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PubMed2004

Segmental adenomyomatosis of the gallbladder predisposes to cholecystolithiasis.

BACKGROUND/PURPOSE: The aim of the present study was to clarify the association between adenomyomatosis of the gallbladder and cholecystolithiasis. METHODS: A cholecystectomy was performed for cholelithiasis or various other conditions in 1099 patients, of whom 608 had cholecystolithiasis. Adenomyomatosis of the gallbladder was classified as one of three variants: segmental, fundal, and diffuse. Segmental adenomyomatosis has an annular stricture dividing the gallbladder lumen into the "neck compartment" and the "fundal compartment". Bile lipid analysis was performed in 8 patients with segmental adenomyomatosis. RESULTS: Adenomyomatosis of the gallbladder was observed in 156 patients (14.2%), of whom 99 had segmental adenomyomatosis, 54 had fundal adenomyomatosis, and 3 had diffuse adenomyomatosis. The prevalence of cholecystolithiasis was higher in patients with segmental adenomyomatosis (88.9%) than in those without adenomyomatosis (52.3%; P < 0.001). Gallstones were detected earlier in patients with segmental adenomyomatosis than in those without ( P < 0.001) and were located predominantly in the fundal compartment. Bile in the fundal compartment had lower concentrations of total bile acids ( P = 0.012), with an increased cholesterol saturation index ( P = 0.012), compared to bile in the neck compartment. CONCLUSIONS: Segmental adenomyomatosis is a condition predisposing to cholecystolithiasis, probably due to the lithogenic environment in the fundal compartment. Fundal or diffuse adenomyomatosis appears to be unrelated to cholecystolithiasis.

Adenomyoma↗
PubMed2001

Eight multicentric hepatocellular carcinomas occurring in the same segment of the liver.

We present a rare case of eight multicentric hepatocellular carcinomas (HCCs) occurring in the same segment of the liver. In a 66-year-old Japanese man, multiple liver tumors were detected during follow-up of chronic hepatitis C infection, and he was admitted to our hospital in 1995. Ultrasonography (US) showed eight tumors, each measuring between 10 and 15 mm in diameter, in the right lobe, and a 10-mm tumor in the left lobe. Angio-ultrasonography (US) showed no enhancement of the tumors, and multicentric occurrence was suspected. Portal angio-US showed eight tumors in the right lobe located in the anterior segment. Accordingly, anterior segmentectomy and partial resection of the S3 subsegment were performed, in December, 1995. On histological examination, all eight tumors in the anterior segment and the tumor in the S3 subsegment were well differentiated HCC. The liver parenchyma showed cirrhosis. The grade and stage of hepatitis did not differ between the anterior segment and the S3 subsegment, but irregular regeneration of hepatocytes was more prominent in the anterior segment. The multicentric occurrence of HCCs in the anterior segment may be related to the more severe damage caused by chronic hepatitis in the anterior segment than in the left lobe of the liver.

Aged↗
PubMed2005

Complete L segment coding-region sequences of Crimean Congo hemorrhagic fever virus strains from the Russian Federation and Tajikistan.

The large (L) RNA segment of Crimean Congo hemorrhagic fever (CCHF) virus strain AST/TI30908, isolated from pooled Hyalomma marginatum ticks collected in 2002 from the Astrakhan region of European Russia, was amplified piecemeal using reverse-transcription/polymerase chain reaction, followed by direct sequencing of gel-purified amplicons. After removal of 5' and 3' primer-generated termini, the assembled AST/TI30908 L segment sequence is 12112 nucleotides long, with 41.3% G + C content, and is greater than 87% and 96% identical at the nucleotide and translated amino acid levels, respectively, to partial or full-length CCHF virus L segment sequences deposited in GenBank. A complete L segment coding-region sequence for CCHF virus strain TAJ/HU8966, isolated from a patient in Tajikistan in 1990, was determined in a similar fashion. This L segment (12133 nucleotides long, 41.1% G + C content) shares 88% nucleotide identity with the full-length strain Matin from Pakistan, and 97% nucleotide identity with a partial L segment sequence of strain Khodzha from Uzbekistan. Strain TAJ/HU8966 shares at least 96% identity at the translated amino acid level with all other CCHF virus L segment sequences. Although, for the most part, CCHF virus L polyprotein primary sequences are uniformly well conserved, a region of marked variability was identified in the N-terminal half of the RNA-dependent RNA polymerase. This region, approximately 50 amino acids in length, is flanked by previously-reported arenavirus and bunyavirus-conserved regions, and may prove useful in CCHF diagnosis and viral taxonomy.

Amino Acid Sequence↗
PubMed2006

Different segmental transit times in patients with irritable bowel syndrome and "normal" colonic transit time: is there a correlation with symptoms?

BACKGROUND: The Rome criteria serve as gold standard for establishing a diagnosis of irritable bowel syndrome (IBS), but only represent a cluster of symptoms. On the other hand, measurement of colonic transit time (CTT) with radiopaque markers is a solid and more objective method to quantify functional abnormalities. The goal of this study was to investigate whether the IBS symptoms, as defined in the Rome II criteria, correspond to objective physiological parameters, i.e. CCTs. METHODS: The study enrolled 148 healthy control subjects and 1385 consecutive IBS patients. Transit times were measured for the whole rectocolon (overall CTT) and for 3 segments (right colon, left colon, rectosigmoid area); segmental distribution of markers and diffusion coefficients were also assessed. In order to analyze homogeneous groups, we restricted analysis to subjects with "normal" CTT (< or =70 hours). RESULTS: Six hundred forty four IBS patients (46%) and 14 control subjects (9%) had CTT >70 h and were eliminated. In subjects with CTT < or =70 h, CTT did not follow a normal (Gaussian) distribution. We identified 3 different CTT clusters in healthy controls and 4 clusters in IBS patients. Even if CTT was not significantly different between clusters, each cluster was characterized by a specific pattern of segmental colonic transit. There was a marked gender difference: women had longer overall CTT values than men, both in control and IBS patient groups (p<0.001). However, female IBS patients had significantly shorter colorectal transit times than female controls (p<0.001), as well as faster transit than in men through the left colon and rectosigmoid area. There were no significant differences in transit time between male IBS patients and male controls with the exception of a faster rectal transit in IBS patients (p<0.01). There was no association between segmental colonic transit values and sign or symptoms comprising the Rome II criteria. CONCLUSIONS: In subjects with CTT < or =70 h, CTT does not follow a normal distribution but is clustered in subgroups that can be distinguished only by measuring segmental colonic transit. Within these subgroups, there is a marked difference in transit times between IBS patients and normal subjects, suggesting that IBS patients with "normal" CTT are not "normal". The Rome II criteria do not reflect differences in segmental transit times in IBS patients with "normal" CTT. We therefore propose to evaluate segmental transit times in IBS patients with "normal" CTT, before and after treatment, in order to correctly interpretate variations in signs and symptoms. These findings have important implications in evaluating the effect of drugs on bowel function and should help define better inclusion criteria for studies evaluating new drugs for the treatment of IBS.

Adolescent↗
PubMedDate not supplied

Segmental neurofibromatosis follows blaschko's lines or dermatomes depending on the cell line affected: case report and literature review.

BACKGROUND: Segmental neurofibromatosis type 1 (NF-1) has the characteristic features of generalized NF-1 but is isolated to a particular segment of the body. Segmental NF-1 results from a postzygotic mutation during embryogenesis in the NF-1 gene on chromosome 17. The embryologic timing of the mutation and cell types affected predict the clinical phenotype. OBJECTIVE: We present a case of a 52-year-old woman with segmental neurofibromas isolated to the right cheek and neck. We review the recent literature on the genetic and cellular differences between the various clinical manifestations of segmental NF-1. METHODS: A MEDLINE search for cases of segmental neurofibromatosis was conducted. RESULTS: In patients with segmental NF-1 presenting as neurofibromas-only, the distribution follows a neural distribution in dermatomes because the genetic mutation appears to be limited to Schwann cells. In patients with pigmentary changes only, the NF-1 mutation has been shown to occur in fibroblasts and the distribution tends to follow the lines of Blaschko. CONCLUSION: Our patient's neurofibromas were secondary to a postzygotic mutation in the NF-1 gene of neural crest-derived cells. This mutation most likely occurred later in embryogenesis in cells that had already differentiated to Schwann cells and were committed to the dermatomal distribution of the right neck and cheek region (C2).

Cheek↗
PubMed2005

Postoperative change of mucosal inflammation at strictureplasty segment in Crohn's disease: cytokine production and endoscopic and histologic findings.

PURPOSE: This study was designed to examine postoperative change of mucosal inflammation at strictureplasty segment in Crohn's disease mainly by cytokine measurements. METHODS: Patients who underwent strictureplasty for Crohn's disease in the terminal ileum were investigated. Mucosal samples at the strictureplasty site were obtained during operation. At 3, 6, and 12 months after operation, biopsy specimens were taken from the strictureplasty site and macroscopically normal ileum at endoscopy. Mucosal cytokine concentrations were measured by enzyme-linked immunosorbent assay. RESULTS: The mucosal concentrations of proinflammatory cytokines (interleukin-1beta, interleukin-6, interleukin-8, and tumor necrosis factor-alpha) and anti-inflammatory mediator (interleukin-1 receptor antagonist) at the strictureplasty segment greatly increased at the time of operation. Interleukin-1beta, interleukin-1 receptor antagonist, interleukin-6, interleukin-8, and tumor necrosis factor-alpha concentrations at the strictureplasty segment decreased during a 12-month period after operation. Twelve months after operation there was no significant difference in each cytokine concentration between the strictureplasty and macroscopically normal segments. The mucosal interleukin-1 receptor antagonist/interleukin-1beta ratio at the strictureplasty segment increased during a 12-month period after operation. Twelve months after operation there was no significant difference in the ratio between the strictureplasty and macroscopically normal segments. The endoscopic and histologic severities of mucosal inflammation at the strictureplasty site also decreased; however, their findings were not normalized during the study. CONCLUSIONS: During one year after strictureplasty for Crohn's disease, cytokine production at the strictureplasty segment was decreased to the level of the macroscopically normal ileum and an imbalance between proinflammatory and antiinflammatory cytokines was corrected.

Adult↗
PubMed2006

Comparison of cell body size and oxidative enzyme activity in motoneurons between the cervical and lumbar segments in the rat spinal cord after spaceflight and recovery.

The cell body sizes and succinate dehydrogenase (SDH) activities of motoneurons in the dorsolateral region of the ventral horn at the cervical and lumbar segments in the rat spinal cord were determined following 9 days of spaceflight with or without 10 days of recovery on Earth. The motoneurons were divided into three types based on their cell body sizes; small-, medium-, and large-sized motoneurons. In control rats, there was no difference in the cell body size or SDH activity of small- and large-sized motoneurons between the cervical and lumbar segments. The SDH activity of medium-sized motoneurons in control rats was higher in the lumbar segment than in the cervical segment, while the cell body sizes of medium-sized motoneurons were identical. The SDH activity of medium-sized motoneurons in the lumbar segment decreased to a level similar to that in the cervical segment of control rats following spaceflight. In addition, the decreased SDH activity of medium-sized motoneurons persisted for at least 10 days of recovery on Earth. It is concluded that spaceflight selectively affects the SDH activity of medium-sized motoneurons in the lumbar segment of the spinal cord, which presumably innervate skeletal muscles having an antigravity function.

Animals↗
PubMed2006

An automatic algorithm for stationary segmentation of extracellular microelectrode recordings.

Extracellular microelectrode recordings (MER) often contain artifact from a variety of sources that confound traditional signal-processing techniques that require stationary signal segments. We designed an algorithm to locate the longest stationary segment of MER signals. In this paper we provide a description of the segmentation algorithm and its performance assessment. Simulation results demonstrate that the automatic segmentation algorithm we proposed is capable of accurately identifying the boundaries of the longest stationary segments in MER signals. In our simulation study the segmentation algorithm correctly identified the boundaries of the longest MER stationary segments in 99.5% of the cases.

Algorithms↗
PubMed1983

Wall motion abnormalities and electrocardiographic changes in acute transmural myocardial infarction: implications of reciprocal ST segment depression.

Left ventricular ejection fraction and regional wall motion were assessed by multigated equilibrium radionuclide ventriculography within 24 hours of onset of first acute transmural myocardial infarction (MI) in 32 patients. Abnormal left ventricular wall motion was noted in all 16 patients with anterior infarction and in 14 of 16 (87.5%) patients with inferior infarction. Regional wall motion abnormalities frequently included areas adjacent to and remote from those predicted by the ECG location of ST elevation and pathologic Q waves. Such remote wall motion abnormalities were associated with reciprocal ST segment depression in 17 of 18 (94%) patients, and conversely reciprocal ST segment depressions were associated with remote wall motion abnormalities in 17 of 24 (71%) patients. The left ventricular ejection fraction was lower in patients with a reciprocal ST segment depression compared to those without (anterior MI 0.29 +/- 0.07 vs 0.43 +/- 0.08, p less than 0.01; inferior MI 0.45 +/- 0.11 vs 0.63 +/- 0.06, p less than 0.001). In addition, the peak MB-CK levels were higher in patients with compared to those without reciprocal ST segment depression (anterior MI 268 +/- 183 vs 102 +/- 60, p less than 0.05; inferior MI 186 +/- 120 vs 67 +/- 20, p less than 0.05). Thirteen of 18 (72%) patients with reciprocal ST segment depression compared to 4 of 13 (31%) patients without reciprocal ST segment depression had a complicated clinical course during their hospital stay. These observation suggest that global left ventricular dysfunction in first acute transmural MI is greater when reciprocal ST segment depression is present on the 12-lead ECG.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Reproducibility and validity of ambulatory ST segment monitoring in patients with chronic stable angina pectoris.

Transient ST segment changes are thought to be an indicator of intermittent myocardial ischemia in patients with chronic stable angina pectoris, and ambulatory ECG monitoring is a potentially useful means of quantifying these changes. In order to evaluate their repeatability, the automated analytical system developed in our department was carefully validated. Ambulatory ST segment monitoring was then performed on two occasions, 6 weeks apart, in 16 patients with established chronic stable angina pectoris of at least 1 year's duration. Both periods of monitoring were undertaken after administration of placebo for 2 weeks, and two bipolar ECG leads (CM5 and CC5) were monitored on both occasions. The total number (mean +/- SEM) of episodes of ST segment depression greater than 1 mm and of 3 minutes' duration or more in 24 hours was 4.9 +/- 1.0 and 5.1 +/- 1.0 on the first and second recordings (p = NS), and the total duration of ST segment depression in 24 hours was 83.6 +/- 27.7 minutes and 78.9 +/- 20.8 minutes, (p = NS) respectively. The maximal depth of ST segment depression observed during 24 hours was 3.5 +/- 0.3 mm and 3.4 +/- 0.2 mm, respectively, in lead CM5 (p = NS), with similar findings from lead CC5. These results demonstrate that ambulatory ST segment depression observed during uncontrolled normal daily activity in patients with established chronic stable angina pectoris is reproducible. This technique could provide a valuable method for assessment of antianginal drugs and patterns of ST segment changes during normal daily activities, provided that manual checks to ensure artifact exclusion are used to supplement the automated analysis.

Adult↗
PubMed1988

Segmental evaluation of left ventricular wall motion after myocardial infarction: magnetic resonance imaging versus echocardiography.

To assess relative capabilities of magnetic resonance (MR) imaging and two-dimensional echocardiography (2DE) for evaluating regional contractile dysfunction in the left ventricle after a myocardial infarction, results from 22 concurrent MR (orthogonal-transaxial, ECG-gated, multiphasic, single-spin echo) and 2DE examinations were compared. By means of the same 11-segment LV description, MR and 2DE examinations were independently scored segment by segment for residual wall motion (point scores: 2 = normal, 1 = hypokinesia, 0 = akinesia, and -1 = dyskinesia). Significant correlation between MR and 2DE scoring was found throughout most of the left anterior descending (LAD) distribution, but right coronary artery (RCA) distribution (i.e., middle-posterior segment not well seen) could not be fully evaluated by MR imaging. When cumulative scores for the 10 segments mutually evaluated were used to derive measures of global residual LV function (i.e., score quotient [SQ] = accumulated points divided by 20 total possible points), MR SQ correlated well overall with both 2DE SQ (r = 0.82; p less than 0.05) and ejection fraction (EF) from ventriculography (r = 0.86, p less than 0.05 vs r = 0.88, p less than 0.05 for 2DE SQ compared with EF). MR evaluation of segmental wall motion was relatively stronger in the LAD distribution (MR SQ compared with 2DE SQ: r = 0.86, p less than 0.05; MR SQ compared with EF: r = 0.96, p less than 0.05) than in the RCA distribution (r = 0.06, p greater than or equal to 0.05 and r = 0.62, p greater than or equal to 0.05, respectively). For 2DE, regional variations were not as evident (2DE SQ compared with EF: r = 0.90, p less than 0.05 for LAD and r = 0.81, p less than 0.05 for RCA). For segmental evaluation of wall motion after myocardial infarction, MR imaging (transaxial, multiphasic) appears to be comparable to 2DE overall but superior in LAD distribution and inferior in RCA distribution.

Adult↗
PubMed1995

Segmental analysis of resting echocardiographic function and stress scintigraphic perfusion: implications for myocardial viability.

In 73 patients with coronary artery disease, we performed segmental analysis of resting two-dimensional echocardiography and stress thallium-201 single photon emission computed tomographic scintigraphy with 24-hour delayed imaging to test the hypotheses that (1) combined analysis of stress thallium-201 scintigraphy (with 24-hour redistribution) and echocardiography provides an evaluation of the viability of most myocardial segments; and (2) the severity of the scintigraphic perfusion abnormality in a given segment is equivalent to the severity of its echocardiographically determined functional impairment. Scintigraphy showed 14% of the 1168 segments analyzed to have fixed severe defects. Echocardiography showed 11% of the 1070 segments analyzed to be akinetic or dyskinetic. However, with combined analysis, only 62 (5%) segments showed no evidence of viability by either imaging technique. We conclude that in this group of patients, 95% of segments have evidence of viability by one of these two conventional imaging techniques.

Aged↗
PubMed1995

Prognostic significance of ST-segment depression during adenosine perfusion imaging.

To determine the significance of ST-segment depression during adenosine perfusion imaging for predicting future cardiac events, 188 patients with interpretable electrocardiograms were assessed 1 to 3 years (mean 21.5 +/- 6.6 months) after adenosine testing. At least 1 mm of ST-segment depression was observed in 32 (17%) patients, with > or = 2 mm of ST-segment depression in 10 (5.3%). Thirty-seven cardiac events occurred during the study period: 2 cardiac deaths, 5 nonfatal myocardial infarctions, 6 admissions for unstable angina, and 24 revascularizations. Univariate predictors of events were a history of congestive heart failure, previous non-Q-wave myocardial infarction, previous coronary angioplasty, use of antianginal medication, ST-segment depression during adenosine infusion (particularly > or = 2 mm), any reversible perfusion defect, transient left ventricular cavity dilation, and the severity of perfusion defects. Multivariate analysis identified > or = 2 mm ST-segment depression as the most significant predictor of cardiac events (relative risk [RR] = 6.5; p = 0.0001). Other independent predictors of events were left ventricular dilation (RR = 3.8; p = 0.002), previous coronary angioplasty (RR = 3.3; p = 0.001), a history of non-Q-wave myocardial infarction (RR = 2.3; p = 0.01), and the presence of any reversible defect (RR = 2.0; p = 0.05). We conclude that ST-segment depression occurs uncommonly during adenosine infusion, but the presence of > or = 2 mm of ST-segment depression is an independent predictor of future cardiac events and provides information in addition to that obtained from clinical variables and the results of adenosine perfusion imaging.

Adenosine↗
PubMed1979

Epicardial ischemia as delineated with epicardial S-T segment mapping andnicotinamide adenine dinucleotide (NADH) fluorescence photography.

In isolated rabbit hearts with an experimental coronary arterial occlusion, epicardial ischemia was identified by reduced nicotinamide adenine dinucleotide (NADH) fluorescence photography, a technique that detects areas of myocardial anoxia. Epicardial S-T segment mapping was performed to evaluate the S-T segment changes across an ischemic border defined by NADH fluorescence. After S-T segment mapping and perfusion with a fluorescein dye, serial selections of the hearts revealed that the ischemic area was transmural and and the border was nearly perpendicular to the epicardial surface. As the epicardial ischemic border was approached, S-T segment elevation was first detected 3.3 mm outside the ischemic border, and increased over a transition zone 7 mm wide. S-T segment negativity was not detected immediately outside the ischemic border. It is concluded from these studies that S-T segment changes give relatively imprecise definition of an ischemic border, and that S-T segment changes across an ischemic border are not consistent with those predicted by solid angle analysis.

Animals↗
PubMed1983

Role of myocardial ischemia in the genesis of stress-induced S-T segment elevation in previous anterior myocardial infarction.

This study tests the hypothesis that myocardial ischemia is responsible for exercise-induced S-T segment elevation in patients with previous anterior myocardial infarction (MI). Exercise stress testing in conjunction with thallium imaging of the myocardium was performed in 28 patients with previously documented anterior MI. Thallium images were analyzed by computer for the presence of initial uptake defects and evidence of abnormal clearance of the isotope from the myocardium (that is, imaging evidence of ischemia). Total S-T segment elevation (sigma ST) in precordial leads V1 to V6 at rest was subtracted from sigma ST at peak stress in order to quantitate the extent of S-T elevation induced by stress (delta ST). Two groups of patients were identified; 1 with stress-induced S-T elevation (Group I, delta ST greater than or equal to 4.0 mm) and 1 without this abnormality (Group II, delta ST less than 4.0 mm). Evidence of abnormal thallium washout from myocardial scan segments occurred in 12 of 15 Group I patients versus 9 of 13 Group II patients (difference not significant). In addition, abnormal tracer washout from anterolateral or septal scan segments occurred in 5 patients in each group. Likewise, abnormal thallium clearance from inferior or posterior scan segments occurred in 8 of 15 Group I patients versus 7 of 13 Group II patients (difference not significant). The patient with the greatest amount of stress-induced S-T elevation (S-T 11.5 mm) had no evidence of ischemia during the stress test. However, Group I patients did have larger anterolateral plus septal initial thallium uptake defect scores than did those of Group II (10 of 15 with defect score greater than or equal to 350 in Group I versus 1 of 13 in Group II, p less than 0.002). Similarly, resting left ventricular ejection fraction greater than or equal to 30% was present in only 4 of 15 Group I patients versus 13 of 13 in Group II (p less than 0.001). Finally, multiple stepwise linear regression analysis demonstrated that delta ST correlated best with the extent of initial anterolateral plus septal thallium uptake defect score (F = 17.3, p less than 0.001) and to a lesser extent with resting ejection fraction (F = 5.2, p less than 0.05) and change in heart rate from rest to peak stress (F = 8.1, p less than 0.01; corrected multiple correlation coefficient = 0.76, p less than 0.001). Thus, in patients with previous anterior MI (1) exercise-induced myocardial ischemia occurs as often with as without S-T segment elevation, (2) myocardial ischemia is not required for the production of stress-induced S-T segment elevation, and (3) stress-induced S-T elevation primarily reflects the extent of previous anterior wall damage and to a lesser extent an increase in heart rate between rest and peak stress.

Adult↗
PubMed1985

Hemodynamic determinants of exercise-induced ST-segment depression in children with valvar aortic stenosis.

To evaluate the hemodynamic factors associated with treadmill-induced ST-segment depression in children with valvar aortic stenosis, 12 patients (mean age 13 years) with ST-segment depression during treadmill exercise and 5 patients (mean age 13 years) without ST-segment depression during treadmill exercise underwent exercise testing during cardiac catheterization. The left ventricular (LV) systolic pressure and LV outflow tract gradient at rest (177 +/- 25 vs 138 +/- 8 mm Hg and 59 +/- 18 vs 23 +/- 7 mm Hg, respectively) and corresponding pressures during maximal supine exercise (248 +/- 37 vs 189 +/- 17 mm Hg and 112 +/- 34 vs 52 +/- 14 mm Hg) were significantly greater (p less than 0.01) in the patients with exercise-induced ST-segment depression, although overlap existed. The LV-O2 supply-demand ratio during maximal supine exercise was significantly less (6.4 +/- 2.7 vs 11.8 +/- 0.7; p less than 0.005) in patients with than in those without exercise-induced ST-segment depression. In fact, an LV-O2 supply-demand ratio less than 11.0 was 100% sensitive and specific in predicting treadmill-induced ST-segment depression. These results suggest that although the development of ST-segment depression during treadmill exercise is related to LV systolic pressure and LV outflow gradient, its major hemodynamic determinant is the LV-O2 supply-demand ratio.

Adolescent↗
PubMed1991

Quantification of ST-segment changes during coronary angioplasty in patients with left bundle branch block.

Electrocardiographic manifestations of ischemia are difficult to interpret in the presence of left bundle branch block (LBBB). Recently developed techniques allow continuous computerized digital analysis of ST segments that can be zeroed to the patient's own baseline electrocardiogram even if that baseline is abnormal conduction. With use of this technology, ST-segment changes during balloon coronary occlusion were compared in 10 patients with LBBB versus an age-, sex-, and coronary anatomy-matched population of 20 control subjects with normal baseline conduction. ST-segment deviation of greater than or equal to 1 mm from baseline was present in 80% of patients with LBBB and in 75% of control patients (difference not significant). There was no significant difference between patients with LBBB versus control patients in maximal ST-segment deviation (2.6 +/- 1.7 vs 2.0 +/- 1.0 mm) or in ST-segment deviation measured after 60 seconds of occlusion (2.4 +/- 1.3 vs 1.8 +/- 1.1 mm). ST-segment deviation reached 1 mm more quickly in patients with LBBB (33 +/- 11 seconds) than in control subjects (60 +/- 36 seconds) (p = 0.003). It is concluded that ST-segment analysis is feasible in patients with LBBB using digital self-referenced ST analysis and may provide important clinical information regarding the presence of myocardial ischemia.

Angioplasty, Balloon, Coronary↗
PubMed1992

Implications of inferior ST-segment elevation accompanying anterior wall acute myocardial infarction for the angiographic morphology of the left anterior descending coronary artery morphology and site of occlusion.

Inferior ST-segment elevation during anterior wall acute myocardial infarction (AMI) due to left anterior descending (LAD) coronary artery occlusion is unusual and was not previously investigated. This study tested the hypothesis that inferior ST-segment elevation during anterior AMI predicts a specific angiographic morphology that satisfies 2 necessary conditions: (1) mass of ischemic anterior wall myocardium is relatively small, resulting in a weaker anterior injury current and less reciprocal inferior ST-segment depression; and (2) there is concomitant inferior wall transmural ischemia that further shifts the inferior ST segments upward. The study group consisted of 42 consecutive patients with anterior AMI undergoing angiography at 4.1 days (range 0 to 14). Coronary angiograms were examined for 3 features: (1) site of LAD artery occlusion (a distal obstruction implying a smaller mass of ischemic anterior wall myocardium), (2) LAD artery extension onto inferior wall of left ventricle (termed a "wrap around" vessel), and (3) collateral flow from LAD artery to inferior wall. The latter 2 features would be expected to contribute to inferior wall transmural ischemia. Acute inferior ST-segment elevation (sum of ST-segment deviation in leads II, III and aVF greater than or equal to 3.0 mm) was seen in 7 patients (16%). A greater number of LAD artery branches proximal to the site of occlusion was significantly correlated with less inferior ST-segment depression (r = 0.59, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗