Cardio SAQs

Question 1

a) Define heart failure and its symptoms and causes, and then briefly contrast the features of the two major forms of heart failure, HFpEF and HFrEF

Answer 1

Heart Failure (HF): Heart failure is a medical condition where the heart’s ability to pump blood is impaired, leading to inadequate circulation of oxygen and nutrients to meet the body’s needs. Symptoms include fatigue, shortness of breath, fluid retention, and exercise intolerance. It can result from various causes, including coronary artery disease, hypertension, heart valve disorders, and cardiomyopathies.

Causes: Heart failure can be caused by conditions that weaken the heart muscle (e.g., cardiomyopathy), restrict blood flow (e.g., coronary artery disease), increase workload (e.g., hypertension), or affect heart valves.

Contrasting HFpEF and HFrEF:

Heart Failure with Preserved Ejection Fraction (HFpEF): In HFpEF, the heart’s pumping ability is preserved (ejection fraction >50%), but the heart struggles to fill with blood properly during relaxation (diastolic dysfunction). This form is often associated with conditions like hypertension, diabetes, and aging. Symptoms include shortness of breath, fatigue, and fluid retention.

Heart Failure with Reduced Ejection Fraction (HFrEF): In HFrEF, the heart’s pumping ability is significantly reduced (ejection fraction <40%), usually due to weakened heart muscle. This form is commonly caused by conditions like ischemic heart disease (heart attack), viral infections, and certain toxins. Symptoms include those of HFpEF along with an increased risk of fluid buildup in the lungs

Question 2

Ultrasound assessment of the heart (called echocardiography) can reveal a lot about the function of the heart.
i. Name one measurement of systolic or diastolic dysfunction

Answer 2

Ejection Fraction (EF)

Question 3

Ultrasound assessment of the heart (called echocardiography) can reveal a lot about the function of the heart.
ii. Give a brief description of how the measurement is obtained

Answer 3

Ejection fraction (EF) is obtained by echocardiography using the Simpson’s method. This involves tracing the endocardial border of the left ventricle during systole and diastole on multiple slices of the echocardiographic images. The software then calculates the volume of blood in the ventricle during both phases of the cardiac cycle. EF is calculated as [(End-Diastolic Volume - End-Systolic Volume) / End-Diastolic Volume] × 100%.

Question 4

Ultrasound assessment of the heart (called echocardiography) can reveal a lot about the function of the heart. iii. State how the measurement changes with the development of dysfunction.

Answer 4

In systolic dysfunction, the heart’s pumping ability is impaired. EF decreases as the heart becomes less efficient at ejecting blood during systole. This leads to a lower EF percentage compared to normal. For instance, a reduced EF might indicate conditions like heart failure with reduced ejection fraction (HFrEF), where the heart pumps less blood with each beat.

Question 5

Describe one arrhythmia that impacts the:
i. the atria

Answer 5

AF can lead to inefficient blood pumping from the atria into the ventricles, potentially causing blood stasis and increasing the risk of blood clots, strokes, and heart failure.

Question 6

Describe one arrhythmia that impacts the:
ii. the ventricle

Answer 6

Ventricular Tachycardia (VT)
VT can compromise cardiac output and lead to hemodynamic instability, reducing the heart’s pumping efficiency. It can progress to a more severe arrhythmia called ventricular fibrillation, which is life-threatening

Question 7

Describe one arrhythmia that impacts the:
Atrioventricular Block (AV Block)

Answer 7

In higher-degree AV blocks, the communication between the atria and ventricles is impaired, leading to slower heart rates and potential hemodynamic compromise. Complete heart block (third-degree AV block) can result in the atria and ventricles beating independently, requiring intervention to maintain adequate cardiac output.