Post-occlusional hyperemia for fractional flow reserve assessment and pull-back curve analysis.

Balloon occlusion is a potential method for inducing hyperemia to measure post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR). The objective of this study was to determine the clinical usefulness of post-occlusional hyperemia. FFRs measured using post-occlusional hyperemia caused by 30 (FFRoccl30) and 60 s (FFRoccl60) of balloon occlusion after PCI were compared in 60 lesions from 60 patients. The duration of hyperemia was also measured. There was a strong correlation between FFRoccl30 and FFRoccl60 (r = 0.969, p < 0.01). The duration of hyperemia was significantly longer with FFRoccl60 than with FFRoccl30 (68 ± 23 vs. 37 ± 15 s, p < 0.01). The time required for pullback curve analysis was around 45 s. However, in 7 (12%) cases, the duration of hyperemia with FFRoccl60 was < 45 s, which was not enough for pull-back curve analysis. To predict the duration of hyperemia with FFRoccl60 ≥ 45 s, the receiver operating characteristic curve analysis revealed a cut-off value of 25 s of hyperemia with FFRoccl30. FFRoccl30 is sufficient for diagnostic purposes. FFRoccl60 is suitable for pull-back curve analysis in select cases based on predictions made using the duration of hyperemia with FFRoccl30.

Ethnic disparities in perioperative management among foreigners residing in Japan.

The objectives of this research were to examine the current status of perioperative treatment among foreigners, to elucidate the health status/outcome disparities that contribute to ethnic differences, and to recommend counter-measures to rectify these ethnic disparities. The authors identified 36 non-Japanese and 111 Japanese females who underwent gynecological surgery from 2004 to 2009 at a single institution. Electronic medical records were reviewed and telephone survey was conducted in order to obtain patient background, preoperative, operative, and postoperative data. The non-Japanese group showed significantly larger number of uninsured, shorter length of stay (LOS), higher rate of emergency surgery, and higher cases of spinal anesthesia. There were significant differences in length of residency in Japan and LOS among four foreign countries. Seventy-nine percent of patients contacted by phone understood informed consent from doctors, 73.7% understood explanation in operating room (OR), and 84.2% understood explanation from anesthesiologists. This research was the first survey of the ethnic disparities in perioperative management among foreign patients treated in Osaka. The authors have demonstrated differences in operative method, emergency surgery, anesthesia, and American Society of Anesthesiologists physical status (ASA-PS) due to the difference in disease structure, language, and culture. It is recommended that the barriers between non-Japanese patients and medical staff are rectified during the perioperative period when mutual understanding is needed the most.

Ultrasonographic assessment of coronary flow reserve and abdominal fat in obesity.

Recent technological advances in transthoracic Doppler echocardiography (TTDE) have provided noninvasive measurement of coronary flow velocity reserve (CFVR). We aimed to quantitate a correlation between endothelial dysfunction and fat distribution. In 36 patients with obesity, 16 with noninsulin-dependent diabetes mellitus (DM) and 12 healthy volunteers, coronary flow velocity was measured at the distal site of the left anterior descending branch. CFVR was defined as the ratio of hyperemic (IV infusion of 0.15 mg/kg/min adenosine) to basal peak diastolic flow velocity. Abdominal wall fat index (AWFI) was estimated by ultrasonography. Insulin resistance was quantified by the euglycemic hyperinsulinemic clump method. AWFI was significantly related to CFVR (r = -0.46, p = 0.011) and insulin resistance (r = -0.71, p < 0.0001). CFVR could be noninvasively evaluated using TTDE. Coronary endothelial dysfunction indicated as CFVR, body fat distribution and insulin resistance was quantitatively correlated in obesity.

[Clinical significance of allergen specific immunotherapy in adult house-dust-mite-sensitive bronchial asthma: impact on disease severity and medical cost].

The objective of this study was to evaluate the clinical significance of allergen-specific immunotherapy in house-dust-mite-sensitive adult bronchial asthma. Fifty patients treated with rush immunotherapy using house dust antigen were examined. The disease severity was compared between before and a year after the maintenance immunotherapy: reduction in the severity was observed in 27 patients (54.0%) following the treatment. The response rate was greater in the patients with step 3 (moderate, persistent) or step 4 (severe, persistent), disease period less than 10 years, or reversible airway obstruction. Patients who showed favorable clinical response also demonstrated the reduction in medical costs. These results suggest that allergen immunotherapy reduces the disease severity and medical cost in a certain population of adult atopic asthma.

Role for Doppler ultrasound in the assessment of renal circulation: effects of dopamine and dobutamine on renal hemodynamics in humans.

To examine the utility of Doppler ultrasound in assessing renal hemodynamics, we investigated the effects of dopamine and dobutamine on renal blood flow using Doppler ultrasound technique and conventional clearance tests in 7 healthy volunteers. After visualization of arterial blood flow in the right renal hilus by two-dimensional color flow mapping, the phasic blood flow velocity in the vessel was obtained by a pulsed Doppler method. Intravenous infusion of dopamine at a low dose increased the velocity and decreased the waveform pulsatility of renal artery blood flow without causing any significant changes in blood pressure, heart rate, or cardiac index. In contrast, dobutamine infusion increased the peak systolic velocity in a dose-dependent manner, but did not increase the mean velocity or decrease the waveform pulsatility. Percent changes of renal blood flow during infusions of both agents correlated well with those of the mean velocity. Furthermore, the degrees of changes of the waveform pulsatility were consistent with those of renal vascular resistance obtained from clearance tests and blood pressure. Our results suggest that mean velocity reflects renal blood flow and the pulsatility of blood flow waveform represents renal vascular resistance. We conclude that the effects of vasoactive agents on renal blood flow and renal vascular resistance can be estimated noninvasively, directly, and repeatedly using Doppler ultrasound.

[Assessment of the distribution of renal cortical blood flow by contrast ultrasonography].

The importance of the distribution of intrarenal blood flow in the regulation of various renal functions, such as urine concentration and sodium excretion, has been well recognized. However, there have been no reliable methods to measure local flow in the kidney in vivo. The present study demonstrated the usefulness of contrast ultrasonography combined with injection of sonicated 5% albumin for assessment of the distribution of renal cortical blood flow in eleven mongrel dogs. The left kidney was displayed by tomographic echography, and microbubbles of sonicated albumin were injected into the abdominal aorta above the left renal artery. Video density time curves were generated and fitted to a time-intensity curve. Intrarenal infusion of acetylcholine (4.0 micrograms/kg/min) increased renal blood flow (RBF) from 2.5 +/- 0.3 to 4.6 +/- 1.0 ml/min/g kwt (p < 0.01), and norepinephrine (0.5 microgram/kg/min) decreased RBF from 2.5 +/- 0.3 to 1.2 +/- 0.5 ml/min/g kwt (p < 0.01). There were significant positive correlations between percent change in RBF and peak intensity and area under the curve, which were calculated with a time-intensity curve. Furthermore, the inner/outer renal cortex ratio of peak intensity significantly increased during acetylcholine infusion (0.72 +/- 0.11 vs 0.86 +/- 0.09; p < 0.01), whereas no significant change was observed during norepinephrine infusion. These results suggest that renal contrast ultrasonography may be useful for real-time assessment of the distribution of renal cortical blood flow in vivo.

Assessment of area at risk and efficacy of treatment in patients with acute coronary syndrome using 99mTc tetrofosmin imaging in humans.

The determination of the myocardium at risk before intervention and the change in that region after intervention constitute a promising measurement tool for the assessment of acute therapy. A new 99mTc labeled myocardial blood flow tracer, 99mTc tetrofosmin, is expected to enable the evaluation of myocardium at risk because of the absence of redistribution. This preliminary study was performed in 9 patients with acute coronary syndrome (4 unstable angina and 5 acute myocardial infarction) to investigate whether recovery of perfusion by tetrofosmin imaging parallels mechanical improvement. Tetrofosmin imaging was performed acutely and 3-30 days later. Visual analysis of defect severity was assessed in both studies. Segments with improvement in perfusion were accompanied by significant wall motion recovery compared with normal and unimproved segments (delta WMI: normal segments 0.40 +/- 0.67, improved segments 1.79 +/- 0.68, unimproved segments -0.15 +/- 0.16, p < 0.01 for improved segments compared with other groups), suggesting the efficacy of this tracer for the assessment of the acute therapy. These data suggest that 99mTc tetrofosmin imaging is a useful method for the assessment of the myocardial area at risk and the efficacy of acute therapy in acute myocardial infarction and unstable angina.

[Perfusion imaging with 99mTc PPN-1011 for the assessment of myocardial area at risk and the efficacy of PTCA/PTCR in myocardial infarction and unstable angina].

The determination of the myocardium at risk before intervention and the change in that region after intervention constitute a promising measurement tool for the assessment of acute therapy. We used 99mTc PPN-1011 in 4 patients with acute myocardial ischemia (2 patients with acute myocardial infarction, 2 unstable angina) and subsequent successful reperfusion. All 4 patients had perfusion defect on the pre-reperfusion image. Perfusion abnormality on post-reperfusion image was all improved significantly compared with pre-reperfusion image, suggesting the efficacy of acute treatment in acute myocardial ischemia. We conclude that 99mTc PPN-1011 scintigraphy is useful method for the assessment of myocardial area at risk and the efficacy of PTCA/PTCR in myocardial infarction and unstable angina.

[The value and limitation of resting 201Tl reinjection after stress-redistribution imaging for the assessment of myocardial viability: comparison with wall motion improvement by revascularization].

Clinical value and limitation of resting reinjection of small dose of thallium (37 MBq) for the assessment of myocardial viability were evaluated. The results were compared with the degree of wall motion improvement by revascularization to infarcted myocardium supplied by chronic total vessels in 12 patients with old myocardial infarction. Thallium uptake was visually scored and judged as normal, reversible defect (Group 1), new fill in after reinjection (Group 2A), and no fill in even after reinjection (Group 2B). Among 53 segments with initial perfusion abnormality, 21 segments reverted to almost normal, while 32 segments remained abnormal on redistribution images. New fill in after reinjection was observed in 11 segments of 32 segments showing persisting defect on stress and delayed image (37%). Wall motion score index of Group 2A improved significantly higher than Group 2B (p less than 0.01) and almost equal to Group 1, suggesting the utility of reinjection for the assessment of tissue viability which may be underestimated by conventional imaging. But significant wall motion improvement (greater than or equal to 0.6 mean SD/chords) was observed in 6 segments (29%) of 21 segments showing neither redistribution nor fill in after reinjection. These data indicate that small dose of thallium reinjection may enhance detection of viable but jeopardized myocardium, although some underestimation of viability remained to be resolved.

Assessment of right atrial (RA) and right ventricular (RV) function by gated blood pool scan with krypton-81m: RA and RV pressure-volume loops with simultaneous pressure data.

We developed a new method of analyzing right atrial (RA) and right ventricular (RV) function by Krypton-81m gated blood pool scan (Kr-81m-GBPS). Pressure data were recorded simultaneously with a modified Swan-Ganz catheter. Krypton-81m (Kr-81m) is ideally suited to hemodynamic study of the right heart because of the following characteristics: physical half-life of 13 seconds; high photon yield and gamma ray energy of 190 KeV; low radiation exposure; and deployment during exhalation when the left heart is not active. A computerized method for list mode data acquisition was developed to collect data from the gamma camera, ECG wave, and RA and RV pressure simultaneously. RA and RV volume curves were obtained by calibrating the time-activity curves with end-diastolic volumes and cardiac output. Ejection fraction (EF) was used in the calculation of volume and cardiac output (CO) was measured by the thermodilution method. From RA and RV pressure and volume curves, RA and RV pressure-volume (P-V) loops were created simultaneously and displayed on the same plane. One spanning cardiac cycle of RV beats was separated into four phases: the ventricular emptying phase, the early ventricular filling phase, equilibrium, and the late ventricular filling phase. One spanning cardiac cycle of RA beats also was separated into four phases as follows: the atrial filling phase, the early atrial emptying phase, equilibrium, and the late atrial emptying phase. P-V loops of RA and RV were shifted after sublingual nitroglycerin administration. This new method is potentially useful in the study of right heart hemodynamics.

[Assessment of cerebral infarction by MRI--particularly fogging effect].

Fogging effect in cerebral infarction was studied by MRI in a 51-year-old male patient. Initial symptoms consisted of mild disturbance of consciousness and left hemiparesis. MRI examination was performed 2, 13 and 22 days after onset and the results were compared with CT findings during the same period. CT on day 2 revealed a wide of infarction in the region of the middle cerebral artery including the basal ganglia. The presence of a fogging effect was seen by CT on day 12 and MRI revealed a high signal intensity in the region of the basal ganglia in T 1 image, a high signal intensity in the peripheral region and a low signal intensity in the center in T 2 image. It was possible to define the lesion as the ordinary infarcted lesion by the subsequent CT and MRI. MRI indicated the infarct lesion was to be a high signal intensity in T1 image and a high signal intensity in the periphery and a low signal intensity in the center in T 2 image. It was concluded that these findings indicated hemorrhage, strongly suggesting that the cause of the fogging effect was hemorrhagic infarction.