Overview
This lecture reviews key echocardiography concepts, common pathologies, waveform interpretations, and exam-style questions to prepare for echo boards.
Waveform Interpretation
- Pulsus paradoxus is a waveform seen in cardiac tamponade.
- Pulsus bigeminus indicates a rhythm with alternating strong and weak beats.
- Pulsus bisferiens is a double-peaked pulse waveform, often in aortic regurgitation or HOCM.
- Electrical alternans is seen in cardiac tamponade.
- Pulsus alternans features alternating pulse strength, associated with left ventricular dysfunction.
Causes and Pathologies
- The most common cause of cardiac tamponade is idiopathic (unknown origin).
- Idiopathic is also the most common cause of cardiomyopathy, systemic hypertension, and pulmonary hypertension.
- After a myocardial infarction, arrhythmia is the most common complication, and aneurysm is the most common mechanical complication.
- Amyloidosis is the most common cause of restrictive left ventricular infiltration.
- Renal cell carcinoma is the most common cause of IVC "claw" sign.
- Systolic dysfunction can cause pseudo-aortic stenosis.
- Familial indicates a genetic or inherited origin.
Valves, Artifacts, and Anatomy
- A xenograft heart valve is made from cow (bovine) tissue.
- Reverberation artifact is caused by a St. Jude bi-leaflet mechanical valve.
- High color gain causes color speckle artifact in echocardiography.
- During a chemical stress test for low-grade aortic stenosis, dobutamine is used first.
- The innominate (brachiocephalic) artery is the first major branch of the aortic arch.
Echocardiogram Limitations
- Measuring left atrial size and evaluating mitral regurgitation can be limited by artifacts from a mechanical valve.
- Evaluating diastolic function is generally not feasible with significant artifacts.
- Peak gradient measurements remain accurate despite artifacts.
Key Terms & Definitions
- Idiopathic — of unknown cause.
- Xenograft — a graft made from a different species (e.g., cow).
- Pulsus paradoxus — abnormally large decrease in systolic BP during inspiration.
- Electrical alternans — alternating ECG amplitude, often in tamponade.
- Pulsus alternans — alternating strong and weak pulse beats.
- Reverberation artifact — ultrasound artifact from repeated sound reflections.
- Familial — inherited or genetic.
Action Items / Next Steps
- Review echocardiography mock exams on the ultrasound board review website.
- Subscribe for additional practice and study material.
- Reach out to the instructor with questions about the echo boards if needed.