(Circulation. 1995;91:171-175.)
© 1995 American Heart Association, Inc.
Articles |
Relation of Ultrasonic Backscatter and Acoustic Propagation Properties to Myofibrillar Length and Myocardial Thickness
From the Medical College of Wisconsin (P.D.O'B., D.C.W., K.B.S.), Milwaukee, Wis; the University of Illinois (W.D.O'B.Jr.) (Urbana); and General Electric, Inc (T.L.R.), Milwaukee, Wis.
Correspondence to Kiran B. Sagar, MD, Medical College of Wisconsin, Division of Cardiology, 8700 W Wisconsin Ave, Box 123, Milwaukee, WI 53226.
Background Ultrasonic backscatter demonstrates a cardiac cycle–dependent modulation. The exact mechanism of the modulation is under debate. The objective of the present study was to test the hypothesis that a change in size and configuration of myofilaments from systole to diastole alters acoustic propagation properties and backscatter.
Methods and Results In vivo measurements were made of integrated backscatter at 5 MHz (IBR5), followed by in vitro measurements of ultrasonic attenuation, speed, and heterogeneity index using a scanning laser acoustic microscope at 100 MHz. Studies were performed in canine hearts (16) arrested in systole (8) with calcium chloride or arrested in diastole (8) with potassium chloride. Sarcomere length was measured with a calibrated eyepiece on a Ziess microscope. Wall thickness was measured with calipers. The attenuation coefficient of 220±34 dB/cm during systole was significantly higher than the coefficient of 189±24 dB/cm during diastole (P<.01); the IBR5 of -44.7±1.2 dB during systole was significantly greater than the IBR5 of -47.0±1.0 dB during diastole (P<.01); the ultrasonic speed of 1591±11 m/s during systole was higher than the speed of 1575±4.2 m/s during diastole (P<.01); and the heterogeneity index of 7.4±1.8 m/s during systole was significantly lower than the index of 9.0±2.0 m/s during diastole (P<.02). The sarcomere length of 1.804±0.142 µm during diastole was significantly higher than the length of 1.075±0.177 µm during systole (P<.01). Wall thickness was significantly greater during systole than during diastole (20±3 versus 9±3 mm, P<.01).
Conclusions Ultrasonic backscatter and propagation properties are directly related to sarcomere length and myocardial thickness and may be responsible for cardiac cycle–dependent variation in backscatter.
Key Words: backscatter • ultrasound • tissue propagation • myofilaments
This article has been cited by other articles:
 |
|
 |
|
  A. Micari, M. Pascotto, A. R. Jayaweera, J. Sklenar, N. C. Goodman, and S. Kaul Cyclic variation in ultrasonic myocardial integrated backscatter is due to phasic changes in the number of patent myocardial microvessels. J. Ultrasound Med., August 1, 2006; 25(8): 1009 - 1019. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Lasserre, P. Gosse, and S. Mansour Myocardial Tissue Characterization in Echocardiography with Videodensitometry: Evaluation of a New Semi-automatic Software Applied on a Population of Hypertensive Patients Eur J Echocardiogr, December 1, 2003; 4(4): 292 - 299. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Giglio, V. Pasceri, L. Messano, F. Mangiola, L. Pasquini, A. Dello Russo, A. Damiani, M. Mirabella, G. Galluzzi, P. Tonali, et al. Ultrasound tissue characterization detectspreclinical myocardial structural changes inchildren affected by Duchenne muscular dystrophy J. Am. Coll. Cardiol., July 16, 2003; 42(2): 309 - 316. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Koyama, P. A. Ray-Sequin, and R. H. Falk Prognostic Significance of Ultrasound Myocardial Tissue Characterization in Patients With Cardiac Amyloidosis Circulation, July 30, 2002; 106(5): 556 - 561. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Imasaka, S. Morita, I. Nagano, M. Masuda, R. Tominaga, and H. Yasui Coronary artery bypass grafting on the beating heart evaluated with integrated backscatter Ann. Thorac. Surg., September 1, 2000; 70(3): 1049 - 1053. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Masugata, S. Senda, A. Kinoshita, Xin Lu, H. Sakamoto, S. Sakamoto, H. Matsuo, and K. Mizushige Tissue Characterization of Myocardial Cells by Use of High-Frequency Acoustic Microscopy: Differential Myocyte Sound Speed and Its Transmural Variation in Normal, Pressure-Overload Hypertrophic, and Amyloid Myocardium Angiology, October 1, 1999; 50(10): 837 - 845. [Abstract] [PDF]
|
|
|
|
|
|
H. Masugata, K. Mizushige, S. Senda, Xin Lu, A. Kinoshita, H. Sakamoto, S. Nozaki, S. Sakamoto, and H. Matsuo Evaluation of Left Atrial Wall Elasticity Using Acoustic Microscopy Angiology, July 1, 1999; 50(7): 583 - 590. [Abstract] [PDF]
|
|
|
|
 |
|
 V. Di Bello, R. Pedrinelli, D. Giorgi, A. Bertini, L. Talarico, M. T. Caputo, B. Massimiliano, G. Dell'Omo, M. Paterni, and C. Giusti Ultrasonic Videodensitometric Analysis of Two Different Models of Left Ventricular Hypertrophy : Athlete's Heart and Hypertension Hypertension, April 1, 1997; 29(4): 937 - 944. [Abstract] [Full Text]
|
|
|
|
 |
|
 E. K. Louie and D. S. Louie New Echocardiographic Technology: Does it Add to Clinical Decision-Making? Seminars in Cardiothoracic and Vascular Anesthesia, March 1, 1997; 1(1): 16 - 31. [PDF]
|
|