Valvular Disease and Heart Failure - Group Teaching

Question 1

How do you calculate cardiac output?

Answer 1

CO= HR x SV
* SV = EDV – ESV

CO: Cardiac Output
HR: Heart Rate
SV: Stroke Volume
EDV: End Diastolic Volume
ESV: End Systolic Volume

Question 2

How do you calculate the ejection fraction?

Answer 2

EF = (SV / EDV) x 100

EF: Ejection Fraction
SV: Stroke Volume
EDV: End Diastolic Volume

Question 3

How do you calculate mean arterial pressure (MAP)?

Answer 3

MAP = (CO x SVR) + CVP
MAP = DP + [(SP - DP) / 3]

MAP: Mean Arterial Pressure
CO: Cardiac Output
SVR: Systemic Vascular Resistance
CVP: Central Venous Pressure
DP: Diastolic Pressure
SP: Systolic Pressure

Question 4

Calculate MAP, SV, CO and EF for the following case:

A 60 year-old man presented with shortness of breath to A+E. He was in type 2 respiratory failure secondary to an infectious exacerbation of COPD. As a result, he needed intensive care support and had more invasive monitoring. A Swan-Ganz catheter was inserted, which measured end diastolic volume as 142ml and end systolic volume as 47 ml. Observations were that this patient was intubated and ventilated using BiPAP of 20/5 with saturations of 95 percent, heart rate 75 beats per minute, respiratory rate 12/minute, blood pressure 115/75mmHg and Temperature 36.5 degrees Celsius. Work out the mean arterial blood pressure, stroke volume, cardiac output and ejection fraction.

Answer 4

• MAP = 88.3 mmHg.
• SV = 95 ml
• CO = 7125 ml/min or 7.125 L/min
• EF = 66.9%

Question 5

What is infective endocarditis?

Answer 5

An infection of the endocardium or vascular endothelium of the heart

Question 6

This is a 21 year old gentleman who presents to A+E with pyrexia (fever) of unknown origin. He has no significant past medical history apart from a known intravenous heroin user. On examination heart rate is 115 beats per minute, blood pressure 90/60mmHg, Temperature 39 degrees Celsius, respiratory rate 17 beats per minute and saturations 99 percent on air. There is an early diastolic murmur in the left sternal edge which is loudest with the patient sitting forward and at end expiration. On examination of the feet you notice that he has cellulitis of his distal right leg with a deep penetrating ulcer.

What are the symptoms of infective endocarditis (5)?

Answer 6

• Fever
• Malaise
• Sweats
• Unexplained weight loss
• New heart murmur on examination

Question 7

This is a 21 year old gentleman who presents to A+E with pyrexia (fever) of unknown origin. He has no significant past medical history apart from a known intravenous heroin user. On examination heart rate is 115 beats per minute, blood pressure 90/60mmHg, Temperature 39 degrees Celsius, respiratory rate 17 beats per minute and saturations 99 percent on air. There is an early diastolic murmur in the left sternal edge which is loudest with the patient sitting forward and at end expiration. On examination of the feet you notice that he has cellulitis of his distal right leg with a deep penetrating ulcer.

What investigations can assist in the diagnosis of infective endocarditis (4)?

Answer 7

• FBC:
  
  • Anaemia
  • Raised markers of infection
• Blood cultures may isolate a microorganism
• Echocardiogram can show a vegetation, abscess, valve perforation and/or new dehiscence of prosthetic valve
• Transoesophageal echo has higher sensitivity compared with transthoracic

Question 8

This is a 21 year old gentleman who presents to A+E with pyrexia (fever) of unknown origin. He has no significant past medical history apart from a known intravenous heroin user. On examination heart rate is 115 beats per minute, blood pressure 90/60mmHg, Temperature 39 degrees Celsius, respiratory rate 17 beats per minute and saturations 99 percent on air. There is an early diastolic murmur in the left sternal edge which is loudest with the patient sitting forward and at end expiration. On examination of the feet you notice that he has cellulitis of his distal right leg with a deep penetrating ulcer.

How do you diagnose infective endocarditis?

Answer 8

Question 9

This is a 21 year old gentleman who presents to A+E with pyrexia (fever) of unknown origin. He has no significant past medical history apart from a known intravenous heroin user. On examination heart rate is 115 beats per minute, blood pressure 90/60mmHg, Temperature 39 degrees Celsius, respiratory rate 17 beats per minute and saturations 99 percent on air. There is an early diastolic murmur in the left sternal edge which is loudest with the patient sitting forward and at end expiration. On examination of the feet you notice that he has cellulitis of his distal right leg with a deep penetrating ulcer.

What features of heart decompensation would you look for (4 symptoms / 3 signs)?

Answer 9

Symptoms:
* Shortness of breath
* Frequent coughing
* Swelling of the legs and abdomen
* Fatigue

Clinical signs:
* Raised Jugular Venous Pressure (JVP)
* Lung crackles
* Oedema

Question 10

This is a 21 year old gentleman who presents to A+E with pyrexia (fever) of unknown origin. He has no significant past medical history apart from a known intravenous heroin user. On examination heart rate is 115 beats per minute, blood pressure 90/60mmHg, Temperature 39 degrees Celsius, respiratory rate 17 beats per minute and saturations 99 percent on air. There is an early diastolic murmur in the left sternal edge which is loudest with the patient sitting forward and at end expiration. On examination of the feet you notice that he has cellulitis of his distal right leg with a deep penetrating ulcer.

What part of the heart does infective endocarditis affect?

Answer 10

• Infective endocarditis affects the endocardium, especially the valves of the heart

Aortic valve is affected most frequently (aortic > mitral > right-sided valves)

Question 11

This is a 21 year old gentleman who presents to A+E with pyrexia (fever) of unknown origin. He has no significant past medical history apart from a known intravenous heroin user. On examination heart rate is 115 beats per minute, blood pressure 90/60mmHg, Temperature 39 degrees Celsius, respiratory rate 17 beats per minute and saturations 99 percent on air. There is an early diastolic murmur in the left sternal edge which is loudest with the patient sitting forward and at end expiration. On examination of the feet you notice that he has cellulitis of his distal right leg with a deep penetrating ulcer.

How does risk of infective endocarditis vary for intravenous drug users?

Answer 11

Intravenous drug users are at increased risk of infective endocarditis due to repeated injection – potentially exposing their bloodstream to bacteria on the surface of the skin or use of non-sterile needles

Question 12

This is a 25 year old gentleman who presents with palpitations and syncope episodes. He has a 24 hour Holter monitor which showed that patient was in fast atrial fibrillation for up to 6 hours in the 24 our recording. A transthoracic echocardiogram showed hypokinesia in the inferolateral walls. He ended up having a cardiac MRI which confirmed the diagnosis of dilated cardiomyopathy.

What is the definition of dilated cardiomyopathy?

Answer 12

Characterised by dilated and thin-walled cardiac chambers with reduced contractility

Question 13

This is a 25 year old gentleman who presents with palpitations and syncope episodes. He has a 24 hour Holter monitor which showed that patient was in fast atrial fibrillation for up to 6 hours in the 24 our recording. A transthoracic echocardiogram showed hypokinesia in the inferolateral walls. He ended up having a cardiac MRI which confirmed the diagnosis of dilated cardiomyopathy.

What are the commonest causes of dilated cardiomyopathy (8)?

Answer 13

• Idiopathic
• Genetic
• Toxins (alcohol, cardiotoxic chemotherapy)
• Pregnancy (peripartum cardiomyopathy)
• Viral infections (myocarditis)
• Tachycardia-related cardiomyopathy
• Thyroid disease
• Muscular dystrophies

Question 14

This is a 25 year old gentleman who presents with palpitations and syncope episodes. He has a 24 hour Holter monitor which showed that patient was in fast atrial fibrillation for up to 6 hours in the 24 our recording. A transthoracic echocardiogram showed hypokinesia in the inferolateral walls. He ended up having a cardiac MRI which confirmed the diagnosis of dilated cardiomyopathy.

How is the condition managed (5)?

Answer 14

• Medical heart failure therapy:
  
  • ACE inhibitors
  • Beta-blockers
  • Mineralocorticoid receptor antagonists
• Diuretics for fluid overload
• Anticoagulation for atrial fibrillation
• Cardiac devices:
  
  • Cardiac resynchronisation therapy and / or implantable cardioverter defibrillator
• Transplant

Question 15

This is a 25 year old gentleman who presents with palpitations and syncope episodes. He has a 24 hour Holter monitor which showed that patient was in fast atrial fibrillation for up to 6 hours in the 24 our recording. A transthoracic echocardiogram showed hypokinesia in the inferolateral walls. He ended up having a cardiac MRI which confirmed the diagnosis of dilated cardiomyopathy.

What will be the implications on this gentleman in the future (6)?

Answer 15

At risk of:
* Heart failure
* Hospitalization
* Cardiac arrhythmias
* Sudden cardiac death due to ventricular arrhythmia
* Reduced survival