Systolic tremor is a small vibration sensation felt in the palm of the hand during palpation, similar to the respiratory tremor felt in the larynx of cats, also known as feline wheezing. The mechanism of tremor is the same as that of interstitial tremor. It is caused by the flow of blood through a narrow caliber or in an abnormal direction to form a vortex that causes vibration of the valve, vessel wall, or heart chamber wall to the chest wall. When tremor is detected, the site and source (valve, large vessel, or septal defect) should be determined first, followed by the phase of the cardiac cycle (systolic, diastolic, or continuous), and finally by an analysis of its clinical significance. The following diseases can cause systolic tremor: 1. Systolic tremor at the second intercostal space on the right edge of the sternum, commonly associated with aortic stenosis. 2, Systolic tremor at the second intercostal space on the left border of the sternum, commonly associated with pulmonary stenosis. 3, Systolic tremor between the third and fourth ribs of the left sternal border, commonly associated with ventricular septal defect 4, Systolic tremor in the apical region, commonly associated with severe mitral valve insufficiency.