Cardiomyopathy, Myocarditis and Pericarditis Flashcards
Define cardiomyopathy.
Generalised term for diseases of the heart muscle, where the heart chamber walls become thickened, stretched or stiff. This reduces the ability of the heart to pump blood about the body.
Define dilated cardiomyopathy.
IN DCM the left ventricle of the heart becomes dilated (stretched), as a result the heart muscle becomes weak and floppy and unable to pump blood around the body properly.
Can be one but more often all chambers dilated and functionally impaired.
What can cause DCM?
Ischaemia and valvular causes.
Genetic and familial DMC, inflammatory, infectious, autoimmune, postpartum, toxic (drugs, exogenous chemicals, endocrine), injury, cell loss, scar replacement.
Alcohol and tropical disease, haemoaochromatosis, sarcoid etc.
Variants of what gene can cause DCM?
SCN5A
What other systemic condition can cause DCM?
Muscular dystrophy.
What is common in DCM patients?
Thrombosis.
Why is important to find the cause of the DCM?
Some causes are specifically sought as they are reversible/partly reversible but most are progressive and irreversible.
What is the incidence of DCM?
5-8 per 100, 000 population/year.
What are the symptoms of DCM?
Progressive, slow onset, dyspnoea, fatigue, orthopnoea, PND, ankle swelling, weight gain of fluid overload, cough.
What may raise index of suspicion in the PMH?
Systemic illness, travel, hypertension, vascular disease, thyroid, neuromuscular disease.
What is important to find out in FH and SH?
Family history?? genetics
Alcohol? Job?
What must you look for in examination if you suspect DCM?
Poor superficial perfusion, thready pulse, irreg if in AF, SoB at rest, narrow pulse pressure, JVP elevated +/- TR waves, displaced apex, S3 and S4, MR murmur often, pulmonary oedema, pleural effusions, ankle oedema, sacral oedema, ascites, hepatomegaly.
What might be involved in basic evaluation of a DCM?
Repeated ECG noting LBBB if present, CXR, N terminal pro BNP, basic bloods - FBC, U+E, echo, CMRI, coronary angiogram, sometimes biopsy.
What is doing a biopsy dependent on?
Time course of cardiomyopathy.
What is probably the best imaging modality for diagnosing DCM?
CMRI.
What general measures are involved in treatment of DCM?
Correct anaemia, remove exacerbating drugs, correct any endocrine disturbance.
Advise on fluid and salt intake (reduce).
Advise on managing weight to identify fluid overload.
HF nurse referral.
What might be an exacerbating drug in DCM patients?
E.g. NSAIDs.
What are some more specific measures you should consider in treating DCM patients?
ACEi, ATII blockers, diuretics. Beta blockers Spirnolactone Anticoagulation if req. Sudden cardiac death risk assessment with implantable cardioverter-defibrillator or CRT-D/P (cardiac resynchronisation therapy device pacemaker) implant. Cardiac transplant.
What is the prognosis of DCM like?
Generally poor and often influenced by the causes where known.
What cause of DCM generally causes the most and least deaths?
Most - peripartum cardiomyopathy.
Least - Due to HIV infection.
Define restrictive cardiomyopathy.
Cardiomyopathy in which the walls of the heart are rigid and the heart is restricted from stretching and filling with blood properly.
Define infiltrative cardiomyopathy.
Cardiac disease characterised by the deposition of abnormal substances within the heart tissue that causes the ventricular walls to develop wither diastolic dysfunction (or if later presentation - systolic dysfunction).
What is needed for a good diagnosis of infiltrative cardiomyopathy?
A high degree of clinical suspicion. Confirmatory evidence obtained via endomyocardial biopsy, echocardiography and CMR (cardiac magnetic resonance).
What are the causes of restrictive and infiltrative cardiomyopathies?
About 50% related to specific clinical disorders, the rest remain unknown.
Non-infiltrative - familial, forms of HCM, scleroderma, diabetic, psuedoxanthoma elasticum.
Infiltrative - amyloid, sarcoid.
Storage diseases - haemachromatosis, Fabry disease.
Endomyocardial - fibrosis, carcinoid, radiation, drug effects.
What does the pathology of R/I CM surround?
The inability to fill well a ventricle whose wall has reduced compliance.
Relaxation of the ventricular wall is an active process that needs functioning intact myocytes, it is not passive.
What is involved in the basic evaluation of R/I CM?
Repeated ECG noting LBBB if present and other conduction defects. CXR, N terminal pro BNP, basic bloods - FBC, U+E, look for sarcoid and haemachromatosis.
Autoantibodies for sclerotic CT diseases, amyloid needs non-cardiac biopsy to determine diagnosis, Fabry - low plasma alpha galactosidase A activity, echo, CMRI,.
Biopsy more helpful but still has high false neg rate.
What measures can you take in the treatment of R/I CM?
Limited diuretic use as low filling pressures will cause problems, beta blockers limited ACEi use, anticoagulants as req.
SCD risk assessment with ICD or CRT-D/P implant.
Cardiac implant.
If iron overload, specific forms of amyloid or Fabrys then specific treatments available.
Endomyocardial fibrosis has little specific treatment.
