The three main causes of holosystolic murmurs are mitral valve regurgitation, tricuspid valve regurgitation, and a ventricular septal defect. On rare occasion, Gallavardin dissociation from aortic stenosis can radiate to the cardiac apex where it may sound holosystolic and mimic the murmur of mitral regurgitation. Using handgrip exercises would increase the murmur of mitral regurgitation, but not change that of aortic stenosis which is helpful to distinguish these two.