CardiologyChapter 1

A 75-year-old man with asthma attended the emergency department complaining of palpitations. They came on suddenly 2 hours ago. He had a past medical history including congestive cardiac failure. On examination, his pulse was 180 beats per minute, irregular and blood pressure was 120/75 mmHg. A 12-lead ECG showed him to be in atrial fibrillation.

What is the most appropriate initial treatment?

A 27-year-old man attended the emergency department in the middle of the night with a history of sudden onset central, crushing chest pain which radiated into his left arm. It occurred whilst he was dancing at a night club. ECG showed ST elevation in the inferior leads.

Which one of the following drugs should be avoided during the acute treatment of this patient?

A 73-year-old man attended his general practitioner complaining of increasingly frequent episodes of dizziness on standing. On examination, he was noted to have a slow rising pulse and a systolic murmur that radiated to the carotids.

What is the most likely underlying cause of this man's dizziness?

2A 59-year-old woman presented to the emergency department having collapsed whilst waiting at a bus stop. An ECG showed a prolonged QT interval.

Which one of the following is the most likely underlying cause for her ECG changes?

A 22-year-old man attended the emergency department with a history of central chest pain whilst playing football. Of note, his uncle had died suddenly on the football field aged 25.

What is the most likely underlying diagnosis?

A 52-year-old man, a taxi driver, attended the emergency department with a history of sudden onset central chest pain, and was found to have an anterior myocardial infarction (MI) on ECG. He underwent angioplasty with the insertion of a single stent. He was fit for discharge 48 hours later.

How long should this patient refrain from driving?

A 40-year-old man presented to the emergency department with a history of fevers and rigors for the preceding 2 weeks. On examination, he was pyrexial and tachycardic, and was noted to have splinter haemorrhages on his right middle and index fingers. A diagnosis of infective endocarditis was suspected and an echocardiogram requested.

Where on the echocardiogram are vegetations most likely to occur?

3A 68-year-old man presented to the emergency department with a history of fever and weight loss. He was admitted and underwent a full septic screen. He was diagnosed with infective endocarditis and 48 hours later his blood cultures grew Streptococcus bovis.

What is the most appropriate next investigation?

A 54-year-old woman presented to the emergency department 10 weeks after having a metallic mitral valve replacement. She was feeling lethargic. On examination, she had a pyrexia of 38.2°C, with a blood pressure of 112/75 mmHg and a pulse of 112 beats per minute. On auscultation, she had a metallic first heart sound, and a late diastolic murmur heard over the apex. As part of the investigations, blood cultures were taken from multiple veins.

What is the most likely growth that would be expected from the blood cultures?

A 24-year old woman presented to her general practitioner with a 3-week history of palpitations. Each episode was short lived and self terminated. Her ECG showed right bundle branch block and right axis deviation with a prolonged PR interval.

What is the most likely underlying diagnosis?

A 67-year-old man presented to the emergency department with central crushing chest pain.

Which one of the following ECG changes would not be an indication for thrombolysis?

4A 65-year-old man was known to be in atrial fibrillation. He did not want to be cardioverted. He had no other past medical history, and was a non-smoker.

What is the most appropriate anticoagulation therapy?

A 74-year-old man had been diagnosed with left ventricular failure. He got breathless when walking briskly uphill, but was able to conduct day-to-day activities free of symptoms.

What grade of heart failure does he have (according to the New York Heart Association classification of heart failure)?

A 38-year-old Afro-Caribbean woman was reviewed by her general practitioner regarding her recently diagnosed hypertension. Despite lifestyle modifications such as salt restriction, increased exercise and weight loss, her blood pressure remained elevated at 162/73 mmHg.

What is the most appropriate next step in management?

A 68-year-old man was admitted to the emergency department with a 1-hour history of central crushing chest pain.

Which cardiac enzyme is the first to rise in myocardial infarction?

A 23-year-old man attended his general practitioner complaining of palpitations. He first noticed the episodes 3 months ago and had had four further episodes. The general practitioner performed an ECG and informed the patient he would be referred to the cardiology clinic for consideration of radiofrequency ablation.

5What abnormality had been identified on the ECG?

A 68-year-old woman was admitted to the emergency department with a diagnosis of an inferior ST elevation myocardial infarction.

What ECG changes would be seen?

A 64-year-old man presented to the emergency department with a history of dyspnoea on climbing the stairs and increased frequency of angina over the past few months. On examination, he was found to have an elevated jugular venous pressure and a positive Kussmaul's sign. His chest was clear on auscultation, but heart sounds were difficult to hear. Chest X-ray showed some areas of calcification at the cardiac border.

What is the most likely underlying diagnosis?

A 73-year-old man presented to the emergency department 1 month after being discharged following percutaneous coronary intervention for an anterior myocardial infarction. He was currently complaining of fevers and central sharp chest pain that was worse on inspiration. Admission blood tests show an elevated erythrocyte sedimentation rate.

What is the most likely underlying diagnosis?

A 58-year-old man was known to have aortic stenosis. He was asymptomatic and was sent by his general practitioner for a routine echocardiogram. The results showed a pressure gradient across the aortic valve of 40 mmHg.

6What is the most appropriate treatment option?

A 68-year-old man admitted to the emergency department with central tearing chest pain, was found to have an aortic dissection involving the ascending aorta. He had a history of hypertension and chronic obstructive pulmonary disease (COPD), for which he used regular inhalers. His pulse was 135 beats per minute and blood pressure 155/84 mmHg.

What is the most appropriate next step in management?

A 56-year-old man, who was on the coronary care unit following percutaneous coronary intervention for an inferior myocardial infarction was noted to have a pulse of 46 beats per minute. His blood pressure was 127/52 mmHg and he was mobilising around his bed space with no problems. A 12-lead ECG revealed complete heart block.

What is the most appropriate initial management?

A 28-year-old woman was brought into the emergency department with a blood pressure 85/36 mmHg and pulse rate 35 beats per minute. Empty packets of her mother's bisoprolol tablets were found beside her by the ambulance crew.

What is the most appropriate next step in management?

A 54-year-old man was brought into the emergency department complaining of sudden onset dyspnoea, and was diagnosed as having an episode of pulmonary oedema. ECG and cardiac enzymes were normal.

7What is the most useful diagnostic investigation?

Which one of the following is a cause of right axis deviation on a 12-lead ECG?

A 28-year-old woman, who was 28 weeks pregnant, was found to have a blood pressure of 172/92 mmHg. Urinalysis: ++ protein.

What is the most appropriate treatment?

Which one of the following features is severe left ventricular failure most likely to be associated with?

A 26-year-old woman presented to the emergency department with severe diarrhoea and vomiting.

Investigations:

What ECG changes would be consistent with these results?

8A 29-year-old man presented to the emergency department with a history of palpitations. He took a salbutamol inhaler as required for asthma, and had no known allergies. His blood pressure was 128/62 mmHg. Electrocardiogram showed a regular narrow complex tachycardia with rate 128 beats per minute.

What is the most appropriate next step in management?

A 67-year-old man attended his general practitioner for a medication review. Twelve months ago, he underwent percutaneous coronary intervention for an ST elevation myocardial infarction. He had no other medical problems and no drug allergies.

What medication should be on his repeat prescription?

Flecainide is the drug most likely to restore sinus rhythm in atrial fibrillation (AF). However, the CAST trial suggests that it should be avoided in left ventricular failure and can be arrhythmogenic post-myocardial infarction. Amiodarone is an antiarrhythmic agent that spans all categories of the Vaughan Williams classification and can be used to terminate acute supraventricular and ventricular arrhythmias. It is of added benefit in this patient as it is the least negatively inotropic arrhythmic, second to digoxin. Beta-blockers should be avoided as the patient has a history of asthma. DC cardioversion is indicated in the acute stage if the patient is haemodynamically unstable. It may also be used in the chronic setting following six weeks of anticoagulation.

This man is having an myocardial infarction (MI), most likely secondary to cocaine use. Cocaine is a potent sympathomimetic agent. It acts by preventing the reuptake, and therefore accumulation of dopamine and noradrenalin at the synaptic junctions. Its positive effect on the α-adrenoceptors results in significant vasoconstriction, leading to hypertension, tachycardia and increased myocardial contractility. This in turn leads to increased oxygen demand of the myofibrils, but because of vasoconstriction of the coronary arteries, that oxygen demand is not met and ischaemia results. Beta-blockers aggravate the vasospasm and worsen the ischaemia. The treatment of choice in cocaine-induced MI is glyceryl trinitrate and calcium channel blockers.

Note that low molecular weight heparin (LMWH) should be used with caution in patients with long-term cocaine abuse, due to the increased risk of intracranial haemorrhage.

Table 1.1 summarises the main features and associations of valvular heart disease.

Prolonged QT interval is associated with syncope and sudden death from ventricular tachycardia. There are multiple causes:

As this man is young and active and has a family history of sudden death, you should be suspicious of an underlying genetic condition. Hypertrophic cardiomyopathy is therefore the most likely from the options available.

Hypertrophic cardiomyopathy is an autosomal dominant condition that affects the cardiac myocytes. Many patients are asymptomatic, but it can present with chest pain, palpitations, dyspnoea or sudden death. Investigations include ECG in the first instance, followed by echocardiogram. Treatment can be medical or surgical. Medications used include beta-blockers, calcium channel blockers or antiarrhythmics, such as amiodarone. In patients with significant outflow obstruction as a result of septal hypertrophy, surgical myomectomy or septal ablation may be considered. In those at risk of sudden death (previous history of cardiac arrest or failure to control symptoms with medications) and implantable cardioverter defibrillator should be inserted.

The UK Driver and Vehicle Licensing Agency (DVLA) has very clear regulations regarding driving following interventional procedures for cardiac conditions.

In an acute coronary syndrome (unstable angina, non-ST segment elevation myocardial infarction [NSTEMI], ST segment elevation myocardial infarction [STEMI]) that is successfully treated with coronary angioplasty, driving may recommence within 1 week. If angioplasty is not successful, driving may recommence after 4 weeks, providing there is no other disqualifying condition.

If a patient undergoes elective primary coronary angioplasty, driving may commence after 1 week.

If a patient undergoes coronary artery bypass grafting (CABG), driving must cease for at least 4 weeks.

The DVLA need not be notified in any of the above situations.

The mitral valve is the most commonly affected valve in infective endocarditis followed, in reducing order of frequency, by the aortic valve, the aortic and mitral valves, the tricuspid valve and rarely the pulmonary valve.

12The vegetations occur on the low pressure surface of the valve. On the mitral valve, vegetations occur on the aortic surface, whereas vegetations occur on the ventricular surface of the aortic valve.

Approximately 70% of cases of endocarditis on native valves are caused by Streptococcus species including viridans Streptococcus, Streptococcus bovis and Enterococcus species. 25% are caused by staphylococcal infections which are more aggressive and have a more acute course.

Streptococcus bovis is associated with colorectal cancer and adenoma. 25–80% of patients with S. bovis bacteraemia have a colorectal cancer. Therefore, once the patient is well enough to tolerate the procedure, a colonoscopy should be performed.

10–20% of all cases of infective endocarditis are associated with prosthetic valves. Eventually 5% of all prosthetic valves will become infected. Early prosthetic valve endocarditis occurs within 60 days of implantation and is associated with coagulase-negative staphylococcal organisms, Candida species and gram-negative bacilli. Late infection occurs 60 days or more after implantation, and tends to be associated with Staphylococcus aureus. α-haemolytic streptococci and enterococci are also implicated.

Metallic valves are more likely to become infected within the first 3 months of implantation and bioprosthetic valves are more likely to be infected 1 year after implantation.

Clinical features of an atrial septal defect (ASD) include wide fixed splitting of the second heart sound, loud P2 and a pulmonary systolic flow murmur. Complications include pulmonary hypertension, Eisenmenger's syndrome, cardiac failure and infective endocarditis. The different characteristics of the different atrial septal defects are outlined in Table 1.2a. Table 1.2b outlines the features of other congenital heart diseases.

Indications for thrombolysis include:

Contraindications to thrombolysis include:

The European Society of Cardiology published new guidelines to replace the CHAD2 scoring system in 2010. This is referred to as the CHA₂DS₂ VASc scoring system and is outlined in Table 1.3 and Table 1.4. Using this system our patient scores 1 point (age), and therefore the preferred method of anticoagulation is warfarin over aspirin.

The New York Heart Association Classification of heart failure is:

Grade 1: No breathlessness, no effect on daily life

Grade 2: Breathless on severe exertion

Grade 3: Breathless on mild exertion

Grade 4: Breathless at rest, severely limited

NB there is no Grade 0

The ABCD rule is helpful here:

Although this patient is young, she is Afro-Caribbean, and therefore she should be started on a calcium channel blocker or a diuretic; hence verapamil is the correct answer. Beta-blockers have been linked with diabetes, and they should no longer be used as first-line agents.

If single-agent therapy is not effective then further agents may be added.

Orlistat is an anti-obesity drug; it has anti-lipase activity and reduces absorption of dietary fat from the gut.

Myoglobin rises first in myocardial infarction. Table 1.5 outlines the behaviour of the different cardiac enzymes.

This patient most likely has Wolff–Parkinson–White syndrome which predisposes to supraventricular tachycardias, as a result of an accessory antrioventricular conduction pathway.

Classic ECG changes include:

Definitive treatment is with radiofrequency ablation of the accessory pathway.

An inferior myocardial infarction involves the right coronary artery and ECG changes involve leads II, III and aVF. Table 1.6 outlines the ECG changes associated with occlusion of the different coronary arteries.

Constrictive pericarditis classically presents as worsening dyspnoea over time.

Clinical findings include:

Causes include:

The presentation of cardiac tamponade may be similar, but dyspnoea often worsens rapidly, and Kussmaul's sign is usually negative. There is also an absent Y descent in the JVP.

Asbestosis may present in a similar fashion, but fine crackles would be heard on auscultation of the chest (pulmonary fibrosis) and Kussmaul's sign would not be present.

18Superior vena caval obstruction is identified by an elevated JVP with absent A and V waves. There is often associated facial swelling with dilated veins across the arms, neck and anterior chest wall.

In congestive cardiac failure the JVP is elevated and there is peripheral oedema. There is also evidence of left heart failure, with pulmonary oedema (bibasal crackles heard on chest examination).

Dressler's syndrome (pericarditis and pleural effusions) occurs 2 weeks to 2 months after myocardial infarction or cardiac surgery. It presents with fever, pleurisy and pericarditis. Blood tests show an elevated erythrocyte sedimentation rate (ESR) with anaemia, and anticardiac muscle antibodies are identified in some cases. Treatment is with non-steroidal anti-inflammatory drugs (NSAIDs).

Reinfarction would not normally be associated with fevers. Myocardial rupture post myocardial infarction can occur between 1 day to 3 weeks after the original event, but usually occurs at 3–5 days. It is a rare complication, and classically presents as a catastrophic event.

Pulmonary embolus should be considered as a differential diagnosis, but would not normally be associated with an elevated ESR.

A drug reaction, secondary to any new medications started following the myocardial infarction, may present with fevers, but would not be expected to cause chest pain. Drug reactions may also present with skin rashes, dyspnoea or lymphoedema, or as a fixed drug eruption.

Currently aortic valve replacement in aortic stenosis is only considered for those who are symptomatic, or have a gradient of >50 mmHg with left ventricular dysfunction. Valvuloplasty may be considered in those unfit for surgery, but who are symptomatic.

The patient should be followed up in clinic as his left ventricular function and pressure gradient across the valve should be monitored for consideration of surgery in the future.

There is no indication within the scenario for emergency valve replacement to be undertaken (e.g. infective endocarditis, not responding to antibiotic therapy).

Aortic dissections can be divided into two categories. Type A affects the ascending aorta and definitive treatment is surgical repair. The mainstay of management is for 19blood pressure to be controlled with intravenous agents whilst awaiting surgery. The aim of surgery is to prevent cardiac tamponade and aortic rupture.

Type B dissections do not involve the ascending aorta and are usually managed by strict blood pressure control with intravenous agents. Beta-blockers are usually used, but calcium channel antagonists are used in patients with chronic obstructive pulmonary disease (COPD).

Other conditions associated with aortic dissection include:

Complete heart block following an inferior myocardial infarction (MI) occurs due to ischaemic damage to the antrioventricular node (supplied by the right coronary artery in 90% of people). It often spontaneously resolves, and as this patient is haemodynamically stable, observation is all that is currently required.

Complete heart block following an anterior MI is an indication for pace-maker insertion.

Figure 1.2 shows an ECG showing an inferior myocardial infarction.

Glucagon is the agent of choice to treat beta-blocker overdose. Table 1.7 outlines the antidotes for common poisons.

This man probably has renal artery stenosis as an underlying cause of his pulmonary oedema, since his ECG and cardiac enzymes were normal, pointing away from a cardiac cause. The gold standard for investigation of renal artery stenosis is MR angiogram of the renal arteries, as it does not involve nephrotoxic contrast agents, or radiation exposure.

Causes of right axis deviation:

Causes of left axis deviation:

This woman has a diagnosis of severe pre-eclampsia. Pre-eclampsia is associated with proteinuria, hypertension and intrauterine growth retardation. Methyldopa is the first line agent to treat elevated blood pressures, but labetalol and nifedipine may also be used. Intravenous agents are used in cases of severe hypertension. Delivery of the baby is the definitive treatment, but the timing of this is made on a case-by-case basis.

NB Labetalol use in maternal hypertension is not known to be harmful. Other beta-blockers are associated with intrauterine growth restriction, neonatal hypoglycaemia, and bradycardia.

Risk factors associated with pre-eclampsia include:

Left ventricular failure is associated with pulsus alternans. Table 1.8 outlines the pulse characteristics associated with various heart conditions.

The blood results show hypokalaemia. U waves would be expected on the ECG. Table 1.9 outlines the ECG changes associated with various electrolyte abnormalities.

In a haemodynamically stable patient with supraventricular tachycardia (as illustrated in Figure 1.3) vagal manoeuvres such as expiration against a closed glottis, are the first-line intervention. If this fails then adenosine should be given. However, adenosine is contraindicated in asthmatics and verapamil is the preferred alternative.

DC cardioversion should be used if the patient is haemodynamically unstable.

Beta-blockers may be considered if adenosine is unsuccessful in reverting to sinus rhythm.

The National Institute of Health and Clinical Excellence (NICE) guidelines state that after an ST elevation myocardial infarction (MI) all patients should be offered long term therapy with aspirin, an ACE inhibitor, bisoprolol and a statin.

After an ST elevation MI clopidogrel and aspirin should be given for 4 weeks. After this, only aspirin is required unless there are other indications for dual antiplatelet therapy (e.g. patients who receive a drug eluting stent during percutaneous intervention (PCI) should receive dual antiplatelet therapy for 1 year. As the question refers to a review 12 months after the PCI, even if the patient did receive a drug eluting stent, dual antiplatelet therapy is no longer required).

For patients who have had an acute MI and who have symptoms or signs of heart failure and left ventricular systolic dysfunction, treatment with an aldosterone antagonist should be initiated within 3–14 days of the MI, preferably after ACE inhibitor therapy.

Clopidogrel in combination with low-dose aspirin is recommended in the management of non-ST-segment-elevation MI in people who are at moderate to high risk of MI or death. This combination should be continued for 12 months.