The Diastolic Function to Cyclic Variation of Myocardial Ultrasonic Backscatter Relation: The Influence of Parametrized Diastolic Filling (PDF) Formalism Determined Chamber Properties

Lloyd, Christopher W.; Shmuylovich, Leonid; Holland, Mark; Miller, James G.; Kovács, Sándor J.

doi:10.1016/j.ultrasmedbio.2011.05.002

Cited by 2 publications

(1 citation statement)

References 47 publications

(67 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, the framework presented in this review allows the effects of, and interplay between, stiffness and relaxation to be appreciated, and, therefore, our approach provides a useful and physiologically legitimate way to quantify global DF. Application of this framework results in increased sensitivity and specificity in the clinical arena (57,72,77,99,100) and new precision and prediction of molecular and physiological phenomena (21,31,32,66,128). …”

Section: What Global Df Is and Is Notmentioning

confidence: 99%

What global diastolic function is, what it is not, and how to measure it

Chung

Shmuylovich

Kovács

2015

American Journal of Physiology-Heart and Circulatory Physiology

Self Cite

View full text Add to dashboard Cite

Leonardo da Vinci's observation (circa 1511) that "the atria or filling chambers contract together while the pumping chambers or ventricles are relaxing and vice versa," the dynamics of four-chamber heart function, and of diastolic function (DF) in particular, are not generally appreciated. We view DF from a global perspective, while characterizing it in terms of causality and clinical relevance. Our models derive from the insight that global DF is ultimately a result of forces generated by elastic recoil, modulated by cross-bridge relaxation, and load. The interaction between recoil and relaxation results in physical wall motion that generates pressure gradients that drive fluid flow, while epicardial wall motion is constrained by the pericardial sac. Traditional DF indexes (, E/E=, etc.) are not derived from causal mechanisms and are interpreted as approximating either stiffness or relaxation, but not both, thereby limiting the accuracy of DF quantification. Our derived kinematic models of isovolumic relaxation and suction-initiated filling are extensively validated, quantify the balance between stiffness and relaxation, and provide novel mechanistic physiological insight. For example, causality-based modeling provides load-independent indexes of DF and reveals that both stiffness and relaxation modify traditional DF indexes. The method has revealed that the in vivo left ventricular equilibrium volume occurs at diastasis, predicted novel relationships between filling and wall motion, and quantified causal relationships between ventricular and atrial function. In summary, by using governing physiological principles as a guide, we define what global DF is, what it is not, and how to measure it. diastolic function; echocardiography; hemodynamics; mathematical modeling; suction pump LEFT VENTRICULAR (LV) DIASTOLIC dysfunction is typically reported and indexed as either an increase in myocardial stiffness or a slowing of relaxation (i.e., cross-bridge dissociation). In actuality, diastolic function (DF) is the result of the continuous interaction between the restoring force of elastic recoil and the opposing force generated by cross bridges that have yet to uncouple from the previous systole. The restoring forces seek to lengthen the muscle, while the cross-bridge forces previously acted to shorten the muscle. The simultaneous action of these two opposing forces during both isovolumic relaxation (IVR) and filling result in wall motion, constrained by pericardial sac volume, and simultaneous generation of pressure gradients. This review discusses the governing physical laws and the constraints of DF, as well as which indexes of DF are consistent with diastolic physiology. Deriving and evaluating indexes of DF using this conceptual framework both clarifies and advances our understanding of DF and diastolic dysfunction in health and disease. Physiology of DiastoleCardiovascular physiology is taught using the Wiggers diagram, which segments the cardiac cycle into systole and diastole ( Fig. 1) (49, 124). Systole begins...

show abstract

Section: What Global Df Is and Is Notmentioning

confidence: 99%

What global diastolic function is, what it is not, and how to measure it

Chung

Shmuylovich

Kovács

2015

American Journal of Physiology-Heart and Circulatory Physiology

Self Cite

View full text Add to dashboard Cite

show abstract

Mechanistic validation of the 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging Guidelines for the assessment of diastolic dysfunction in heart failure with reduced ejection fraction

Goldberg

Megyessi

Flam

et al. 2020

Cardiovasc Ultrasound

View full text Add to dashboard Cite

Background The American Society for Echocardiography/European Association of Cardiovascular Imaging (ASE/EACVI) 2016 guidelines for assessment of diastolic dysfunction (DD) are based primarily on the effects of diastolic dysfunction on left ventricular filling hemodynamics. However, these measures do not provide quantifiable mechanistic information about diastolic function. The Parameterized Diastolic Filling (PDF) formalism is a validated theoretical framework that describes DD in terms of the physical properties of left ventricular filling. Aims We hypothesized that PDF analysis can provide mechanistic insight into the mechanical properties governing higher grade DD. Methods Patients referred for echocardiography showing reduced left ventricular ejection fraction (< 45%) were prospectively classified into DD grade according to 2016 ASE/EACVI guidelines. Serial E-waves acquired during free breathing using pulsed wave Doppler of transmitral blood flow were analyzed using the PDF formalism. Results Higher DD grade (grade 2 or 3, n = 20 vs grade 1, n = 30) was associated with increased chamber stiffness (261 ± 71 vs 169 ± 61 g/s2, p < 0.001), increased filling energy (2.0 ± 0.9 vs 1.0 ± 0.5 mJ, p < 0.001) and greater peak forces resisting filling (median [interquartile range], 18 [15–24] vs 11 [8–14] mN, p < 0.001). DD grade was unrelated to chamber viscoelasticity (21 ± 4 vs 20 ± 6 g/s, p = 0.32). Stiffness was inversely correlated with ejection fraction (r = − 0.39, p = 0.005). Conclusions Higher grade DD was associated with changes in the mechanical properties that determine the physics of poorer left ventricular filling. These findings provide mechanistic insight into, and independent validation of the appropriateness of the 2016 guidelines for assessment of DD.

show abstract

The Diastolic Function to Cyclic Variation of Myocardial Ultrasonic Backscatter Relation: The Influence of Parametrized Diastolic Filling (PDF) Formalism Determined Chamber Properties

Cited by 2 publications

References 47 publications

What global diastolic function is, what it is not, and how to measure it

What global diastolic function is, what it is not, and how to measure it

Mechanistic validation of the 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging Guidelines for the assessment of diastolic dysfunction in heart failure with reduced ejection fraction

Contact Info

Product

Resources

About