Echocardiographic prediction of left ventricular dysfunction after mitral valve repair for mitral regurgitation as an indicator to decide the optimal timing of repair

OBJECTIVES: This study sought to determine whether echocardiography before mitral valve repair (MVR) for mitral regurgitation (MR) was predictive of postoperative left ventricular (LV) dysfunction and useful for deciding the optimal timing of repair. BACKGROUND: Some reports have shown that the preoperative echocardiographic data of left ventricular ejection fraction (LVEF) and left ventricular end-systolic diameter (LVDs) were good predictors of postoperative LV dysfunction. However, few reports were based on long-term follow-up data of large numbers of patients who underwent MVR in the last decade. METHODS: A total of 274 patients with moderate or severe MR underwent MVR between October 1, 1991, and September 30, 2000. Among them, 171 patients who had both an operation for isolated MR due to degenerative pathology and a postoperative echocardiogram were studied. Postoperative echocardiograms were performed 3.9 +/- 2.4 years after the operation.The LVEF decreased from 66 +/- 10% before surgery to 63 +/- 11% after surgery (p < 0.0001). On univariate analysis, preoperative LVEF and LVDs correlated with postoperative LVEF (r = 0.41 and r = -0.39, respectively). Overall, postoperative LV dysfunction (defined as LVEF <50%) was not frequent (12%). However, the incidence of postoperative LV dysfunction was high in patients with preoperative LVEF <55% (38%) or LVDs > or =40 mm (23%). CONCLUSIONS: In patients with MR, the echocardiographic data of LVEF and LVDs were good predictors of postoperative LV dysfunction. When a decrease in LVEF or an increase in LVDs is detected, MVR should be considered to preserve postoperative LV function.     

Infective endocarditis associated with quadricuspid aortic valve

A 26-year old Japanese woman experienced new aortic valve regurgitation associated with a preceding high fever of unknown cause. During the fever episode, although bacteremia or fungemia was not evident despite frequent blood cultures, intravenous panipenem/betamipron (PAPM/BP) gradually resulted in decline of the fever. Echocardiography and operative procedures revealed a quadricuspid aortic valve (QAV), which was composed of two equal larger cusps and two unequal smaller cusps (type f). A smaller accessory cusp was damaged but showed no active vegetation. A Medtronic Freestyle bioprosthesis was implanted using a subcoronary technique. Although the risk of endocarditis for this rare valve abnormality is not well documented, the present case may support the conventional assumption that patients with unequal small cusps are prone to endocarditis.     

Transcellular iodide transport and iodination on the apical plasma membrane by monolayer porcine thyroid cells cultured on collagen-coated filters

Isolated porcine thyroid follicular cells were cultured on a collagen-coated Millipore filter to form a monolayer. The monolayer could translocate 125I added in the medium beneath the filter (basal medium) into the medium above the monolayer (apical medium) and form an iodide concentration gradient of several-fold. Transcellular iodide pump activity was observed when the cells were cultured with TSH in the basal medium. In the absence of TSH, the translocation of iodide was very slow. The concentration of TSH required to activate the iodide pump was 0.1-0.3 mU/ml. Addition of ClO4- to the basal medium inhibited transcellular transport, whilst addition of ClO4- to the apical medium was much less effective. Constituents labelled with 125I in the apical medium were analysed. The amount of protein-bound 125I measured by acid precipitation was 3-8% of the total radioactivity. The residual radioactivity was found to be iodide ion by paper chromatography. Further analysis by sodium dodecylsulphate-polyacrylamide gel electrophoresis revealed that most of the 125I-labelled protein was at the position of bovine serum albumin which had been added to the culture medium. The monolayer culture of cells on collagen-coated filter would be a useful experimental system for analysing thyroid cell functions for which the cell polarity is essential.     

Circadian Variation of the Myocardial Ischemic Threshold in Patients with Ischemic Heart Disease

Purpose. Circadian variation of the heart rate (HR) at the myocardial ischemic threshold was compared with that of the HR at the sympathetic tone threshold in 16 cases of effort angina pectoris. Methods. The high (0.15–0.40 Hz, Hf) and low (0.03–0.15 Hz, Lf) frequency spectral components were extracted every twenty seconds, using frequency domain analysis of the RR interval recorded by a 24-hour Holter ECG with an accelerometer. HR-Hf data collected every five minutes were plotted as the X-Y coordinates, and a two-compartment analysis was performed. The HR at the autonomic tone threshold was then determined at the intersection point of the lines. A loop of the HR-ST segment was drawn during walking to determine the ischemic threshold at which heart rate ischemic ST segment depression began and circadian variation was observed. Results. The circadian rhythm at the sympathetic tone threshold and the HR at the ischemic threshold were high during the day and low at night. The HR at the ischemic threshold was 15–20% higher than that at the sympathetic tone threshold at night but only 9–13% higher during the day. Also, there was a period during which there was no significant difference between the HR at the two thresholds. Conclusion. In comparing circadian variation between HR at the sympathetic tone threshold and HR at the ischemic threshold, there was a period during which there was no significant difference between the HRs. This might suggest a period in which a high incidence of cardiac ischemic attack is likely. This information could provide a feasible indicator for appropriate exercise training for patients with ischemic heart disease.     

Multiple small subcortical infarction required to distinguish from lacunar infarction: evaluation by use of diffusion-weighted imaging]

Lacunar infarctions are small lesions caused by occlusion of the deep and penetrating vessels. Occlusion of such vessels are resulted from thrombosis based on atherosclerotic change. However, we occasionally encounter a patient with lacunar infarction seemed to be caused by embolic mechanism, as who has had previous experience of TIA or presented with clinical symptoms suddenly. Diffusion-weighted imaging (DWI) has high accuracy for depicting small ischemic lesions and discrimination of recent infarctions from old ones. We studied frequency, risk factors and stroke mechanism in the territory of penetrating arteries detected on DWI, and sensitivity of ischemic lesions by DWI as compared with conventional MRI images. Fifty-three consecutive patients with lacunar infarction in the territory of penetrating arteries who admitted to our hospital and were studied by DWI within 24 hours. Nine (17.0%) of 53 patients had multiple high signal lesions on DWI. These lesions were found in single arterial territory in 4 patients and in more than 2 territories in 5 patients. It was presumed that stroke mechanisms were artery to artery or cardiogenic embolism. DWI revealed all 38 hyperintensity lesions, while conventional MRI revealed 35 lesions, although the latter was resulted from retrospectively referring to the DWI finding. Therefore, conventional MRI alone might have been difficult to detect multiple lesions. DWI was enable to distinguish embolic infarction from small vessel lacunar infarction, leading to feasible patient management. Therefore, DWI should be performed in all patients with lacunar infarction, even if neurological finding is correspondent with the conventional MRI finding.     

Length measuring device for transrectal ultrasonography of anorectal lesions

We, herein, describe an attachable measuring device for transrectal ultrasonography. It is a useful piece of equipment for measuring the precise length of a lesion and for fixing the position of the transducer under examination for sphincteric dynamics.     

Bicuspid aortic valve with sudden onset of aortic insufficiency due to rare causes: report of two cases]

This report describes two cases of aortic valve replacement which was warranted by the suddenly developed aortic regurgitation due to a congenitally bicuspid aortic valve. Aortic insufficiency was caused by the rupture of the strand which lifted a larger cusp to the aortic wall in one, and by the perforation of valvular aneurysm in another. Reviewing the literature these types of aortic insufficiency are rarely reported.     

Immunoglobulins Specific to Mosquito Salivary Gland Proteins in the Sera of Persons with Common or Hypersensitive Reactions to Mosquito Bites

Using the immunoblot technique, we analyzed the quality and quantity of IgG, IgG₄, and IgE specific to mosquito salivary gland (hereafter abbreviate as SG) components of Aedes albopictus in the sera of volunteers with common reactions and of 3 patients with severe reactions. In the volunteers with delayed reactions only or with both delayed and immediate reactions, IgG against SG components of A. albopictus formed several faint or moderately stained bands. Those with immediate reactions showed several intense bands and many other weak bands. In volunteers, who had been bitten by Aedes sp. frequently but had no skin reaction, and in severe cases, many intense IgG bands were observed. IgG₄ bound to SG components were found in the sera of the common reaction group at the levels of 24 and 48 kD, but, in one severe case, no bands were observed, although the total IgG was very high. IgE levels specific to SG components were much higher in severe cases than in the volunteers. These results indicate that high titers of specific IgG and IgE and lack of IgG₄ for particular components of SG may lead to severe allergic reactions in severe cases. Immunoblotting analysis of the antibodies also verified the possibility of developing in vitro tests to identify causative species of the mosquito for severe cases.