An ECG or EKG is a recording of the electrical activity of the heart. An echocardiogram is an ultrasound recording of the heart and its blood flow.
Echo is a program. '' is not a program. '' does not perform any action. Echo returns what you type. '' does not.
Sonar location is in the water and echo location is in the air.
rem is a comment that is only seen if you edit the batch echo actually is printed when the batch is running
echo cat will print out the word 'cat' on the command line. cat echo will attempt to list the contents of a file called 'echo'.
the time between the two R waves in ECG
The print function is slightly more dynamic than the echo function by returning a value, and the echo function is slightly (very slightly) faster. The printf function inserts dynamic variables/whatever into wherever you want with special delimiters, such as %s, or %d. For example, printf('There is a difference between %s and %s', 'good', 'evil') would return 'There is a difference between good and evil'.
Print always returns a value of true, but echo doesn't. echo also has a short cut syntax meaning you can immediately follow the php tags by an equals sign and it will echo the result like in the example shown below: <?=$hello?>
Both measure electrical activity -- the ECG in the heart and the EEG in the brain.An EEG is an electroencephalogram and an ECG also known as an EKG is an electrocardiogram. An EEG records brainwave/electrical activity. An ECG records the electrical activity that the heart produces.
On an ECG, PVC (premature ventricular contraction) is an early heartbeat originating from the ventricles, while PAC (premature atrial contraction) is an early heartbeat originating from the atria. Both can indicate potential heart rhythm abnormalities.
Premature Atrial Contraction (PAC) occurs when the heart's upper chambers contract too early, causing an abnormal heartbeat on an ECG. Premature Ventricular Contraction (PVC) happens when the heart's lower chambers contract prematurely, also leading to an abnormal rhythm on an ECG. The key difference is the origin of the early contraction within the heart's chambers.
Reverberation is the persistence of sound in an enclosed space due to multiple reflections, while an echo is a distinct repetition of sound caused by reflection off a surface.
Echo is the reflection of sound waves off of a surface, resulting in a distinct repeat of the original sound. Reflection of sound is the general term for any sound wave bouncing off a surface, whether or not it produces a distinct echo.