Evaluation of a theoretical doppler index to noninvasively estimate peak dp/dt using continuous wave doppler ultrasound of ascending aortic flow in man

Abstract

A theoretical formula for calculation of peak dP/dt was derived using parameters obtained from continuous wave Doppler echocardiography signals of aortic blood flow. The direct proportional relationship between the main variables of this formula and invasively measured peak dP/dt was validated in 20 patients undergoing routine diagnostic cardiac catheterization. Doppler signals of aortic flow were obtained simultaneously to invasive pressure recordings with a 2 MHz continuous wave transducer via the suprasternal echocardiographic window. The Doppler signals were recorded on magnetic tape and measurements were made with digital calipers by two independent, blinded observers. The following parameters were measured: peak velocity (V) and time from onset of ejection to peak velocity (T). V2/T, the variable of the derived formula, was calculated for each of the observer's measured parameters and showed a very high interobserver correlation. The two observers' measurements of each parameter were averaged for each patient and the resulting mean was used in calculating the V2/T and mean acceleration. 4. A good correlation of V2/T with invasively measured peak dP/dt was obtained. Our derived index of left ventricular function showed a higher correlation with peak dP/dt compared to other Doppler indices of ventricular function. V2/T may provide a noninvasive method for estimating peak dP/dt.

Aortic acceleration as a noninvasive index of left ventricular contractility in the mouse

“…4A) and in agreement with the findings by others 11,34,35 , but found that correlation coefficient of P′ versus v p was the lowest of the four parameters we evaluated. Hunt et al also found that P′ had the lowest correlation to v p 34 and Lambert et al reported that that v p was much less sensitive than mean or peak aortic accelerations in assessing LV contractility 25 .…”

“…researchers have attempted to develop noninvasive indices of cardiac contractility in humans 11,[34][35][36] and in animal models, like dogs 5,32,37,38 , pigs 7,39 , sheep 8,40 , rabbits 41 , rats 9,42,43 and even in mice 44 . The noninvasive methods included echocardiography [44][45][46] , tissue Doppler imaging 47 , Tei index 48,49 , maximal rate of change aortic volume flow 38 , to list a few.…”

“…The parameter peak aortic velocity squared/rise time (v p 2 /T) was adopted from Hunt et al, who derived a mathematical equation from the basic principle that force generated by LV translates into kinetic energy of blood flow, implying that P′ was directly proportional to v p 2 /T and found that v p 2 /T had the best correlation with P′ in humans (r = 0.77, p < 0.001) 34 . In this study we found P′ had the second highest and significant correlation v p 2 /T (r = 0.93; Fig.…”

A simultaneous study of doppler‐echo and catheterization in noninvasive assessment of the left ventricular dp/dt

“…7 Graph showing correlation between LV-dp/dt derived by Doppler and LV-dp/dt measured by fluid-filled catheter in the 21 patients. y = 0.741 x + 487.60, r = 0.90, SEE = 325 mmHg/s, p < 0.001.…”

Fusion of Color Doppler and Magnetic Resonance Images of the Heart

“…Color Doppler blood flow imaging is the primary method for the detection of hemodynamic changes within the heart in clinical practice [3]. However, compared with magnetic resonance imaging (MRI), echocardiography has its limitation for testing structure because of the poor resolution of ultrasound and disadvantage of the field of view (FOV) [4].…”