1. When a doctor uses a stethoscope, what is being monitored?
-The sound made by the vibration of the heart and blood as pumping occurs.
Listening to the heart through a stethoscope usually allows one to hear the two heart sounds. The first sound occurs at the moment of mitral and tricuspid valve closing, the second sound at the moment of aortic and pulmonic valve closing. Some patients with disease have additional vibrations that can lead to other discrete sounds, or they may have turbulence, caused by flow through narrow arteries, that is picked up as a murmur.
2. Which of the following conditions can cause irregularities in the sound of the heart?
-Moderate bradycardia and mild mitral valve regurgitation
Bradycardia is an abnormally slow heart beat rhthym. It's possible that the natural variation in the heart beat rate between individuals or in the same person may make it difficult to diagnose a slow heart beat as a clinical condition, but in principle, this condition is detectable based purely sound. Mitral valve regurgitation occurs because of an inability of the mitral valve to prevent the blood from flowing back from the left ventricle to the left atrium during systole. The back flow of blood (regurgitation) creates an abnormal 'whoosh' that can easily be detected. Atheroscierosis is deposition of fatty plaques in the wall of the arteries. When it occurs in the coronary arteries, that is, the blood vessels that supply the heart muscles, it can constrict the passage of blood and cause a heart attack. However, without other secondary symptoms, atheroscierosis is not easily detectable by sound alone.
3. What is a murmur?
- A rumbling or blowing sound that is made by the heart, often by malfunctioning heart valves.
Murmors are often associated with problems involving the heart, often by malfunctioning heart valves.
1. How are the echocardiography images made?
- Images are complied from ultrasound and reflected from the heart tissue.
Echocardiography uses ultrasound emitted from a probe. The sound is when reflected back to the probe when it encounters a solid object. The results are complied with a computer. X-rays, optical equipment or radar (using radio waves) are not used.
2. What do orange and blue colors on the blood represent in Doppier echo images?
-The colors indicate whether the blood is moving toward or away from the probe.
Doppler echocardiography detects movement of blood. It has nothing to do with oxygenation or temperature. The colors are assign depending on whether the blood is moving toward or away from the probe.
3. Which of the following characteristics of the heart cannot be measure with echocardiography?
-The oxygen content of the blood.
Echocardiography can provide very good real-time images of the heart. The valve movements can be monitored, the heartbeat can be measured by observing the movements, and the size of the chambers can be calculated. It does not however, monitor chemical compositions of the blood. So it cannot measure the oxygen content.
