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Biomedical subjects

P Block

Publications and source records attributed to P Block.

At least 37 records · Page 2Linked to original sources

Measurement and interrelations of psychiatric symptomatology in inpatients.

For 152 psychiatric inpatients scores on the Beck Depression Scale, State form of the State-Trait Anxiety Inventory, the Self-report Inventory, Hopelessness Scale and 3 MMPI scales, Hypochondriasis, Schizophrenia, and Hypomania, were factor analyzed. The two factors appeared to confirm Gotlib's 1984 suggestion that such questionnaires measure general distress, as responding endorses negative affect.

Adult↗

Late potentials and ejection fraction at hospital discharge: prognostic value in thrombolyzed and non-thrombolyzed patients. A preliminary report. The Belgian Working Group for Signal Averaging.

The prognostic value of the use of thrombolytic therapy (TL), the ejection fraction (EF) and the presence of late potentials (LP) in the signal-averaged ECG (filter less than 40 Hz) at the time of hospital discharge was assessed in a multicenter prospective study. This report presents the follow-up at 4 months of the first 263 patients. Thrombolytic therapy was given to 41%. The mean ejection fraction was 45%. The average duration of the high frequency QRS complex (HFQRS) was 104 ms. The mean duration of the terminal signal under 40 microV (D40) was 31 ms. The combination of both HFQRS greater than 110 ms and a D40 greater than 40 ms was considered as presence of LP. The cardiac mortality at 4 months was 5.7% (15 patients). Late ventricular tachycardia or fibrillation occurred in 2.3% (6 patients). The relative risk (RR) for cardiac death or late events was 5.14 with a 95% confidence interval (CI) of 1.2 to 22.0 when no thrombolytic therapy was used. The RR was 3.39 (CI: 1.4 to 8.4) for patients with an EF lower than 30%. The single most important electrocardiographic parameter was a D40 greater than 40 ms (RR: 3.14, CI: 1.3 to 7.8). The presence of LP had a RR of 4.28 (CI: 1.7 to 10.5). With stepwise regression analysis it was evident that cardiac function and information obtained by signal averaging offered independent prognostic information. The presence of LP at hospital discharge after acute infarction offers additional prognostic information to EF for the risk of later cardiac death, especially in patients without thrombolysis.

Aged↗

Detection of late potentials on the averaged QRS signal recorded at rest and during a standardized stress test after acute myocardial infarction.

The high-amplification signal-averaged ECG (SAECG) allows the detection and analysis of late potentials (LP), which are related to a higher risk of severe ventricular arrhythmias in patients with myocardial disease and coronary artery disease. Because of excessive noise, this technique is usually performed at rest and occasionally immediately after interruption of exercise. Until now, however, it has not been used during exercise. The authors relate in this paper the method and results of the SAECG recorded at rest and during a standard stress test on 30 patients with a recent first myocardial infarction (day 10-14), in good condition, without ECG evidence of significant residual ischemia or bundle branch block. The SAECG was recorded during the steady state of a standardized stress test when a heart rate (HR) corresponding to 80% of the maximal HR was reached during a first test. Three patients had three criteria for LP, three others had two criteria, and two had only one. It has been impossible to analyze the SAECG during exercise because of excessive noise. One patient out of 30 in our study, 21 subjects had normal SAECG at rest and during exercise. None of the 6 patients with more than 1 abnormal criterion at rest became normal during the stress test despite a decrease of the duration criteria in all and an increase of the amplitude (root mean square) the terminal 40 ms (RMS40), as opposed to the 2 patients with just one positive criterion at rest (RMS 40 less than 25 muV) who became normal during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗

The use of videoendoscopy in the study of fluorescence.

Diagnosis of malignancies by means of fluorescence detection is effected, at present, using fiberoptic endoscopes. Difficulties in the detection of fluorescence arise from the low fluorescent efficiency of the most widely used drug (hematoporphyrin derivative), and from the loss of intensity of the signal within the fiberoptic bundles and the ocular lens of the fiberendoscope. The electronic video-endoscope, carrying a microchip camera at its tip, permits a more sensitive detection of fluorescence, since the signal is drawn directly from the cavities. Furthermore the electronic image, stored in a computer, can be manipulated to produce a more enhanced contrast between the fluorescence of normal and malignant tissues. An example of electronic manipulation would be the subtraction of the image obtained under green light excitation from that obtained under violet light excitation.

Endoscopy↗

Endogenous and non-endogenous depressions: relations to life events, dysfunctional attitudes and event perceptions.

A comparison was made between endogenous and non-endogenous depressed patients on several characteristics on which they traditionally have been asserted to differ, and which play important roles in cognitive approaches to depression. The non-endogenous patients reported more dysfunctional attitudes and a greater number of recent life events than did endogenous patients. These results support the distinction between endogenous and non-endogenous depressions, and suggest that cognitive theories of aetiology may be more relevant for the latter group. However, both groups perceived their recent upsetting events in relatively maladaptive ways, consistent with the idea that biased perceptions are more related to the depressive state, whereas dysfunctional attitudes may represent a trait vulnerability.

Adaptation, Psychological↗

Dysfunctional attitudes in depressed patients before and after clinical treatment and in normal control subjects.

To evaluate the role of maladaptive thinking patterns in depression, the authors administered the Dysfunctional Attitude Scale to 112 depressed patients before and after 3-6 weeks of treatment with antidepressants or placebo. Twenty-two normal subjects were also assessed twice. Depressed patients had a significantly higher initial mean score than control subjects, but during treatment their score significantly decreased, and the posttreatment score of those with complete recoveries was nearly as low as the control subjects' final score. The higher the initial dysfunctional attitude score the poorer the response to treatment. Patients with endogenous depression had significantly lower scores than nonendogenously depressed patients.

Adolescent↗

[Mean high-amplification electrocardiogram during a submaximal exercise test following acute myocardial infarction].

The mean high-amplification ECG (MECG) used to detect delayed potentials (DPs) has so far been used only at rest and after exertion. In this article, the results are reported of recording the MECG at rest and during exercise (ER) obtained in 19 patients, the ER having been carried out at the subacute stage of myocardial infarction. Despite a significant increase in the background noise during exercise from 0.9 microV to 2.2 microV, it was possible to analyse the MECG recorded during exercise to detect DPs in all cases. In this small group of patients, no significant changes occurred with regard to the appearance or delayed potentials during exercise, although there was a reduction in the duration of HFQRS and an increase in the amplitude of RMS40 during exercise which was, however, much less marked in patients presenting DP.

Aged↗

Relations of sociotropic and autonomous personality characteristics to specific symptoms in depressed patients.

A number of writers have suggested that two sets of personality characteristics are associated both with vulnerabilities to depression in response to different classes of events and with different clinical presentations of depression. The present study examined the relations between levels of sociotropic and autonomous personality characteristics and specific, theoretically derived clusters of symptoms in 80 unipolar depressed patients. As was predicted, sociotropy was related to the cluster of symptoms associated with the concept of anxious-reactive depression and was unrelated to the autonomous symptoms cluster. In contrast, the predicted relations of autonomous personality characteristics and symptoms were not found. These results support the idea that the symptom picture in depression may be related to personality characteristics, but they also suggest that the measurement of autonomy may require revision.

Adolescent↗

Radionuclide assessment of right ventricular regional wall motion abnormalities in anterior left ventricular infarction.

Because of its potential use in the detection of right ventricular myocardial infarction, we performed radionuclide ventriculography in 80 consecutive cases of electrocardiographically anterior acute MI. Regional wall motion of both ventricles was studied on amplitude-phase images. Forty-five patients (56%) showed normal right ventricular function and 35 (44%) regional right ventricular dyskinesia: 19 in the septal, 14 in the apical and 2 in the free wall region. Right ventricular septal, respectively apical asynergy were virtually always associated with asynergy in the homologous parts of the left ventricle. This could be a consequence of the proximity of these regions, or alternatively be due to a common vascular supply. Thus it remains uncertain if asynergy in these regions signifies necrosis of part of the right ventricular wall. Free wall asynergy was considered as evidence of right ventricular wall necrosis. Thus, in our study group the prevalence of right ventricular myocardial infarction in anterior left ventricular myocardial infarction was at least 2.5%.

Adult↗

Gastric emptying of liquids after highly selective vagotomy for duodenal ulcer.

In a group of clinical patients with duodenal ulcer submitted to highly selective vagotomy, gastric emptying studies were performed pre-operatively and 2 weeks and 6 months after surgery. A standard liquid meal labeled with radioactive technetium was used for scanning. In this group of duodenal ulcer patients, no abnormal emptying was noted prior to surgery as compared with controls. After highly selective vagotomy, the gastric emptying time for liquids was statistically shorter as compared with preoperative values. It is concluded that highly selective vagotomy may be the operative treatment of choice for duodenal ulcer patients with respect to acid secretion, but that it alters gastric motility and emptying significantly.

Duodenal Ulcer↗

Management of gallstone pancreatitis during pregnancy and the postpartum period.

In a 22 year study, 21 women had acute pancreatitis develop during pregnancy (11 women) or within six weeks post partum (ten women). Gallstones were the cause of the pancreatitis in all. Operation during the acute attack of pancreatitis was required in only two. Acute pancreatitis subsided in the remaining 19 patients; they were operated upon during the second trimester or the early postpartum period. During pregnancy, surgical treatment for gallstone pancreatitis should consist of cholecystectomy and exploration of the common bile duct without operative cholangiography. During the postpartum period, operative cholangiography is used to determine whether or not exploration of the common bile duct is necessary. Acute pancreatitis associated with pregnancy is "gallstone" pancreatitis; there is no evidence that pregnancy is a specific etiologic factor in pancreatitis. As opposed to nonoperative treatment of symptomatic gallstone pancreatitis in pregnancy, which is accompanied by maternal morbidity or fetal mortality, surgical treatment during the optimal time of the second trimester or early postpartum period was associated with no maternal morbidity or fetal mortality and no recurrent pancreatitis.

Acute Disease↗

Echocardiography and magnetic resonance imaging in cardiac amyloidosis.

Cardiac amyloidosis is an uncommon cause of heart failure. Based on an observation of immunocytic cardiac amyloidosis with a fatal course, the diagnostic modalities are reviewed with special emphasis on echocardiographic findings. The possible role of magnetic resonance imaging is discussed.

Amyloidosis↗

Personal vulnerability, life events, and depressive symptoms: a test of a specific interactional model.

We tested Beck's (1983) hypothesis that depressive symptoms occur when an individual experiences a negative life event that specifically matches the individual's personal motivational vulnerability. Ninety-eight undergraduates completed measures of depression level, recent life events, and sociotropic and autonomous achievement motivations. Consistent with the theory, sociotropy was associated with depression level and also served as a moderator of the relations between depression and frequency of recent negative social events. However, sociotropy also demonstrated nonpredicted interactive effects with negative events categorized a priori as autonomy related. Autonomy was unrelated to depression and showed no evidence of being a vulnerability to any type of life event. The findings generally support the value of examining the role in depression of interactions between personality characteristics and life events, although they do not support the specific matching predictions.

Achievement↗

Treatment of malignant pericardial tamponade with sclerosis induced by instillation of bleomycin.

Five patients with pericardial tamponade of neoplastic origin were treated by pericardiocentesis, drainage and local instillation of bleomycin. The pericardial effusion was adequately controlled in all patients. Survival was influenced not by the pericardial involvement, but by the natural evolution of the tumour. Side effects were minimal. The technique of drainage and bleomycin sclerosis is simple, safe, effective and inexpensive for the management of a malignant pericardial tamponade, providing all precautions necessary for diagnosis and pericardiocentesis are adequately taken.

Aged↗

Effect of carvedilol on ambulatory blood pressure, renal hemodynamics, and cardiac function in essential hypertension.

A randomized, double-blind, placebo-controlled study was set up to study the effects of acute and chronic administration of carvedilol, a vasodilatory beta-blocker in essential hypertension. Acute administration of a single dose of 50 mg of carvedilol reduced systolic and diastolic blood pressure, without inducing reflex tachycardia. Renal blood flow was preserved; accordingly renal vascular resistance was significantly reduced. A significant reduction of glomerular filtration rate and filtration fraction was observed. Plasma renin activity (PRA) and plasma aldosterone were not changed. Chronic carvedilol treatment produced a significant fall in systolic and diastolic office and ambulatory blood pressure, heart rate, cardiac output, PRA and plasma aldosterone. Blood pressure variability was not changed. Renal blood flow, glomerular filtration rate and filtration fraction also remained unchanged; renal vascular resistance decreased significantly. It is concluded that carvedilol possesses definite antihypertensive and renal vasodilating properties, both acutely and after chronic treatment.

Adrenergic beta-Antagonists↗

Identification of best electrocardiographic leads for diagnosing anterior and inferior myocardial infarction by statistical analysis of body surface potential maps.

In view of the increasing interest in quantifying and modifying the size of myocardial infarction (MI), it is important to look for clinically practical subsets of electrocardiographic leads that allow the earliest and most accurate diagnosis of the presence and electrocardiographic type of MI. A practical approach is described, taking advantage of the increased information content of body surface potential maps over standard electrocardiographic techniques for facilitating clinical use of body surface potential maps for such a purpose. Multivariate analysis was performed on 120-lead electrocardiographic data, simultaneously recorded in 236 normal subjects, 114 patients with anterior MI and 144 patients with inferior MI, using as features instantaneous voltages on time-normalized QRS and ST-T waveforms. Leads and features for optimal separation of normal subjects from, respectively, anterior MI and inferior MI patients were selected. Features measured on leads originating from the upper left precordial area, lower midthoracic region and the back correctly identified 97% of anterior MI patients, with a specificity of 95%; in patients with inferior MI, features obtained from leads located in the lower left back, left leg, right subclavicular area, upper dorsal region and lower right chest correctly classified 94% of the group, with specificity kept at 95%. Most features were measured in early and mid-QRS, although very potent discriminators were found in the late portion of the T wave.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗