Keitaro Ogawa

Automated Assessment of Left Atrial Function From Time-Left Atrial Volume Curves Using a Novel Speckle Tracking Imaging Method

BACKGROUND Using a novel speckle-tracking imaging method, time-left atrial (LA) volume curves (TLAVCs) can be automatically obtained. The aim of this study was to evaluate whether this method can be used for the measurement of LA function with TLAVCs. METHODS In 10 normal subjects and 20 patients, apical 4-chamber images were obtained. Maximum volume, reservoir volume, conduit volume, booster pump volume, and minimum volume were measured from TLAVCs. The results were compared with those obtained by the manual tracing method on every frame during 1 cardiac cycle. RESULTS There was good agreement between the speckle-tracking imaging and manual methods for maximum LA volume (r = 0.98, P < .001), reservoir volume (r = 0.82, P < .001), conduit volume (r = 0.87, P < .001), booster pump volume (r = 0.80, P < .001), and minimum volume (r = 0.98, P < .001). The time to obtain TLAVCs was significantly shorter with the speckle-tracking imaging method (64 +/- 22 seconds) than with the manual method (22 +/- 4 minutes). CONCLUSION TLAVCs obtained using the speckle-tracking imaging method can be used for the rapid and noninvasive automated quantitation of LA function.

Arachidonic acid and docosahexaenoic acid supplementation increases coronary flow velocity reserve in Japanese elderly individuals

Background: Arachidonic acid (ARA) and docosahexaenoic acid (DHA) are important components of phospholipids and cell membranes. There has, however, been no clinical report on the direct effects of ARA and DHA on coronary circulation. Objective: To evaluate the effects of ARA and DHA on coronary circulation using the measurement of coronary flow velocity reserve (CFVR) by transthoracic Doppler echocardiography (TTDE). Methods: A double-blind, placebo-matched study of 28 Japanese elderly individuals (19 men, mean age 65 years) conducted to compare the effects of polyunsaturated fatty acids (PUFA; ARA 240 mg/day, DHA 240 mg/day) and placebo on CFVR. Coronary flow velocity (CFV) of the left anterior descending coronary artery was measured at rest and during hyperaemia by TTDE to determine CFVR. Results: There were no significant differences in CFV at rest or during hyperaemia in CFVR at baseline in the two groups (PUFA versus placebo 17 (7 SD) versus 16 (6), 62 (20) versus 59 (12), and 3.85 (1.04) versus 3.98 (0.83) cm/s, respectively). After three months’ supplementation, CFV during hyperaemia was significantly higher in the PUFA than in the placebo group (73 (19) versus 64 (12) cm/s, p<0.01) although no significant difference was found between the two groups in CFV at rest (17 (7) versus 16 (4) cm/s). CFVR thus significantly increased after PUFA consumption (3.85 (1.04) versus 4.46 (0.95), p = 0.0023). Conclusion: Three months’ supplementation of PUFA increased CFVR in Japanese elderly individuals, which suggests beneficial effects of PUFA on the coronary microcirculation.

Usefulness of three-dimensional automated quantification of left ventricular mass, volume, and function by 64-slice computed tomography.

OBJECTIVES Quantification of left ventricular (LV) mass has important prognostic implications. However, accurate measurement of LV mass has been difficult, in part because of the oblique angle at which the heart lies within the chest and the continuous movement of the heart itself. Multislice computed tomography (MSCT) allows assessment not only of coronary stenosis but LV volume, function, and mass. A novel three-dimensional (3D) region-growing-based semi-automated segmentation algorithm for measurements of LV mass, volume, and function was recently developed. This study evaluated this new 3D automated method for measurement of LV mass, by comparison with a well-established 2D manual contour-drawing algorithm. METHODS AND RESULTS The study population consisted of 50 consecutive patients who underwent ECG-gated MSCT for evaluation of coronary arteries. The 3D algorithm for reliable segmentation was unsuccessful in two patients. In the remaining 48 patients, however, LV segmentation using this algorithm was performed and delivered visually reliable segmentation results. The 3D algorithm for analysis of LV function and mass is feasible based on volumetric data, and exhibits good correlation and agreement with the results obtained with the conventional 2D algorithm. The time required for the new automated algorithm was significantly shorter than that for the manual contour-drawing algorithm (P<0.0001) (automated algorithm: 468.0±205.1 s, manual algorithm: 1362.4±410.5 s, mean ±S.D.). CONCLUSIONS The 3D semi-automated region-growing segmentation algorithm for analysis of LV function and mass is feasible based on volumetric data, and exhibits good correlations and agreement with the results of the conventional 2D manual contour-drawing algorithm.

Three dimensional echocardiography of tako-tsubo cardiomyopathy with atrial myxoma.

A 63-year-old woman without any significant medical history presented with acute thoracic pain and dyspnoea after alcohol abuse and an argument with her husband. Her initial electrocardiography showed giant negative T waves in all precordial leads. Troponin T, creatine kinase and creatine kinase MB concentrations were only slightly increased. Two dimensional …