Week 1: Following the heart using ECHO

I started working at the Cardiology department last week, and for the first few days, I shadowed a fellow in the department, Dr. Fay Lin, who showed me some echo cardiography. The first task I received was learning how to read echos, or ultrasound images of the cardiac systems. I got access to several references (Fay told me about Yale's med school web site, which has an excellent outline), and two texts; one is a textbook, and the other is the list of protocols used at Weill. The patient data are currently stored in VCRs, and at Weill Cornell, echo data will soon be stored using digital medium at some point during the summer. What really interested me was the protocol involved in getting a set of images in about 10-15 minutes. The echo images are shaped in a flat fanbeam, so one can only see the 2-D profile of the heart. Therefore, the echocardiographer obtains images of the cardiac cycle from about 3 or 4 positions, and rotates the probe by 60 degrees at each; this gives many different image profiles, such as 2-chamber view, 4-chamber, and 5-chamber view, that are useful for observing different chambers, valves, and blood vessels. Interestingly, the fifth chamber in the 5-chamber view is actually the aorta.

I also got to observe a trans-esophageal echo, which involved a probe that was threaded down to the stomach and obtained the cardiac image closer to the source. The probe tip can be controlled tp move in 4 directions, and while I was observing, another fellow/resident was learning how to control the probe, while the doctor leading the exam, Dr. James Min, operated on the computer. The images obtained during this procedure were much clearer than typical echo cardiograms. While the setup/sedation process took easily over an hour, the imaging part took about 10 minutes altogether.

While the trans-esophageal procedure seems to provide much better images than typical echocardiograms, it is also much more difficult to perform in a hospital. The trans-esophageal procedure requires sedation of the patient using moderate anesthesia, which does not require the presence of an anesthesiologist, and in total takes about 2 hours to perform on a single patient.

In addition, I also got to follow my mentor, Dr. Jonathan Weinsaft, in the Cardiology ICU for the morning rounds, usually starting around 8 am, and going on until noon. I got a lucky break from day 3, where I could join them a little bit into the rounds. Sometimes, such as on Saturday, the rounds apparently took until 2:30 pm in the afternoon. During the rounds, there were about eight medical students, residents, and fellows who gathered around Dr. Weinsaft on a workstation computer set up in the middle of the ICU, and they gave details on what happened to each patient overnight to Dr. Weinsaft. Since the patients all have conditions that require constant care, the entire team spends anywhere between 15 minutes to even half an hour or more looking through each patient's case. While the rounds were quite exhausting, it is an integral part of providing care to the patients.

Also, I got to observe a CATH (Catheter) exam. X-ray angiography was used to look for stenosis in the coronary arteries, and the insertion of the catheter into the femoral artery surprised me a little.

In summary, the first week has been a novel experience. In addition to the clinical aspects, it's great to hang out with fellow BME PhDs again.