Feasibility of non-invasive measurement of the left ventricular max (dp/dt) by continuous recording of the ascending aortic diameter change: principle and experimental study.
If a method produces a pressure contour with an arbitrary relative amplitude and without a base line, i.e. a pressure tracing without scale, and another method gives two out of the following three values: peak; bottom; and mean pressures, then we can obtain a pressure contour with a specified pressure scale. We can also obtain the value of the derivative of pressure with respect to time. If the curve of the ascending aortic diameter change closely resembles the pressure contour at the same portion (assumption 1), we can obtain the aortic pressure contour with an arbitrary pressure scale measuring the aortic diameter by a non-invasive ultrasonic method. The aortic peak systolic, end-diastolic and mean pressures can be measured by other non-invasive methods. Therefore, we can specify the pressure scale of the contour, and obtain the maximum derivative of the aortic pressure. If the maximum derivative of the left ventricular pressure (max dp/dt) can be substituted by that of the aortic pressure (assumption 2), we can obtain the former (max dp/dt) by non-invasive measurements only. We confirmed assumptions 1 and 2 by animal experiments, and showed the feasibility of non-invasive measurements of the left ventricular max (dp/dt) by interpreting the aortic diameter change curve as the pressure contour.
Akiyama
K
K
Department of Cardiovascular Surgery, Heart Institute of Japan, Tokyo Women's Medical College.
Sugawara
M
M
Beppu
T
T
Harada
Y
Y
Higashidate
M
M
Koyanagi
H
H
D000818:Animals; D001011:Aorta / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000187:drug effects; D001794:Blood Pressure; D004285:Dogs; D004452:Echocardiography / Q000379:methods; D005240:Feasibility Studies; D006339:Heart Rate / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D008729:Methoxamine / Q000494:pharmacology; D008991:Monitoring, Physiologic / Q000379:methods; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D016277:Ventricular Function, Left / Q000187:drug effects / Q000502:physiology*
D011433:Propranolol; D008729:Methoxamine; D007545:Isoproterenol; D010646:Phentolamine