Fractional shortening (FS) is a key parameter in cardiology that is used to estimate the ejection fraction of the heart. It is calculated by measuring the percentage change in left ventricular diameter during systole. FS is measured in parasternal long axis view (PLAX) using M-mode. The end-systolic and end-diastolic left ventricular diameters are measured to calculate the FS. FS is widely used to assess left ventricular dysfunction (LV dys) and has been shown to be an accurate predictor of ejection fraction.
Cardiology is a medical specialty that is concerned with the study, diagnosis, treatment, and management of heart disorders. Cardiac subspecialties include clinical cardiology, interventional cardiology, heart failure, adult congenital heart disease, neonatal, and pediatric cardiology. The Department of Cardiology from the National Heart Centre Singapore (NHCS) comprises cardiologist specialists of various cardiac subspecialties and provides a broad range of services in the diagnosis and management of all types of heart diseases. Your GP or cardiologist would most likely have explained to you the key risk factors for heart disease, which include body mass index (BMI) and high blood pressure.
Key Takeaways
- Fractional shortening (FS) is a key parameter in cardiology that is used to estimate the ejection fraction of the heart.
- Cardiology is a medical specialty that is concerned with the study, diagnosis, treatment, and management of heart disorders.
- The Department of Cardiology from the National Heart Centre Singapore (NHCS) comprises cardiologist specialists of various cardiac subspecialties and provides a broad range of services in the diagnosis and management of all types of heart diseases.
Fundamentals of Cardiac Structure and Function
The heart is a complex organ that plays a vital role in the circulatory system. It is responsible for pumping blood to all parts of the body, ensuring that oxygen and nutrients are delivered to the tissues and organs. Understanding the cardiac structure and function is essential for diagnosing and treating various cardiac conditions.
Cardiac Cycle and Ventricular Dynamics
The cardiac cycle is the sequence of events that occur during one heartbeat. It consists of two main phases: systole and diastole. During systole, the ventricles contract, and blood is ejected into the aorta and pulmonary artery. During diastole, the ventricles relax, and blood flows into the atria from the veins.
The left ventricle is the most important chamber of the heart, responsible for pumping oxygenated blood to the rest of the body. It is thicker and more muscular than the right ventricle, which pumps blood to the lungs. The left ventricular function is crucial for maintaining adequate cardiac output and tissue perfusion.
Assessment of Left Ventricular Function
Assessment of left ventricular function is essential for diagnosing and monitoring various cardiac conditions. Echocardiography is the most commonly used non-invasive technique for assessing left ventricular function. It uses ultrasound waves to create images of the heart, allowing for the measurement of various parameters such as ejection fraction, stroke volume, and cardiac output.
Other techniques for assessing left ventricular function include cardiac MRI, which provides detailed images of the heart and its function, and radionuclide ventriculography, which uses radioactive tracers to assess ventricular function.
In conclusion, understanding the fundamentals of cardiac structure and function is essential for diagnosing and treating various cardiac conditions. Assessment of left ventricular function is crucial for monitoring cardiac function and guiding treatment decisions. Non-invasive techniques such as echocardiography, cardiac MRI, and radionuclide ventriculography are useful tools for assessing left ventricular function.
Echocardiographic Techniques
Echocardiography is a non-invasive imaging technique that uses ultrasound waves to create images of the heart. It is a valuable tool in the diagnosis and management of cardiovascular diseases. There are two main types of echocardiography: conventional echocardiography and advanced echocardiography methods.
Conventional Echocardiography
Conventional echocardiography involves the use of M-mode and 2D measurements to assess cardiac structure and function. M-mode is a one-dimensional representation of cardiac motion, while 2D echocardiography provides a two-dimensional image of the heart.
M-mode is useful for measuring the thickness of the heart walls and the size of the heart chambers. It is also used to calculate fractional shortening (FS), which is a measure of left ventricular function. FS is the percentage change in left ventricular diameter during systole.
2D echocardiography is used to assess the overall structure and function of the heart. It can provide information on the size and shape of the heart chambers, the thickness of the heart walls, and the motion of the heart valves. It is also used to calculate ejection fraction (EF), which is a measure of the heart’s pumping function.
Advanced Echocardiography Methods
Advanced echocardiography methods include tissue Doppler, speckle tracking, three-dimensional echocardiography, strain, and strain rate imaging.
Tissue Doppler imaging measures the velocity of myocardial motion and is useful for assessing diastolic function. Speckle tracking is a newer technique that measures myocardial deformation and can provide information on regional myocardial function. Three-dimensional echocardiography provides a three-dimensional image of the heart, which can improve the accuracy of measurements and enhance visualization.
Strain and strain rate imaging are newer techniques that measure myocardial deformation and can provide information on regional myocardial function. Strain is a measure of the percentage change in myocardial length, while strain rate is the rate of change in strain over time.
It is important to note that advanced echocardiography methods require specialized training and expertise. They are not routinely used in clinical practice and are typically reserved for research or specialized clinical applications.
Overall, echocardiography is a valuable tool in the diagnosis and management of cardiovascular diseases. Conventional echocardiography provides important information on cardiac structure and function, while advanced echocardiography methods can provide additional insights into regional myocardial function. However, it is important to use these techniques appropriately and to interpret the results in the context of the patient’s clinical history and other diagnostic tests.
Clinical Applications and Interpretation
Diagnosis of Cardiac Conditions
Cardiac conditions can be diagnosed through various methods, including physical examination, electrocardiogram (ECG), and imaging techniques such as echocardiography. Echocardiography is a non-invasive technique that provides information on ventricular function, wall motion abnormalities, and left ventricular systolic function. The ejection fraction and fractional shortening can also be calculated from echocardiography to assess ventricular function.
In addition to echocardiography, cardiac troponin testing has become the standard of practice for the diagnosis of acute myocardial infarction (AMI) and non-AMI myocardial injury. The International Federation of Clinical Chemistry (IFCC) Committee on Clinical Application of Cardiac Bio-Markers (C-CB) provides educational materials about cardiac biomarker use, emphasizing high-sensitivity cardiac troponin assays.
Monitoring and Prognostic Assessment
Monitoring and prognostic assessment of cardiac conditions can be achieved through various methods, including echocardiography and cardiac biomarkers. Echocardiography can be used to monitor ventricular function and detect changes in left ventricular systolic function, right ventricular dysfunction, and mitral regurgitation.
Cardiac biomarkers, including cardiac troponin, can also be used for monitoring and prognostic assessment. The 2020 European Society of Cardiology guidelines recommend the use of high-sensitivity cardiac troponin assays for the diagnosis and management of acute coronary syndrome.
It is important to note that while these diagnostic and monitoring methods can provide valuable information, they should always be interpreted in the context of the patient’s overall clinical presentation. A thorough clinical evaluation should always be performed to ensure accurate diagnosis and appropriate management of cardiac conditions.
Quantitative Parameters and Indices
Cardiac function can be assessed using various quantitative parameters and indices. In echocardiography, these parameters include measurements of cardiac dimensions, wall thickness, and function. Doppler and tissue imaging are also used to evaluate cardiac function.
Echocardiographic Measurements
Echocardiography is a widely used non-invasive imaging modality for assessing cardiac function. It provides measurements of cardiac dimensions and function, including fractional shortening (FS), end-diastolic diameter (EDD), end-systolic diameter (ESD), and stroke volume (SV). FS is calculated as the percentage change in left ventricular diameter during systole and is a measure of systolic function. EDD and ESD are measures of ventricular size, while SV is the amount of blood ejected from the ventricle per beat.
Fractional area change (FAC) is another measure of systolic function that can be obtained from echocardiography. It is calculated as the percentage change in ventricular area during systole. FAC is a more accurate measure of systolic function than FS in patients with regional wall motion abnormalities.
Doppler and Tissue Imaging
Doppler and tissue imaging are used in echocardiography to assess cardiac function. Doppler imaging provides information on blood flow velocities and pressures within the heart, while tissue imaging provides information on myocardial motion and deformation.
Cardiac output (CO) and cardiac index (CI) can be calculated using Doppler imaging. CO is the amount of blood ejected from the heart per minute, while CI is CO adjusted for body surface area. These measures are useful in assessing cardiac function and determining the severity of heart failure.
DP/dt is a measure of the rate of change of ventricular pressure during systole and is a measure of contractility. It can be obtained from invasive pressure-volume measurements or non-invasive echocardiography.
Overall, echocardiography provides a range of quantitative parameters and indices for assessing cardiac function. However, it is important to note that these measures are not always accurate and should be interpreted in the context of the patient’s clinical history and other diagnostic tests.
Frequently Asked Questions
What is the normal range for fractional shortening in an echocardiogram?
The normal range for fractional shortening in an echocardiogram is between 25% and 45%. However, it is important to note that this range can vary depending on the individual’s age, sex, and overall health.
How does fractional shortening vary with age?
Fractional shortening tends to decrease with age, as the heart muscle becomes less flexible and less efficient. This is why it is important to monitor fractional shortening levels regularly, especially in older individuals.
What is the significance of left ventricular fractional shortening measurements?
Left ventricular fractional shortening measurements are important because they can help doctors assess the overall function of the heart. A decrease in fractional shortening can indicate a problem with the heart’s ability to pump blood effectively.
How is fractional shortening indicative of cardiac function?
Fractional shortening is indicative of cardiac function because it measures the amount of blood that is ejected from the left ventricle with each heartbeat. This measurement can help doctors determine how well the heart is functioning and identify any potential problems.
What implications does a heightened fractional shortening value have?
A heightened fractional shortening value can indicate that the heart is working harder than it should be, which can lead to problems over time. It is important to monitor fractional shortening levels regularly to ensure that the heart is functioning properly.
What are the primary causes behind diminished fractional shortening?
Diminished fractional shortening can be caused by a variety of factors, including heart disease, high blood pressure, and ageing. It is important to identify the underlying cause of decreased fractional shortening in order to develop an appropriate treatment plan.
Note: The information provided in this section is intended for informational purposes only and should not be used as a substitute for professional medical advice. If you have any concerns about your heart health, please consult a qualified medical professional.