Diastolic Backward-Traveling Decompression (Suction) Wave Correlates With Simultaneously Acquired Indices of Diastolic Function and Is Reduced in Left Ventricular Stunning

Abstract

4As coronary flow is predominantly diastolic, the predominant driver of coronary flow, particularly in the left coronary artery, 5 is thought to be the BEW (or suction wave), generated by myocardial microcirculatory decompression in early diastole. 4 It has been suggested that the measurement of the BEW might have future utility in testing myocardial viability at the time of percutaneous coronary intervention (PCI) 6 or even predicting the timing of intervention in aortic valve disease. 7 The BEW has been shown to correlate with parameters known to be associated with LV diastolic performance, 4 specifically LV hypertrophy. However, in patients with coronary disease, coronary wave intensity has not previously been compared with simultaneously acquired LV hemodynamics, fromBackground-Wave intensity analysis can distinguish proximal (propulsion) and distal (suction) influences on coronary blood flow and is purported to reflect myocardial performance and microvascular function. Quantifying the amplitude of the peak, backwards expansion wave (BEW) may have clinical utility. However, simultaneously acquired wave intensity analysis and left ventricular (LV) pressure-volume loop data, confirming the origin and effect of myocardial function on the BEW in humans, have not been previously reported. Methods and Results-Patients with single-vessel left anterior descending coronary disease and normal ventricular function (n=13) were recruited prospectively. We simultaneously measured LV function with a conductance catheter and derived wave intensity analysis using a pressure-low velocity guidewire at baseline and again 30 minutes after a 1-minute coronary balloon occlusion.

Major influence of a ‘smoke and mirrors’ effect caused by wave reflection on early diastolic coronary arterial wave intensity

“…In the experimental data, a strong correlation was found between the size of the incident wave (FDW A→C ) and BDW dia (R 2 > 0.6), but there was no correlation with LV τ and only a weak-to-moderate correlation with LV dP/dt min (R 2 = 0.3) that lost significance in a multivariate model. Previous studies have reported R 2 values of 0.21−0.35 between LV dP/dt min and the coronary BDW dia , in agreement with our findings (Kyriacou et al 2012;Ladwiniec et al 2016), although Ladwiniec and colleagues also reported a correlation (R 2 = 0.35) between LV τ and BDW dia (Ladwiniec et al 2016).…”

“…; Ladwiniec et al . ; Raphael et al . ) and has been interpreted to arise from transmission of the aortic FCW dia into the coronary arteries (Davies et al .…”

“…), although Ladwiniec and colleagues also reported a correlation ( R 2 = 0.35) between LV τ and BDW dia (Ladwiniec et al . ).…”

“…While the current explanations for early-diastolic coronary arterial waves are intuitive, they have not been confirmed by any direct approach, while close inspection of published coronary WIA data suggest that the picture is not yet complete. Specifically, although correlations have been observed between BDW dia magnitude and indices of isovolumic relaxation derived from LV cavity pressure, the reported R 2 values (0.21-0.35) suggest that more than 60% of the variability in BDW dia magnitude is currently unexplained (Kyriacou et al 2012;Ladwiniec et al 2016). Indeed, it is unclear why the BDW dia is much larger than a backward compression wave occurring during iso-volumic contraction (BCW ic , Fig.…”

“…; Ladwiniec et al . ). Indeed, it is unclear why the BDW dia is much larger than a backward compression wave occurring during isovolumic contraction (BCW ic , Fig.…”