Inhibition of fibrotic changes in infrapatellar fat pad alleviates persistent pain and articular cartilage degeneration in monoiodoacetic acid-induced rat arthritis model.

OBJECTIVE: We have reported that fibrotic changes in infrapatellar fat pad (IFP) after acute joint inflammation are closely associated with persistent pain in rats. In this study, to examine the effects of anti-fibrotic treatment on persistent pain, we used C-type natriuretic peptides (CNP) at the recovery phase after acute joint inflammation. DESIGN: Thirty-two male Wistar rats were used in this study. Monoiodoacetic acid (MIA) was injected intra-articularly to induce IFP fibrosis and persistent pain. CNP was injected after acute inflammatory phase in the same knee joint. Time-course pain-avoidance behavior tests and histological analyses were performed to examine the effects of CNP. RESULTS: Histological evaluations indicated that intra-articular injection of CNP inhibited fibrotic changes in IFP after acute inflammation. Incapacitance tests indicated that MIA injection into rat knee joint quickly decreased the percent weight on ipsilateral limb. In the vehicle group, the decrease was maintained up to day 28, suggesting that pain persistence occurred after acute inflammation (Day 0/Day 28, Est Dif -8.15, CI -10.78∼-5.53, Linear mixed-effect model). In contrast, the pain was alleviated in the CNP group after day 14 (Day0/Day 14, -0.51, -2.62-1.59). In addition, we observed significant improvement in the degree of articular cartilage degeneration at day 14 in the CNP group (OARSI score: vehicle 16.14 ± 4.37 vs CNP 6.87 ± 3.44, P < 0.01; Wilcoxon rank sum test). CONCLUSION: Fibrotic changes in IFP may play important roles in both persistent pain and articular cartilage degeneration.

Efficiency of genomic selection for breeding population design and phenotype prediction in tomato.

Genomic selection (GS), which uses estimated genetic potential based on genome-wide genotype data for a breeding selection, is now widely accepted as an efficient method to improve genetically complex traits. We assessed the potential of GS for increasing soluble solids content and total fruit weight of tomato. A collection of big-fruited F1 varieties was used to construct the GS models, and the progeny from crosses was used to validate the models. The present study includes two experiments: a prediction of a parental combination that generates superior progeny and the prediction of progeny phenotypes. The GS models successfully predicted a better parent even if the phenotypic value did not vary substantially between candidates. The GS models also predicted phenotypes of progeny, although their efficiency varied depending on the parental cross combinations and the selected traits. Although further analyses are required to apply GS in an actual breeding situation, our results indicated that GS is a promising strategy for future tomato breeding design.

Professional oral health care reduces the number of oropharyngeal bacteria.

Silent aspiration of oropharyngeal pathogenic organisms is a significant risk factor causing pneumonia in the elderly. We hypothesized that regular oral hygiene care will affect the presence of oropharyngeal bacteria. Professional cleaning of the oral cavity and/or the gargling of a disinfectant liquid solution was performed over a five-month period in three facilities for the dependent elderly. Total oropharyngeal bacteria, streptococci, staphylococci, Candida, Pseudomonas, and black-pigmented Bacteroides species were monitored. The levels of these oropharyngeal bacteria decreased or disappeared after weekly professional oral health care, i.e., cleaning of teeth, dentures, tongue, and oral mucous membrane by dental hygienists. After lunch, gargling with povidone iodine was shown to be less effective than professional oral care. These findings indicate that weekly professional mechanical cleaning of the oral cavity, rather than a daily chemical disinfection of the mouth, can be an important strategy to prevent aspiration pneumonia in the dependent elderly.

Comparison of wear rate and osteolysis between second-generation annealed and first-generation remelted highly cross-linked polyethylene in total hip arthroplasty. A case control study at a minimum of five years.

BACKGROUND: There is no previous report that directly compared wear resistance of second-generation annealed highly cross-linked polyethylene with that of first-generation remelted highly cross-linked polyethylene. We therefore performed a retrospective study at a minimum of 5-year follow-up comparing second-generation annealed and first-generation remelted highly cross-linked polyethylene in order to: (1) assess wear rates and (2) compare the incidence of osteolysis between, (3) identify the frequency of complication related to the two types of highly cross-linked polyethylene. HYPOTHESIS: There is a difference in the linear wear rate and the incidence of osteolysis between the two types of highly cross-linked polyethylene in total hip arthroplasty. MATERIALS AND METHODS: In a single centre study, we reviewed 123 primary cementless total hip arthroplasties between 2010 and 2011 that were performed with 32mm alumina ceramic on second-generation annealed (X3) or first-generation remelted (Longevity) highly cross-linked polyethylene liner. There was no specific reason for the choice of the type of highly cross-linked polyethylene. There were no significant differences between the two groups in respect of gender, diagnosis, body mass index, pre- and post-operative functional and activity score, cup size, and cup orientation except the younger age in the X3 group. The mean wear rate and the incidence of osteolysis were evaluated at the latest follow-up. RESULTS: One hundred nine cases followed over 5 years post-operatively (88.6% in all consecutive cases) were evaluated. X3 and Longevity were used in 54 and 55 cases, respectively. The mean follow-up was 5.3 years in both groups. The mean linear wear rate of X3 and Longevity group was 0.045±0.023mm/year and 0.076±0.031mm/year, respectively (P<0.001). No osteolysis was found on plain X-rays in both groups and no specific complication was related to these highly cross-linked components. DISCUSSION: Excellent wear resistance of both types of highly cross-linked polyethylene liner was revealed in our study. The difference of wear rate between two materials should be monitored in a longer follow-up. LEVEL OF EVIDENCE: Level III retrospective case control study.

The intron 5-inserted form of rat erythropoietin receptor is expressed as a membrane-bound form.

The cDNA encoding an intron 5-inserted form of the erythropoietin receptor (I5Epo-R) has been cloned from rat. DNA sequence analysis reveals that the insertion of intron 5, which consists of 79 bp, causes a shift in reading frame and results in termination in the region of exon 7. The deduced amino acid sequence is composed of 316 amino acid residues, which is a molecular weight of 34220. To study the function of rat I5Epo-R, we established a Chinese hamster ovary cell line expressing rat I5Epo-R. Western blot analysis and binding studies with 125I-recombinant human erythropoietin showed that the transfected cells expressed rat I5Epo-R with a molecular size of 36 kDa as a membrane-bound form, but not as a soluble form, and had a single class of binding sites with a Kd of 700 pM.

Cobalamin deficiency results in severe metabolic disorder of serine and threonine in rats.

Dietary cobalamin (vitamin B12; Cbl) deficiency caused significant increases in plasma serine, threonine, glycine, alanine, tyrosine, lysine and histidine levels in rats. In particular, the serine and threonine levels were over five and eight times, respectively, higher in the Cbl-deficient rats than those in the sufficient controls. In addition, some amino acids, including serine and threonine, were excreted into urine at significantly higher levels in the deficient rats. When Cbl was supplemented into the deficient rats for 2 weeks, in coincidence with the disappearance of the urinary excretion of methylmalonic acid (an index of Cbl deficiency), the plasma serine and threonine levels were normalized. These results indicate that Cbl deficiency results in metabolic disorder of certain amino acids, including serine and threonine. The expression level of hepatic serine dehydratase (SDH), which catalyzes the conversion of serine and threonine to pyruvate and 2-oxobutyrate, respectively, was significantly lowered by Cbl deficiency, even though Cbl does not participate directly in the enzyme reaction. The SDH activity in the deficient rats was less than 20% of that in the sufficient controls, and was normalized 2 weeks after the Cbl supplementation. It is thus suggested that the decrease of the SDH expression relates closely with the abnormalities in the plasma and urinary levels of serine and threonine in the Cbl-deficient rats.

Disordered expression of the sucrase-isomaltase complex in the small intestine in Otsuka Long-Evans tokushima fatty rats, a model of non-insulin-dependent diabetes mellitus with insulin resistance.

To clarify the relationship between diabetes mellitus and carbohydrate digestion, the activities of sucrase and isomaltase, which form a complex enzyme (SI complex) on the brush border membranes, were compared in the progression of diabetes mellitus in Otsuka Long-Evans Tokushima fatty (OLETF) rats, a model of human non-insulin-dependent diabetes mellitus with insulin resistance, and Long-Evans Tokushima Otsuka (LETO) rats as non-diabetic controls. Until 40 weeks of age, OLETF rats were obese and had a high plasma glucose level, compared to age-matched LETO rats, but the sucrase and isomaltase activities showed no significant differences between the two strains. Oral glucose tolerance test revealed that during 40-48 weeks of age, NIDDM became very severe with advancing insulin resistance in OLETF rats. In OLETF rats, in contrast to LETO rats, at 48 weeks of age, abnormal increases in the sucrase and isomaltase activities occurred, along with a remarkable decrease in body weight and a further great increase in the plasma glucose level in the non-fasting state. Hyperinsulinemia occurred in 20-week-old OLETF rats; however, at 40 and 48 weeks of age, the plasma insulin level in the non-fasting state in OLETF rats was not significantly different from that in LETO rats. The level of mRNA encoding the SI complex increased abnormally in 48-week-old OLETF rats. These results suggest that the advance of insulin resistance leads to an increase in the expression of the SI complex on the transcriptional level.

Plasma brain natriuretic peptide as a prognostic indicator in patients with primary pulmonary hypertension.

BACKGROUND: Plasma brain natriuretic peptide (BNP) level increases in proportion to the degree of right ventricular dysfunction in pulmonary hypertension. We sought to assess the prognostic significance of plasma BNP in patients with primary pulmonary hypertension (PPH). METHODS AND RESULTS: Plasma BNP was measured in 60 patients with PPH at diagnostic catheterization, together with atrial natriuretic peptide, norepinephrine, and epinephrine. Measurements were repeated in 53 patients after a mean follow-up period of 3 months. Forty-nine of the patients received intravenous or oral prostacyclin. During a mean follow-up period of 24 months, 18 patients died of cardiopulmonary causes. According to multivariate analysis, baseline plasma BNP was an independent predictor of mortality. Patients with a supramedian level of baseline BNP (>/=150 pg/mL) had a significantly lower survival rate than those with an inframedian level, according to Kaplan-Meier survival curves (P<0.05). Plasma BNP in survivors decreased significantly during the follow-up (217+/-38 to 149+/-30 pg/mL, P<0. 05), whereas that in nonsurvivors increased (365+/-77 to 544+/-68 pg/mL, P<0.05). Thus, survival was strikingly worse for patients with a supramedian value of follow-up BNP (>/=180 pg/mL) than for those with an inframedian value (P<0.0001). CONCLUSIONS: A high level of plasma BNP, and in particular, a further increase in plasma BNP during follow-up, may have a strong, independent association with increased mortality rates in patients with PPH.

Gene transfer of human prostacyclin synthase ameliorates monocrotaline-induced pulmonary hypertension in rats.

BACKGROUND: Prostacyclin is a potent vasodilator that also inhibits platelet adhesion and cell growth. We investigated whether in vivo gene transfer of human prostacyclin synthase (PGIS) ameliorates monocrotaline (MCT)-induced pulmonary hypertension in rats. METHODS AND RESULTS: The cDNA encoding PGIS was intratracheally transfected into the lungs of rats by the hemagglutinating virus of Japan-liposome method. Rats transfected with control vector lacking the PGIS gene served as controls. Three weeks after MCT injection, mean pulmonary arterial pressure and total pulmonary resistance had increased significantly; the increases were significantly attenuated in PGIS gene-transfected rats compared with controls [mean pulmonary arterial pressure, 31+/-1 versus 35+/-1 mm Hg (-12%); total pulmonary resistance, 0.087+/-0.01 versus 0.113+/-0.01 mm Hg x mL x min(-1) x kg(-1) (-23%), both P:<0.05]. Systemic arterial pressure and heart rate were unaffected. Histologically, PGIS gene transfer inhibited the increase in medial wall thickness of peripheral pulmonary arteries that resulted from MCT injection. PGIS immunoreactivity was intense predominantly in the bronchial epithelium and alveolar cells. Lung tissue levels of 6-keto-PGF(1alpha), a stable metabolite of prostacyclin, were significantly increased for >/=1 week after transfer of PGIS gene. The Kaplan-Meier survival curves demonstrated that repeated transfer of PGIS gene every 2 weeks increased survival rate in MCT rats (log-rank test, P:<0.01). CONCLUSIONS: Intratracheal transfer of the human PGIS gene augmented pulmonary prostacyclin synthesis, ameliorated MCT-induced pulmonary hypertension, and thereby improved survival in MCT rats.

Hemodynamic, renal, and hormonal effects of adrenomedullin infusion in patients with congestive heart failure.

BACKGROUND: Experimental studies have shown that adrenomedullin (AM) causes vasodilatation, diuresis, and a positive inotropic effect. In humans, however, whether infusion of AM has beneficial effects in congestive heart failure (CHF) remains unknown. METHODS AND RESULTS: Hemodynamic, renal, and hormonal responses to intravenous infusion of human AM (0.05 microg. kg(-1). min(-1)) were examined in 7 patients with CHF and 7 normal healthy subjects (NL). In NL group, AM significantly decreased mean arterial pressure (-16 mm Hg, P<0. 05) and increased heart rate (+12 bpm, P<0.05). In CHF group, AM also decreased mean arterial pressure (-8 mm Hg, P<0.05) and increased heart rate (+5 bpm, P<0.05), but to a much lesser degree (P<0.05 versus NL). AM markedly increased cardiac index (CHF, +49%; NL, +39%, P<0.05) while decreasing pulmonary capillary wedge pressure (CHF, -4 mm Hg; NL, -2 mm Hg, P<0.05). AM significantly decreased mean pulmonary arterial pressure only in CHF (-4 mm Hg, P<0.05). AM increased urine volume (CHF, +48%; NL, +62%, P<0.05) and urinary sodium excretion (CHF, +42%; NL, +75%, P<0.05). Only in CHF, plasma aldosterone significantly decreased during (-28%, P<0.05) and after (-36%, P<0.05) AM infusion. These parameters remained unchanged in 7 patients with CHF and 6 healthy subjects who received placebo. CONCLUSIONS: Intravenous infusion of AM has beneficial hemodynamic and renal effects in patients with CHF.

Functional myocardial perfusion abnormality induced by left ventricular asynchronous contraction: experimental study using myocardial contrast echocardiography.

OBJECTIVES: The aim of this study was to clarify how myocardial perfusion is impaired by asynchronous contraction. BACKGROUND: False septal hypoperfusion is noted in some patients with left bundle branch block. METHODS: Eight dogs were examined with epicardial pacing at the left ventricular posterior wall, the right ventricular anterior wall and, as a control, the right atrial appendage. The pacing rate was 80, 110 and 150 beats/min (bpm). Myocardial perfusion was assessed by contrast echocardiography. RESULTS: Left ventricular pacing at 80 and 110 bpm did not change systolic wall thickening or contrast intensity at the pacing site, although an early excitation notch was noted at the pacing site. However, at 150 bpm, systolic thickening was impaired (23.3 +/- 4.2% vs. 37.0 +/- 2.6% during atrial pacing, p < 0.05), and the peak intensity ratio of the pacing site to the ventricular septum was significantly decreased (24.1 +/- 5.7% vs. 37.0 +/- 2.8% at a pacing rate of 80 bpm, p < 0.01). The peak intensity ratio correlated with systolic wall thickening at the pacing site (y = 0.413 x -0.028, r = 0.81, p < 0.0001). However, right ventricular pacing did not change either systolic thickening or the peak intensity ratio at any pacing rate, although an early excitation notch was noted on the ventricular septum. CONCLUSIONS: Wall motion abnormalities after early excitation vary depending on the pacing mode. When tachycardia induces regional wall motion abnormalities, the ventricular wall of the pacing site is functionally hypoperfused.

Plasma atrial natriuretic peptide response to direct current cardioversion of atrial fibrillation in patients with mitral stenosis.

OBJECTIVES: The purpose of this study was to evaluate the effect of direct current cardioversion therapy on the plasma concentration of atrial natriuretic peptide and to determine the main factors that influence the change in plasma atrial natriuretic peptide levels in patients with atrial fibrillation. BACKGROUND: In atrial arrythmias, whether the fast atrial rate itself or the associated elevation of atrial pressure, or both, contributes to the increase in atrial natriuretic peptide is a subject of debate. METHODS: In 15 patients with mild mitral stenosis, plasma atrial natriuretic peptide levels were measured and transmitral flow pattern was obtained by continuous wave Doppler echocardiography immediately before cardioversion and at 5 min, 4 h, 24 h and 5 days after direct current cardioversion. Mean mitral pressure gradient and atrial filling fraction were calculated on the basis of transmitral flow. RESULTS: In three patients who did not have a successful return to sinus rhythm, plasma atrial natriuretic peptide levels remained elevated after cardioversion. In 12 patients who maintained sinus rhythm, plasma atrial natriuretic peptide levels were significantly reduced from 79 +/- 29 to 36 +/- 11 pg/ml 4 h after cardioversion to sinus rhythm. However, the mitral pressure gradient did not change significantly during the observation period. There were progressive increases in atrial filling fraction throughout the observation period. From 4 h to 5 days after direct current cardioversion, plasma atrial natriuretic peptide levels gradually increased concomitantly with the recovery of atrial mechanical function. CONCLUSION: The reduction of plasma atrial natriuretic peptide levels after direct current cardioversion might be due to recovery from the high rate of atrial firing and not to an alteration in the mitral pressure gradient. Direct current cardioversion itself does not seem to influence atrial natriuretic peptide secretion. The increase in atrial natriuretic peptide levels from 4 h to 5 days after cardioversion concomitantly with an increase in atrial filling fraction may be due to recovery of atrial mechanical function.

Clinical application of transpulmonary contrast-enhanced Doppler technique in the assessment of severity of aortic stenosis.

OBJECTIVE: The aim of this study was to demonstrate the clinical usefulness of the transpulmonary contrast-enhanced Doppler technique by using it to assess the severity of aortic stenosis. BACKGROUND: Sonicated albumin microbubbles can pass through the pulmonary circulation after peripheral venous injection and have been reported to enhance Doppler signals from the left side of the heart. Therefore, their use to determine aortic flow velocity would facilitate the assessment of the severity of aortic stenosis. METHODS: Twenty-two patients with aortic stenosis and seven normal volunteers were examined. Aortic flow velocity was recorded with continuous wave Doppler technique from an apical window before and after injection of 2 ml of sonicated albumin. RESULTS: In 10 patients with aortic stenosis, the aortic velocity envelope was too indistinct to determine the peak velocity before sonicated albumin was injected. After injection, the aortic flow Doppler signal was enhanced in 9 of the 10 patients and the velocity envelope became clear enough to measure the peak velocity, enabling calculation of the transaortic pressure gradient. In the remaining 12 patients with aortic stenosis and in all 7 normal volunteers, the velocity envelope was clear before injection and became much clearer after injection. The calculated transaortic pressure gradient showed a good agreement with catheterization measurements (y = 1.1x-6.5, r = 0.88, p less than 0.001, SEE = 16 mm Hg, n = 13). Duration of Doppler signal enhancement was measured as the time during which the envelope was clearer than before injection throughout the ejection period. The duration was significantly shorter in patients with aortic stenosis than in normal volunteers (16 +/- 5 vs. 52 +/- 32 s, p less than 0.01). There was a significant correlation between left ventricular systolic pressure measured by catheterization and the duration of signal enhancement (r = -0.69), suggesting that albumin microbubbles were fragile at high pressure. CONCLUSIONS: The transpulmonary contrast-enhanced Doppler technique using sonicated albumin is useful for assessing the severity of aortic stenosis even in patients with poor Doppler recordings, although the duration of signal enhancement might be affected by left ventricular systolic pressure.

Detection of coronary blood flow associated with left main coronary artery stenosis by transesophageal Doppler color flow echocardiography.

Demonstration of disordered blood flow in a coronary artery may be helpful in anticipating the presence of stenosis. To examine the possibility of disordered coronary blood flow associated with left main coronary stenosis, left main coronary flow was visualized by transesophageal Doppler color flow echocardiography in 52 patients undergoing coronary angiography. Twenty patients had significant left main coronary stenosis (Group 1) and 32 patients did not (Group 2). Adequate two-dimensional echocardiographic images of the left main coronary artery were obtained in 17 patients in Group 1 and 30 patients in Group 2. Sixteen patients in Group 1, including five patients in whom the stenosis could not clearly be defined by two-dimensional echocardiography, exhibited the aliased reddish-yellowish elements producing the mosaic pattern at the stenotic or poststenotic segments, or both. In contrast, nonaliased bluish jets, suggesting laminar flow away from the transducer, were seen in echocardiograms from 27 patients in Group 2. This group included four patients with stenosis-like images on two-dimensional echocardiography. The aliased mosaic pattern was found in only three patients in Group 2 (p less than 0.01). Thus, sensitivity to detect the stenosis was improved when Doppler color flow imaging was applied. Flow velocity was significantly higher at the site of stenosis in patients in Group 1 (116 +/- 28 cm/s, n = 10, mean +/- SD) than in Group 2 (29 +/- 12 cm/s, n = 21, p less than 0.01), suggesting that the augmentation of flow velocity with or without turbulence due to the stenosis contributed to the appearance of the mosaic flow images.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term follow-up of atrial contraction after the maze procedure in patients with mitral valve disease.

OBJECTIVES: We sought to determine the effectiveness of the maze procedure for maintaining sinus rhythm and atrial contraction for a long period in patients with mitral valve disease. BACKGROUND: Although the maze procedure for atrial fibrillation (AF) has been effective in restoring sinus rhythm in patients with mitral valve disease, the long-term results of this procedure have not been determined. METHODS: We echocardiographically studied 94 consecutive patients with mitral valve disease before, as well as early (3.1 +/- 3.3 months) and late (2.2 +/- 0.9 years) after, the maze procedure. Peak velocity and the time-velocity integral of the left ventricular (LV) diastolic filling wave during atrial contraction (A wave), as well as the atrial filling fraction (calculated as the ratio of the time-velocity integral of the A wave to total diastolic filling), were obtained from transmitral flow recordings. Peak A wave velocity > or =10 cm/s was considered to indicate echocardiographic evidence of effective atrial contraction. RESULTS: Regular rhythm with P waves was restored in 70 patients (74%) in the early stage and in 59 patients (63%, p = 0.09) in the late stage after the maze procedure. Forty-seven patients (50%) in the early stage and 36 patients (38%, p = 0.14) in the late stage showed effective atrial contraction by Doppler echocardiography. Left atrial (LA) and LV end-diastolic diameters significantly decreased after the procedure (from 59 +/- 13 to 48 +/- 7 mm, p < 0.01; and from 54 +/- 9 to 47 +/- 5 mm, p < 0.01, respectively) and did not show significant changes during the follow-up period. Once atrial contraction was resumed, its degree did not change between the early and late stages after the maze procedure (17 +/- 6% vs. 17 +/- 6% for atrial filling fraction). CONCLUSIONS: Sinus rhythm and atrial contraction recovered early after the maze procedure in most patients and were maintained for more than two years. Once active atrial contraction was resumed, the degree of contraction did not change thereafter. These results demonstrate that the maze procedure is effective for a long period in patients with mitral valve disease.

Extension of hemorrhage after reperfusion of occluded coronary artery: contrast echocardiographic assessment in dogs.

OBJECTIVES: The aim of this study was to elucidate the progression of intramural hemorrhage complicated by reperfusion with the use of myocardial contrast echocardiography. BACKGROUND: Although hemorrhagic infarction is known to occur in ischemia followed by reperfusion, its onset and sequence have not been well characterized. METHODS: In 20 anesthetized dogs, 3-h occlusion of the left circumflex-coronary artery was followed by reperfusion. The area at risk during coronary occlusion was approximately 25%. Myocardial contrast echocardiogram was examined, and the time-intensity curves for both ischemic and nonischemic areas were obtained at baseline, at 3 min after reperfusion and then at 15-min intervals until 90 min after reperfusion. The wall thickness of both areas was also measured. RESULTS: Gross hemorrhage in the reperfused areas was observed in five dogs (Group H) but not in seven dogs (Group NH). All wall segments were opacified at 3 min after reperfusion in both groups. However, the contrast defect spread significantly with time after reperfusion in Group H but not in Group NH (18.7 +/- 3.4% and 3.3 +/- 1.8%, respectively, at 90 min after reperfusion p < 0.005). The wall of the risk area at 90 min after reperfusion had thickened to 1.3 times baseline thickness in Group H but was unchanged in Group NH. The other eight dogs were excluded from study because of fatal arrhythmias or the existence of collateral circulation during coronary occlusion. CONCLUSIONS: Both progression of the contrast defect area on myocardial contrast echocardiography and a gradual thickening of the wall with reperfusion are characteristic of hemorrhagic infarction.

Serial doppler echocardiographic evaluation of bioprosthetic valves in the tricuspid position.

OBJECTIVES: This study sought to evaluate bioprosthetic valve dysfunction in the tricuspid position by serial Doppler echocardiography. BACKGROUND: Few reports on the long-term results of tricuspid valve replacement with bioprosthetic valves are evaluated by serial Doppler echocardiography. METHODS: Between September 1979 and December 1993, 95 patients underwent tricuspid valve replacement with bioprosthetic valves at our facility. Sixty patients who underwent serial Doppler echocardiographic examination at intervals of at least 2 years after operation were included in the final analysis. These patients were followed up from 1.5 to 13.0 years (mean 5.8 +/- 2.5). RESULTS: The actuarial rates of freedom from bioprosthetic valve stenosis and regurgitation at 10 years were 46% and 51%, respectively. The prevalence of bioprosthetic valve stenosis and regurgitation increased progressively in a linear manner beginning 1 or 2 years after tricuspid valve replacement. Right heart failure developed during follow-up in 20 of the 25 patients with bioprosthetic valve dysfunction. CONCLUSIONS: The long-term durability of bioprosthetic valves in the tricuspid position was substantially lower in our study than that reported in previous studies. Tricuspid bioprosthetic valve dysfunction increased progressively in a linear manner beginning 1 to 2 years after tricuspid valve replacement.

Enhancement of Doppler flow signals in the left heart chambers by intravenous injection of sonicated albumin.

OBJECTIVES: The objective of this study was to evaluate the effect of a transpulmonary contrast agent on Doppler flow signals in the left heart chambers. BACKGROUND: Echo contrast agents are good ultrasound reflectors and could be used as Doppler signal enhancers. Sonicated albumin microbubbles are transpulmonary echo contrast agents and could enhance left heart Doppler signals after peripheral venous injection. METHODS: Thirty-one patients with various heart diseases without intracardiac shunts were assessed with Doppler echocardiography before and after injection of sonicated albumin. RESULTS: After an intravenous injection, pulsed Doppler signals of transmitral flow became more intense in all 16 patients examined, although flow velocity itself was not changed. In Doppler color flow imaging, the maximal mitral regurgitant signal area increased from 312 +/- 405 mm2 to 434 +/- 465 mm2, an average increase of 59 +/- 40% in all 17 patients with mitral regurgitation (p < 0.01). These effects were considered to be due to improvement of signal to noise ratio by the enhancement of Doppler flow signals. The duration of enhancement of pulsed Doppler transmitral flow signals was significantly longer than that of the left ventricular echocardiographic opacification (44 +/- 11 s vs. 17 +/- 7 s, p < 0.01). CONCLUSIONS: Intravenous injection of sonicated albumin can enhance the Doppler flow signals in the left heart chambers. This effect may be useful to improve the sensitivity of the Doppler system for detecting abnormalities of left heart blood flow such as mitral regurgitation.

Comparative efficacy of the maze procedure for restoration of atrial contraction in patients with and without giant left atrium associated with mitral valve disease.

OBJECTIVES: We sought to determine the effectiveness of the maze procedure for restoring atrial contraction in patients with and without giant left atrium (GLA). BACKGROUND: Although the maze procedure has been reported to be effective for refractory atrial fibrillation, it is unknown whether this procedure can restore effective atrial contraction in patients with GLA. METHODS: Nineteen patients with and 32 patients without GLA were studied with Doppler echocardiography before and after the maze procedure. Peak velocity and the time-velocity integral of the left ventricular diastolic filling wave during atrial contraction (A wave) and the atrial filling fraction calculated as the ratio of the time-velocity integral of the A wave to that of total diastolic filling were compared between patients with and without GLA. A peak A wave velocity > or =10 cm/s was considered to indicate echocardiographic evidence of effective atrial contraction. RESULTS: Regular rhythm with P waves was restored in 10 patients (53%) with and 26 (81%, p < 0.05) without GLA. Four patients (21%) with and 21 patients (66%, p < 0.01) without GLA showed effective atrial contraction by echocardiography. Once atrial contraction was resumed, the degree of atrial contraction was comparable between patients with and without GLA (17+/-5% vs. 17+/-4% for atrial filling fraction at 12 months, respectively). CONCLUSIONS: Although most patients without GLA had restored atrial contraction by the maze procedure, it was resumed in fewer patients with GLA. However, once atrial contraction was resumed, the degree of atrial contraction was comparable between patients with and without GLA. Therefore, the maze procedure may be an option in selected patients with GLA.

Peak negative myocardial velocity gradient in early diastole as a noninvasive indicator of left ventricular diastolic function: comparison with transmitral flow velocity indices.

OBJECTIVES: We sought to assess the clinical significance of peak negative myocardial velocity gradient (MVG) in early diastole as a noninvasive indicator of left ventricular (LV) diastolic function. BACKGROUND: Peak systolic MVG has been shown useful for the quantitative assessment of regional wall motion abnormalities, but limited data exist regarding the diastolic MVG as an indicator of LV diastolic function. METHODS: Peak negative MVG was obtained from M-mode tissue Doppler imaging (TDI) in 43 subjects with or without impairment of systolic and diastolic performance: 12 normal subjects, 12 patients with hypertensive heart disease (HHD) with normal systolic performance and 19 patients with dilated cardiomyopathy (DCM), and was compared with standard Doppler transmitral flow velocity indices. In a subgroup of 30 patients, effects of preload increase on these indices were assessed by performing passive leg lifting. In an additional 11 patients with congestive heart failure at the initial examination, the measurements were repeated after 26+/-16 days of volume-reducing therapy. RESULTS: Peak negative MVG was significantly depressed both in HHD (-3.9+/-1.3/s, p < 0.01 vs. normal=-7.7+/-1.5/s) and DCM (-4.4+/-1.4/s, p < 0.01 vs. normal). In contrast, transmitral flow indices failed to distinguish DCM from normal due to the pseudonormalization. Transmitral flow velocity indices were significantly altered (peak early/late diastolic filling velocity [E/A]=1.1+/-0.5 to 1.5+/-0.7, p < 0.01; E deceleration time=181+/-41 to 153+/-38 ms, p < 0.01), while peak negative MVG remained unchanged (-5.3+/-2.2 to -5.3+/-2.0/s, NS) by leg lifting. Volume-reducing therapy resulted in the apparent worsening of the transmitral flow velocity pattern toward abnormal relaxation, as opposed to peak negative MVG, which improved by the therapy (p < 0.05). CONCLUSIONS: Peak negative MVG derived from TDI may be a noninvasive indicator of LV diastolic function that is less affected by preload alterations than the transmitral flow velocity indices, and thereby could be used for the follow-up of patients with nonischemic LV dysfunction presenting congestive heart failure.