Week 1 Cardiology Rotation Day 3 & 4

Yesterday we learned more about the diagnostic utility of echocardiography with Dr. Huang as he saw several patients for echocardiograms. He showed us how to see the left ventricle, left atrium and & aorta with a parasternal long axis view, the tricuspid & mitral valves from a parasternal short axis view, and the 4 chambers from the apical view. As soon-to-be second years, we've had minimal exposure to ultrasound in school and our one lab experience was a very general overview that raised more questions than it answered. Dr. Chen had explained to us on our first day of echocardiography that the results are heavily dependent on the operator's skill and that became clear to us during the last couple days of observing the cardiologists find unbelievably clear views of the valves, papillary muscles, pericardium and many other features that I didn't know were possible to find on echocardiograms.
The most interesting case we saw yesterday was a 34yo male patient who presented with dyspnea on exertion (DOE). His CXR showed an abnormal heart contour with slight bulging of the left heart border. Dr. Huang said that this could possibly be indicative of left atrial enlargement. As he performed the echo, he showed us in the parasternal long axis view that the right ventricle diameter was nearly equal to the left ventricle diameter, indicating RV enlargement, since a normal RV diameter should only be 1/3-1/2 the diameter of the LV from that view. He also showed us how to measure the diameter of the RV using a snapshot from the echocardiogram - the patient had a RV diameter of 2.86, indicating RV hypertrophy (normal diameter is <2.3cm) and the RA was also enlarged. He also measured the pulmonary artery pressure since high PA pressure can cause RVH, but in this case the PA pressure was not elevated. Then, as he moved the transducer to obtain a parasternal short axis view, we saw a very clear atrial septal defect with a left to right atrial shunt. Dr. Huang said that he only sees 1-2 cases of ASD per year so we felt fortunate to be able to see one with him. The echo was clear enough to make a definitive diagnosis of ASD, which explained the RVH & RAE, the abnormal heart contour on CXR and the DOE.

Today we were with Dr. Wang as he was called for an ER consult for a 93yo (!) female patient who was brought to the hospital by her family after they found her unconscious this morning. The patient was stable but unresponsive and fluctuated between unarousable to minimally arousable while Dr. Wang examined her. The ER physician had ordered several labs upon admission and found an elevated troponin I level of 1.0 so cardiology was called. Dr. Wang explained that while elevated troponin I suggests possible MI, he didn't think it was very likely that an MI would cause loss of consciousness. Dr. Wang informed us that the patient's Glasgow Coma Scale score was E1 (no eye opening), V2 (verbal response incomprehensible), M5 (motor response localizes to pain). The patient's PMH was significant for HTN, T2DM, and CKD, with a creatinine level of 3.4 today. Her family said she recently had a cold and was complaining of dizziness, nausea & vomiting, but no fever.
Dr. Wang performed a bedside echocardiogram to examine heart wall motion and found that motion was generally preserved, with mild hypokinesia over the IV septum & lateral wall. He said the motion abnormality could be from causes other than MI and he would need to compare it to previous echocardiogram results in order to accurately interpret the data. After reviewing the labs and imaging studies, the differential diagnosis included meningitis, MI, sepsis, CVA, ischemic heart disease, CHF & neoplasm, with more studies needed to narrow down the DDx.
This case highlighted the fact that although we learn the classical textbook presentations for MI, sepsis, neoplasms, CHF etc in our didactic years, the reality is that once we begin our clinical years, we'll be seeing cases that won't fit into a simple pattern or be as clear cut as our textbooks may lead us to believe. Medicine is truly an art that requires practice, expansive knowledge and clinical reasoning skills in order to solve the difficult cases.