Sinus Arrhythmia
photo and audio recording by Janelle Aby, MD interactive image provided by http://expand2web.com
During ascultation of the heart, an assessment of the rhythm is important. In the newborn, because heart rate is the primary contributor to cardiac output and may vary considerably with breathing and activity, rhythm can at times be difficult to assess. In the patient above, marked variability of heart rate in can be heard at the left upper sternal border and over the left lateral chest. At the left lower sternal border, the variability is also associated with an exaggerated pause between two beats. EKG showed this to be a benign sinus arrhythmia. The baby was asymptomatic and the irregularity improved over the next two days. No treatment was required.
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