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OBJECTIVES: To validate the accuracy of real-time three-dimensional echocardiography (RT3DE) for quantifying aneurysmal left ventricular (LV) volumes. BACKGROUND: Conventional two-dimensional echocardiography (2DE) has limitations when applied for quantification of LV volumes in patients with LV aneurysms. METHODS: Seven aneurysmal balloons, 15 sheep (5 with chronic LV aneurysms and 10 without LV aneurysms) during 60 different hemodynamic conditions and 29 patients (13 with chronic LV aneurysms and 16 with normal LV) underwent RT3DE and 2DE. Electromagnetic flow meters and magnetic resonance imaging (MRI) served as reference standards in the animals and in the patients, respectively. Rotated apical six-plane method with multiplanar Simpson's rule and apical biplane Simpson's rule were used to determine LV volumes by RT3DE and 2DE, respectively. RESULTS: Both RT3DE and 2DE correlated well with actual volumes for aneurysmal balloons. However, a significantly smaller mean difference (MD) was found between RT3DE and actual volumes (-7 ml for RT3DE vs. 22 ml for 2DE, p = 0.0002). Excellent correlation and agreement between RT3DE and electromagnetic flow meters for LV stroke volumes for animals with aneurysms were observed, while 2DE showed lesser correlation and agreement (r = 0.97, MD = -1.0 ml vs. r = 0.76, MD = 4.4 ml). In patients with LV aneurysms, better correlation and agreement between RT3DE and MRI for LV volumes were obtained (r = 0.99, MD = -28 ml) than between 2DE and MRI (r = 0.91, MD = -49 ml). CONCLUSIONS: For geometrically asymmetric LVs associated with ventricular aneurysms, RT3DE can accurately quantify LV volumes.

OBJECTIVES: To determine the effect of preload in color M-mode Doppler flow propagation velocity (v(p)). BACKGROUND: The interpretation of Doppler filling patterns is limited by confounding effects of left ventricular (LV) relaxation and preload. Color M-mode v(p) has been proposed as a new index of LV relaxation. METHODS: We studied four dogs before and during inferior caval (IVC) occlusion at five different inotropic stages and 14 patients before and during partial cardiopulmonary bypass. Left ventricular (LV) end-diastolic volumes (LV-EDV), the time constant of isovolumic relaxation (tau), left atrial (LA) pre-A and LV end-diastolic pressures (LV-EDP) were measured. Peak velocity during early filling (E) and v(p) were extracted by digital analysis of color M-mode Doppler images. RESULTS: In both animals and humans, LV-EDV and LV-EDP decreased significantly from baseline to IVC occlusion (both p < 0.001). Peak early filling (E) velocity decreased in animals from 56 +/- 21 to 42 +/- 17 cm/s (p < 0.001) without change in v(p) (from 35 +/- 15 to 35 +/- 16, p = 0.99). Results were similar in humans (from 69 +/- 15 to 53 +/- 22 cm/s, p < 0.001, and 37 +/- 12 to 34 +/- 16, p = 0.30). In both species, there was a strong correlation between LV relaxation (tau) and v(p) (r = 0.78, p < 0.001, r = 0.86, p < 0.001). CONCLUSIONS: Our results indicate that color M-mode Doppler v(p) is not affected by preload alterations and confirms that LV relaxation is its main physiologic determinant in both animals during varying lusitropic conditions and in humans with heart disease.

Background — Myocardial fiber strain is directly related to left ventricular (LV) contractility. Strain rate can be estimated as the spatial derivative of velocities (dV/ds) obtained by tissue Doppler echocardiography (TDE). The purposes of the study were (1) to determine whether TDE-derived strain rate may be used as a noninvasive, quantitative index of contractility and (2) to compare the relative accuracy of systolic strain rate against TDE velocities alone. Methods and Results — TDE color M-mode images of the interventricular septum were recorded from the apical 4-chamber view in 7 closed-chest anesthetized mongrel dogs during 5 different inotropic stages. Simultaneous LV volume and pressure were obtained with a combined conductance–high-fidelity pressure catheter. Peak elastance (E max ) was determined as the slope of end-systolic pressure-volume relationships during caval occlusion and was used as the gold standard of LV contractility. Peak systolic TDE myocardial velocities (S m ) and peak (ε′ p ) and mean (ε′ m ) strain rates obtained at the basal septum were compared against E max by linear regression. E max as well as TDE systolic indices increased during inotropic stimulation with dobutamine and decreased with the infusion of esmolol. A stronger association was found between E max and ε′ p ( r =0.94, P y =0.29 x +0.46) and ε′ m ( r =0.88, P m ( r =0.75, P Conclusions — TDE-derived ε′ p and ε′ m are strong noninvasive indices of LV contractility. These indices appear to be more reliable than S m , perhaps by eliminating translational artifact.

Myocardial tissue Doppler echocardiography (TDE) has been proposed as a tool for the assessment of diastolic function. Controversy exists regarding whether TDE measurements are influenced by preload. In this study, left ventricular volume and high-fidelity pressures were obtained in eight closed-chest dogs during intermittent caval occlusion. The time constant of isovolumic ventricular relaxation (τ) was altered with varying doses of dobutamine and esmolol. Peak early diastolic myocardial ( E m) and transmitral ( E) velocities were measured before and after preload reduction. The relative effects of changes in preload and relaxation were determined for E m and compared with their effects on E. The following results were observed: caval occlusion significantly decreased E (Δ E = 16.4 ± 3.3 cm/s, 36.6 ± 13.7%, P < 0.01) and E m (Δ E m = 1.3 ± 0.4 cm/s, 32.5 ± 26.1%, P < 0.01) under baseline conditions. However, preload reduction was similar for E under all lusitropic conditions ( P = not significant), but these effects on E m decreased with worsening relaxation. At τ < 50 ms, changes in E m with preload reduction were significantly greater (Δ E m = 2.8 ± 0.6 cm/s) than at τ = 50–65 ms (Δ E m = 1.2 ± 0.2 cm/s) and at τ >65 ms (Δ E m = 0.5 ± 0.1 cm/s, P < 0.05). We concluded that TDE E m is preload dependent. However, this effect decreases with worsening relaxation.

The Maze procedure for atrial arrhythmias is designed to eliminate atrial fibrillation, and preserve atrial function. Initial data after short-term follow-up indicates that 60% patients show restoration of atrial systolic function. The long-term evaluation by echo-Doppler of left and right atrial function has not been well studied. We performed pulsed Doppler and two dimensional echocardiographyon 19 patients (16 males, mean age 54 years) who underwent the Maze procedure for atrial fibrillation and who had a follow-up study greater than 3 months (mean duration = 17 months) after the procedure. Measurements included the peak left ventricular (LV) inflow and right ventricular (RV) inflow A-wave velocity, maximum (Max) and minimum (Min) off-line digitized left atrial (LA) and right atrial (RA) areas and fractional area change (FAC). Left Atrium Right Atrium Pre Post Pre Post Max (cm 2 ) 26.1 23.1 20.8 21.7 Min (cm 2 ) 19.6 18.1 16.0 17.6 FAC (%) 27.0 22.0 23. 20.0 Twelve patients (63%) had evidence of LA function, while 16 patients (84%) had evidence of RA function. The LV inflow A-wave velocity (33 ± 9 cm/s) and the RV inflow A-wave velocity (35 ± 12 cm/s) did not differ significantly; however, the LA inflow A-wave was significantly lower than agematched controls (59 ± 14, p l 0.001). Both the mean LA FAC and the RA FAC tended to decrease at follow-up (p = 0.13). Conclusions 1) In long-term follow-up of 17 months after the Maze procedure, left atrial systolic function is preserved in 63% of patients, while the right atrial systolic function is preserved in 86% of patients. 21 LA peak A-wave velocity post Maze is considerably less than that shown in agematched controls. These findings suggest that the Maze procedure is only partially successful in achieving its goals of preserving atrial function.

Objectives.This study sought to establish the prognostic implications of ischemic and viable myocardium identified by dobutamine echocardiography in patients with left ventricular dysfunction.Background.Recent studies have suggested that in patients with viable myocardium identified by positron emission tomography, medical treatment is associated with recurrent cardiac events. Dobutamine echocardiography has been used to identify viable myocardium in patients with left ventricular dysfunction, but the prognostic significance of this test is undefined.Methods.One hundred thirty-six consecutive patients (mean [±SD] age 67 ± 7.9 years; 104 men) with moderate or severe left ventricular dysfunction (left ventricular ejection fraction 30 ± 5%) undergoing dobutamine echocardiography were included in the study. Dobutamine was administered using a standard incremental protocol (5 to 40 μg/kg body weight per min intravenously in 3-min stages) with additional atropine (1 mg intravenously) as required. Standard body weight echocardiographic views were digitized on-line and compared using a side-by-side display. Viable myocardium was identified by enhancement of regional function at low dose (