Circannual changes in ventricular function assessed by echocardiography.

Cardiac function may vary predictably along the 1-year scale. A circannual rhythm, more or less in phase is documented for 5 echocardiographic variables in clinically healthy Japanese adults.     

Effects of cardiopulmonary bypass surgery on coronary flow in children assessed with transthoracic Doppler echocardiography

Perturbation of coronary blood flow (CF) is an important contributor to myocardium-related complications. The study was primarily designed to assess the impact of cardiopulmonary bypass (CPB) surgery on CF by aid of transthoracic Doppler echocardiography. Changes in CF after off-pump coarctation surgery were also studied. All ultrasounds were performed before and 5 +/- 1 days after surgery. Eighteen children underwent CPB surgery of ventricular left-to-right shunts at the mean age of 6 mo, while off-pump surgery (aortic coarctectomy) was undertaken at the mean age of 10 days in 12 children. After CPB surgery, both left anterior descending coronary artery mean diameter and basal CF increased from 1.7 +/- 0.3 to 2.1 +/- 0.4 mm (P = 0.001) and 27 +/- 10 to 47 +/- 15 ml/min (P = 0.0001), respectively. These two coronary variables decreased after off-pump coarctectomy: left anterior descending coronary artery mean diameter from 1.8 +/- 0.1 to 1.7 +/- 0.1 mm (P = 0.06), and CF from 44 +/- 12 to 25 +/- 8 ml/min (P = 0.001). The findings are in keeping with the hypothesis that the previously reported impairment of coronary flow reserve after CPB surgery could be due to increase in basal coronary flow after CPB. Off-pump coarctectomy seems to have little impact on CF, as the postsurgical decline in flow in these patients seems to relate to the reduction in cardiac pressure afterload.     

猫冠状动脉缺血与再灌注对房室传导的影响

急性下壁心肌梗塞常引起房室传导功能障碍,然而这种障碍与心肌缺血的内在联系并不很清楚,本实验在去植物性神经传出纤维的猫上进行,通过模板匹配方法从Ｈｉｓ束电图检测Ａ,Ｈ,Ｖ波并测量两心房间期（ＡＡ）,心房波与Ｈｉｓ波间期（ＡＨ）,Ｈｉｓ波与心室波间期（ＨＶ）和心房波与心室波间期（ＡＶ）。结果如下：结扎右冠状动脉后,２０只动物的ＡＨ间期１４只出现增加（Ａ组）６只未出现增加（Ｂ组）对Ｂ组进行快速心房起博和     

Estimation of diastolic intraventricular pressure gradients by Doppler M-mode echocardiography

Previous studies have shown that small intraventricular pressure gradients (IVPG) are important for efficient filling of the left ventricle (LV) and as a sensitive marker for ischemia. Unfortunately, there has previously been no way of measuring these noninvasively, severely limiting their research and clinical utility. Color Doppler M-mode (CMM) echocardiography provides a spatiotemporal velocity distribution along the inflow tract throughout diastole, which we hypothesized would allow direct estimation of IVPG by using the Euler equation. Digital CMM images, obtained simultaneously with intracardiac pressure waveforms in six dogs, were processed by numerical differentiation for the Euler equation, then integrated to estimate IVPG and the total (left atrial to left ventricular apex) pressure drop. CMM-derived estimates agreed well with invasive measurements (IVPG: y = 0.87x + 0.22, r = 0.96, P < 0.001, standard error of the estimate = 0.35 mmHg). Quantitative processing of CMM data allows accurate estimation of IVPG and tracking of changes induced by beta-adrenergic stimulation. This novel approach provides unique information on LV filling dynamics in an entirely noninvasive way that has previously not been available for assessment of diastolic filling and function.     

Functional reserves of the human body as assessed by Doppler sonography

A study was performed to find informative functional tests for assessing cerebrovascular reactivity. The effects of the hypoxic (breathing a gas mixture containing 10% O₂), closed-loop rebreathing, voluntary hyperventilation, and Stange and Hench tests on the cerebral blood flow were compared. Doppler sonography was used to determine the linear velocity of the blood flow in the middle cerebral artery without imaging the vascular lumen. The hyperventilation and closed-loop rebreathing tests caused significant changes in the calculated vasomotor activity (?48 and +61%, respectively). A combination of these two tests can be used as a clinical test for cerebrovascular reactivity.     

Ovarian tissue features assessed in bovine fetuses after vitrification and xenotransplantation procedures

Cryopreservation and transplantation of ovarian tissue are proposed methods for the restoration of endocrine function and reproductive potential. Therefore, this study aimed to evaluate the effects of vitrification and xenotransplantation on follicle viability, activation, stromal cell integrity, vascularization, and micronuclei formation. Bovine fetal ovaries were fragmented and assigned to the following groups: Fresh control (FC), ovarian fragments immediately fixed; Vitrified control (VC), ovarian fragments vitrified; Vitrified xenotransplanted (VX), ovarian fragments vitrified and xenotransplanted; and Fresh xenotransplanted (FX), ovarian fragments xenotransplanted. Ovarian fragments were grafted in female BALB/c mice and recovered after 14 days. Follicular viability was preserved (P > 0.05) in VC group. The rate of developing follicles was greater (P < 0.05) in the FX group compared to other groups. Follicular density was higher (P < 0.05) in the VC group than the FC, VX, and FX groups. A decrease (P < 0.05) of stromal cell density was recorded after vitrification (VC vs. FX). Blood vessel density decreased in VC, VX, and FX groups compared with the FC group, and blood vessel density was correlated with follicular viability (positively; P = 0.07) and developing follicles (negatively; P < 0.001). Both vitrification and xenotransplantation groups (VC, VX, and FX) had a greater (P < 0.05) number of cells with one MN compared to the FC group. In summary, our findings showed that both vitrification and xenotransplantation modified blood vessel, follicular and stromal cell densities, follicular viability and activation, and micronuclei formation in ovarian tissue.     

Sensorimotor central conduction time in comatose patients

Motor evoked potentials (MEPs) following magnetic stimulation were recorded in 22 patients comatose as a result of head injury (13 cases), stroke (7 cases) or anoxia (2 cases). Somatosensory evoked potentials (SEPs) from median nerve were recorded as well in 19 cases in the same session.Thirteen patients died or remained vegetative (59.1%), 3 were severely disabled (13.6%) and 6 showed a good recovery (27.3%). MEPs were significantly related to the outcome; they appeared to be a more accurate prognostic indicator than the Glasgow Coma Scale (GCS). However, 1 out of 6 patients with bilaterally absent MEPs (16.7%) showed a good recovery.SEPs were significantly related to the outcome as well, but the combined use of SEP and MEP improved the outcome prediction, decreasing the rate of false negatives. Two patients had normal sensorimotor function, 13 a combined sensorimotor dysfunction, while 4 had a pure motor dysfunction.Our results suggest that SEPs and MEPs may improve the assessment of sensorimotor dysfunction in comatose patients. A significant relationship between MEPs and outcome appears to exist, but the assessment of MEP reliability requires further study.     

Effect of streptozotocin-induced diabetes on myocardial blood flow reserve assessed by myocardial contrast echocardiography in rats

Background

Hypertension and type 2 diabetes are common co-morbidities. Preliminary studies suggest that thiazolidinediones reduce blood pressure (BP). We therefore used ambulatory BP to quantify BP lowering at 6–12 months with rosiglitazone used in combination with metformin or sulfonylureas compared to metformin and sulfonylureas in people with type 2 diabetes.

Methods

Participants (n = 759) in the multicentre RECORD study were studied. Those taking metformin were randomized (open label) to add-on rosiglitazone or sulfonylureas, and those on sulfonylurea to add-on rosiglitazone or metformin.

Results

24-Hour ambulatory BP was measured at baseline, 6 months and 12 months. At 6 and 12 months, reductions in 24-hour ambulatory systolic BP (sBP) were greater with rosiglitazone versus metformin (difference at 6 months 2.7 [95% CI 0.5–4.9] mmHg, p = 0.015; 12 months 2.5 [95% CI 0.2–4.8] mmHg, p = 0.031). Corresponding changes for ambulatory diastolic BP (dBP) were comparable (6 months 2.7 [95% CI 1.4–4.0] mmHg, p < 0.001; 12 months 3.1 [95% CI 1.8–4.5] mmHg, p < 0.001). Similar differences were observed for rosiglitazone versus sulfonylureas at 12 months (sBP 2.7 [95% CI 0.5–4.9] mmHg, p = 0.016; dBP 2.1 [95% CI 0.7–3.4] mmHg, p = 0.003), but differences were smaller and/or not statistically significant at 6 months (sBP 1.5 [95% CI -0.6 to 3.6] mmHg, p = NS; dBP 1.3 [95% CI 0.0–2.5] mmHg, p = 0.049). Changes in BP were not accompanied by compensatory increases in heart rate, did not correlate with basal insulin sensitivity estimates and were not explained by changes in antihypertensive therapy between the various strata.

Conclusion

When added to metformin or a sulfonylurea, 12-month treatment with rosiglitazone reduces ambulatory BP to a greater extent than when metformin and a sulfonylurea are combined.

Trial registration

NCT00379769 http://clinicaltrials.gov/     

Progressive development of pulmonary hypertension leading to right ventricular hypertrophy assessed by echocardiography in rats.

The present study aimed to evaluate the development of pulmonary hypertension by serial echocardiography, including measurements of pulmonary artery (PA) flow velocities, and correlate echocardiographic indices with pathological findings in rats administered monocrotaline (MCT). MCT (60 mg/kg body weight) or physiologic saline was administered to a total of 9 male Wistar rats at the age of 4 weeks (MCT group: n = 4, control group: n = 5, respectively). Echocardiography was performed serially until the age of 8 weeks. The ratio of right ventricular (RV) outflow tract dimensions to aortic dimensions increased progressively in the MCT group and became significantly greater than that of the control group after the age of 6 weeks. Peak PA velocity (Peak V) in the MCT group was significantly less than that of the control group at the ages of 7 and 8 weeks. The ratio of acceleration time to ejection time (AT/ET) in PA flow waveforms declined progressively and was significantly less than that of the control group after the age of 6 weeks. The ratio of RV weight to body weight (RVW/BW) in the MCT group was significantly greater than that of the control group. Both AT/ET ratio and Peak V were significantly inversely correlated with RVW/BW ratio. Furthermore, these echocardiographic findings were also significantly inversely correlated with the mean cross-sectional RV myocyte area. In conclusion, the progressive development of pulmonary hypertension leading to RV hypertrophy can be evaluated appropriately by echocardiography including PA flow Doppler indices in rats.     

Coronary artery diameter can be assessed reliably with transthoracic echocardiography

We studied whether diameters of coronary arteries can be measured accurately with the use of transthoracic echocardiography (TTE). By knowing the anatomic diameter of the coronary artery together with coronary flow velocity it is possible to measure coronary flow volume more precisely by TTE. However, the suitability of TTE for measurement of diameters of all main epicardial coronary arteries has not been systematically validated. We measured the diameters of the left main (LM), left anterior descending (LAD), left circumflex (LCX), and right coronary arteries (RCA) with the use of TTE [manual two-dimensional (2D), color-Doppler, and automated 2D analysis] in 30 patients who had normal coronary anatomy. We compared these diameters to those measured with quantitative coronary angiography (QCA). We could measure diameters of LM, LAD, LCX, and RCA by TTE in up to 37%, 63%, 7%, and 60% of patients, respectively. The overall correlation coefficients between TTE and QCA measurements were 0.83 (P < 0.01) with manual 2D analysis, 0.82 (P < 0.01) with automated 2D analysis, and 0.94 (P < 0.01) with a color-Doppler-based analysis. Interobserver variability of TTE measurements was low (coefficient of variation 5.4 +/- 4.6-7.5 +/- 8.8%). TTE is an accurate method to evaluate coronary artery diameter in patients with healthy coronary arteries.     

49例先天性胎儿心脏疾病的静脉导管血流频谱分析

目的：不同的胎儿先天性心脏疾病通过不同的作用机制影响到胎儿心脏功能,会引起胎儿体内血循环的不同改变。静脉导管是胎儿血循环中重要的组成,也会随之出现相应的频谱改变。通过对49例合并先天性心脏疾病胎儿的静脉导管血流频谱及参数进行分析,研究胎儿不同类型心脏疾病对静脉导管（DV）血流频谱的影响。方法：选取2009年1月至2012年12月间我们在产前超声检查中发现的49例合并先天性心脏疾病的胎儿,分别测量DV血流频谱并进行参数分析,根据DV频谱是否正常分为两组。结果：DV频谱正常组有29例（59.18%）,表现为S波、a波的流速和方向正常,PVIV及DVRI指标位于正常范围。DV频谱异常组有20例,表现为S波流速降低、a波缺失或反向,PVIV及DVRI升高。结论：DV血流频谱和参数是评价胎儿心功能的良好指标。不同种类胎儿心脏发育异常对胎儿心功能影响的作用机制不同,其DV频谱也有着不同改变。通过对DV频谱的波形和参数分析,了解胎儿心脏异常的病生理机制,评价其严重程度和预后,这对于指导临床诊疗有着重要意义。     

49 例先天性胎儿心脏疾病的静脉导管血流频谱分析

目的：不同的胎儿先天性心脏疾病通过不同的作用机制影响到胎儿心脏功能,会引起胎儿体内血循环的不同改变。静脉导 管是胎儿血循环中重要的组成,也会随之出现相应的频谱改变。通过对49 例合并先天性心脏疾病胎儿的静脉导管血流频谱及参 数进行分析,研究胎儿不同类型心脏疾病对静脉导管（DV）血流频谱的影响。方法：选取2009 年1 月至2012 年12 月间我们在产 前超声检查中发现的49 例合并先天性心脏疾病的胎儿,分别测量DV血流频谱并进行参数分析,根据DV频谱是否正常分为两 组。结果：DV频谱正常组有29 例(59.18%),表现为S 波、a 波的流速和方向正常,PVIV 及DVRI指标位于正常范围。DV频谱异 常组有20 例,表现为S波流速降低、a 波缺失或反向,PVIV 及DVRI升高。结论：DV血流频谱和参数是评价胎儿心功能的良好 指标。不同种类胎儿心脏发育异常对胎儿心功能影响的作用机制不同,其DV频谱也有着不同改变。通过对DV频谱的波形和参 数分析,了解胎儿心脏异常的病生理机制,评价其严重程度和预后,这对于指导临床诊疗有着重要意义。     

Residual eDNA detection sensitivity assessed by quantitative real‐time PCR in a river ecosystem

Several studies have demonstrated that environmental DNA (eDNA) can be used to detect the presence of aquatic species, days to weeks after the target species has been removed. However, most studies used eDNA analysis in lentic systems (ponds or lakes), or in controlled laboratory experiments. While eDNA degrades rapidly in all aquatic systems, it also undergoes dilution effects and physical destruction in flowing systems, complicating detection in rivers. However, some eDNA (i.e. residual eDNA) can be retained in aquatic systems, even those subject to high flow regimes. Our goal was to determine residual eDNA detection sensitivity using quantitative real‐time polymerase chain reaction (qRT–PCR), in a flowing, uncontrolled river after the eDNA source was removed from the system; we repeated the experiment over 2 years. Residual eDNA had the strongest signal strength at the original source site and was detectable there up to 11.5 h after eDNA source removal. Residual eDNA signal strength decreased as sampling distance downstream from the eDNA source site increased, and was no longer detectable at the source site 48 h after the eDNA source water was exhausted in both experiments. This experiment shows that residual eDNA sampled in surface water can be mapped quantitatively using qRT–PCR, which allows a more accurate spatial identification of the target species location in lotic systems, and relative residual eDNA signal strength may allow the determination of the timing of the presence of target species.     

Effects of permanent magnets on resting skin blood perfusion in healthy persons assessed by laser Doppler flowmetry and imaging

Effects on skin blood perfusion of permanent ceramic magnets [0.1 T (1000 G) surface field], individually (disk shaped, 4 cm diameter x 1 cm thick) or in the form of a 11 x 7 in pad ( approximately 28 x 17.8 cm) with an array of 16 rectangular magnets (4.5 x 2.2 cm), were investigated in 16 female volunteers (27.4 +/- 1.7 years, range 21-48 years) using three separate protocols. In protocol A, a disk magnet was placed on the palmar surface of the hand in contact with the thenar eminence (n = 5). In protocol B, the magnet was placed on the hand dorsum overlying the thenar eminence (n = 5). In protocol C, the entire palm and fingers rested on the magnetic pad (n = 6). Magnets were in place for 36 min on one hand, and a sham was in place on the other hand. Blood perfusion was measured on the middle finger dorsum by laser Doppler flowmetry (LDF) and on the index finger by laser Doppler imaging (LDI). Perfusion measurements were simultaneously taken in sham and magnet exposed hands, before and during the entire magnet exposure interval. Magnetic field effects were tested by comparing skin blood perfusion sequences in magnet and sham exposed regions. Results showed no significant changes in either LDF or LDI perfusion at magnet or sham sites during exposure, nor were there any significant differences between sham and magnet sites for any protocol. Measurements of skin temperature at the LDF measurement sites also showed no significant change. It is concluded that in the healthy subjects studied with normal, unstressed circulation, magnets of the type and for the duration used, showed no detectible effect on skin blood perfusion in the anatomical area studied.     

Predicting time of parturition from changing vaginal temperature measured by data-logging apparatus in beef cows with twin fetuses

Vaginal temperatures (VT) of crossbred (Japanese Black crossed Holstein-Friesian) beef cows (n = 31) were measured by a data-logging apparatus to obtain serial data from days 0 to 6 before parturition. For both single and twin pregnancies, no significant differences were observed in VT during days 3-6 before parturition. Maternal VT was not affected by maternal weight just after parturition, parity, fetal sex, or total fetal litter weight. Average of twin litter weights for two males (MM) and two females (FF) had the strong positive correlations (r = 0.84; P < 0.05) with maternal VT, whereas twin weights of mixed-gender twins (FM) did not correlate with maternal VT (r = -0.26; P = 0.61). Maternal temperature decreased as weights of the female fetus of FM twins became heavier (r = -0.82; P < 0.05). In contrast, maternal VT of FF and MM twins increased as twin weights increased. We defined when the VT began to decrease before parturition by two different methods. One was the "same hours method" where differences in VT between a particular time of day and the corresponding time of the preceding day were compared when the VT was consistently > or =0.3 or > or =0.5 degrees C for more than 3h. The second method was the "maximum-minimum method" where decreased in the maximum or the minimum values of the day over > or =0.3 and > or =0.5 degrees C were compared to values of preceding day. Onset of decreased VT before expulsion was not different between singletons and twins. In an attempt to define the critical condition in predicting parturition, we estimated assumable predicting probability using the 31 cows that were collected VT. When the parturition occurred within 60 h in the "same hours method" and 72 h since VT was > or =0.3 degrees C and in the "maximum-minimum method", the assumable probability was 100%. In verification experiment under these condition, the "same hours method" had a higher probability of predicting the time of parturition than the "maximum-minimum method", and it was possible to detect the onset of decreased VT at the correct time by the minutes. We concluded that "same hours method" was useful for predicting parturition time in cattle with single and twin pregnancies by the serial measurement of vaginal temperature.     

Cancer therapy and cardiotoxicity: The need of serial Doppler echocardiography

Morbidity and mortality rates are higher in patients with severe left ventricular (LV) systolic dysfunction and ECG-derived prolonged QRS interval than in those with normal QRS duration. QRS duration is currently used on the grounds that it reflects the presence of ventricular dyssynchrony. However, 30–40% of patients selected on the basis of a prolonged QRS do not receive benefit by cardiac resynchronization therapy (CRT) since they do not show any significant inverse LV remodeling and QRS duration does not accurately distinguish responders to CRT. Consequently, mechanical dyssynchrony (particularly intra-ventricular dyssynchrony) seems to be much more important than electrical dyssinchrony. Pre- and post-echocardiographic assessment should require the combination of conventional and specific applications ranging from M-mode and pulsed/continuous Doppler, to pulsed Tissue Doppler, the off-line analysis of colour Tissue Velocity Imaging, Strain Rate Imaging, and real time three-dimensional reconstruction However, there is not no consensus about the best approach and the best ultrasound parameter for selecting candidates to CRT and ECG representation of abnormal cardiac conduction still remains as the main criterion in guidelines. This review is a practical update of ultrasound methods and measurements of atrio-ventricular, inter-ventricular and intra-ventricular dyssynchrony and describes experiences which used either conventional Doppler echocardiography and more advanced techniques. By these experiences, the global amount of LV dyssynchrony seems to be critical: the greater intra-ventricular dyssynchrony, the higher the possibility of significant LV inverse remodeling. After CRT, it is necessary also to evaluate the optimal atrio-ventricular delay and ventricular-ventricular delay setting that maximizes LV systolic function.