In cardiovascular physical examination, auscultation is organized around three sequential listening phases (heart sounds, systole, diastole), with the first (S1: mitral/tricuspid closure) and second (S2: aortic/pulmonic closure) heart sounds defining the cardiac cycle, and additional gallop sounds (S3, S4) providing diagnostic information about ventricular filling and compliance. Physiologic splitting of S2 during inspiration reflects normal respiratory-driven changes in right heart filling and pulmonic valve closure timing, while paradoxic splitting (e.g., from left bundle branch block) reflects delayed aortic valve closure; stethoscope choice (diaphragm for high-pitched sounds, bell for low-pitched sounds) and patient positioning are applied according to the acoustic properties and physiologic origin of each sound.
In cardiovascular physical examination, auscultation is organized around three sequential listening phases (heart sounds, systole, diastole), with the first (S1: mitral/tricuspid closure) and second …