the septum, causing the obstruction of flow out of the left ventricle and turbulent flow.
What manoeuvre’s can increae outflow tract murmurs?
- Valsalva manoeuvre
- Standing
What manoeuvres can decrease outflow tract murmurs?
- Squatting
- Hand gripping exercises
Why might you get murmur of mitral regurgitation in hypertrophic cardiomyopathy?
Due to a combination of systolic anterior motion (SAM) of the anterior leaflet of the mitral valve and increased back pressure from the left ventricle
https://www.youtube.com/watch?v=Kplt9wqS5b0
Why might you get a 4th heart sound in hypertrophic cardiomyopathy?
Forceful contraction of the atrium pushes blood into a non-compliant left ventricle. The sudden deceleration of blood against the stiff ventricular wall produces a low-frequency vibration, recognised as the fourth heart sound.
Why might you get a prominent a-wave on examination of JVP in hypertrophic cardiomyopathy?
Reduced RV compliance due to left heart disease
Why does reduced compliance of the ventricular wall occur in hypertrophic cardiomyopathy?
Caused by the hypertrophic wall, which causes LV diastolic pressure to increase. This leads to back pressure into the LA, and subsequently into the pulmonary veins and arteries. This causes an imbalance between hydrostatic and oncotic pressure, leading to pulmonary oedema.
What is the mode of inheritence of HOCM?
Autosomal dominant
How would you investigate someone with suspected HOCM?
- ECG
- ECHO
- Family screening/genetics
What might you see on an ECG in someone with HOCM?
- LVH
- Progressive T-wave inversion
- Deep Q waves
- AF
- WPW syndrome
- Ventricular ectopics
- VT
What might you see on ECHO in hypertrophic cardiomyopathy?
- Asymmetrical septal hypertrophy
- Small LV cavity
- Hypercontractile posterior wall
- Midsystolic closure of aortic valve
- SAM of anterior mitral leaflet
How would you manage someone with HOCM?
- Treat symptoms - B-blockers or verapamil
- Manage arrhythmias - Amiodarone, Anticoagulate (AF)
- Implantable defibrillator
-
Procedures
- Septal Ablation
- Surgical resection
What arrhythmias can occur in HOCM?
- AF
- VT
What are risk factors for sudden cardiac death in HOCM?
- Massive LVH - >30 mm
- FH of sudden cardiac death - <50 years old
- Non-sustained VT on 24-hour Holter monitoring
- Prior unexplained syncope
- Abnormal blood pressure response on exercise
What is dilated cardiomyopathy?
https://www.youtube.com/watch?v=Aao_4IfWOuI
Dilatation of the ventricular chambers and loss of systolic function/contraction (in one of both ventricles), with preserved wall thickness.
What are some of the causes of dilated cardiomyopathy?
- Idiopathic
- Myocarditis
- Toxins
- Autoimmunity
- Thyrotoxicosis
What toxins can cause dilated cardiomyopathy?
- Alcohol
- Chemotherapy
- Lead
- Cobalt
- Mercury
- Arsenic
How might someone with dilated cardiomyopathy present symptomatically?
- Dyspnoea
- Fatigue
- Palpitations
- Sudden death
What signs might you see in someone with dilated cardiomyopathy?
- Signs of HF - increased JVP, pleural effusion, oedema, hepatomegaly, ascites
- Tachycardia
- Hypotension
- Displaced, diffuse apex
- S3 heart sound
- Mitral/tricupsid regurgitation
Why might you get mitral/tricuspid regurgitation in dilated cardiomyopathy?
Dilated cardiomyopathy causes dilation of the annulus of each valve, resulting in valvular regurgitation
What investigations would you do if you suspected dilated cardiomyopathy?
- Bloods - BNP, U+Es
- CXR
- ECG
- ECHO
What might you find on investigating bloods in dilated cardiomyopathy?
Raised BNP due to heart failure
What might you see on CXR in someone with dilated cardiomyopathy?
- Cardiomegaly
- Pulmonary oedema
What might you see on ECG in someone with dilated cardiomyopathy?
No specific ECG features, however the ECG is usually NOT normal.
The most common ECG abnormalities are those associated with atrial and ventricular hypertrophy, interventricular conduction delays (due to dilatation)
What might you see on ECHO in someone with dilated cardiomyopathy?
- Globally dilated hypokinetic heart
- Low ejection fraction
- Mural thrombus
- Valve regurgitation
How would you manage someone with dilated cardiomyopathy?
- Bed rest
- Heart failure management - Digoxin, Diuretics, ACE-i
- Anticoagulation
- Implantable cardioverter defibrillator
- Cardiac Resynchronisation Therapy
- Cardiac transplantation
What is a cardiac (atrial) myxoma?
Most common primary cardiac tumour. The majority of myxomas are solitary, usually develop in the left atrium and are polypoid, gelatinous structures attached by a pedicle to the atrial septum
What symptoms may be seen in atrial myxoma?
- Dyspnoea
- Syncope
- Mild fever
- Weight loss
What signs might you find in atrial myxoma?
- Loud first heart sound
- Tumour ‘plop’ - loud 3rd heart sound produced as the pedunculated tumour comes to an abrupt halt
- Mid-diastolic murmur
- Signs of embolization.
How would you treat an atrial myxoma?
Surgical excision
What is myocarditis?
Acute inflammation of the myocardium
What are causes of myocarditis?
- Idiopathic
- Infection - viral, bacterial, spirochaetes, protozoa
- Drugs
- Toxins
- Vasculitis/Autoimmune
What are viral causes of myocarditis?
- Flu
- Hepatitis
- Mumps
- Coxsackie
- Polio
- HIV
What are the bacterial causes of myocarditis?
- Streptococcus
- Clostridia
- Diptheria
- TB
- Meningococcus
- Mycoplasma
- Brucellosis
- Psittacosis
What spirochaete infection can cause myocarditis?
- Leptospirosis
- Syphilis
- Lyme disease
What drugs can cause myocarditis?
- Cyclophosphamide
- Herceptin
- Penicillin
- Chloramphenicol
- Methyldopa
- Spironolactone
- Phenytoin
- Carbemazepine
What toxins can cause myocarditis?
Alcohol
What are symptoms of myocarditis?
- Fatigue
- Dyspnoea
- Chest pain
- Fever
- Palpitations
- Orthopnoea - if heart failure
What signs might you get in someone with myocarditis?
- Soft S1
- S4 gallop
- Tachycardia
- Pericardial rub
- Signs of congestive HF - if severe
What autoimmune conditions can cause myocarditis?
- SLE
- Polymyositis
What can be cahracteristic of chest pain in myocarditis?
It can be positional
What investigations might you do if you suspected myocarditis?
- CXR
- ECG
- Bloods - troponin, CK
- ECHO
- Biopsy
What might an ECG show in someone with acute myocarditis?
- Sinus tachycardia
- ST elevation/depression
- T-wave inversion
- Atrial arrhythmias
- Transient AV block
What might you see on CXR in myocarditis?
Enlarged heart
How would you manage someone with acute myocarditis?
- Treat the cause
- Supportive treatment
- Avoid athletic activites for 6 months
- Treat heart faillure
What changes might you see in cardiac enzymes in someone with myocarditis?
Raised troponin and CK
What is the most common feature of myocarditis?
2-3 weeks of viral prodrome
What is the most common cause of myocarditis worldwide?
Chagas Disease
What is takotsubos cardiomyopathy?
Stress cardiomyopathy - The pathophysiology of the condition is uncertain but may be due to transient catecholamine excess, coronary vasospasm, abnormalities of the coronary microcirculation and hypertrophy of the basal septum. The syndrome is more common in middle-old aged women, and is also known as broken heart syndrome
