重合奔馬調律
- S3とS4が癒合
- If a patient with a quadruple rhythm develops tachycardia, disatole becomes shorter in duration, the S3 and S4 colesce, and a summation gallop results. The summation of S3 and S4 is heard as a long middiastolic, low-pitched sound, often louder than S1 and S2. (PHD.38)