In the fast-paced world of echocardiography, conduction disorders often slip into the study without an appointment. From an irregularly irregular rhythm to dropped beats or fluttering atria, these electrical disturbances can throw a wrench into your measurements—and sometimes even mislead your interpretation of systolic and diastolic function.
While echo isn’t used to diagnose arrhythmias (that’s EKG territory), it plays a vital role in evaluating their hemodynamic consequences. You might see fusion of E and A waves, irregular LV outflow patterns, or inconsistent timing of valve motion—all clues pointing toward a rhythm problem. For example, atrial fibrillation may erase the A wave entirely, atrial flutter can group beats together and alter diastolic timing, and PVCs often produce low-output, underfilled beats that affect stroke volume and Doppler tracing quality.
Even subtle findings—like inconsistent mitral inflow or unexpected pauses—can tip you off that something’s off rhythmically. And if you don't catch it, your measurements might look wildly abnormal (or falsely reassuring).
Understanding Rhythm Regularity
Regularly Regular:
The rhythm is completely consistent—each beat occurs at a predictable interval (e.g., normal sinus rhythm). The R-R intervals are equal or nearly equal.Regularly Irregular:
The rhythm has a repeating pattern of irregularity. For example, in Mobitz I (Wenckebach), the PR interval progressively lengthens before a beat is dropped, creating a predictable irregular rhythm.Irregularly Irregular:
There is no predictable pattern to the rhythm at all. The timing between beats varies randomly, as seen in atrial fibrillation.Ectopic/Interrupted Rhythm:
Occasional extra or missing beats (like PVCs) interrupt an otherwise regular rhythm. These create isolated irregularities rather than a consistent pattern.
In this article, we’ll walk through four of the most common rhythm issues seen on echo—atrial fibrillation, atrial flutter, premature ventricular contractions (PVCs), and heart blocks—and explore what they look like, how they affect the study, and what to watch for when they show up unexpectedly.