Question 66#

A patient with severe aortic stenosis is noted to have a fourth heart sound.

Which part of the ECG does this best correlate with?

A. U wave

Correct Answer C: The first heart sound (S1) is caused by closure of the mitral and tricuspid valves whilst the second heart sound (S2) is due to aortic and pulmonary valve closure.

Heart sounds:

S1:

• Closure of mitral and tricuspid valves
• Soft if long PR or mitral regurgitation
• Loud in mitral stenosis

S2:

• Closure of aortic and pulmonary valves
• Soft in aortic stenosis
• Splitting during inspiration is normal

S3:

• Caused by diastolic filling of the ventricle
• Considered normal if < 30 years old (may persist in women up to 50 years old)
• Heard in left ventricular failure (e.g. dilated cardiomyopathy), constrictive pericarditis (called a pericardial knock)

S4:

• May be heard in aortic stenosis, HOCM, hypertension
• Caused by atrial contraction against a stiff ventricle
• In HOCM a double apical impulse may be felt as a result of a palpable S4

Question 67#

Which of the following signs is not associated with the development of Eisenmenger's syndrome in a patient with a ventricular septal defect?

A. Worsening of systolic murmur

Correct Answer A: Eisenmenger's syndrome is characterized by the reversal of the left-right shunt due to pulmonary hypertension. The original murmur may disappear once Eisenmenger's syndrome develops.

Eisenmenger's syndrome:
Describes the reversal of a left to right shunt in a congenital heart defect due to pulmonary hypertension.

Associated with:

• VSD
• ASD
• PDA

Features:

• Original murmur may disappear
• Cyanosis
• Clubbing
• Right ventricular failure
• Haemoptysis, embolism

Management:

• Heart-lung transplantation is required

Question 68#

A 79-year-old woman is reviewed. She has taken bendroflumethiazide 2.5mg od for the past 10 years for hypertension. Her current blood pressure is 150/94 mmHg. Clinical examination is otherwise unremarkable. An echocardiogram from two months ago is reported as follows:

Ejection fraction 48%, moderate left ventricular hypertrophy. Minimal MR noted.

What is the most appropriate next step in management?

A. Increase bendroflumethiazide to 5mg od

Correct Answer C: The echocardiogram shows a degree of left ventricular impairment. It is important an ACE inhibitor is started in such patients. This will help to both control her blood pressure and also slow the deterioration in her cardiac function.

A beta-blocker should also be added in the near future given the left ventricular impairment.

Hypertension: diagnosis and management:
NICE published updated guidelines for the management of hypertension in 2011. Some of the key changes include:

• Classifying hypertension into stages
• Recommending the use of ambulatory blood pressure monitoring (ABPM) and home blood pressure monitoring (HBPM)
• Calcium channel blockers are now considered superior to thiazides
• Bendroflumethiazide is no longer the thiazide of choice

Blood pressure classification:
This becomes relevant later in some of the management decisions that NICE advocate.

Diagnosing hypertension If a BP reading is >= 140 / 90 mmHg patients should be offered ABPM to confirm the diagnosis. Patients with a BP reading of >= 180/110 mmHg should be considered for immediate treatment. Ambulatory blood pressure monitoring (ABPM)

• At least 2 measurements per hour during the person's usual waking hours (for example, between 08:00 and 22:00)
• Use the average value of at least 14 measurements If ABPM is not tolerated or declined HBPM should be offered. Home blood pressure monitoring (HBPM)
• For each BP recording, two consecutive measurements need to be taken, at least 1 minute apart and with the person seated
• BP should be recorded twice daily, ideally in the morning and evening
• BP should be recorded for at least 4 days, ideally for 7 days
• Discard the measurements taken on the first day and use the average value of all the remaining measurements

Managing hypertension:
 ABPM/HBPM >= 135/85 mmHg (i.e. stage 1 hypertension):

• Treat if < 80 years of age and any of the following apply; target organ damage, established cardiovascular disease, renal disease, diabetes or a 10-year cardiovascular risk equivalent to 20% or greater

ABPM/HBPM >= 150/95 mmHg (i.e. stage 2 hypertension):

• Offer drug treatment regardless of age

For patients < 40 years consider specialist referral to exclude secondary causes.

Step 1 treatment:

• Patients < 55-years-old: ACE inhibitor (A)
• Patients > 55-years-old or of Afro-Caribbean origin: calcium channel blocker 

Step 2 treatment:

• ACE inhibitor + calcium channel blocker (A + C) 

Step 3 treatment:

• Add a thiazide diuretic (D, i.e. A + C + D)
• NICE now advocate using either chlorthalidone (12.5-25.0 mg once daily) or indapamide (1.5 mg modified-release once daily or 2.5 mg once daily) in preference to a conventional thiazide diuretic such as bendroflumethiazide
• NICE define a clinic BP >= 140/90 mmHg after step 3 treatment with optimal or best tolerated doses as resistant hypertension. They suggest step 4 treatment or seeking expert advice

Step 4 treatment:

• Consider further diuretic treatment
• If potassium < 4.5 mmol/l add spironolactone 25mg od
• If potassium > 4.5 mmol/l add higher-dose thiazide-like diuretic treatment
• If further diuretic therapy is not tolerated, or is contraindicated or ineffective, consider an alpha- or betablocker

If BP still not controlled seek specialist advice. 

Blood pressure targets:

New drugs:
Direct renin inhibitors:

• e.g. Aliskiren (branded as Rasilez)
• By inhibiting renin blocks the conversion of angiotensinogen to angiotensin I
• No trials have looked at mortality data yet. Trials have only investigated fall in blood pressure. Initial trials suggest aliskiren reduces blood pressure to a similar extent as angiotensin converting enzyme (ACE) inhibitors or angiotensin-II receptor antagonists
• Adverse effects were uncommon in trials although diarrhoea was occasionally seen
• Only current role would seem to be in patients who are intolerant of more established antihypertensive drugs

Question 69#

Which one of the following would not be considered a normal variant on the ECG of an athletic 28- year-old man?

A. Wenckebach phenomenon

Correct Answer E: 

ECG: normal variants:
The following ECG changes are considered normal variants in an athlete:

• Sinus bradycardia
• Junctional rhythm
• First degree heart block
• Wenckebach phenomenon

Question 70#

Which one of the following statements regarding B-type natriuretic peptide is incorrect?

A. Effective treatment for heart failure lowers a patients BNP level

Correct Answer E: BNP has a good negative predictive value rather than positive predictive value.

B-type natriuretic peptide:

B-type natriuretic peptide (BNP) is a hormone produced mainly by the left ventricular myocardium in response to strain.

Whilst heart failure is the most obvious cause of raised BNP levels any cause of left ventricular dysfunction such as myocardial ischaemia or valvular disease may raise levels. Raised levels may also be seen due to reduced excretion in patients with chronic kidney disease. Factors which reduce BNP levels include treatment with ACE inhibitors, angiotensin-2 receptor blockers and diuretics.

Effects of BNP:

• Vasodilator
• Diuretic and natriuretic
• Suppresses both sympathetic tone and the renin-angiotensin-aldosterone system

Clinical uses of BNP:
Diagnosing patients with acute dyspnoea:

• A low concentration of BNP(< 100pg/ml) makes a diagnosis of heart failure unlikely, but raised levels should prompt further investigation to confirm the diagnosis
• NICE currently recommends BNP as a helpful test to rule out a diagnosis of heart failure

Prognosis in patients with chronic heart failure:

• Initial evidence suggests BNP is an extremely useful marker of prognosis 

Guiding treatment in patients with chronic heart failure:

• Effective treatment lowers BNP levels

Screening for cardiac dysfunction:

• Not currently recommended for population screening