Relation of ultrasonic tissue characterization with integrated backscatter to contractile reserve in patients with chronic coronary artery disease

Abstract

SummaryBackground: Previous studies have shown that viable but stunned myocardium displays contractile reserve and exhibits cardiac cycle-dependent variations of integrated backscatter (CVIB), whereas infarcted myocardium does not.Hypothesis: This study was designed to clarify whether assessment of the acoustic properties of the myocardium can predict contractile reserve in patients with chronic coronary artery disease (CAD).Methods: In all, 21 patients with chronic CAD and 19 normal control subjects were studied. The magnitude of CVIB of the myocardium was measured in the basal and mid segment of the anterior septum and posterior wall of the left ventricle, using a real-time, two-dimensional integrated backscatter imaging system. The results were compared with the percent systolic wall thickening and the wall motion before and after revascularization. The wall motion was graded as normal, hypokinetic, or akinetic, and contractile reserve was considered present when an akinetic or hypokinetic segment improved after revascularization.Results: The average magnitude of CVIB was lower among dysfunctional segments of CAD than among normal segments of controls (3.73 ± 1.71 vs. 6.35 ± 0.69, p < 0.001). Of the 77 segments examined, 38 showed reversible dysfunction. Before revascularization, percent systolic wall thickening was similar among segments showing contractile reserve compared with those with persistent dysfunction myocardium (17.97 ± 8.41 vs. 16.83 ± 6.37%, p = 0.19), and the mean CVIB was significantly greater in segments with than in those without contractile reserve (4.73 ± 1.47 vs. 2.75 ± 1.31, p < 0.001). The CVIB above 3 dB before percutaneous transluminal coronary angioplasty predicted segments with con-

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

“…The results in Table 3 are for the parameters in Table 2, but indicate that the magnitude of cyclic variation did not correlate with any of these parameters. The results, coupled with previous studies that indicate that the magnitude of cyclic variation is altered in the presence of function- and structure-altering pathologies, suggest that the magnitude of the cyclic variation of backscatter is primarily influenced by systolic function as opposed to diastolic function (Naito 1996; Yuda 2002; Hu 2003). …”

Quantitative Analysis of the Magnitude and Time Delay of Cyclic Variation of Myocardial Backscatter from Asymptomatic Type 2 Diabetes Mellitus Subjects

“…This form of tissue characterization analysis has been employed to characterize a number of cardiac pathologies including ischemia (Barzilai et al 1984), myocardial infarction (Hancock et al 2002; Iwakura et al 2003; Ohara et al 2005), cardiac hypertrophy (Losi et al 2007; Masuyama et al 1989), and changes in myocardial size, structure, and function (Di Bello et al 1998; Giglio et al 2003; Hu et al 2003; Komuro et al 2005; Madaras et al 1983; Micari et al 2006; Naito et al 1996). One such study from our laboratory examined differences in magnitude and normalized time delay of cyclic variation of backscatter among type 1 diabetic patients with systemic complications and normal controls (Perez et al 1992).…”

Bayesian Parameter Estimation for Characterizing the Cyclic Variation of Echocardiographic Backscatter to Assess the Hearts of Asymptomatic Type 2 Diabetes Mellitus Subjects

“…Ultrasonic backscatter from myocardium has long been known to vary systematically over the cardiac cycle (Madaras et al, 1983; Mottley et al, 1984; Barzilai et al, 1984; Wickline et al, 1985; Mobley et al, 1995; Naito et al, 1996; Bello et al, 1998; Hu et al, 2003; Holland et al, 2004, 2007, 2009; Gibson et al, 2009). Quantification of this cyclic variation of myocardial backscatter has provided a tool for non-invasive ultrasonic tissue characterization in a range of pathologies, including diabetes (Gibson et al, 2009; Holland et al, 2007; Wagner et al, 1995; Bello et al, 1995; Pérez et al, 1992).…”

“…Traditionally, cyclic variation has been quantified by using the magnitude and time delay (phase) of the systematic variation of backscatter over the heart cycle. Both of these parameters have been shown to be useful for characterizing myocardial function (Holland et al, 2007; Gibson et al, 2009; Wagner et al, 1995; Bello et al, 1995; Hu et al, 2003; Finch-Johnston et al, 2000). However, other features of the cyclic variation waveform may be more sensitive to the early onset of diabetic cardiomyopathy.…”