Flashcards in Myocardial disease Deck (27):
What is myocarditis?
Inflammation of the mycardium
What is the most common cause of myocarditis in the UK
Viral infection, particularly Coxsackie virus infection
What are the other causes of myocarditis?
Some drugs- penicillin, sulfonamides, methyldopa, spironolactone
What are the symptoms and signs of myocarditis?
What investigations are done to confirm myocarditis? What may they show?
CXR: may show cardiac enlargement
ECG: shows non-specific T wave and ST changes
Diagnosis is supported by demonstrration of an increase in serum viral tires and inflammation on cardiac biopsy
In absence of MI, positive troponin confirms diagnopsis
How is myocarditis managed?
Treatment of heart failure and any underlying cause
Prognosis is good
What are cardiomyopathies
Cardiomyopathies are a group of disease of the myocardium that affect the mechanical or electrical function of the heart
What cardiomyopathies affect the mechanical function of the heart?
Hypertrophic, dilated and restrictive cardiomyopathy
What is the characteristic feature of hypertrophic cardiomyopathy?
Marked ventricular hypertrophy in the absence of abnormal loading conditions such as hypertension and valvular disease
The hypertrophic non-compliant ventricles impair diastolic filling so that stroke volume is reduced
Describe the epidemiology/prevalance of HCM
Autosomal dominant inheritance
50% of cases are sporadic
70% of cases have mutations in genes encoding beta-myosin, alpha-tropomyosin and troponin T
MOST COMMON CAUSE OF SUDDEN CARDIAC DEATH IN YOUNG PEOPLE
What are the clinical features of HCM?
May be symptom free and detected through family screening
Symptoms include breathlessness, angina or syncope
What are the complications of HCM?
Artial and ventricular arrhythmias
What clinical features may be seen O/E in HCM
Jerky carotid pulse because of rapid ejection and sudden obstruction to ventricular outflow during systole
An ejection systolic murmur occurs because of left ventricular outflow obstruction
What investigations are done for HCM. What do they show?
ECG: abnormal. Pattern of left ventricular hypertrophy with no discernable cause is diagnostic
Echo/MRI: Ventricular hypertrophy
How is HCM managed?
1. Amioderone reduces risk of arrhythmias and sudden death
2. Individuals at highest risk are fitted with an implantable cardiac defibrillator
3. Chest pain and dyspnoea are treated with beta-blockers and verapamil
What is dilated cardiomyopathy (DCM)
LV is dilated and contracts poorly
How is DCM inherited in its familial form?
What other conditions are associated with DCM?
Peri- or post-partum
How do patients with DCM present?
Shortness of breath is usually the first complaint
More rarely, patients present with embolism from mural thrombus or arrhythmia
Subsequently there is progressive heart failure with the symptoms and signs of biventricular failure
What is seen on an echo of a patient with DCM?
Globally dilated, hypokinetic heart and low ejection fraction
How is DCM treated?
Heart failure and arrhythmias are treated in the normal way
Cardiac resynchronization therapu and implantable cardiac defibrillators are used in patients with NYHA III/IV grading
Severe cardiomyopathy is treated with cardiac transplantation
What are considered poor prognostic factors for HCM?
Syncope at presentation
Family history of HCM/sudden death
What is primary restrictive cardiomyopathy?
The ridgid myocardium restrictis diastolic and ventricular filling and the clinical features resemble those of constrictive pericarditis
What is the most common cause of restrictive cardiomyopathy in the UK? What else might cause restrictive cardiomyopathy?
How is restrictive cardiomyopathy diagnosted?
Cardiac catheterization which shows characteristic pressure changes
What is the treatment and prognosis of restrictive cardiomyopathy?
No specific treatment- treat the cause
Prognosis is poor