Amlodipine has a preventive effect on temporal left ventricular hypokinesia after emotional stress compared with an angiotensin II receptor blocker.

PURPOSE: We previously reported that α- and ß-blockers protected against emotional stress-induced cardiac dysfunction, but the protective effects of other antihypertensive drugs is unknown. The purpose of this study is to evaluate the ability of a calcium channel blocker, amlodipine, to prevent temporal left ventricular hypokinesia after emotional stress compared with an angiotensin II receptor blocker, olmesartan medoxomil. METHODS: Rats premedicated with amlodipine (0.2 mg/kg), olmesartan (0.8 mg/kg), or vehicle were restrained for 30 min (immobilization stress: IMO) to reproduce emotional stress and then anesthetized to release stress. We measured the fractional area change (FAC) using echocardiography (SONOS5500) with a s12 probe (frequency 5-12 MHz, frame rate 120 Hz) and blood pressure and heart rate at the end of IMO and every 10 for 60 min after IMO. RESULTS: During IMO, FAC in the amlodipine or the olmesartan group was as high as that in the vehicle group. At 20 min after IMO, FAC in the amlodipine group was significantly higher than in the other two groups (84 ± 8 vs. 60 ± 7 or 68 ± 15 %, p < 0.05). During IMO, blood pressure in the amlodipine or the olmesartan group was significantly lower than with vehicle (119 ± 6 and 110 ± 7 vs. 124 ± 5 mmHg, p < 0.05). After IMO, blood pressure in the olmesartan group was significantly lower than in the other two groups. CONCLUSION: Acute administration of amlodipine could prevent a sudden drop in cardiac function after acute stress like IMO, but olmesartan did not. Amlodipine might have a protective effect on temporal left ventricular hypokinesia after emotional stress, which might not be related to decreased blood pressure.

Monocrotaline-induced pulmonary hypertension with sufficient tricuspid regurgitation in a rat model.

BACKGROUND AND PURPOSE: It is well known that monocrotaline (MCT) induces pulmonary hypertension (PH) in rats. This model is very useful for understanding the physiology of PH and developing treatments for PH. However, it is very difficult to estimate pulmonary artery pressure (PAP) in this model. The purpose of this study is to establish a PH model with sufficient tricuspid regurgitation (TR) to evaluate PAP. METHOD: We studied 17 male rats that received 15 injections of 5 mg/kg/day of MCT (PH) or vehicle (control). Three weeks after the first MCT injection, we measured left and right ventricular dimensions, the ratio of acceleration to ejection time in pulmonary flow, and the development of TR using an echocardiograph (SONOS5500) with a s12 probe (frequency: 5-12 MHz, frame rate: 120 Hz). RESULTS: The right ventricular end-diastolic area in the PH group was significantly larger than that in the control group. The acceleration time/ejection time ratio and velocity time integral of the pulmonary artery in the PH group were smaller than those in the control group. In 78 % of rats in the PH group, sufficient TR was observed and estimated PAP was 75.4 ± 13.8 mmHg. There was a good correlation between PAP estimated by a Doppler method and directly measured right ventricular pressure (r = 0.94, P < 0.0001). CONCLUSION: Fifteen injections of 5 mg/kg/day of MCT could induce PH with sufficient TR in rats. Transthoracic echocardiography could be used for monitoring the progress of PH in the rat model.

Cardiac hypertrophy is inhibited by antagonism of ADAM12 processing of HB-EGF: metalloproteinase inhibitors as a new therapy.

G-protein-coupled receptor (GPCR) agonists are well-known inducers of cardiac hypertrophy. We found that the shedding of heparin-binding epidermal growth factor (HB-EGF) resulting from metalloproteinase activation and subsequent transactivation of the epidermal growth factor receptor occurred when cardiomyocytes were stimulated by GPCR agonists, leading to cardiac hypertrophy. A new inhibitor of HB-EGF shedding, KB-R7785, blocked this signaling. We cloned a disintegrin and metalloprotease 12 (ADAM12) as a specific enzyme to shed HB-EGF in the heart and found that dominant-negative expression of ADAM12 abrogated this signaling. KB-R7785 bound directly to ADAM12, suggesting that inhibition of ADAM12 blocked the shedding of HB-EGF. In mice with cardiac hypertrophy, KB-R7785 inhibited the shedding of HB-EGF and attenuated hypertrophic changes. These data suggest that shedding of HB-EGF by ADAM12 plays an important role in cardiac hypertrophy, and that inhibition of HB-EGF shedding could be a potent therapeutic strategy for cardiac hypertrophy.

Low testosterone levels in patients with mild hypertension recovered after antidepressant therapy in a male climacterium clinic.

Recently, middle-aged men who have begun frequently complaining of erectile dysfunction and nonspecific symptoms similar to those of postmenopausal women, visited a male climacterium clinic in Japan. Some patients, who were already taking antihypertensive medication, discontinued or reduced their dosages of antihypertensive medication after anti-depressant therapy. Forty-nine males over the age of 40 years were studied to evaluate the relationships between blood pressure, mental stress, and testosterone levels. The systemic blood pressure (sBP) of 24 patients was higher than the criteria for mild hypertension: 140/90 mmHg (HT group) at first visit. The sBP of the other 25 patients was normal (N group). The international index of erectile function (IIEF5) score (normal >21), self-rating depression scale (SDS) score (normal <40), and plasma testosterone levels were also evaluated before and after anti-depressant therapy without androgen replacement therapy. There were no significant differences between the groups in IIEF5 or SDS scores. The plasma testosterone levels in the HT group at first visit were significantly lower than those in the N group (230+/-77 vs. 343+/-92 ng/dL, p<0.001). After treatment, the IIEF5 scores were unchanged, whereas SDS scores were lower in both groups. Mean systemic blood pressure (mBP) in the HT group significantly decreased from 112+/-7 to 94+/-7 mmHg after treatment, concomitant with the disappearance of nonspecific complaints and the increase of testosterone levels. In the N group, however, neither mBP nor testosterone levels changed. Psychotherapy can ameliorate mild systemic hypertension in climacteric men with low testosterone levels. Mental stress might suppress the hypothalamic-pituitary-gonadal axis to decrease testosterone levels.

A fundamental study for quantitative measurement of ultrasound contrast concentration by low mechanical index contrast ultrasonography.

PURPOSE: In high mechanical index (MI) contrast ultrasonography it has been shown that the power of contrast signal intensity (CI) has a strong linear correlation with the concentration of the ultrasound contrast agent under conditions of constant applied acoustic pressure. However, it is unclear whether the linearity is preserved in low-MI contrast ultrasonography. Thus, we investigated the relationship between ultrasound contrast concentration and CI in vitro. METHODS: Solutions of the ultrasound contrast agents Definity and Imagent were prepared at concentrations of 0.5, 2, 8, 32, and 128 µl/l. Placing a jelly block between the transducer and the solution, the solutions were transmitted using pulse subtraction imaging with an MI of 0.05, 0.1, and 0.5. CI was measured in dB in a region of interest 3 mm in height placed just below the border between the jelly and the solution. Data were plotted using double logarithm scales, where the concentration was expressed in dB as 10 × log (concentration). RESULTS: CI in dB had a strong linear correlation with concentration in dB for both agents with any MI. Best fitted slopes were close to 1, indicating that the power of CI is proportional to the concentration. CONCLUSIONS: In low-MI contrast ultrasonography, the power of CI is proportional to contrast concentration, and CI in dB is logarithmic to the concentration. Thus, the microbubble concentration can be quantitatively measured even in low-MI contrast ultrasonography.

Noninvasive vessel-selective perfusion imaging with intravenous myocardial contrast echocardiography.

BACKGROUND: Intravenous myocardial contrast echocardiography (MCE) cannot identify each perfusion area of coronary vessels separately. However, by destroying microbubbles passing through a specific vessel using high-power ultrasound during intravenous MCE, vessel-selective perfusion imaging (VSPI) may be feasible. METHODS: In 10 open-chest dogs, intermittent short-axis images were obtained during contrast agent infusion using an ultrasound system. For VSPI, a probe coupled to another ultrasound machine was placed on the proximal left circumflex coronary artery (LCx). High-power ultrasound pulses were transmitted to destroy bubbles passing through the LCx. A negative contrast area on VSPI was considered to represent the perfusion area of the LCx (LCx-VSPI). A negative contrast area on conventional MCE during LCx occlusion and a region without staining by Evans blue dye were used as gold standards for defining the LCx perfusion area. LCx-VSPI was compared with a negative contrast area on conventional MCE during LCx occlusion and a region without staining by Evans blue dye. RESULTS: Despite lack of LCx occlusion, high-power destructive pulses produced a definite area of negative contrast on the LCx region. Decreased power of ultrasound pulses resulted in disappearance of the negative contrast area. An excellent relationship was demonstrated between both LCx-VSPI and a negative contrast area on conventional MCE during LCx occlusion (r = 0.93, P <.0001), and LCx-VSPI and a region without staining by Evans blue dye (r = 0.92, P =.0002). CONCLUSION: VSPI during intravenous MCE may be feasible for noninvasive assessment of perfusion areas associated with specific vessels.

Adenosine triphosphate stress myocardial contrast echocardiography detects coronary artery stenosis with greater sensitivity than wall-motion abnormality measurements.

BACKGROUND: Although stress myocardial contrast echocardiography (MCE) can be used to detect coronary stenosis, its efficacy relative to other methods, such as detection of wall-motion abnormalities, remains unknown. Thus, the goal of this study was to compare the sensitivity of MCE versus wall-motion abnormality detection in the assessment of coronary artery stenosis. METHOD: Nine dogs with severe but nonflow limiting stenosis in the circumflex coronary artery underwent evaluation with real-time MCE along the short-axis view during infusion of Optison. The equation of y = a (1 - e -betat ) + c, which fits the replenishment curve of MCE, was calculated in the midseptum (normal region) and in the lateral wall (ischemic region) before and during adenosine triphosphate infusion. Wall-motion abnormalities were also evaluated by visual assessment and by measurement of wall thickening. RESULTS: Area under the receiver operating characteristic curve in beta- and A x beta-value, and percent wall thickening, was 0.963, 0.963, and 0.889, respectively, indicating that the diagnostic accuracy for detecting the coronary artery stenosis by real-time MCE was higher than that by the wall-motion assessment. CONCLUSION: Real-time MCE has higher sensitivity in detecting coronary stenosis during adenosine triphosphate stress test when compared with wall-motion assessment.

Myocardial blood flow parameters derived from contrast replenishment using harmonic power Doppler imaging are underestimated by ultrasound signal attenuation.

The effect of ultrasound signal attenuation on myocardial blood flow parameters derived from contrast replenishment was evaluated using harmonic gray-scale (HGS) and harmonic power Doppler (HPD) imaging. In vitro experiments were performed in a flow model, whereas in vivo experiments were performed in 5 open-chest dogs. In each study, intermittent HGS and HPD images were acquired at various pulsing intervals during contrast infusion. A silicone pad was interposed between the transducer and target region to simulate attenuation conditions. Baseline-subtracted HGS and HPD signal intensities were measured with and without silicone pad, and myocardial blood flow parameters A and beta were calculated using contrast replenishment. Attenuation with HGS images could be offset by baseline subtraction, as baseline images provided the reference for attenuation. However, attenuation with HPD images could not be compensated for, as baseline signal intensity was theoretically 0. In HGS mode, silicone attenuation produced no significant decreases in A and beta. In HPD mode, however, A and beta were significantly decreased by silicone attenuation (A, P <.001; beta, P <.05). Compared with nonattenuated regions, myocardial blood flow parameters in attenuated regions are underestimated when HPD imaging is used. Baseline-subtracted HGS imaging may be useful to compensate for thoracic wall attenuation.

Significance of acoustic field for the myocardial opacification by intravenous contrast echocardiography.

PURPOSE: Myocardial opacification is not always homogeneous even in a normal heart. The aim of this study is to clarify why myocardial opacification is faint at the lateral side of the field or at the part far from the focus point. METHODS: In canine study, videointensity of the opacification at septal and lateral walls of the short axis view was examined by using both electric and mechanical transducers. In in vitro study, acoustic pressure at several points away from the beam direction was measured using a hydrophone in a water tank. In particular, the effect of position of focus point was evaluated with an electronic transducer. RESULTS: In canine experiment, myocardial opacification of the lateral wall was faint with the electronic transducer, however the mechanical one obtained homogeneous opacification. In vitro, using the electronic type the acoustic pressure was low as the beam shifted, laterally, whereas it was almost uniform in the mechanical type. With the electronic type, moreover, the beam width at the near field was not sharp when the focus point was far, resulting in execessive acoustic pressure. CONCLUSION: To obtain homogeneous opacifiction, a homogeneous acoustic field is indispensable.

Factors associated with perceived feasibility and willingness of non-psychiatric doctors in Japan to treat depressed patients.

OBJECTIVES: We previously reported that many non-psychiatric doctors in Japan believe that treating depression was not part of their duties. Educational interventions must address motivation of physicians to play a role in depression care. In this study, we explored factors associated with perceived feasibility and willingness of non-psychiatric doctors in Japan to treat depression. METHODS: The study population included non-psychiatric doctors of the General Physician-Psychiatrist (G-P) Network group in Japan. We explored perceived feasibility and willingness to treat depressed patients, and examined preliminary associations with attitudes toward depression (the Depression Attitude Questionnaire: DAQ) and current depression treatment in routine medical practice. RESULTS: Responses were obtained from 56 non-psychiatric doctors (response rate: 35.4%). The doctors who scored high on the "Professional" and "Pessimism" subscale of the DAQ believed that treating depressed patients was not feasible (chi2 = 13.6, p < 0.01; chi2 = 7.3, p < 0.05, respectively) and were not willing to treat depressed patients (chi2 = 9.4, p < 0.01; chi2 = 6.6, p < 0.05, respectively) as part of their routine medical practice. The doctors who scored high on the "Professional" subscale referred fewer depressed patients to psychiatrists (r = -0.33, p < 0.05), and those who scored high on the "Pessimism" subscale recognized fewer depressed patients (r = -0.39, p < 0.01). CONCLUSIONS: The present study showed that attitudes toward depression were associated with perceived feasibility and willingness to treat depressed patients and with under-diagnosis of depression. Educational interventions optimized for these attitudes should be developed to improve recognition and treatment of depression in Japan.

Azelnidipine, unique calcium channel blocker could prevent stress-induced cardiac dysfunction like α·ß blocker.

BACKGROUND: We have reported that α and ß adrenergic blockers could protect against emotional stress-induced cardiac dysfunction. Azelnidipine is a unique calcium blocker which does not increase heart rate. The purpose of this study is to evaluate the effect of azelnidipine to prevent stress-induced cardiac dysfunction. METHODS AND RESULTS: Rats premedicated with azelnidipine (0.3 mg/kg), labetalol (3 mg/kg), or vehicle, were restrained for 30 min (immobilization stress: IMO) to reproduce emotional stress, and anesthetized to release stress. We measured the fractional area change (FAC) by echocardiography, blood pressure, and heart rate at the end of IMO and every 10 min for 60 min after IMO. During IMO, FAC in the labetalol group was significantly lower than that in the other two groups. At 20 min after IMO, FAC in the azelnidipine or labetalol group was significantly higher than that in the vehicle group (86 ± 9%, 73 ± 5% vs. 56 ± 11%, p<0.05). During IMO, mean blood pressure in the azelnidipine or labetalol group was significantly lower than that in the vehicle group (107 ± 5 mmHg, 106 ± 17 mmHg vs. 124 ± 5 mmHg, p<0.05). CONCLUSION: Acute administration of azelnidipine could prevent a sudden drop of cardiac function after acute stress like IMO. Azelnidipine might have a protective effect on stress-induced cardiac dysfunction like α and ß adrenergic blockers.

Acute effects of beta-blocker with intrinsic sympathomimetic activity on stress-induced cardiac dysfunction in rats.

BACKGROUND: We have reported that α and ß adrenergic blockers could protect against emotional stress-induced cardiac dysfunction but those protective effects of ß adrenergic blockers with intrinsic sympathomimetic activity (ISA), such as celiprolol, are unknown. The purpose of this study is to evaluate whether ISA could relate with this protective effect. METHODS AND RESULTS: Rats medicated with celiprolol (8 mg/kg), metoprolol (4 mg/kg), or vehicle, were restrained for 30 min (immobilization stress: IMO) to reproduce emotional stress, and anesthetized to release stress. We measured the fractional area change (FAC) using an echocardiography (SONOS5500) with s12 probe (frequency: 5-12 MHz, frame rate: 120 Hz) at the end of IMO and every 10 min for 1h. During IMO, FAC in rats with a premedication of metoprolol was lower than in those with a premedication of vehicle or celiprolol. At 20 min after IMO, FAC in rats with a premedication of celiprolol was significantly higher than that with a premedication of metoprolol or vehicle (84 ± 9% vs. 65 ± 3% or 60 ± 7%, p<0.05). At 60 min after IMO, FAC in rats with a premedication of vehicle or celiprolol recovered, but FAC in rats with a premedication of metoprolol did not. CONCLUSION: Acute premedication with celiprolol could prevent a sudden drop of cardiac function after acute stress such as IMO. ISA might have an important role in preventing stress-induced cardiac dysfunction.

Attitudes toward depression among Japanese non-psychiatric medical doctors: a cross-sectional study.

BACKGROUND: Under-recognition of depression is common in many countries. Education of medical staff, focusing on their attitudes towards depression, may be necessary to change their behavior and enhance recognition of depression. Several studies have previously reported on attitudes toward depression among general physicians. However, little is known about attitudes of non-psychiatric doctors in Japan. In the present study, we surveyed non-psychiatric doctors' attitude toward depression. METHODS: The inclusion criteria of participants in the present study were as follows: 1) Japanese non-psychiatric doctors and 2) attendees in educational opportunities regarding depression care. We conveniently approached two populations: 1) a workshop to depression care for non-psychiatric doctors and 2) a general physician-psychiatrist (G-P) network group. We contacted 367 subjects. Attitudes toward depression were measured using the Depression Attitude Questionnaire (DAQ), a 20-item self-report questionnaire developed for general physicians. We report scores of each DAQ item and factors derived from exploratory factor analysis. RESULTS: We received responses from 230 subjects, and we used DAQ data from 187 non-psychiatric doctors who met the inclusion criteria. All non-psychiatric doctors (n = 187) disagreed with "I feel comfortable in dealing with depressed patients' needs," while 60 % (n = 112) agreed with "Working with depressed patients is heavy going." Factor analysis indicated these items comprised a factor termed "Depression should be treated by psychiatrists" - to which 54 % of doctors (n = 101) agreed. Meanwhile, 67 % of doctors (n = 126) thought that nurses could be useful in depressed patient support. The three factors derived from the Japanese DAQ differed from models previously derived from British GP samples. The attitude of Japanese non-psychiatric doctors concerning whether depression should be treated by psychiatrists was markedly different to that of British GPs. CONCLUSIONS: Japanese non-psychiatric doctors believe that depression care is beyond the scope of their duties. It is suggested that educational programs or guidelines for depression care developed in other countries such as the UK are not directly adaptable for Japanese non-psychiatric doctors. Developing a focused educational program that motivates non-psychiatric doctors to play a role in depression care is necessary to enhance recognition and treatment of depression in Japan.

Evaluation of left ventricular rotation by two-dimensional speckle tracking method and real-time three-dimensional echocardiography: comparison with MRI tagging method.

BACKGROUND: Recently, it has become possible to evaluate left ventricular (LV) torsion by two-dimensional (2D) speckle tracking images. However, LV torsion is a three-dimensional (3D) performance, which per se cannot be assessed by the 2D speckle tracking method. The present study investigated the accuracy of the 2D speckle tracking method and real-time 3D echocardiography in measuring LV rotation, comparing with the MRI tagging method. METHODS: We assessed LV apical rotation using the 2D speckle tracking method, real-time 3D echocardiography, and MRI tagging method in 26 normal subjects, and compared the results of these three methods. LV apical rotation was measured just before the level in which the posterior papillary muscle was absorbed into the free wall. RESULTS: The degree of LV apical rotation evaluated by the 2D speckle tracking method (Δθ 2D) was significantly smaller than that evaluated by 3D echocardiography (Δθ 3D) and the MRI tagging method (Δθ MRI) (Δθ 2D 7.3 ± 2.8°; Δθ 3D 8.8 ± 3.4°; Δθ MRI 9.0 ± 3.4°; Δθ 2D vs. Δθ 3D, p = 0.0001; Δθ 2D vs. Δθ MRI, p < 0.0001). There were good correlations among Δθ 2D, Δθ 3D, and Δθ MRI, but agreement between Δθ 3D and Δθ MRI (mean difference 0.14 ± 1.43°) was better than that between Δθ 2D and Δθ MRI (mean difference 1.68 ± 1.89°). CONCLUSION: The degree of LV apical rotation was underestimated with the 2D speckle tracking method compared with the MRI tagging method, whereas it could be precisely measured by 3D echocardiography.

Assessment of myocardial ischemic memory using persistence of post-systolic thickening after recovery from ischemia.

OBJECTIVES: We sought to investigate the time course of post-systolic thickening (PST) and systolic abnormality after recovery from brief myocardial ischemia. BACKGROUND: Myocardial ischemic memory imaging, denoting the visualization of abnormalities provoked by ischemia and sustained even after restoration of perfusion, is desirable and allows after-the-fact recognition of ischemic insult. PST offers a sensitive marker of myocardial ischemia, but whether this abnormal thickening remains after relief from brief ischemia is unclear. METHODS: Tissue strain echocardiographic data were acquired from 27 dogs under 2 different conditions of myocardial ischemia induced by either brief coronary occlusion (15 or 5 min) followed by reperfusion (Protocol 1) or by dobutamine stress during nonflow-limiting stenosis (Protocol 2). Peak systolic strain and post-systolic strain index (PSI), a parameter of PST, were analyzed. RESULTS: In Protocol 1, peak systolic strain was significantly decreased in the risk area during occlusion. This decrease in peak systolic strain in the 15-min group did not completely recover to baseline levels even 120 min after reperfusion, whereas the decrease in the 5-min group recovered immediately after reperfusion. We found that PSI was significantly increased during occlusion, but increased PSI in the 5-min group remained until 30 min after reperfusion (-0.19 +/- 0.18 [baseline] vs. 0.19 +/- 0.14 [30 min], p < 0.05) despite the rapid recovery of peak systolic strain. In Protocol 2, increased PSI was sustained until 20 min after the end of dobutamine infusion (-0.26 +/- 0.11 [baseline] vs. -0.16 +/- 0.10 [20 min], p < 0.05), although peak systolic strain recovered by 5 min after the end of dobutamine infusion. CONCLUSIONS: PST remained longer than abnormal peak systolic strain after recovery from ischemia. Assessment of PST may be valuable for detecting myocardial ischemic memory.

Effect of sildenafil citrate (Viagra) on coronary flow in normal subjects.

BACKGROUND: The purpose of this study was to evaluate the effect of sildenafil citrate (Viagra) on coronary function in normal subjects. METHODS: The study assessed mean blood pressure, left anterior descending coronary artery (LAD) flow, and echocardiographic variables before and 30 and 60 minutes after taking 50 mg of sildenafil citrate. The mean velocity of LAD flow was assessed with Doppler flow imaging. The study subjects were 6 healthy male volunteers (mean age 37 years). RESULTS: The mean velocity of LAD flow increased 60 minutes after taking sildenafil citrate, but there were no other changes. Two volunteers felt mild flashing and one had mild headache during the study. CONCLUSION: Sildenafil citrate caused vasodilatation in a normal coronary artery without systemic pressure drops. These results suggest that the agent itself did not have negative effects on the heart in normal subjects.

Catecholamines and estrogen are involved in the pathogenesis of emotional stress-induced acute heart attack.

Emotional stress triggers takotsubo cardiomyopathy in postmenopausal women. Clinical analysis of autonomic nervous function has revealed a transient increase of sympathetic nervous activity and decrease of vagal nervous activity. Immobilization (IMO) stress of rats can reproduce the electrocardiographic and left ventriculographic changes that occur in takotsubo cardiomyopathy, both of which are prevented by combined blockade of alpha- and beta-adrenoceptors. Estrogen supplementation partially attenuated these cardiac changes. It also attenuated the IMO-induced increase of c-Fos immunoreactivity, or c-fos mRNA expression in the lateral septum, medial amygdaloid nucleus, paraventricular hypothalamic nucleus, dorsomedial hypothalamic nucleus, laterodorsal tegmental nucleus, and locus ceruleus; these regions contain central sympathetic neurons and neurons with immunoreactive estrogen receptors. It also downregulated c-fos mRNA expression in the adrenal gland and the heart, suggesting an increase of estrogen attenuated the stress-induced hypothalamo-sympathoadrenal outflow from the central nervous system to the target organs. Estrogen treatment also upregulated the levels of cardioprotective substances, such as atrial natriuretic peptide and heat shock protein 70, in the heart. These data suggest that reduction of estrogen levels following menopause might be involved in the primary cause of takotsubo cardiomyopathy both by indirect action on the nervous system and by direct action on the heart.

Three-dimensional reconstruction of coronary arteriole plexus image by contrast echocardiography using a high-frequency transducer.

OBJECTIVE: This study was established to examine the efficacy of a high-frequency liner probe for visualizing fine anatomy of coronary microcirculation. METHODS: The vessel size and its velocity-time integral at the anterior wall in dogs by real-time contrast echocardiography with high-frequency liner probe and pulse Doppler methods, and the coronary flow volume, were measured before and after adenosine triphosphate injection. A 3-dimensional (3D) image was reconstructed by the built-in 3D system using intermittent flash echocardiographic images. RESULTS: The increments of flow volume calculated from vessel sizes and velocity-time integral were well correlated with those of coronary flow volume. Using intermittent flash echocardiographic images, fine dots and lines of contrast echocardiographic-expected arterioles were evident, and easily and quickly reconstructed as coronary plexus by 3D system. CONCLUSION: A high-frequency liner probe provides the fine-vessel images to evaluate those morphologic changes; a 3D reconstruction image could provide new information about coronary arterioles.