Figure 200d

The left panel: Wide physiological splitting of S2 is seen in a patient with complete RBBB. Audible expiratory splitting that widens normally with inspiration is present. Also, note the wide splitting of the first heart sound into its mitral (M 1) and tricuspid (T 1) components, as recorded at the apex. The base phonocardiogram is recorded simultaneously with high-fidelity catheters in the right ventricle and pulmonary artery during cardiac catheterization. There is marked prolongation of the Q to the onset of the right ventricular pressure rise of 96 ms resulting in wide physiologic splitting of S2. The delayed P2 is secondary to the delayed activation of the right ventricle.