Effects of ultrasound energy application on cardiac performance in open-chest Guinea pigs.
BACKGROUND
Although ultrasound (US) is widely used in cardiology, little is known about the effects of US energy on cardiac performance. This study aimed to investigate the mechanical effects of high-intensity continuous US energy (1.0 MHz with 3 different intensities) on cardiac performance.


RESULTS
Either left ventricular (LV) pressure or aortic blood flow (ABF) was evaluated in open-chest guinea pigs (n=30) under surface ECG monitoring. LV systolic pressure and ABF increased significantly (ie, maximum percent increases in these parameters were 2.5%, 3.1% and 7.1% for LV systolic pressure and 9.4%, 4.9% and 8.8% for mean ABF at intensities of 0.06, 0.67 and 2.90 W/cm2, respectively). LV end-diastolic pressure was reduced significantly by US (5.3+/-0.9 to 4.8+/-0.8, 5.5 +/-1.3 to 4.8+/-1.0 and 5.8+/-2.0 to 5.0+/-1.2 mmHg, respectively), indicating positive inotropic and lusitropic effects and resultant ABF augmentation. Local temperature was not significantly changed. ECG showed neither chronotropic action nor arrhythmogenesis.


CONCLUSIONS
Although the basic mechanisms of these phenomena remain unclear, this pilot study of the short-term effects of US energy on cardiac performance suggests the possibility of physical therapy for heart failure.
Kuma
Fumiaki
F
Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
Ueda
Norihiro
N
Ito
Hiroyuki
H
Maruyama
Toru
T
Kaji
Yoshikazu
Y
Fujino
Takehiko
T
Harada
Mine
M
D000818:Animals; D001011:Aorta / Q000502:physiology; D001775:Blood Circulation; D003326:Coronary Circulation; D004562:Electrocardiography; D006168:Guinea Pigs; D006333:Heart Failure / Q000628:therapy; D006334:Heart Function Tests; D008297:Male; D010865:Pilot Projects; D014464:Ultrasonic Therapy / Q000009:adverse effects*; D014465:Ultrasonics / Q000009:adverse effects*; D016277:Ventricular Function, Left