Myocardial disease

Question 1

What is myocarditis?

Answer 1

Inflammation of the mycardium

Question 2

What is the most common cause of myocarditis in the UK

Answer 2

Viral infection, particularly Coxsackie virus infection

Question 3

What are the other causes of myocarditis?

Answer 3

Diptheria
Rheumatic fever
Radiation injury
Some drugs- penicillin, sulfonamides, methyldopa, spironolactone

Question 4

What are the symptoms and signs of myocarditis?

Answer 4

Fatigue
Dyspnoea
Chest pain
Fever
Palpitations
Tachycardia
S4 gallop

Question 5

What investigations are done to confirm myocarditis? What may they show?

Answer 5

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

Question 6

How is myocarditis managed?

Answer 6

Bed rest
Treatment of heart failure and any underlying cause
Prognosis is good

Question 7

What are cardiomyopathies

Answer 7

Cardiomyopathies are a group of disease of the myocardium that affect the mechanical or electrical function of the heart

Question 8

What cardiomyopathies affect the mechanical function of the heart?

Answer 8

Hypertrophic, dilated and restrictive cardiomyopathy

Question 9

What is the characteristic feature of hypertrophic cardiomyopathy?

Answer 9

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

Question 10

Describe the epidemiology/prevalance of HCM

Answer 10

Prevalance=0.2%

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

Question 11

What are the clinical features of HCM?

Answer 11

May be symptom free and detected through family screening

Symptoms include breathlessness, angina or syncope

Question 12

What are the complications of HCM?

Answer 12

Sudden death
Artial and ventricular arrhythmias
Thromboembolism
IE
Heart failure

Question 13

What clinical features may be seen O/E in HCM

Answer 13

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

Question 14

What investigations are done for HCM. What do they show?

Answer 14

ECG: abnormal. Pattern of left ventricular hypertrophy with no discernable cause is diagnostic

Echo/MRI: Ventricular hypertrophy

Question 15

How is HCM managed?

Answer 15

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

Question 16

What is dilated cardiomyopathy (DCM)

Answer 16

LV is dilated and contracts poorly

Question 17

How is DCM inherited in its familial form?

Answer 17

autosomal dominant

Question 18

What other conditions are associated with DCM?

Answer 18

Alcohol
High BP
Haemochromatosis
Viral infection
Autoimmune
Peri- or post-partum
Hyperthyroidism

Question 19

How do patients with DCM present?

Answer 19

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

Question 20

What is seen on an echo of a patient with DCM?

Answer 20

Globally dilated, hypokinetic heart and low ejection fraction

Question 21

How is DCM treated?

Answer 21

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

Question 22

What are considered poor prognostic factors for HCM?

Answer 22

Age <14
Syncope at presentation
Family history of HCM/sudden death

Question 23

What is primary restrictive cardiomyopathy?

Answer 23

The ridgid myocardium restrictis diastolic and ventricular filling and the clinical features resemble those of constrictive pericarditis

Question 24

What is the most common cause of restrictive cardiomyopathy in the UK? What else might cause restrictive cardiomyopathy?

Answer 24

Amyloidosis

Haemochromatosis
Sarcoidosis

Question 25

How is restrictive cardiomyopathy diagnosted?

Answer 25

Cardiac catheterization which shows characteristic pressure changes

Question 26

What is the treatment and prognosis of restrictive cardiomyopathy?

Answer 26

No specific treatment- treat the cause

Prognosis is poor

Question 27

What is cardiac myxoma?

Answer 27

Rare, benign cardiac tumour. May mimic infective endocarditis (fever, weight loss, clubbing, raised ESR) or mitral stenosis (keft atrial obstruction, systemic emboli, AF)