High-definition blood flow imaging in the assessment of left ventricular function: Initial experience and comparison with contrast echocardiography.

OBJECTIVES: The study aimed to assess the accuracy and reproducibility of the high-definition blood flow imaging (HD-Flow) in evaluation of left ventricular (LV) function by comparison with contrast echocardiography (Contrast). BACKGROUND: Contrast improves endocardial border visualization and assists in precise assessment of LV function. HD-Flow, a novel ultrasound technique that enhances blood flow discrimination in LV, could possibly be used for improving endocardial border definition without contrast. METHODS: Eighty patients with technically limited transthoracic echocardiograms had HD-Flow, and contrast performed sequentially. LV endocardial visualization, image acquisition time, wall motion, volumes, ejection fraction (EF), stroke volume (SV), and stroke volume index (SVI) were compared. Inter- and intra-observer agreements were examined in a randomly selected subgroup. RESULTS: Both HD-Flow and contrast significantly improved the percentage of the well-defined endocardial border segments (71% at baseline vs 94.1% by HD-Flow vs 94.9% by contrast, X2  = 401, P < 0.001). The acquisition time for HD-Flow was significantly less when compared to contrast (2.13 ± 1.18 minutes vs 10.96 ± 3.51 minutes, P < 0.001). LV end-diastolic volume (EDV), end-systolic volume (ESV), EF, SV, and SVI measured by the two methods correlated well (EDVr = 0.97, ESVr = 0.96, EFr = 0.90, SVr = 0.77, SVIr = 0.74, all P < 0.001). In comparison, HD-Flow was neither significantly different in detecting LV wall motion abnormality nor in EF, SV, and SVI measurements, but slightly underestimated LV volumes. CONCLUSIONS: HD-Flow imaging is feasible and user-friendly in enhancing LV endocardial definition. This technique is useful in both qualitative and quantitative assessment of LV function.

Real time three-dimensional echocardiography and endovascular stenting.

A 52-year-old male with HIV and chronic renal failure presented with 2-day history of fever and chills. He had recent superior vena cava (SVC) stent placement for SVC stenosis following multiple dialysis-catheter insertions. Patient's blood cultures grew methicillin-resistant staphylococcus aureus. Two-dimensional (2D) echocardiography showed no vegetations. With high clinical suspicion, 2D transesophageal echocardiogram (TEE) was obtained and confirmed no endocarditis and patent stent at SVC right atrial junction; however, entire stent was not visualized. Simultaneous three-dimensional TEE provided superior views of SVC stent in cross-sectional and longitudinal planes, clearly demonstrating patent stent without vegetations, stenosis, migration, or thrombosis.

Assessment of left atrial appendage by live three-dimensional echocardiography: early experience and comparison with transesophageal echocardiography.

BACKGROUND: Live Three-Dimensional Echocardiography (L3D, Sonos 7500, Philips) has the potential to visualize all cardiac structures including left atrial appendage (LAA). We tested the feasibility of evaluating LAA by L3D and compared the findings to transthoracic echocardiography (2D) and in a subset of patients with transesophageal echocardiography (TEE). METHODS: L3D images were obtained in 204 consecutive patients referred for routine 2D or TEE. We performed wide-angled acquisitions from parasternal and apical views. TomTec system (4D Cardio-view, RT 1.2) was used to visualize LAA from multiple vantage points. RESULTS: LAA was adequately visualized by L3D in 139 of 204 (68.1%) patients. L3D visualization was dependent on image quality, suboptimal in 100 and diagnostic in 104 patients. Overall, LAA was visualized in 93 (45.5%) patients by 2D compared to 139 (68.1%) by L3D (P < 0.0001). In 100 patients with suboptimal image quality by L3D, LAA visualization was 16% by 2D and 35% by L3D, whereas in 104 patients with diagnostic images, LAA was visualized in 77 (74%) by 2D and in all 104 (100%) patients by L3D (P < 0.0001). In 37 patients referred for transesophageal echocardiography (TEE), live three-dimensional echocardiography (L3D) visualized left atrial appendage (LAA) in 34 patients with diagnostic image quality. Eight patients with LAA thrombi on TEE had thrombi detected by L3D as well. All patients with LAA thrombus had enlarged LA by both 2D and TEE. CONCLUSIONS: L3D is a promising technique in evaluation of LAA with and without thrombi. In patients with good quality transthoracic images L3D may be used as a screening tool in assessment of LAA.

Color M-mode flow propagation velocity and conventional doppler indices in the assessment of diastolic left ventricular function during isometric exercise.

BACKGROUND AND OBJECTIVE: Color M-mode flow propagation velocity (Vp) was shown to be a preload-independent measure of diastolic function. To study the effects of an increase in afterload induced by isometric handgrip exercise on diastolic function assessment in patients with cardiomyopathy, we measured Vp and conventional Doppler indices at baseline and at 30% of predetermined maximum handgrip strength. METHODS: Twenty-four patients with systolic dysfunction were divided into two groups: Group I comprising 12 patients with E/A < 1 (early filling velocity/atrial contraction velocity) and Group II comprising 12 patients with E/A > 1. All the patients underwent measurement of Vp, E velocity, its deceleration time (DT), A velocity, isovolumic relaxation time (IVRT), and pulmonary atrial flow reversal velocity (PFR) at baseline and at 30% of predetermined maximum handgrip strength. Twelve healthy controls underwent these same measurements. RESULTS: When comparing baseline to peak echocardiographic data, no significant changes were noted in Vp in any of the groups while a shift of pulsed Doppler indices of Group I toward a pattern closer to that of Group II was noted and a decrease in E velocity and E/A ratio with an increase in IVRT occurred in healthy controls. CONCLUSIONS: Color M-mode flow propagation velocity seems to be an afterload-independent measure of diastolic function in patients with moderate to severe cardiomyopathy while pulsed Doppler indices are more sensitive to loading conditions induced by isometric exercise.

Rapid screening of cardiac patients with a miniaturized hand-held ultrasound imager--comparisons with physical examination and conventional two-dimensional echocardiography.

BACKGROUND: Rapid screening of cardiac patients with a hand-held ultrasound imager (SonoHeart [SH]) could provide valuable clinical information. HYPOTHESIS: Whether the use of this device yields additional information to a carefully conducted physical examination and comparable findings to those of conventional two-dimensional echocardiography (2-D) during inpatient rounds is not well established and is the subject of this study. METHODS: In all, 100 consecutive telemetry patients underwent rapid screening with 2-D and color Doppler SH during inpatient rounds. SonoHeart findings were compared with results from conventional 2-D and physical examination conducted by an attending cardiologist. RESULTS: All patients had interpretable images. Mean scanning time with SH was 5.0 +/- 1.2 min; 2-D and SH findings were comparable. The parameters studied included chamber sizes, left ventricular (LV) systolic function, presence of LV hypertrophy (LVH), wall motion abnormalities (WMA), pericardial effusion (PE), and valvular regurgitations. Mild to moderate valvular regurgitation and LV systolic dysfunction were reliably diagnosed by SH in a number of patients whose symptoms were unrelated to the abnormalities detected. CONCLUSIONS: Rapid screening with SH provides accurate and valuable information that would otherwise be undetected during physical examination. Its introduction into clinical practice may redefine the initial approach to patients with cardiovascular disease.

Real-time three-dimensional echocardiography versus two-dimensional echocardiography in the diagnosis of left ventricular apical thrombi: preliminary findings.

PURPOSE: Real-time 3-dimensional transthoracic echocardiography (RT-3D-TE) with real-time volume rendering (RTVR) offers multiple simultaneous views and spatial definition of intracardiac structures superior to that attainable by 2-dimensional transthoracic echocardiography (2D-TE). We hypothesized that RT-3D-TE would therefore improve identification of left ventricular apical thrombi (LVT). METHODS: Patients were referred to our echocardiography laboratory over an 8-month period. Those diagnosed with a "suspicious" or "definite" LVT on the basis of 2D-TE images underwent RT-3D-TE on the same day. All 2D-TE, RT-3D-TE, and RTVR images were reviewed by 2 independent observers. RT-3D-TE findings were considered positive for LVT if LVT was visualized in both B-scan (apical orthogonal) and C-scan (short axis, with and without tilting angle) planes and on RTVR images, nondiagnostic (or suspicious) for LVT if it was not visualized in all planes, and negative for LVT if it was not visualized in any plane. RESULTS: Thirty patients (19 men and 11 women) with a mean age (+/- standard deviation) of 52 +/- 13 years were enrolled. The interobserver agreement coefficient was 63% for 2D-TE interpretations of LVT and 93% for RT-3D-TE interpretations of LVT (p<0.05). The final interpretations by RT-3D-TE with RTVR were positive for LVT in 16 patients (53%), suspicious for LVT in 4 patients (13%), and negative for LVT in 10 patients (30%). CONCLUSIONS: RT-3D-TE with RTVR offers dramatically clearer echocardiographic findings than does 2D-TE. In particular, RT-3D-TE is able to provide a clear diagnosis of LVT/non-LVT when 2D-TE images are merely suggestive of the disorder. Therefore, RT-3D-TE with RTVR, which is a clinically feasible alternative to 2-dimensional echocardiography, has great potential to positively affect the diagnosis, follow-up, and care of patients with suspected LVT.

Color M-mode flow propagation velocity versus conventional Doppler indices in the assessment of diastolic left ventricular function in patients on chronic hemodialysis.

BACKGROUND AND OBJECTIVE: Color M-mode flow propagation velocity (Vp) has been reported as a preload-independent measure of diastolic function. To study the effects of loading conditions on diastolic function assessment in patients on chronic hemodialysis, we measured Vp and conventional Doppler indices pre- and posthemodialysis. METHODS: Twenty hemodialysis patients with normal systolic function underwent measurement of Vp, early filling velocity (E), its deceleration time (DT), atrial contraction velocity (A), isovolumic relaxation time (IVRT), and pulmonary atrial flow reversal velocity (PFR) pre- and posthemodialysis. Twelve healthy controls underwent these same measurements. RESULTS: Hemodialysis patients had significantly slower Vp at baseline than normal controls, while E/A, DT, IVRT, and pulmonary flow reversal were not significantly different. E, IVRT, and PFR were affected by hemodialysis, while color M-mode flow propagation velocities, A, and DT were not. CONCLUSION: Color M-mode flow propagation velocity seems to be a preload-independent measure of diastolic function in chronic hemodialysis patients in whom isolated diastolic dysfunction appears prevalent.