ECHOCARDIOGRAPHY Flashcards
What is echocardiography?
A group of applications using ultrasound to interrogate cardiac structures
It utilizes acoustic waves generated by piezoelectric crystals in the ultrasound probe.
What are the main characteristics of ultrasound waves?
Frequency, wavelength, velocity, and amplitude
These characteristics define how ultrasound interacts with tissues.
What is the frequency range typically used in echocardiography?
2 to 10 MHz
What does the time it takes for ultrasound to return to the probe indicate?
The depth of the structures relative to the probe
What is the principle of Doppler ultrasonography?
Based on the change between transmitted and receiving frequencies reflecting the speed and direction of moving blood
List some appropriate indications for obtaining an echocardiogram.
- Symptoms possibly related to cardiac etiology
- Initial evaluation of left-sided ventricular function after acute myocardial infarction
- Evaluation of cardiac murmur in suspected valve disease
- Sustained ventricular tachycardia or supraventricular tachycardia
- Evaluation of suspected pulmonary artery hypertension
- Evaluation of acute chest pain with nondiagnostic markers
- Evaluation of known valve disease with change of clinical status
- Evaluation of suspected endocarditis or tamponade
- Evaluation of cardiotoxic effects of chemotherapy
- Evaluation for cardiac injury in chest trauma
What are some uncertain indications for echocardiography?
- Cardiovascular source of embolic event with normal TTE
- Surveillance of prosthetic valves in clinically stable patients
- Initial evaluation of systemic hypertension without symptoms
What are inappropriate indications for echocardiography?
- Routine monitoring of stable conditions
- Not the test of choice for initial evaluation of pulmonary embolus
- Not for screening asymptomatic hypertensive patients
What are some appropriate indications for Transesophageal echocardiography (TEE)?
- Evaluation of suspected aortic pathology
- Guidance during percutaneous cardiac procedures
- Determine mechanism of regurgitation
- Diagnose/manage endocarditis in high probability patients
- Persistent fever with an intracardiac device
What are the different modalities used in echocardiography?
- One-dimensional motion mode (M-mode)
- Two-dimensional (2D) imaging
- Three-dimensional (3D) imaging
- Doppler
What is the primary use of 2D echocardiography?
Identifying cardiac anatomy and morphology
How does M-mode differ from 2D echocardiography?
M-mode transmits a single line of ultrasound and provides better temporal resolution, while 2D provides better spatial resolution
What are the advantages of 3D echocardiography?
- Eliminates geometric assumptions
- Quantifies volumes of complex structures
- Views structures from multiple perspectives
What does Doppler measure in echocardiography?
Movement of blood in and around the heart based on frequency shifts
Name the three modes of Doppler used in echocardiography.
- Pulsed Doppler
- Continuous-wave Doppler
- Color Doppler
What is the purpose of the parasternal long-axis (PLAX) view?
Provides information on left ventricular structure and function
How is the parasternal short-axis (PSAX) view obtained?
By turning the ultrasound beam approximately 90 degrees clockwise from the PLAX position
What is assessed in the apical views of echocardiography?
- LV size
- Ejection fraction
- Wall motion
- Diastolic function
What is the standard method for measuring left ventricular ejection fraction (LVEF)?
LVEF = (End diastolic volume - End systolic volume) / End diastolic volume
What is Simpson’s method in echocardiography?
Tracing the LV endocardial border in systole and diastole to compute volumes