transthoracic echocardiogram

TTE uses ultrasound waves emitted from a transducer placed on the chest to generate real-time images of the heart in multiple views (parasternal long/short axis, apical 4-chamber, subcostal, etc.). It employs 2D imaging, M-mode, and Doppler (color, pulsed-wave, continuous-wave) to assess: left ventricular ejection fraction (LVEF) and systolic/diastolic function, valve morphology and function (stenosis, regurgitation), chamber size and hypertrophy, wall motion abnormalities (suggesting ischemia/infarction), pericardial effusion/tamponade, congenital heart defects, and intracardiac masses or thrombi. Clinical indications include heart failure workup, murmur evaluation, endocarditis screening (though TEE is more sensitive), post-MI assessment, syncope evaluation, and monitoring of cardiotoxic chemotherapy. Advantages include being non-invasive, widely available, radiation-free, and relatively low-cost. Limitations include poor acoustic windows in obese patients, COPD, or mechanically ventilated patients, in which case transesophageal echocardiogram (TEE) may be preferred for better image quality, especially for posterior structures (left atrium, mitral valve, prosthetic valves, aorta) or to rule out endocarditis/thrombus. Understanding TTE is essential for Step 1/2 because it links physiology (ejection fraction calculation, Doppler principles) with clinical decision-making in cardiology (e.g., differentiating HFrEF vs HFpEF, diagnosing valvular disease, and guiding management of heart failure and ischemic heart disease).