Design and characterization of the time-resolved opacity spectrometer (OpSpecTR) for the NIF iron opacity campaign.

A new time-resolved opacity spectrometer (OpSpecTR) is currently under development for the National Ignition Facility (NIF) opacity campaign. The spectrometer utilizes Icarus version 2 (IV2) hybridized complementary metal-oxide-semiconductor sensors to collect gated data at the time of the opacity transmission signal, unlocking the ability to collect higher-temperature measurements on NIF. Experimental conditions to achieve higher temperatures are feasible; however, backgrounds will dominate the data collected by the current time-integrating opacity spectrometer. The shortest available OpSpecTR integration time of ∼2 ns is predicted to reduce self-emission and other late-time backgrounds by up to 80%. Initially, three Icarus sensors will be used to collect data in the self-emission, backlighter, and absorption regions of the transmission spectrum, with plans to upgrade to five Daedalus sensors in future implementations with integration times of ∼1.3 ns. We present the details of the diagnostic design along with recent characterization results of the IV2 sensors.

Relationship between pain and hesitation during movement initiation after distal radius fracture surgery: A preliminary study.

We investigated the relationship between pain and hesitation during movement initiation among 11 adult female patients who had undergone surgery for a distal radius fracture. Data on the patients' pain at rest, pain during movement and score on the Pain Catastrophizing Scale were analyzed. Movement characteristics were assessed by the administration of a finger tapping (FT) task using the thumb and index finger, with the movement repeated 10 times, recorded and analyzed to determine the patient's hesitation when opening or closing her thumb/forefinger during the task. Hesitation of movement initiation was significantly correlated with subjective factors such as pain at rest, pain during movement, and rumination. Pain was not significantly correlated with the physical range of motion. Our findings suggest that hesitation during movement initiation for the FT task may be a type of behavior that is affected by subjective pain. Movement hesitation is a novel clinical sign indicating the possible progression of acute pain into chronic pain. The kinematic evaluation described herein is a convenient clinical measurement that captures a subjective factor.

TAK1 regulates hepatic lipid homeostasis through SREBP.

Sterol-regulatory element-binding proteins (SREBPs) are key transcription factors regulating cholesterol and fatty acid biosynthesis. SREBP activity is tightly regulated to maintain lipid homeostasis, and is modulated upon extracellular stimuli such as growth factors. While the homeostatic SREBP regulation is well studied, stimuli-dependent regulatory mechanisms are still elusive. Here we demonstrate that SREBPs are regulated by a previously uncharacterized mechanism through transforming growth factor-ß activated kinase 1 (TAK1), a signaling molecule of inflammation. We found that TAK1 binds to and inhibits mature forms of SREBPs. In an in vivo setting, hepatocyte-specific Tak1 deletion upregulates liver lipid deposition and lipogenic enzymes in the mouse model. Furthermore, hepatic Tak1 deficiency causes steatosis pathologies including elevated blood triglyceride and cholesterol levels, which are established risk factors for the development of hepatocellular carcinoma (HCC) and are indeed correlated with Tak1-deficiency-induced HCC development. Pharmacological inhibition of SREBPs alleviated the steatosis and reduced the expression level of the HCC marker gene in the Tak1-deficient liver. Thus, TAK1 regulation of SREBP critically contributes to the maintenance of liver homeostasis to prevent steatosis, which is a potentially important mechanism to prevent HCC development.

Snapping pes syndrome after total knee arthroplasty.

Snapping syndrome rarely occurs at the knee joint. This is the first report of snapping pes syndrome after total knee arthroplasty. Surgeons should be aware of the presence of such a case and pay attention to the fact that snapping symptoms could be caused by a residual bony prominence and a change in alignment after total knee arthroplasty.

TAK1 kinase determines TRAIL sensitivity by modulating reactive oxygen species and cIAP.

TNF-related apoptosis-inducing ligand (TRAIL) is a potent inducer of cell death in several cancer cells, but many cells are resistant to TRAIL. The mechanism that determines sensitivity to TRAIL-killing is still elusive. Here we report that deletion of TAK1 kinase greatly increased activation of caspase-3 and cell death after TRAIL stimulation in keratinocytes, fibroblasts and cancer cells. Although TAK1 kinase is involved in NF-kappaB pathway, ablation of NF-kappaB did not alter sensitivity to TRAIL. We found that TRAIL could induce accumulation of reactive oxygen species (ROS) when TAK1 was deleted. Furthermore, we found that TAK1 deletion induced TRAIL-dependent downregulation of cIAP, which enhanced activation of caspase-3. These results show that TAK1 deletion facilitates TRAIL-induced cell death by activating caspase through ROS and downregulation of cIAP. Thus, inhibition of TAK1 can be an effective approach to increase TRAIL sensitivity.

Quantitative assessment of harmonic power Doppler myocardial perfusion imaging with intravenous Levovist in patients with myocardial infarction: comparison with myocardial viability evaluated by thallium-201 single-photon emission computed tomography and coronary flow reserve.

BACKGROUND: Intravenous myocardial contrast echocardiography with harmonic power Doppler imaging is a novel technique for assessing myocardial perfusion. AIMS: The aim of this study was to quantitatively assess myocardial perfusion by harmonic power Doppler imaging in patients with a previous myocardial infarction and compare myocardial contrast echocardiography results with myocardial viability evaluated by thallium-201 single-photon emission computed tomography ((201)Tl-SPECT) and the results of Doppler flow measurement of coronary flow velocity reserve. METHODS: Twenty-three patients with anterior myocardial infarction who were scheduled for adenosine stress (201)Tl-SPECT underwent myocardial contrast echocardiography with harmonic power Doppler imaging. Harmonic power Doppler imaging was performed at rest and during adenosine infusion (0.15 mg/kg/min) using an intravenous infusion of Levovist. The peak colour pixel intensity ratios of the risk area to the control area were used for quantitative analysis of myocardial perfusion by harmonic power Doppler imaging. Coronary blood flow velocity was measured using Doppler-tipped guidewire in the distal portion of left anterior descending artery and coronary flow velocity reserve was calculated. RESULTS: In patients with myocardial viability assessed by (201)Tl-SPECT, pixel intensity ratios both at rest and during hyperaemia were significantly higher compared with those in patients without myocardial viability (at rest: 0.62 +/- 0.28 vs 0.37 +/- 0.17, P=0.038, during hyperaemia 0.72 +/- 0.19 vs 0.40 +/- 0.18, P=0.003). Coronary flow velocity reserve was significantly different between two groups (2.35 +/- 0.43 vs 1.49 +/- 0.53, P <0.01). CONCLUSIONS: Quantitative assessment of microvascular integrity by harmonic power Doppler imaging corresponds to the evaluation of the microcirculation by coronary flow velocity reserve.

Validity and reliability of single-item questions about physical activity.

The Japan Collaborative Cohort Study for Evaluation of Cancer Risk Sponsored by Monbusho (JACC Study) included in its self-administered questionnaires some single-item questions concerning physical activity. We examined the validity of the questions among 1,730 Japanese adults and the reliability of the questions among 1,075 Japanese adults. The validity of the sports and physical exercise questions was estimated by comparing the self-administered questionnaire responses with the time spent on the activity and the energy expenditure index for the previous 12-month period, elicited by the interviewing method used in the Japan Lifestyle Monitoring Study with a minor modification. The Spearman's rank correlation coefficients ranged from 0.43 to 0.60, showing moderate correlations. On the other hand, test-retest reliability was estimated by comparing the responses from two separate surveys conducted roughly one year apart. Weighted kappa coefficients of sports and physical exercise questions, classified according to sex and age, ranged from 0.39 to 0.56, showing moderate reliability; and those of a question about walking ranged from 0.25 to 0.39, showing fair reliability. We suggest that measuring physical activity level with these single-item questions may be appropriate for establishing baseline data that reflects long-term physical activity in a large-scale cohort study targeting lifestyle-related diseases.

Smoking, alcohol, sleep and risk of idiopathic sudden deafness: a case-control study using pooled controls.

Sudden deafness sometimes has an identifiable cause, but in most cases the cause is unknown (idiopathic sudden deafness). Vascular impairment has been proposed as an aetiological mechanism for this condition, but it is unclear whether traditional cardiovascular risk factors, such as smoking or alcohol intake, are associated with this condition. We accordingly investigated associations of idiopathic sudden deafness with smoking, alcohol intake and sleep duration in a case-control study. Cases were consecutive patients diagnosed with idiopathic sudden deafness between October 1996 and August 1998 at collaborating hospitals in Japan. Controls were obtained from a nationwide database of pooled controls, with matching for age, gender and residential district. Exposure variables were assessed from a self-administered questionnaire. Subgroup analyses were performed using audiometric subtypes of sudden deafness. Data were obtained for 164 cases and 20,313 controls. Increased risks of idiopathic sudden deafness were observed among participants who consumed two or more units of alcohol per day (OR=1.90, 95% CI=1.12-3.21), and among participants who slept less than seven hours per night (OR=1.61, 95% CI=1.09-2.37). The direct association with alcohol intake was particularly strong for the participants with profound hearing loss. There was little evidence of an association with smoking. This study suggests that alcohol intake and short sleep duration might be risk factors for idiopathic sudden deafness.

Comparative effects of all-trans beta-carotene vs. 9-cis beta-carotene on carcinogen-induced neoplastic transformation and connexin 43 expression in murine 10T1/2 cells and on the differentiation of human keratinocytes.

9-cis beta-Carotene was extracted from a commercial extract of the algae Dunaliella salina (Betatene), and its actions on proliferation and gene expression were examined in murine 10T1/2 cells and human HaCaT keratinocytes. The 9-cis isomer was less active than all-trans beta-carotene in reducing proliferation and in upregulating expression of connexin 43 in 10T1/2 cells. However, it had comparable ability to suppress carcinogen-induced neoplastic transformation. When tested in HaCaT cells in organotypic culture, it was less active in inducing connexin 43 expression and suppressing expression of keratin K1. In this assay the all-trans isomer was highly active at 10(-6) M, whereas 10(-5) M 9-cis beta-carotene was required to produce a comparable effect. Only small reductions in expression of the basal keratin 5 were seen. All-trans and 9-cis retinoic acids, potential metabolites of beta-carotene isomers, were studied in the same systems. In contrast to the carotenoids, the 9-cis isomer of retinoic acid was approximately 10-fold more active in suppressing neoplastic transformation and inducing connexin 43 expression in both cell types than the all-trans isomer. The retinoic acid isomers were about equipotent in suppressing K1 expression. Cellular levels of 9-cis beta-carotene were approximately 3.5-fold lower than levels of all-trans beta-carotene, suggesting that part, but not all, of this decreased activity of the 9-cis isomer was due to decreased cell uptake. Thus 9-cis beta-carotene is consistently less active than the all-trans isomer; that 9-cis retinoic acid is, in general, much more potent than the all-trans isomer suggests little or no conversion from the carotenoid to the retinoid under these culture conditions.

A probable relationship between an endogenous digitalis-like substance and concentric cardiac hypertrophy in primary aldosteronism.

A 44-year-old woman was admitted to our hospital due to severe hypertension. An electrocardiogram (ECG) and an echocardiogram showed severe left ventricular hypertrophy. Her plasma aldosterone level was elevated. Magnetic resonance imaging revealed a small mass in the right adrenal gland. Before removal of the tumor, plasma endogenous digitalis-like substance (EDLS) levels were elevated. After removal of the tumor, EDLS levels quickly returned to the normal level. A series of echocardiograms and ECGs over a 6- year period after removal of the tumor showed marked regression of cardiac hypertrophy. These findings suggest that EDLS may be closely related to the development of concentric cardiac hypertrophy in primary aldosteronism.

[Evaluation of mitral valve lesions in patients with infective endocarditis by three-dimensional echocardiography].

Recognition of the involved lesions is extremely important in mitral valve repair for infective endocarditis. Transesophageal echocardiography (TEE) is more sensitive for the detection of lesions than transthoracic echocardiography, but localization of the lesions is sometimes difficult by TEE. Three-dimensional (3D) TEE provides images of the mitral valve similar to the view from the left atrium. This study evaluated the value of 3D echocardiography for the diagnosis of involved lesions in 12 patients who underwent surgery for mitral regurgitation due to infective endocarditis. The location of the lesion in the mitral valve was classified as the medial, central and lateral portions of the anterior leaflet, and the medial, middle and lateral scallops of the posterior leaflet, respectively. In all patients, the involved sites were confirmed at operation. The sensitivities of 3D TEE for detecting the lesions at the medial, central and lateral portions of the anterior leaflet, and the medial, middle and lateral scallops of the posterior leaflet were 100%, 78% and 67%, and 100%, 100% and 100%, respectively. The specificities were 90%, 100% and 78%, and 100%, 100% and 100%, respectively. The lesions diagnosed by 3D TEE coincided with lesions confirmed at operation in 23 (92%) of 25 lesions. 3D TEE is useful for the assessment of the involved lesion of the mitral valve in patients with infective endocarditis.

[Assessment of coronary flow reserve in patients with hypertrophic cardiomyopathy using transthoracic color Doppler echocardiography].

Abnormal coronary flow pattern and coronary vasodilator reserve have been identified in patients with hypertrophic cardiomyopathy (HCM) using invasive techniques. The characteristics of coronary flow velocity and coronary flow reserve were evaluated by noninvasive-recording of coronary flow velocity in the distal portion of the left anterior descending coronary artery in 7 patients with HCM and 7 normal subjects using transthoracic color Doppler echocardiography. Coronary flow velocity was measured at rest and during intravenous infusion of adenosine triphosphate (0.15 mg/kg/min). Diastolic peak velocity, diastolic mean velocity, the time from the beginning of diastole to peak velocity (TVP) and velocity half time from peak velocity was measured in each group. Coronary flow reserve was obtained as the ratio of hyperemic mean velocity to resting mean velocity. TVP was significantly prolonged in the patients with HCM compared with the normal subjects (159 +/- 38 vs 103 +/- 54 msec, p < 0.05). Velocity half time was significantly shorter in the patients with HCM compared with the normal subjects (304 +/- 138 vs 451 +/- 109 msec, p < 0.05). Although diastolic mean velocity during hyperemia was not different between the 2 groups (62 +/- 8 vs 70 +/- 19 cm/sec), diastolic mean velocity at rest was significantly higher in the patients with HCM than in the normal subjects (39 +/- 6 vs 26 +/- 7 cm/sec, p < 0.01). Therefore, coronary flow reserve was significantly lower in the patients with HCM than in the normal subjects (1.6 +/- 0.4 vs 2.7 +/- 0.4, p < 0.001). There was a good correlation between diastolic mean velocity and the ratio of interventricular septal to posterior left ventricular wall thickness (y = 0.024x + 0.46, r = 0.75). Transthoracic assessment of coronary flow velocity using color Doppler echocardiography reveals that coronary flow reserve is reduced in patients with HCM because of increased baseline resting diastolic mean velocity.

Restricted coronary flow reserve in patients with mitral regurgitation improves after mitral reconstructive surgery.

OBJECTIVES: The purpose of this study was to assess coronary flow characteristics in patients with chronic mitral regurgitation (MR). BACKGROUND: Coronary flow reserve (CFR) has been reported to be restricted in cases with left ventricular (LV) volume overload caused by aortic regurgitation and increased LV preload. METHODS: The study populations consisted of 31 patients with nonrheumatic chronic MR. Eleven with chest pain and normal coronary arteries served as control subjects. Phasic coronary flow velocities were obtained in the proximal segment of the angiographically normal left anterior descending coronary artery at rest and during hyperemia (0.14 mg/kg/min adenosine infusion intravenously) using a 0.014-in. (0.036 cm), 15-MHz Doppler guide wire. Coronary flow reserve was obtained from the ratio of hyperemic/baseline time-averaged peak velocity (APV). Thirteen cases who underwent mitral valve reconstructive surgery were also studied 1 month after surgery. RESULTS: Compared with control subjects, CFR was significantly reduced in cases with MR (2.1+/-0.5 vs. 33+/-0.6, respectively, p < 0.01) because baseline APV was significantly greater (28+/-8 vs. 19+/-6 cm/s, respectively, p < 0.01), although maximal hyperemic APV was not significantly different (56+/-14 vs. 61+/-16 cm/s, respectively, p = NS). Significant correlations were obtained between CFR and LV end-diastolic pressure (LVEDP) (r = 0.70, p < 0.01), LV mass index (r = 0.42, p < 0.01), LV end-diastolic volume (r = 038, p = 0.04) and MR volume (r = 0.39, p = 0.03), and stepwise regression analysis showed LVEDP was the most important determinant of CFR in MR (r2 = 0.49, p < 0.0001). This restricted CFR improved significantly after mitral valve reconstructive surgery (2.1+/-0.5 vs. 3.1+/-0.6, respectively, p < 0.01) because of reduction of baseline APV (28+/-8 vs. 21+/-8 cm/s, respectively, p < 0.01). CONCLUSIONS: Coronary flow reserve is limited in cases with MR because of elevation of baseline resting flow velocity. This reduction of CFR correlates well with increase in LV preload, mass and volume overload, especially with increase in LV preload, and this restricted CFR improves after mitral valve surgery.

Noninvasive assessment of coronary flow velocity and coronary flow velocity reserve in the left anterior descending coronary artery by Doppler echocardiography: comparison with invasive technique.

OBJECTIVES: The purpose of this study was to evaluate whether transthoracic Doppler echocardiography (TTDE) can reliably measure coronary flow velocity (CFV) and coronary flow velocity reserve (CFVR) in the left anterior descending coronary artery (LAD) in the clinical setting. BACKGROUND: Coronary flow velocity measurement has provided useful clinical and physiologic information. Advancement in TTDE provides noninvasive measurement of CFV and CFVR in the distal LAD. METHODS: In 23 patients, CFV in the distal LAD was measured by TTDE (5 or 3.5 MHz) under the guidance of color Doppler flow mapping at the time of Doppler guide wire (DGW) examination. Coronary flow velocity in the distal LAD were measured at baseline and hyperemic conditions (intravenous administration of adenosine 0.14 mg/kg/min) by both TTDE and DGW techniques. Coronary flow velocity reserve was defined as the ratio of peak hyperemic to basal averaged peak velocity in the distal LAD. RESULTS: Clear envelopes of basal and hyperemic CFV in the distal LAD were obtained in 18 (78%) of 23 study patients by TTDE. There were excellent correlations between TTDE and DGW methods for the measurements of CFV (averaged peak velocity: r=0.97, y=0.94x + 0.40; averaged diastolic peak velocity: r=0.97, y=0.94x + 0.69; systolic peak velocities: r=0.97, y=0.91x + 0.87; diastolic peak velocity: r=0.98, y=0.95x + 1.10). Coronary flow velocity reserve from TTDE correlated highly with those from DGW examinations (r=0.94, y=0.95x + 0.21). CONCLUSIONS: Noninvasive measurement of CFV and CFVR in the distal LAD using TTDE accurately reflects invasive measurement of CFV and CFVR by DGW method.

Noninvasive assessment of significant left anterior descending coronary artery stenosis by coronary flow velocity reserve with transthoracic color Doppler echocardiography.

BACKGROUND: Coronary flow reserve has been considered an important diagnostic index of the functional significance of coronary artery stenosis. With Doppler technique, it has been assessed as the ratio of hyperemic to basal coronary flow velocity (coronary flow velocity reserve [CFVR]) by invasive or semiinvasive methods with a Doppler catheter, a Doppler guide wire, and a transesophageal Doppler echocardiographic probe. Recent technological advancement in transthoracic Doppler echocardiography (TTDE) provides measurement of coronary flow velocity in the distal portion of the left anterior descending coronary artery (LAD) and may be useful in the noninvasive CFVR measurement. The purpose of this study was to evaluate the value of CFVR determined by TTDE for the assessment of significant LAD stenosis. METHODS AND RESULTS: We studied 36 patients who underwent coronary angiography for the assessment of coronary artery disease. The study population consisted of 12 patients with significant LAD stenosis (group A) and 24 patients without significant LAD stenosis (group B). With TTDE, coronary flow velocities in the distal LAD were recorded at rest and during hyperemia induced by intravenous infusion of adenosine (0.14 mg x kg(-1) x min(-1)) under the guidance of color Doppler flow mapping. Adequate spectral Doppler recordings of coronary flow in the distal LAD for the assessment of CFVR were obtained in 34 of 36 study patients (94%). The peak and mean diastolic coronary flow velocities at baseline did not differ between groups A and B (23.6+/-10.3 versus 22.9+/-6.6 cm/s and 16.4+/-8.6 versus 14.5+/-4.0 cm/s, respectively). However, the peak and mean coronary flow velocities during hyperemia in group A were significantly smaller than those in group B (35.6+/-16.3 versus 54.2+/-16.3 cm/s and 24.7+/-13.1 versus 37.9+/-13.0 cm/s, respectively; P<.01). There were significant differences in CFVR obtained from peak and mean diastolic velocity between groups A and B (1.5+/-0.2 versus 2.4+/-0.4 and 1.5+/-0.2 versus 2.6+/-0.4, respectively; P<.001). A CFVR from peak diastolic velocity <2.0 had a sensitivity of 92% and a specificity of 82% for the presence of significant LAD stenosis. A CFVR from mean diastolic velocity <2.0 had a sensitivity of 92% and a specificity of 86% for the presence of significant LAD stenosis. CONCLUSIONS: CFVR determined by TTDE is useful in the noninvasive assessment of significant stenotic lesion in the LAD.

Flow dynamics of angiographically no-flow patent internal mammary artery grafts.

OBJECTIVES: This study sought to assess the flow dynamics of internal mammary artery grafts (IMAGs) in no-flow situations by use of a Doppler guide wire. BACKGROUND: Functionally no-flow and anatomically patent IMAGs have been reported by angiography in patients with a patent recipient coronary artery. METHODS: The study included 12 patients with an IMAG to the left anterior descending coronary artery (LAD) in whom no-flow patency of the graft was suspected angiographically. Thirteen patients with a normally functioning IMAG whose LAD was occluded in the proximal portion and was supplied only from the graft served as control patients. Phasic flow velocities were recorded in the distal portion of the graft and the recipient LAD using a 0.014-in., 15-MHz Doppler guide wire at rest and during hyperemia (0.14-mg/kg body weight per min intravenous adenosine infusion). RESULTS: There were no significant differences in systolic (15+/-3 vs. 19+/-6 cm/s, p = NS), diastolic (35+/-11 vs. 37+/-7 cm/s, p = NS) and time-averaged peak velocities at rest (20+/-5 vs. 21+/-5 cm/s, p = NS), during hyperemia (51+/-12 vs. 54+/-8 cm/s, p = NS) and in coronary flow velocity reserve (2.8+/-0.9 vs. 2.7+/-0.3, NS) in the native LAD in patients with a no-flow patent graft versus control patients. Within the graft, to and fro signals with systolic reversal and diastolic anterograde flow were seen in the no-flow patent grafts, although anterograde flow signals were recorded in systole and diastole in control patients. Systolic (-28+/-19 vs. 22+/-9 cm/s, p < 0.01), diastolic (18+/-17 vs. 44+/-14 cm/s, p < 0.01) and time-averaged (-2+/-6 vs. 26+/-9 cm/s, p < 0.01) peak velocities at rest were significantly smaller in the no-flow patent grafts than in control grafts. During hyperemia, anterograde flow became predominant, with a reduction in retrograde systolic flow signal and an increase in diastolic flow velocity and time-averaged peak velocity in the no-flow patent grafts, and no-flow situations disappeared temporarily. CONCLUSIONS: Functionally no-flow situations of IMAGs manifesting to and fro signals with systolic flow reversal and diastolic antegrade low flow velocity are temporary conditions in certain hemodynamic circumstances, and these grafts function as conduits during hyperemic states.

[Long-term results of mitral valve repair with artificial chordae tendineae].

The long-term results of mitral valve repair using artificial polytetrafluorethylene (PTFE) chordae were assessed in 61 consecutive patients with pure mitral regurgitation who underwent mitral valve repair with replacement of elongated or ruptured chordae tendineae between 1992 and 1996. There were 36 men and 25 women aged from 14 to 73 years (mean 52.1 +/- 13.8 years). The patients were followed up for between 1 to 73 months (mean 29.3 +/- 17.6 months). Fifty-five patients underwent mitral valve repair of the anterior leaflet and 6 repair of the posterior leaflet. There were two hospital and two late deaths. Actual survival rate at 5 years was 93.1%. Freedom from cardiac events at 5 years was 87.8%. Two patients required reoperation due to hemolysis. There were three occurrences of non-fatal thromboembolism. Although further investigation is necessary in a large population, expanded PTFE sutures are excellent for chordal replacement during mitral valve repair.

Phasic coronary flow characteristics in patients with constrictive pericarditis: comparison with restrictive cardiomyopathy.

BACKGROUND: Phasic coronary flow characteristics have been reported in patients with aortic valve disease and hypertrophic cardiomyopathy. The purpose of this study was to assess the differences in coronary flow characteristics between patients with constrictive pericarditis and those with restrictive cardiomyopathy. METHODS AND RESULTS: The study populations consisted of 7 case patients with constrictive pericarditis, 8 with restrictive cardiomyopathy, and 11 control subjects with chest pain and normal coronary arteries. Five minutes after injection of 3 mg of isosorbide dinitrate, phasic coronary flow velocity patterns were analyzed in the proximal segment of the angiographically normal left anterior descending coronary artery at rest using a 0.014-in, 15-MHz Doppler guidewire. Coronary flow reserve was obtained from the ratio of adenosine-induced (0.14 mg x kg(-1) x min(-1) I.V.) hyperemic/baseline time-averaged peak velocity. Although in case patients with constrictive pericarditis and restrictive cardiomyopathy maximal hyperemic time-averaged peak velocity (21+/-8 and 31+/-17 versus 60+/-19 cm/s, respectively; P<.001) and coronary flow reserve (1.3+/-0.4 and 1.6+/-0.6 versus 3.6+/-0.4, respectively, P<.001) were significantly lower than in control subjects, there were no significant differences in these indexes between the two groups of case patients. Velocity half-time of diastolic flow velocity corrected by square root(RR), which indicates deceleration of diastolic flow, in the groups of case patients with constrictive pericarditis and restrictive cardiomyopathy was significantly less than that in control subjects (6.2+/-2.6 and 10.6+/-1.5 versus 16.9+/-2.7, respectively; P<.001); this was also significantly smaller in constrictive pericarditis than restrictive cardiomyopathy (P<.001). This index <9.5 could distinguish constrictive pericarditis from restrictive cardiomyopathy with a sensitivity of 86% and a specificity of 88%. Furthermore, time from the beginning of diastole to diastolic peak velocity corrected by square root(RR) indicating acceleration of diastolic flow velocity in constrictive pericarditis was significantly less than that in restrictive cardiomyopathy and control subjects (2.8+/-1.2 versus 4.8+/-0.8 and 4.4+/-0.6, respectively; P<.001). CONCLUSIONS: Although coronary flow reserve is limited in both constrictive pericarditis and restrictive cardiomyopathy because of restriction of hyperemic response, rapid acceleration and more rapid deceleration of diastolic flow velocity are more characteristic in constrictive pericarditis than in restrictive cardiomyopathy.