Search

To identify an early, simple, noninvasive predictor of left main (LM) or 3-vessel disease (3-VD), we retrospectively studied clinical variables on admission in 310 patients with acute coronary syndromes with non-ST-segment elevation. Univariate analysis indicated that many factors were related to LM/3-VD. Multivariate analysis showed that ST-segment elevation in lead aVR of/=0.5 mm was the strongest predictor of LM/3-VD, followed by positive troponin T (odds ratio 19.7, p0.001, and odds ratio 3.08, p = 0.048, respectively). ST-segment elevation in lead aVR of/=0.5 mm and positive troponin T identified LM/3-VD with sensitivities of 78% and 62%, specificities of 86% and 59%, positive predictive values of 57% and 26%, and negative predictive values of 95% and 87%, respectively (p0.05). Our findings suggest that in patients with non-ST-segment elevation acute coronary syndromes, ST-segment elevation in lead aVR of/=0.5 mm and positive troponin T on admission (especially the former) are useful predictors of LM/3-VD.

Biventricular pacing therapy is effective in patients with severe congestive heart failure. Strain Doppler imaging (SDI) is a new tool for measuring regional myocardial deformation. We evaluated regional wall motion by strain Doppler imaging in 13 patients who had conventional indications for a pacemaker (74 +/- 6 years old) and in six with NYHA Class III or IV heart failure with a biventricular pacemaker (HF-RV: during right ventricular pacing, HF-BV: during biventricular pacing). The other seven patients had normal LV function (N-RV). Wall motion was assessed by strain of the myocardium, and the interval between the Q wave of the surface ECG and the peak strain (QPSI) was measured in three septal and three lateral segments. Interventricular contraction delay was determined as the interval between the onset of the left and right ventricular outflow waves. Intraventricular contraction delay was determined as the time difference between minimum and maximum QPSI. Strain of HF-RV was significantly greater than that of N-RV (-9.6%+/- 2.5% vs -14.4%+/- 2.3%, P < 0.0001). Intraventricular contraction delay of HF-RV was significantly greater than that of N-RV (273 +/- 12 vs 151 +/- 69 ms, P = 0.0004). Strain of HF-RV was not significantly greater than that of HF-BV (-9.6% +/- 2.5% vs -10.6% +/- 2.9%). Interventricular contraction delay of HF-RV was greater than that of HF-BV (37.2 +/- 44.7 vs 16.2 +/- 47.4 ms, P < 0.0001). Intraventricular contraction delay of HF-RV was significantly greater than that of HF-BV (322 +/- 101 vs 209 +/- 88 ms, P = 0.0006). In conclusion, biventricular pacing improves both interventricular contraction delay and intraventricular contraction delay in patients with conventional indications for a pacemaker with severe congestive heart failure, and SDI is useful to predict the efficacy of biventricular pacing.

Changes in the abundance of an endemic amphipod, Jesogammarus annandalei, that inhabits the profundal zone of Lake Biwa were examined from 1966 to 1999. The abundance of J. annandalei increased suddenly during the mid-1980s and thereafter stayed at a level that was seven-fold higher than that before 1980. Compared with the amphipod in the 1960s, both the clutch and body size of the matured individuals decreased during the 1990s, which suggests that per capita food supply decreased. Thus, the increase in the abundance of J. annandalei appeared to be due largely to an increase in their survival rate and not their growth or reproduction rates. In accord with the increase in amphipod abundance, the fishery catch of an endemic gobiid fish species that is dominant in the profundal zone and preys on this amphipod as a major food, decreased dramatically during the mid1980s. These results suggest that long-term changes in abundance of J. annandalei in Lake Biwa are mainly regulated by fish predation rather than by food supply.

Background: Although anterior acute myocardial infarction (AMI) with ST-segment elevation in lateral leads is associated with a poor prognosis, the significance of the pattern of lateral ST-segment elevation has not been examined. Hypothesis: The aim of the study was to examine the relation of the pattern of lateral ST-segment elevation to myocardial reperfusion and infarct size in patients with AMI. Methods: We studied 111 patients who had a first AMI presenting with anterolateral ST-segment elevation and Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow of the left anterior descending coronary artery within 6 h from symptom onset. Patients were classified into two groups according to the pattern of lateral ST-segment elevation on the admission electrocardiogram: Group 1, 42 patients with equivalent or greater ST-segment elevation in lead I than in lead aVL, and Group 2, 69 patients with lesser ST-segment elevation in lead I in than in lead aVL. Left ventricular ejection fraction (LVEF) was measured by predischarge left ventriculography. Results: There were no differences between the two groups in age, gender, time from onset to recanalization, culprit lesion, or collateral development. Group 1 patients had a higher probability of impaired myocardial reperfusion as indicated by a myocardial blush grade of 0 or 1 after recanalization, a higher peak creatine kinase level, and a lower LVEF than Group 2 patients (p = 0.0001, respectively). Conclusions: We conclude that equivalent or greater ST-segment elevation in lead I than in lead aVL is associated with impaired myocardial reperfusion and less myocardial salvage in patients with recanalized AMI who present with anterolateral ST-segment elevation on the admission electrocardiogram.

Background Biatrial pacing has a significant problem with memory function that misinterprets normal sinus rhythm as atrial tachyarrhythmias and in addition estimation of the atrial pacing thresholds (biatrial and uniatrial pacing thresholds) is sometimes difficult because of small P waves. Methods and Results The intracardiac electrograms recorded by a pacemaker in 10 patients (age, 66.7±10.7 (SD) years) with implanted biatrial pacemakers were analyzed. Atrial sensing within the atrial refractory period after atrial pacing was counted in 6 of the 10 patients (timing of the double counting was 143±64 ms) when pacing failed in the left or right atrium. Atrial sensing within the atrial refractory period after atrial pacing disappeared when biatrial pacing was successfully performed. Atrial double-counts depend on interatrial conduction delay. The memory function of implanted pacemaker devices misinterpreted normal sinus rhythm as atrial tachyarrhythmias because of atrial double-counts. On the other hand, the biatrial pacing threshold was easily recognized using this phenomenon. Conclusions The memory function of pacemaker devices is unreliable because of atrial double-counting during sinus rhythm in patients with biatrial pacing. However, the biatrial pacing threshold is easily checked using this phenomenon. (Circ J 2004; 68: 131 - 134)

In recent years, advances in computer and communication technology and the associated rapid increase in the number of Internet users are encouraging advances in Electronic Commerce (EC). Business models of EC are being actively developed by many different enterprises and engineers, and implemented in many kinds of fields. Meanwhile Web services that reuse remote components over the Internet are drawing attention. Web services are based on SOAP/WSDL/UDDI and are given an important position as the infrastructure of the EC systems. The article analyzes the functions and structures of various business models, establishing the patterns of their distinctive and common features, and proposes a method of determining the implementation specifications of business models utilizing these patterns and Web service functions. This method has been applied to a parts purchasing system, which is a typical pattern of the B to B (Business to Business) EC applications. The article also discusses the results of evaluating this prototype system.

The clinical significance of the white blood cell (WBC) count on admission in relation to the duration of ischemia in acute myocardial infarction (AMI) remains unclear.The relationship of the WBC count on admission to myocardial reperfusion was examined in 135 patients with recanalization of an anterior AMI within 6 h of symptom onset. Patients were classified according to the WBC count on admission: Group L (n=75), WBC count12,000 cells/mm(3) and group H (n=60), WBC countor=12,000 cells/mm(3). Peak creatine kinase (CK) was higher and impaired myocardial reperfusion, defined as a myocardial blush grade of 0/1, was more frequent in group H than in group L. Among the patients in group H, those with early (or=3 h) recanalization had a lower QRS score before recanalization than those with late (3 h) recanalization; however, peak CK and the incidence of impaired myocardial reperfusion were similar in these subgroups of patients. Multivariate analysis showed that WBC countor=12,000 cells/mm(3) on admission was an independent predictor of impaired myocardial reperfusion in patients with early recanalization (odds ratio 7.9, p=0.04), but not in those with late recanalization.A higher WBC count may be associated with progression of myocardial damage after recanalization in patients with early recanalization of an anterior AMI.

We evaluated the usefulness of the total myocardial uptake ratio (TMUR) of 15-(p-[ 123 I]iodophenyl)-3(R,S)-methyl-pentadecanoic acid ( 123 I-BMIPP) for predicting cardiac complications in patients with mitochondrial encephalomyopathy or myotonic dystrophy. Six patients with mitochondrial encephalomyopathy, four with myotonic dystrophy, and 10 control subjects were studied. Quantitative assessment of 123 I-BMIPP dynamic myocardial imaging was performed, and the TMUR of 123 I-BMIPP was calculated according to the Ishii-MacIntyre method. Then, the TMUR was compared in the 10 patients and 10 healthy controls, and all patients were followed for 56.1±22.1 months to evaluate cardiac complications. TMUR in patients (2.69±0.64) was significantly (P=0.01) lower than that in controls (3.28±0.25). Three patients in whom the TMUR value was above 3.00 had no cardiac complications. On the other hand, all patients in whom TMUR was below 3.00 had some kind of cardiac complication during the follow-up period. Two patients showed progressive conduction abnormality and underwent pacemaker implantation, one patient had sick sinus syndrome and underwent pacemaker implantation, another patient showed non-sustained ventricular tachycardia and paroxysmal atrial fibrillation, and four of seven patients, including one with a pacemaker, showed an increased cardiothoracic ratio value over 50%. In conclusion, measurement of the TMUR by the Ishii-MacIntyre method is useful for evaluating the development of cardiac complications in patients with mitochondrial encephalomyopathy or myotonic dystrophy.

Although pre-interventional thrombolysis has recently been shown to restore early patency and preserve left ventricular function in patients with acute myocardial infarction, the significance of Thrombolysis in Myocardial Infarction (TIMI) grade flow early after thrombolysis remains unclear. Patients were classified into 3 groups according to TIMI grade flow 45 min after thrombolysis; 38 patients with TIMI grade 0 or 1 flow (group T0) and 46 with TIMI grade 2 flow (group T2) additionally received immediate percutaneous coronary intervention (PCI) and 50 patients with TIMI grade 3 flow (group T3) were treated conservatively after thrombolysis. Although the door-to-balloon times did not differ in groups T0 and T2, group T2 had lower peak creatine kinase, a higher rate of complete (>/=70%) ST resolution and better regional wall motion at discharge as compared with group T0, similar to group T3 (group T2, group T3 vs group T0; 2,857+/-1,756, 2,314+/-1,948 vs 3,779 +/-2,214 mU/ml; 57, 72 vs 34%; -1.5+/-1.6, -1.2+/-1.6 vs -2.2+/-1.6; all p

In patients with implanted DDD pacemaker, cardiac output is maximal when atrioventricular (AV) delay is set to give the maximum QT interval (QTI). QTI is used as a sensor of a rate-responsive pacemaker and the evoked QTI (eQTI) is measured as the time duration from the ventricular pace-pulse and the T sense point, which is the steepest point of the intracardiac T wave. The relationship between the changes in eQTI according to AV delay variations and cardiac function was studied in 13 patients (74.2+/-9.3 [SD] years old) with an implanted QT-driven DDDR-pacemaker. A special software module was downloaded into the pacemaker memory and a personal computer equipped with the special software was connected to the programmer for eQTI date-logging. AV delay was set at 100, 120, 150, 180 and 210 ms. Delta eQTI was defined as maximal eQTI - minimal eQTI. The ejection fraction (EF) was measured by echocardiography. When the AV delay was prolonged, eQTI gradually increased and reached a peak, and then decreased. Delta eQTI in patients with reduced cardiac function (EF40%) was significantly greater than that in normal cardiac function (EF55%, 7.6+/-4.9 vs 2.7+/-9.8 ms, p0.05). There was significant negative correlation between EF and delta eQTI (r=-0.63, p0.05). The peak of changes in eQTI according to AV delay variations was steeper in patients with reduced cardiac function than in those with normal cardiac function. In conclusion, changes in eQTI according to AV delay variation are greater in patients with reduced cardiac function than in those with normal cardiac function, and the AV delay that gives the maximal eQTI can be easily determined in patients with reduced cardiac function.

OHKUSU, Y., et al.: Effect of Biventricular Pacing on Myocardial Glucose Metabolism in Patients with Heart Failure Using Fluoro-18-Deoxyglucose Positron Emission Tomography.Biventricular pacing has recently been found beneficial in the treatment of congestive heart failure (CHF). Meanwhile, positron emission tomography (PET) has emerged as a new method to analyze glucose metabolism in the heart. Five patients (mean age68.8 ± 8.1 years, 4 men) who received biventricular pacing therapy for5.8 ± 6.6weeks for CHF were studied. Myocardial glucose metabolism was evaluated by PET with fluoro-18-deoxyglucose (18F-FDG), and percent uptake (%uptake) of 18F-FDG was calculated during biventricular pacing and compared with that during 1 hour of conventional RV pacing. Biventricular pacing was associated with a significant decrease in NYHA functional Class from 3.67 ± 0.52 to 2.50 ± 0.55. After 18F-FDG PET, three of five patients remained clinically stable, and two died during follow-up. Mean 18F-FDG %uptake during biventricular pacing was not different than during short-term RV pacing (62.1 ± 18.4vs. 63.6 ± 17.0%). However, patients who remained clinically stable had a lower value of 18F-FDG %uptake in the septal region than patients who died (46.9 ± 5.6vs80.3 ± 1.3%, P < 0.01). One patient whose cardiac function improved significantly also had a small septal region of decreased 18F-FDG uptake during RV pacing. In conclusion, biventricular pacing therapy was effective in this small group of patients with severe, drug-resistant CHF. An evaluation of the effects of biventricular pacing on glucose metabolism in the subacute phase may help identify patients with a favorable long-term response to this therapy. (PACE 2003; 26[Pt. II]:144–147)

In the present study, the effectiveness of 123I-beta-methyliodophenyl pentadecanoic acid (BMIPP) single photon emission computed tomography (SPECT) for predicting cardiac death of patients with chronic heart failure was evaluated. Abnormalities of fatty acid metabolism are found in patients with chronic heart failure and BMIPP was developed as a tracer for scintigraphic assessment of myocardial fatty acid utilization. The study group comprised 74 patients with chronic heart failure with a left ventricular ejection fraction (LVEF)

In steel bridges fatigue cracks are sometimes repaired by placing drilled holes at the crack tips. From the meaning that the drilled holes stop the propagation of cracks, they are called stop-holes. Since stop-holes are regarded as an emergency measure to delay crack propagation, usually some substantial repair follows. However, if the stress at the stop-holes is below their fatigue limit, fatigue cracks would not be expected to occur. The purpose of this study is to present the conditions under which stop-holes prevent the re-initiation of fatigue cracks. The fatigue limit of stop-holes and the equations necessary to estimate the maximum stress on the circumference of the stop-holes are provided.

SUMMARY 1. Population dynamics and production of Jesogammarus annandalei, an endemic amphipod in Lake Biwa, were examined from April 1997 to June 1998. The life cycle of this species was 1 year with the new generation beginning in early autumn. They preferred low temperature (

QT interval (QTI) may change when cardiac function is improved by optimizing the AV delay. QTI is used as the sensor for rate responsive pacemakers. Evoked (e)QTI is measured as the time duration from the ventricular pace-pulse to the T sense point, which is the steepest point of the intracardiac T wave. The relationship between AV delay and eQTI and cardiac function was studied in 13 patients (74.2 +/- 9.3 [SD] years old) with an implanted QT-driven DDDR pacemaker. A special pacemaker software module was downloaded into the pacemaker memory for eQTI data logging. AV delay was set at 100, 120, 150, 180, 210, and 240 ms. Cardiac output (CO) was measured by continuous Doppler echocardiography. eQTI was 343.3 +/- 22.4, 345.1 +/- 22.5, and 343.4 +/- 23.2 ms (P < 0.01, repeated ANOVA) and CO was 4.2 +/- 0.8, 4.6 +/- 0.8, and 4.2 +/- 0.8 L/min (P < 0.0001, repeated ANOVA) when AV delay was set at the AV delay shortened by one step (AV[-]) and prolonged by one step (AV[+]) from the AV delay at which QT interval was maximum (AV[max]) in seven patients, in whom the peak AV delay at which the eQTI was maximal could be identified. eQTI decreased from 341.1 +/- 20.9 to 339.4 +/- 21.1 ms (P < 0.0001) and CO decreased from 4.4 +/- 1.4 to 4.1 +/- 1.3 L/min (P < 0.005) when AV delay was prolonged from AV(max) to AV(+) in all patients. eQTI decreased from 345.1 +/- 22.5 to 343.3 +/- 22.4 ms (P < 0.0005) and CO decreased from 4.6 +/- 0.8 to 4.2 +/- 0.8 L/min (P < 0.05) when AV delay was shortened from AV(max) to AV(-) in seven patients. Thus, CO was maximal when AV delay was set at the AV delay at which eQTI was maximal. In conclusion, the optimal AV delay can be predicted from the eQTI sensed by an implanted pacemaker, and automatic setting of the optimal AV delay can be achieved by the QT sensor of an implanted pacemaker.

Forty-eight-hour experimental manipulations of zooplankton biomass were performed to examine the potential effects of zooplankton on nutrient availability and phytoplankton biomass (as measured by seston concentration) and C : N : P stoichiometry in eutrophic nearshore waters of Lake Biwa, Japan. Increasing zooplankton, both mixed-species communities and Daphnia alone, consistently reduced seston concentration, indicating that nearshore phytoplankton were generally edible. The zooplankton clearance rates of inshore phytoplankton were similar to rates measured previously for offshore phytoplankton. Increased zooplankton biomass led to increased concentrations of nutrients (NH4-N, soluble reactive phosphorus [SRP]). Net release rates were higher than those found in previous measurements made offshore, reflecting the nutrient-rich nature of inshore seston. Zooplankton nutrient recycling consistently decreased TIN : SRP ratios (TIN = NH4 + NO3 + NO2). This effect probably resulted from the low N : P ratios of nearshore seston, which were lower than those commonly found in crustacean zooplankton and thus resulted in low retention efficiency of P (relative to N) by the zooplankton. Thus, zooplankton grazing inshore may ameliorate algal blooms due to direct consumption but tends to create nutrient supply conditions with low N : P, potentially favoring cyanobacteria. In comparison with previous findings for offshore, it appears that potential zooplankton effects on phytoplankton and nutrient dynamics differ qualitatively in inshore and offshore regions of Lake Biwa.

Background: ST-segment elevation of ± 1.0 mm in lead V4R has been shown to be a reliable marker of right ventricular involvement (RVI), a strong predictor of a poor outcome in patients with inferior acute myocardial infarction (IMI). However, patients with no ST-segment elevation in lead V4R despite the presence of RVI have received little attention. Hypothesis: The study was undertaken to study the clinical features of patients with no ST-segment elevation in lead V4R despite the presence of RVI, which means false negative, as such patients have received little attention in the past. Methods: We studied 62 patients with a first IMI. who had total occlusion of the right coronary artery (RCA) proximal to the first right ventricular branch and successful reperfusion within 6 h from symptom onset, to examine the implications of the absence of ST-segment elevation in lead V4R despite the presence of RVI. Results: A standard 12-lead electrocardiogram (ECG) and right precordial ECG (lead V4R) were recorded on admission, and three posterior chest ECGs (leads V7 to V9) were additionally recorded in 34 patients. Patients were classified according to the absence (Group 1, n = 18) or presence (Group 2, n = 44) of ST-segment elevation of ± 1.0 mm in lead V4R on admission. Patients in Group 1 had a greater ST-segment elevation in leads V7 to V9 (2.9 ± 2.4 vs. 1.4 ± 3.0 mm, p < 0.05), a higher frequency of a dominant RCA (defined as the distribution score ≥ 0.7) (72 vs. 11%, p < 0.001), and a higher peak creatine kinase level (3760 ±; 1548 vs. 2809 ± 1824 mU/ml, p < 0.05) than those in Group 2. Conclusions: In patients with IMI caused by the occlusion of the RCA proximal to the first right ventricular branch, no ST-segment elevation in lead V4R can occur because of concomitant posterior involvement. In such patients, the incidence of RVI may be underestimated on the basis of ST-segment elevation in lead V4R.

Cardiac function is improved by bi-ventricular pacing in patients with severe reduced cardiac function. Atrioventricular (AV) delay optimization is also important in this therapy. However, the AV delay required to achieve the optimal AV synchrony varied from time to time. We have reported that the critical AV delay that induces diastolic mitral regurgitation (MR) may represent the upper limit of the optimal AV delay. The optimal AV delay can be predicted by a simple method; slightly prolonged AV delay-interval between the end of atrial kick and complete closure of the mitral valve (duration of diastolic MR) at the AV delay setting. [Case] 60 year old Japanese male with dilated cardiomyopathy. He was repeatedly admitted to our hospital due to congestive heart failure. Ejection fraction was 14%. ECG showed complete left bundle branch block and his PQ interval was 0.22 sec. He was dependent on intravenous injections of catecolamine and could not be discharged from the hospital for over one year. Optimal AV delay was predicted as 80 msec during bi-ventricular pacing by our formula. Cardiac output was 4.9, 6.0, 5.1 l/min when the AV delay was set at 50, 80, 110 msec. Cardiac function was improved from NYHA class III to II and he has been relieved from the dependency on intravenous catecholamine injections. AV delay was optimized (70-100 msec) by our method during follow-up for one year. This case indicates that AV delay optimization is important in bi-ventricular pacing.

It has been reported that cardiac function can be improved by implanting a DDD pacemaker (PM) and setting a short atrioventricular (AV) delay in patients with impaired cardiac function. A previous report found that the critical AV delay that induces diastolic mitral regurgitation (MR) may represent the upper limit of the optimal AV delay. The optimal AV delay can be predicted by a simple method: slightly prolonged AV delay minus the interval between the end of the atrial kick and complete closure of the mitral valve (duration of diastolic MR) at the AV delay setting. The patient was a 84-year-old man with an old myocardial infarction. He had repeated admissions to hospital for congestive heart failure. ECG showed prolongation of the PQ interval (0.28 s) and complete left bundle branch block. Cardiac function was improved by AV sequential pacing when the AV delay was set at 120 ms. After DDD-PM implantation, the cardiothoracic ratio decreased from 57 to 45% and cardiac function was improved from New York Heart Association class III to I. The AV delay was optimized during follow-up. Four years after PM implantation, the patient was in good condition without further hospital admission. (Jpn Circ J 2001; 65: 46 - 49)

It is unknown whether the pathogenetic mechanisms underlying acute myocardial infarction (AMI) differ according to the clinical presentation of preinfarction angina, so the present study measured plasma levels of C-reactive protein (CRP) in 280 patients with AMI in whom serum creatine kinase levels were normal on admission and increased subsequently. Patients were classified into 3 groups according to the type of preinfarction angina: no angina (n=95), stable angina (n=48), and unstable angina (n= 137). Patients with unstable angina were subdivided according to the Braunwald classification: class IB (n=39), class IIB (n=22), and class RIB (n=76). There were no differences among the 5 groups in baseline characteristics. CRP on admission was significantly higher and the level of physical activity at symptom onset was significantly lower in the Braunwald class RIB group than in the other groups, but no differences were observed among the other groups. Patients with preinfarction Braunwald class IIB unstable angina had higher CRP levels on admission and symptom onset at a lower level of physical activity. In such patients, the pathogenetic mechanisms may differ from those in other subsets of patients with AMI and active inflammation may play a more important role in AMI onset.

The present study investigated the relationship between myocardial damage and C-reactive protein (CRP) levels, with no increase in creatine kinase (CK) activity, immediately after the onset of acute myocardial infarction (AMI) in 85 patients with their first reperfused anterior AMI without CK elevation on admission and no ischemic events during hospitalization. Patients were classified into those with low levels (0.3 mg/dl) of CRP (Group L; n=67) and those with high levels (or =0.3 mg/dl) of CRP (Group H; n=18). Group H had a higher proportion of patients with a history of preinfarction angina (89 vs 55%, p0.01), especially unstable angina. SigmaST in leads V1-6 on admission ECG was lower in Group H than in Group L (14+/-7 vs 21+/-13 mm, p0.05). Predischarge left ventriculography showed that the left ventricular global ejection fraction (55+/-11 vs 48+/-10%, p0.01) and SD/chord at the left anterior descending artery lesion (-1.7+/-0.9 vs -2.3+/-0.9, p0.01) were better in Group H. Multivariate analysis demonstrated that both CRP on admission (p=0.011) and preinfarction angina (p=0.002) were independently associated with better regional wall motion (SD/chord-2.0) before discharge. These results suggest that the clinical situation of elevated CRP immediately after onset is associated with less myocardial damage and better left ventricular function in reperfused anterior AMI.

To the Editor: Because clinical features of Takotsubo cardiomyopathy (TC) mimic those of anterior acute myocardial infarction (AMI) ([1][1]), the differential diagnosis is important in selecting the appropriate treatment strategy, especially in the acute phase. This study assessed the value of the

Long-term follow-up was performed in patients with intra-Hisian atrioventricular (AV) block who were implanted with permanent pacemakers. Subjects were 14 consecutive patients (3 men and 11 women, 65.4±9.7 [SD] years old), who exhibited intra-Hisian block at the time of pacemaker generators were replaced due to battery depletion. Electrophysiological examinations were performed at both the initial implantation and pacemaker replacement. The mean duration from the initial implantation to the replacement was 9.4±4.3 years. All patients had severe symptoms such as syncope, dizziness, or dyspnea, and these symptoms were relieved by pacemaker implantation. Seven patients had complete AV block, and the other seven had advanced or paroxysmal AV block at the time of implantation. Seven patients, who had advanced AV block at the time of implantation, developed complete AV block. Five of the seven patients who had complete AV block at the time of implantation remained in complete AV block, one patient had advanced AV block, and one patient of complete AV block increased significantly from 50% to 93% during the two electrophysiological examinations (P

Atrial flutter (AF) is a troublesome arrhythmia for patients with an implanted pacemaker. Although it has recently become possible to eliminate AF by radiofrequency catheter ablation (RF-CA), the incidence of AF before and after pacemaker implantation has not been clarified. The present study was conducted with 123 consecutive patients (69.3+/-11.6 (SD) years old) implanted with pacemakers, excluding patients who had chronic atrial fibrillation (AFib) when the pacemaker was implanted; 69 patients with atrioventricular (AV) block and 54 patients with sick sinus syndrome (including 29 patients with bradycardia-tachycardia syndrome). All patients were implanted with physiological pacemakers. The follow-up period was 4.7+/-1.9 years. In 11 of the 123 patients (8.9%), AF was observed before pacemaker implantation and the incidence was significantly higher in patients with sick sinus syndrome than in those with AV block (16.7 vs 2.9%, p

In patients with an implanted DDD pacemaker (PM), the atrial contribution may be interrupted by too short an atrioventricular (AV) delay, and filling time may be shortened by too long an AV delay. The AV delay at which the end of the A wave on transmitral flow coincides with complete closure of the mitral valve may be optimal. The subjects were 15 patients [70.3+/-12.3 (SD) years old] with an implanted DDD PM. Cardiac output (CO) and pulmonary capillary wedge pressure (PCWP) were measured by Swan-Ganz catheter. Transmitral flow was recorded by pulsed Doppler echocardiography. AV delay was prolonged stepwise by 25 msc. When the AV delay was set at 155+/-26 ms, the end of the A wave coincided with complete closure of the mitral valve. When the AV delay was prolonged 25, 50, 75, and 100 ms from this AV delay, the interval between the end of the A wave and complete closure of mitral the valve was prolonged 16+/-5, 39+/-6, 65+/-4 and 88+/-5 ms, respectively (r = 0.97, P

QT interval may change when cardiac function is improved by optimizing the atrioventricular the (AV) delay. The relationship between AV delay, QT interval and cardiac function in patients with implanted DDD pacemakers was studied in 12 patients (aged 71&12 SD years) with complete or high degree AV block. Cardiac output (CO) was measured using a Swan‐Ganz catheter or by continuous Doppler echocardiography. The pacing rate was fixed at 70‐80/min to eliminate the influence of heart rate. The AV delay was prolonged stepwise by 30 ms starting from 90 ms. All measurements were performed after 5 min of pacing. When the AV delay was prolonged, the CO and QT interval gradually increased and reached a peak, and then decreased. When the CO was increased from the minimum to the maximum value by optimizing the AV delay, the QT interval was significantly prolonged from 440&40 to 456&39 ms (P

In 10 patients with uncomplicated anterior acute myocardial infarction, within 24 hours after onset, heart rate, plasma renin activity, and the low- to high-frequency power ratio increased and high-frequency power decreased during nitroglycerin infusion; however, both heart rate and plasma renin activity did not change, the low- to high-frequency power ratio decreased, and high-frequency power increased during atrial natriuretic peptide infusion. Atrial natriuretic peptide seems to be more beneficial in its effect on autonomic nervous activity, plasma renin activity, and myocardial oxygen consumption than nitroglycerin for the treatment of anterior acute myocardial infarction.

Recently there have been many reports on the stress measurement of highway bridges. However, a generalized method is not still provided on how to introduce the results of stress measurement into the fatigue reliability assessment. In this paper, two new parameters, called “fatigue resistance c” and “fatigue-damage-accumulation q”, are proposed to make it easy to introduce the results of stress measurement of a monitored bridge into the fatigue reliability assessment of highway bridges. Using a fatigue test database, the probability distribution of c is determined for various structural details. It is shown that for fatigue failure, the assumption of q=c is equivalent to the Miner's linear damage rule. The characteristics of the fatigue-damage-accumulation q of highway bridges are discussed. The application of the advanced first-order second-moment method to the state function of g=c-q gives the fatigue reliability assessment of highway bridges. It is expressed in terms of the design equivalent stress range and the allowable fatigue stress range with partial safety factors. The relation between the safety index and the lapse of time from opening to traffic is formulated. The safety index is shown to decrease with the time in logarithm scale.

To examine whether resolution in ST elevation without ST reelevation immediately after reperfusion indicates successful reperfusion with myocardial salvage, we studied 40 patients who had an extensive acute myocardial infarction with early reperfusion: 24 patients had ST reelevation and 16 patients had no ST reelevation. Results indicate that (1) in the group with ST reelevation, rapid progression of myocardial damage occurs by reperfusion itself (i.e., reperfusion injury) and (2) in the group without ST reelevation, myocardial damage had already been extensive and irreversible at the time of reperfusion; thus, the absence of ST reelevation is not always a sign of reperfusion with myocardial salvage.

The patient was a 78-year-old man with dilated cardiomyopathy. His cardio-thoracic ratio was 60.4% and left ventricular ejection fraction (LVEF) was 33%. He had been repeatedly admitted for congestive heart failure. He underwent implantation of an implantable cardioverter-defibrillator (ICD) for ventricular fibrillation. We compared the values of BNP and shock impedance stored by the ICD. The correlation coefficient (p-value) between BNP and shock impedance was −0.700 (p < 0.0005), increase of BNP and shock impedance was −0.778 (p < 0.0001), percent increase of BNP and shock impedance was −0.767 (p < 0.0005). In conclusion, there is an inverse relation between BNP and shock impedance, and measurements of shock impedance may be useful in the management of congestive heart failure.

Many studies have reported that there is no significant difference in survival rate between rhythm control and rate control strategies in combination of with anticoagulation in patients with atrial fibrillation. Even in patients with atrial fibrillation and with heart failure there is no significant difference in survival rate between both strategies. There is no need of strict rate control. In patients with permanent atrial fibrillation, lemient rate control(resting heart rate of below 110 beats per minute) is as effective as strict rate control (70 beats per minute) and easier to achieve. Digitalis, beta-blockers and Ca channel blockers are used for rate control treatments. Digitalis is the only drug that has both decreasing ventricular response by suppressing atrioventricular conduction and inotropic effects. However, digitalis can not suppress heart rates during exercise. Beta-blockers and Ca channel blockers can suppress heart rates not only at rest but also during exercise. Ca channel blockers can not be used for patients with heart failure due to reduction in contractility of heart muscle. It has been reported that cardiac function and survival rate can be improved by beta-blockers in patients with heart failure if starting low dose and increasing gradually.

Recently, corrosion damages on upper surfaces of orthotropic steel deck plates are often found during the bridge pavement repair work in urban expressways. Repair methods for these damages are required to be finished quickly, for example within one or two hours, during the pavement repair work. In addition, decrease of thickness or pitting corrosion will lead to stress increase and the acceleration of fatigue damage.In this study, the authors focused on the repair method of bonding steel patch plates from the upper surface side. In order to investigate the basic mechanical behaviour, finite element analysis and bending tests of thickness-reduced plates repaired with bonding steel plate under bending were carried out. Simple equations for designing the thickness and length of patch plate repair were proposed.

The present study examined alterations in left atrial diameter (LAD) and diastolic left ventricular diameter (LVDd) in 37 patients (72.2 +/- 9.8 years old) who received physiological pacemakers; 22 with atrioventricular (AV) block and 15 with sick sinus syndrome (SSS). After pacemaker implantation, LAD and LVDd were serially measured using echocardiography, and their diameters were expressed per body surface area (LADI and LVDdI; mm/m2). Pulmonary capillary wedge pressure (PCWP) and cardiac output (CO) were measured in ten patients with SSS and ten with AV block during both right ventricular and AV sequential pacing. After AV sequential pacing, CO increased in 19 of 20 patients (3.2 +/- 0.9 L/min to 3.9 +/- 1.0 L/min; P < 0.001). LADI decreased from 24.9 +/- 4.2 mm/m2 to 21.8 +/- 4.4 mm/m2 (P < 0.001) in 22 patients with AV block and from 24.1 +/- 3.4 mm/m2 to 20.4 +/- 3.8 mm/m2 (P < 0.001) in 15 SSS patients. However, LVDdI did not change significantly in either group of patients. The changes in LAD after the implantation of a physiological pacemaker occurred rapidly, i.e., LAD began to decrease within 1 minute after the procedure, and then reached a plateau. This plateau phase continued for at least 7 days during physiological pacing. There was a positive correlation between the changes in LADI after pacemaker implantation and those in PCWP observed during the AV sequential pacing performed prior to the implantation (r = 0.86; P < 0.001). The reduction in LAD following pacemaker implantation was rapid and seemed to be accompanied by improvement of cardiac function. Thus, it is suggested that the serial measurement of LADI is useful to predict the efficacy of physiological pacemaker implantation.

右冠動脈 (ROA) 閉塞の急性下壁梗塞のST偏位を, RCA潅流域の広さと閉塞部位から検討した.発症6時間以内のROA閉塞による初回下壁梗塞59例を冠動脈造影 (OAG) で閉塞部位が右室枝より近位の27例と遠位の32例に分類し, 再疎通前の心電図からΣST上昇 (II・III・aVFのST上昇の和) , ΣST低下 (V1-4のST低下の和) を, OAG所見からROA潅流域を示すWongらのangiographic distribution soore (AS: ROAが潅流する後下壁領域の割合) を算出した.両群でAS, ΣST上昇に差はなかったが, ΣST低下は近位群が遠位群に比し小であった (P