This is a young woman with new systolic heart failure related to drug use. There is a gallop and because of tachycardia, it is difficult to determine whether it’s an S3 or an S4. It could be a summation gallop. (Notes: Oddly S2 appears to be the loudest sound over the apex and not S1. But this is only way it could be. The extra sound is just after S2 or just before S1, so could either be a 3 or a 4).