Question 201#

A 35-year-old man who is an intravenous drug user is admitted to hospital. He has had three previous admissions with infective endocarditis but presents on this occasion feeling generally unwell, complaining of upper abdominal discomfort and leg swelling. On examination he has an elevated jugular venous pressure, tender hepatomegaly and peripheral oedema. A diagnosis of tricuspid regurgitation is suspected.

Which one of the following additional features would be most supportive of this diagnosis?

A. Split first heart sound

Correct Answer C:

Tricuspid regurgitation:

Signs:

• Pan-systolic murmur
• Giant V waves in JVP
• Pulsatile hepatomegaly
• Left parasternal heave

Causes:

• Right ventricular dilation
• Pulmonary hypertension e.g. COPD
• Rheumatic heart disease
• Infective endocarditis (especially intravenous drug users)
• Ebstein's anomaly
• Carcinoid syndrome 

Question 202#

A 55-year old man with a history of ischaemic heart disease presents to the Emergency Department with palpitations for the past 10 days. Examination of his pulse reveals a rate of 130 bpm which is irregularly irregular. He has had one previous episode of atrial fibrillation 3 months ago which was terminated by elective cardioversion following warfarinization.

What term best describes his arrhythmia?

A. Paroxysmal atrial fibrillation

Correct Answer D:
Atrial fibrillation: classification:

An attempt was made in the joint American Heart Association (AHA), American College of Cardiology (ACC) and European Society of Cardiology (ESC) 2012 guidelines to simplify and clarify the classification of atrial fibrillation (AF).

It is recommended that AF be classified into 3 patterns:

• First detected episode (irrespective of whether it is symptomatic or self-terminating)
• Recurrent episodes, when a patient has 2 or more episodes of AF. If episodes of AF terminate spontaneously then the term paroxysmal AF is used. Such episodes last less than 7 days (typically < 24 hours). If the arrhythmia is not self-terminating then the term persistent AF is used. Such episodes usually last greater than 7 days
• In permanent AF there is continuous atrial fibrillation which cannot be cardioverted or if attempts to do so are deemed inappropriate. Treatment goals are therefore rate control and anticoagulation if appropriate 

Question 203#

Which of the following is least associated with a poor prognosis in hypertrophic cardiomyopathy?

A. Non-sustained ventricular tachycardia on 24 or 48-hour Holter monitoring

Correct Answer B:

There is no recognized prognostic association with left ventricular outflow gradient.

HOCM: prognostic factors:

Hypertrophic obstructive cardiomyopathy (HOCM) is an autosomal dominant disorder of muscle tissue caused by defects in the genes encoding contractile proteins. Mutations to various proteins including beta-myosin, alpha tropomyosin and troponin T have been identified. Septal hypertrophy causes left ventricular outflow obstruction. It is an important cause of sudden death in apparently healthy individuals. 

Poor prognostic factors:

• Syncope
• Family history of sudden death
• Young age at presentation
• Non-sustained ventricular tachycardia on 24 or 48-hour Holter monitoring
• Abnormal blood pressure changes on exercise
• An increased septal wall thickness is also associated with a poor prognosis

Question 204#

Which one of the following statements regarding arrhythmogenic right ventricular cardiomyopathy is correct?

A. Inherited in an autosomal recessive pattern

Correct Answer D:

Drug therapy is used in patients with well tolerated or non life-threatening ventricular arrhythmias. 

Arrhythmogenic right ventricular cardiomyopathy:

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a form of inherited cardiovascular disease which may present with syncope or sudden cardiac death. It is generally regarded as the second most common cause of sudden cardiac death in the young after hypertrophic cardiomyopathy.

Pathophysiology:

• Inherited in an autosomal dominant pattern with variable expression
• The right ventricular myocardium is replaced by fibrofatty tissue 

Presentation:

• Palpitations
• Syncope
• Sudden cardiac death

Investigation:

• ECG abnormalities in V1-3, typically T wave inversion. An epsilon wave is found in about 50% of those with ARV - this is best described as a terminal notch in the QRS complex
• Echo changes are often subtle in the early stages but may show an enlarged, hypokinetic right ventricle with a thin free wall
• Magnetic resonance imaging is useful to show fibrofatty tissue

Management:

• Drugs: sotalol is the most widely used antiarrhythmic
• Catheter ablation to prevent ventricular tachycardia
• Implantable cardioverter-defibrillator 

Naxos disease:

• An autosomal recessive variant of ARVC
• A triad of ARVC, palmoplantar keratosis, and wooly hair

Question 205#

A 62-year-old female with a known history of a sigmoid adenocarcinoma is admitted to hospital with shortness of breath and pyrexia. On examination a murmur is heard and an echo reveals a vegetation on the aortic valve.

Which one of the following organisms is most characteristically associated with causing infective endocarditis in patients with colorectal cancer?

A. Escherichia coli

Correct Answer E:

Streptococcus bovis endocarditis is associated with colorectal cancer.

Infective endocarditis:

The strongest risk factor for developing infective endocarditis is a previous episode of endocarditis.

The following types of patients are affected :

• Previously normal valves (50%, typically acute presentation)
• Rheumatic valve disease (30%)
• Prosthetic valves
• Congenital heart defects
• Intravenous drug users (IVDUs, e.g. Typically causing tricuspid lesion) 

Causes:

• Streptococcus viridans (most common cause - 40-50%)
• Staphylococcus epidermidis (especially prosthetic valves)
• Staphylococcus aureus (especially acute presentation, IVDUs)
• Streptococcus bovis is associated with colorectal cancer
• Non-infective: systemic lupus erythematosus (Libman-Sacks), malignancy: marantic endocarditis

Culture negative causes:

• Prior antibiotic therapy
• Coxiella burnetii
• Bartonella
• Brucella
• HACEK: Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella) 

Following prosthetic valve surgery Staphylococcus epidermidis is the most common organism in the first 2 months and is usually the result of perioperative contamination. After 2 months the spectrum of organisms which cause endocarditis return to normal, except with a slight increase in Staph. aureus infections.