Cardiomyopathy Flashcards
Dilated cardiomyopathy overview
Ventricular function is impaired, can be primary or as a result of any pathological insult to the myocardium except ischemia and valvular causes.
Can be in all or one chambers and thrombosis is common
Causes of dilated cardiomyopathy
Genetics eg SCN5A gene, muscular dystrophy
Inflammatory, infection, autoimmune, postpartum, tropical disease, haemochromatosis, sarcoid
Toxig eg drugs, exogenous chemicals, endocrinology
Injury, cell loss, scar replacement
Symptoms of dilated cardiomyopathy
Progressive, slow onset, dysphasia (can’t speak), fatigue, orthopnoea, PND, ankle swelling, weight gain of fluid overload, cough
Possible PMH for dilated cardiomyopathy
Systemic illness, travel, HT, vascular disease, thyroid, neuromuscular disease
Examination findings for dilated cardiomyopathy
Poor superficial perfusion, thready pulse, irregular if in AF, SOB at rest, narrow pulse pressure, elevated JVP, TR waves if tricuspid valve is incompetent due to expansion, displaced apex, gallop rhythm (S3 and S4), MR murmur, pulmonary oedema, pleural effusion, ankle oedema, sacral oesdema, acites, hepatomegaly
Investigations dilated cardiomyopathy
Repeated ECG noting Left Bundle Branch Block
CXR for PO, pleural effusion, cardiac shadow
N termial pro brain natriuretic peptide (screen before doing an echo)
Basic bloods FBC, U&E
Echo
cMRI
Coronary angiogram
Maybe biopsy
Treatment for dilated cardiomyopathy
Correct anaemia Remove exacerbating drugs eg NSAIDs Correct endocrine disturbance Reduce fluid and salt intake Manage weight to identify fluid overload HF nurse referral ACEI, ATII blockers, diuretics Beta blockers Spironolactone Anticoagulants if thrombus SCD risk and maybe pacemaker Transplant
Prognosis for dilated cardiomyopathy
Poor
Worst with HIV
Best is peripartum
Restrictive and infiltrative cardiomyopathy
Less common, again describes the physiology of filling and myocyte relaxation capacity, the systolic function may or not be impaired
About 50% are related to specific clinical disorders, the rest remain unknown
The pathology surrounds 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.
causes of infilrative myopaythy
Amyloid, Sarcoid
causes of non infiltrative myopathy
Familial, forms of HCM, Scleroderma, diabetic, pseudoxanthoma elasticum
causes of storage cardiomyopathy
Endomyocardial; Fibrosis, carcinoid, radiation, drug effects
basic investigations for restrictive (less compliant) and infiltrative cardiomyopathy
Repeated ECG noting LBBB if present and other conduction defects
CXR
N terminal pro Brain Natriuetic Peptide (indicates stretch)
Basic bloods FBC, U+E, be on the look out for sarcoid and haemachromatosis
Auto antibodies for sclerotic CT diseases
Amyloid needs non cardiac biopsy to help establish the diagnosis
Fabry; low plasma alpha galactosidase A activity
Echo
CMRI, probably best imaging modality
Biopsy more helpful but still has high false negative rate
specific measures for restrictive and infiltrative cardiomyopathy
More specific measures
Limited diuretic use as low filling pressures will cause problems
Beta blockers limited ACEI use
Anticoagulants as required
SCD risk assessment with ICD or CRT-D/P implant
Cardiac transplant
If iron overload, specific forms of amyloid or Fabrys then specific treatments are available
Endomyocardial fibrosis has little specific treatment
hypertrophic cardiomyopathy
Again impaired relaxation is a common feature and systolic function is usually adequate albeit with some functional abnormality
Myocyte hypertrophy and disarray
Can be generalised or segmental wall thickness >14mm or >12mm in primary relative
Can be apical, septal or generalised
Impaired relaxation so behaves in a restrictive manner
If septal hypertrophy this can with mitral valve defect lead to LVOT obstruction
Coronary arteries also affected with small vessel narrowing and consequent ischaemia and fibrosis, arrhythmias are common
symptoms of hypertrophic cardiomyopathy
Asymptomatic for many, fatigue, dyspnoea, anginal like chest pain, exertional pre syncope, syncope related to arrhythmias or LVOT obstruction
Breathless, palpitations, syncope, exertional symptoms, SCD
examination findings in hypertrophic cardiomyopathy
Can be none !
Notched pulse pattern
Irreg pulse if in AF or ectopy
Double impulse over apex, thrills and murmurs, often dynamic, LVOT murmur will increase with valsalve and decrease with squatting (aortic murmur due to hypertrophy of left ventricle makes it obstricted)
JVP can be raised in very restrictive filling
assessment for hypertrophic cardiomyopathy
ECG, often abnormal but a few are normal where phenotype is poorly expressed in genotype +ve individuals
Echo
CMRI
Risk stratification for SCD, may need ICD
Holters repeatedly, ETT, FH ?
general measures for hypertrophic cardiomyopathy
Avoid heavy exercise
Avoid dehydration
Explore FH and first degree relatives, ECGs and echoes may be required
Consider genetic testing
Regular FU to re appraise the risks and progress
specific measures for hypertrophic cardiomyopathy
Drugs to try and enhance relaxation, variable results but often if symptomatic, beta blockers, verapamil(CCB), disopyrimide(SCB antiarrhythmia)
If in AF anticoagulate
Obstructive form; surgical or alcohol septal ablation
ICD if required based on risk stratification
myocarditis
Acute or chronic inflammation of the myocardium
Can be in association with pericarditis
Can impair myocardial function, conduction and generate arrhythmia
Long list of possible causes………
However often the cause is not found despite investigations
Can eventually take on the dilated cardiomyopathy appearance
Prevalence 8-10 pre 100000
Most common is viral
pathology of myocarditis
Infiltration of inflammatory cells into the myocardial layers, reduced function and heart failure, heart block as conduction system is involved and arrhythmias
symptoms of myocarditis
Heart failure with fatigue, SOB, CP in only 26%
Shorter course of a few weeks
May not have fever
Signs of HF
assessment for myocarditis
ECG usually abnormal Biomarkers often elevated but not falling in a pattern consistent with MI Echo, can get RWMA (regional wall motion abnormalities) CMRI can see oedema in certain images Low threshold for biopsy Viral DNA PCR Auto antibodies Step antibodies Lyme B burgdorferi HIV
