Figure 6From: Digital Subtraction Phonocardiography (DSP) applied to the detection and characterization of heart murmurs Sample PCGs (first & second panels) from a simulated ASD patient. Murmurgram (third graph) between S1 and S2 isn't "flat". The murmur has frequency components that extend to over 600 Hz. The second heart sound is clearly split in both PCG tracings (Simulated Case 3).Back to article page