S1W11 echo intro 2024 MT
Echocardiography Overview
What are the types of Echocardiogram?
Includes transthoracic, transoesophageal, stress echo, Doppler echo.
What are the learning outcomes?
Definitions of echo investigations with indications.
Discuss advantages and disadvantages of echo investigations.
Understand Doppler TTE types (pulsed, continuous, color flow).
Learn fractional shortening and Simpsons Biplane for ejection fraction.
Recognize disadvantages of methods, windows, and views in TTE.
What is Transthoracic Echo (TTE)?
Definition: Most common echo, performed noninvasively using ultrasound transducer placed on the chest or abdomen.
Applications: Evaluates heart function and valves; assesses ejection fraction and other heart metrics.
What is Transoesophageal Echo (TOE / TEE)?
Description: Utilizes a small, high-frequency transducer mounted on a steerable endoscope for visually capturing the heart.
Indications:
When TTE results are inconclusive.
Evaluation for prosthetic heart valves or left atrial appendage issues.
Procedure guidance.
Advantages: Superior images compared to TTE, especially for great vessels and posterior cardiac structures.
What is Stress Echo?
Indications: Used when initial imaging is inconclusive; not first-line imaging.
Process: Echo performed before and after exercise to compare heart function under stress.
Methods: Patients can be stressed physically or chemically (e.g., using dobutamine).
What is Doppler Echo?
Purpose: Part of the echo examination that assesses blood flow non-invasively.
Functionality: Measures blood flow direction, speed, and tissue velocities utilizing the Doppler effect.
Outcome: Helps estimate left ventricular filling pressures.
What are the Clinical Applications of TTE?
Patients: Any requiring heart structure visualization for diagnosis.
Advantages:
Portable and non-invasive.
Real-time information acquisition and cost-effectiveness.
Disadvantages:
Limited continuous monitoring capacity.
Difficulties in achieving all necessary views.
What are the Measurement Insights?
Basic Measurements:
Echo provides various metrics such as volumes, flows, and pressures.
Direct measurements include length from 2D imaging and velocity from spectral Doppler.
Planimetry: Can be used for area measurements and helpful for certain calculations.
What are the Advantages of Echo Measurements?
Quantitative Assessment: Doppler echocardiography allows for the calculation of volumes, flows, pressures, and evaluation of ventricular function, valve pathology, and filling status.
Clinical Importance: Provides essential information to guide clinical decisions throughout diagnosis and treatment pathways.
What is the Understanding of the Doppler Effect?
Overview: The Doppler effect refers to frequency shifts of reflected sound waves, which can indicate blood flow speed and direction.
Measurement Guidelines:
Utilize data from multiple cycles for accuracy.
Ensure ultrasound beam is perpendicular to the structure for correct measurements.
What are the Spectral Doppler Types?
Pulsed Wave Doppler (PW): Sends short pulses of ultrasound, good for locating velocity measurement but limited in max velocity. Continuous Wave Doppler (CW): Provides continuous ultrasound wave analysis, allowing detection of higher velocities but cannot identify exact location along the flow line.
What are the Key Metrics in Echo?
Mitral Valve Flow: Typical antegrade flow during diastole, any flow during systole suggests dysfunction.
Color Flow Doppler: Assigns colors to flow direction, crucial in assessing mitral regurgitation severity through visual jet pattern assessment.
What is M-Mode Echocardiography?
Description: Offers one-dimensional imaging related to time and distance, useful in specific cardiac structure evaluations.
What are the Clinical Considerations?
LV Function: Both left ventricular twist and torsion should be assessed across multiple views; ejection fraction (EF) measures must be evaluated with caution.
Measuring Techniques: Measurements are typically from inner-edge to inner-edge to promote accuracy, ensuring perpendicular lines are achieved where feasible.
What is Ejection Fraction Assessment?
Definition: Ratio of blood volume ejected during systole to volume at end-diastole; crucial for evaluating left ventricular function.
Measurement Techniques: Subjective (visual) and objective (quantitative) methods are used; no single gold standard exists, and each method carries the potential for error.
What are the Reference Intervals & Functional Assessment?
Interpretation of Measurements: Reference intervals are adjusted based on population measurements and are crucial in assessing chamber dimensions during echocardiography.
Indexing: Important for accurate interpretation of variables related to chamber dimensions and left ventricle function.