Author + information
- Received June 5, 1984
- Revision received August 3, 1984
- Accepted August 22, 1984
- Published online February 1, 1985.
- Toshiyuki Ishimitsu, MD,
- Damon Smith, BME,
- Barbara Berko, MD and
- Ernest Craige, MD, FACCa
- ↵aAddress for reprints: Ernest Craige, MD, 338 Clinical Sciences Building 229H, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27514.
To investigate the left ventricular wall dynamics conducive to the third heart sound (S3) in both hyper- and hypodynamic filling conditions, eight dogs were studied in which an S3was produced by hypoxemia and in eight others by acute mitral regurgitation. Pulse transit sonomicrometry crystals were used to measure external left ventricular dimension dynamics in the two principal axes. A miniature accelerometer was used to detect the epicardial S3vibration. The development of the S3was invariably associated with an increased peak velocity of long-axis external dimensional expansion in early diastole. This enhanced long-axis filling activity was not dependent on increased global chamber or short-axis filling dynamics and sometimes occurred when global filling rate was unchanged. In addition, the short-axis filling rate was sometimes reduced as the S3developed.
It is concluded that the common denominator of S3generation in this acute dog model is exaggerated longaxis diastolic expansion activity which is present in both hyper- and hypodynamic left ventricular filling.
This study was supported by Grant 5-RO1-HL27459-03 from the National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland and the Henry A. Foscue Fund of the University of North Carolina Medical Foundation, Chapel Hill, North Carolina.
- Received June 5, 1984.
- Revision received August 3, 1984.
- Accepted August 22, 1984.
- American College of Cardiology Foundation