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Biomedical subjects

R Hatala

Publications and source records attributed to R Hatala.

At least 19 recordsLinked to original sources
PubMed2005

Body surface integral maps in patients with arrhythmogenic right ventricular cardiomyopathy.

OBJECTIVES: The aim of this study was to evaluate changes in QRST integral maps in patients with ARVC. BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a progressive disorder of predominantly right ventricle characterized with arrhythmic events possibly leading to sudden cardiac death. QRST integral maps reflect local disparities of ventricular repolarization and resulting vulnerability to arrhythmias. METHODS: A group of 8 patients with ARVC and a control group of 8 patients with a concealed accessory pathway were studied. Body surface mapping was performed using a 63-lead Savard's system. RESULTS: Mean QRST integral map of patients with ARVC showed abnormal characteristics. The area of negativity was larger than normal and extended to lower border of thorax. Departure map of the mean QRST integral map of patients with ARVC showed areas with departure index < 2 and > 2 in lower part of chest and upper part of back. When statistically analyzed, areas with p < 0.05 covered nearly lower half of chest and upper half of back. CONCLUSIONS: We consider body surface QRST integral mapping to be an adequate method for evaluation of dispersion of ventricular repolarization in ARVC patients (Tab. 1, Fig. 5, Ref. 17).

Adolescent↗
PubMed2005

Arrhythmogenic right ventricular cardiomyopathy/dysplasia.

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a progressive disease of predominantly right ventricle, characterized by ventricular arrhythmias possible leading to sudden cardiac death. Genetic predisposition was confirmed more than 15 years ago. Autosomal dominant are forms ARVD1-9, Naxos disease (with subtype Carvajal syndrome) is recessive. In ARVC/D forms associated with desmosomal disorders are ventricular arrhythmias caused by the presence of myocardial damage and in forms associated with ryanodine receptor mutation is electrical instability and subsequent myocardial damage caused by calcium cell overload. Main clinical signs are ventricular arrhythmias originated from areas with slow conduction. Progression of ARVC/D is manifested by RV dilatation and LV echocardiographic abnormalities both considered as main risk factors of fatal ventricular arrhythmias and sudden cardiac death. Therapeutic possibilities include antiarrhythmic drugs, catheter ablation and implantation of cardioverter-defibrillator, in severe right or both ventricle involvement even heart failure treatment (Tab. 1, Ref. 56).

Arrhythmogenic Right Ventricular Dysplasia↗
PubMed2003

Effect of head-down bed rest on the neuroendocrine response to orthostatic stress in physically fit men.

The role of neuroendocrine responsiveness in the development of orthostatic intolerance after bed rest was studied in physically fit subjects. Head-down bed-rest (HDBR, -6 degrees, 4 days) was performed in 15 men after 6 weeks of aerobic training. The standing test was performed before, after training and on day 4 of the HDBR. Orthostatic intolerance was observed in one subject before and after training. The blood pressure response after training was enhanced (mean BP increments 18+/-2 vs. 13+/- 2 mm Hg, p<0.05, means +/- S.E.M.), although noradrenaline response was diminished (1.38+/-0.18 vs. 2.76+/-0.25 mol.l(-1), p<0.01). Orthostatic intolerance after HDBR was observed in 10 subjects, the BP response was blunted, and noradrenaline as well as plasma renin activity (PRA) responses were augmented (NA 3.10+/-0.33 mol.l(-1), p<0.001; PRA 2.98+/-1.12 vs. 0.85+/-0.15 ng.ml(-1), p<0.05). Plasma noradrenaline, adrenaline and aldosterone responses in orthostatic intolerant subjects were similar to the tolerant group. We conclude that six weeks of training attenuated the sympathetic response to standing and had no effect on the orthostatic tolerance. In orthostatic intolerance the BP response induced by subsequent HDBR was absent despite an enhanced sympathetic response.

Adult↗
PubMed2001

Endocrine activation in tachycardias.

This article reviews the complex character of neuroendocrine response to paroxysmal tachycardia. While the endocrine influences in arrhythmogenesis are well perceived by the cardiologists, less attention has been paid to influence of tachycardia on neuroendocrine activation. However, this may significantly alter the clinical course of tachycardias and its responses to pharmacotherapeutic interventions. Main characteristics of hormones with direct relationship to cardiovascular system (ANP, AVP, catecholamines, angiotensin and others) are listed with description of regulation of their secretion and main biological effects, especially with regard to regulation of circulation. Changes in hemodynamics during tachycardia with accompanying changes in ANP, AVP renin-angiotensin-aldosterone system, sympatho-neural and sympatho-adrenal activation are reviewed. Further research and understanding require more complex approach and concentration on interrelationship of different regulatory hormones in tachycardia. (Fig. 2, Ref. 96.)

Atrial Natriuretic Factor↗
PubMed2000

The defibrillator in acute myocardial infarction trial (DINAMIT): study protocol.

BACKGROUND: The implantable cardioverter/defibrillator (ICD) has been shown to be superior to antiarrhythmic drug therapy for the secondary prevention of sudden cardiac death. Its role in the primary prevention of sudden death after myocardial infarction is unknown. Methods and Results The Defibrillator in Acute Myocardial Infarction Trial (DINAMIT) is a randomized, open-label, parallel-group comparison of ICD therapy versus no ICD therapy in selected survivors of acute myocardial infarction. It will test the hypothesis that reduction of sudden arrhythmogenic death by means of the ICD will result in reduction of overall mortality rates in patients at high risk after acute myocardial infarction. Accordingly, this international multicenter study aims to enroll patients shortly after their infarction (day 6 to day 40) who have reduced left ventricular function (left ventricular ejection fraction </=0. 35) and impairment of cardiac autonomic function shown by depressed heart rate variability (standard deviation of normal-to-normal R-R intervals </=70 ms) or elevated average 24-hour heart rate (mean 24-hour R-R interval </=750 ms, assessed by Holter monitoring). Patients will be followed for approximately 3 years on average with subsequent data analysis based on the intent-to-treat principle. Primary outcome is all-cause death. The trial is expected to be completed in 2003. CONCLUSIONS: DINAMIT is the first prospective study to evaluate the benefit of ICD therapy for the primary prevention of sudden cardiac death in patients at high risk after acute myocardial infarction.

Defibrillators, Implantable↗
PubMed1999

The rational clinical examination. Does this adult patient have acute meningitis?

CONTEXT: Early clinical recognition of meningitis is imperative to allow clinicians to efficiently complete further tests and initiate appropriate therapy. OBJECTIVE: To review the accuracy and precision of the clinical examination in the diagnosis of adult meningitis. DATA SOURCES: A comprehensive review of English- and French-language literature was conducted by searching MEDLINE for 1966 to July 1997, using a structured search strategy. Additional references were identified by reviewing reference lists of pertinent articles. STUDY SELECTION: The search yielded 139 potentially relevant studies, which were reviewed by the first author. Studies were included if they described the clinical examination in the diagnosis of objectively confirmed bacterial or viral meningitis. Studies were excluded if they enrolled predominantly children or immunocompromised adults or focused only on metastatic meningitis or meningitis of a single microbial origin. A total of 10 studies met the criteria and were included in the analysis. DATA EXTRACTION: Validity of the studies was assessed by a critical appraisal of several components of the study design. These components included an assessment of the reference standard used to diagnose meningitis (lumbar puncture or autopsy), the completeness of patient ascertainment, and whether the clinical examination was described in sufficient detail to be reproducible. DATA SYNTHESIS: Individual items of the clinical history have low accuracy for the diagnosis of meningitis in adults (pooled sensitivity for headache, 50% [95% confidence interval [CI], 32%-68%]; for nausea/vomiting, 30% [95% CI, 22%-38%]). On physical examination, the absence of fever, neck stiffness, and altered mental status effectively eliminates meningitis (sensitivity, 99%-100% for the presence of 1 of these findings). Of the classic signs of meningeal irritation, only 1 study has assessed Kernig sign; no studies subsequent to the original report have evaluated Brudzinski sign. Among patients with fever and headache, jolt accentuation of headache is a useful adjunctive maneuver, with a sensitivity of 100%, specificity of 54%, positive likelihood ratio of 2.2, and negative likelihood ratio of 0 for the diagnosis of meningitis. CONCLUSIONS: Among adults with a clinical presentation that is low risk for meningitis, the clinical examination aids in excluding the diagnosis. However, given the seriousness of this infection, clinicians frequently need to proceed directly to lumbar puncture in high-risk patients. Many of the signs and symptoms of meningitis have been inadequately studied, and further prospective research is needed.

Acute Disease↗
PubMed1999

Impact of a clinical scenario on accuracy of electrocardiogram interpretation.

To examine the effect of clinical history on the electrocardiogram (ECG) interpretation skills of physicians with different levels of expertise, we randomly allocated to an ECG test package 30 final-year medical students, 15 second-year internal medicine residents, and 15 university cardiologists at university-affiliated teaching hospitals. All participants interpreted the same set of 10 ECGs. Each ECG was accompanied by a brief clinical history suggestive of the correct ECG diagnosis, or the most plausible alternative diagnosis, or no history. Provision of a correct history improved accuracy by 4% to 12% compared with no history, depending on level of training. Conversely, a misleading history compared with no history reduced accuracy by 5% for cardiologists, 25% for residents, and 19% for students. Clinical history also affected the participants' frequencies of listing ECG features consistent with the correct diagnosis and features consistent with the alternative diagnosis (all p values < .05). For physicians at all levels of expertise, clinical history has an influence on ECG diagnostic accuracy, both improving accuracy when the history suggests the correct diagnosis, and reducing accuracy when the history suggests an alternative diagnosis.

Adult↗
PubMed1999

Therapeutic equivalence: all studies are not created equal.

With an increasing number of available treatment options, clinicians must frequently evaluate whether comparable therapies are equivalent in terms of efficacy and safety. Two methodologically distinct study designs are used to establish therapeutic equivalence: standard superiority trials and true equivalence trials. In either study design, clinician-readers assess equivalence by examining both the statistical significance and the clinical importance of the study results (as defined by the minimally important difference, the smallest difference in patient outcome that would lead to an important difference in patient health status). Once therapeutic equivalence has been established, clinicians may select one therapy as the preferred treatment option because it offers other clinical benefits, such as a lower cost or a more convenient drug administration schedule.

Female↗
PubMed1997

The concept of archiving unedited and edited digital coronary angiograms.

Digital image data acquired during cardiac catheterization will soon be archived on standardized digital storage media. However, with the enormous amount of generated data, considerable time will be wasted at later reviewing or at conferences, or when performing additional quantitative studies. As a result major advantages of a digital acquisition and archiving technique will be lost. The concept of two way archiving includes an unedited (primary) digital archive as well as a (secondary) archive edited by operator guided "intelligent" data reduction (IDR). IDR is based upon the elimination of useless and redundant frame sequences (FS), documentation of coronary interventions on one representative single frame (F) and on the reduction of relevant FS and physiological data to and ECG-controlled representative cardiac cycle (CC). With a heart rate of 72/min and an acquisition rate of 12.5 F/s a documentation of each FS may be obtained with only 10 F. A redundancy-free set of 130 F of a diagnostic study as well as only 41-85 F of an interventional study will be archived on an individual 3.5" MOD or on a CD-R. Two cardiologists and two cardiosurgeons studied independently 24 IDR-edited and the corresponding unedited digital angiograms and found no significant differences in the diagnostically relevant coronary morphology and left ventricular function. IDR provides an edited digital coronary angiogram, e.g. a set of images free of redundance and without loss of relevant information. Uneditable FS can be archived in their unedited (primary) form. IDR is managed on-line by an operator interacting with the angiographer.

Angiography, Digital Subtraction↗
PubMed1997

Single daily dosing of aminoglycosides in immunocompromised adults: a systematic review.

We examined the efficacy and toxicity of single daily dosing (SDD) of aminoglycosides for febrile, immunocompromised adults by systematically reviewing four randomized, controlled trials of SDD vs. standard dosing regimens. We assessed the methodological quality of each study and extracted data pertaining to efficacy and toxicity outcomes. Pooled risk ratios for the efficacy outcomes were bacteriologic cure, 1.00 (95% confidence interval [CI], 0.86-1.16); clinical cure, 0.97 (95% CI, 0.91-1.05); and mortality, 0.93 (95% CI, 0.62-1.41). The pooled nephrotoxicity risk ratio was 0.78 (95% CI, 0.31-1.94). Only one study assessed ototoxicity. Although our study was limited by the small number of trials available for review, the results suggest that SDD of aminoglycosides may be efficacious for febrile, immunocompromised patients. Additional studies are necessary for more precise quantification of the mortality and toxicity risk ratios.

Adult↗
PubMed1997

[Diagnostic and therapeutic potential of transesophageal cardiac pacing in the management of patients with arrhythmias].

BACKGROUND: Transoesophageal cardiostimulation is a semiinvasive method of stimulation of atrii enabling the performance of the programmed atrial stimulation without the inevitability of an invasive vascular approach. This method was used in 124 patients with the following indication spectrum. Diagnostic indications: total 82%, paroxysmal supraventricular tachycardia (SVT), and WPW sy-22%, tachycardia with wide QRS-complex-8%. SSS syndrome and bradycardia-20%, sycopes and collapses with unclear etiology-13%, palpitations-11%, control of antiarrhythmic therapy-4%, and other states-6%. Therapeutic indications: total-18%, versions of paroxysmal SVT and flutter of atrii. RESULTS: The patients with SVT were assumed to develop the arrhythmogenic mechanism--AV nodal re-entry tachycardia in 80%, orthodrome AV-re-entry tachycardia in 30%, and flutter of atrii in 20%. All patients with WPW-syndrome were stratified by the use of this method. The origin of this state from ventricular arrhythmia was verified in 40% of patients with tachycardia with a wide QRS complex. In coincidence with other indications, the diagnostic benefit of transoesophageal cardiostimulation was evaluated as follows: syncopes-68%, palpitations-64%, syndrome SSS and bradycardia-48%. The therapeutic indication of SVT version and flutter of atrii, was totally successful in 40%, partly successful in 45% and unsuccessful in 15% of patients. CONCLUSION: Transoesophageal cardiostimulation has contributed to the assessment of the diagnosis in 69% of patients and has acutely managed arrhythmia in 85% of cases. According to our experience, this method is effective in the initial management of patients with arrhythmia. Its low technical and economic demands make its wider utilisation appropriate in clinical practice of internal medicine. (Tab. 4, Fig. 9, Ref. 22).

Arrhythmias, Cardiac↗
PubMed1997

[Arrhythmogenic right ventricular dysplasia].

Arrhythmogenic dysplasia of the right ventricle as a nosological entity was described relatively recently. However, at present, it is gradually being diagnosed more frequently. The authors describe the typical clinical picture of this disease in one of several patients with this disease, who were hospitalised at SUSCH. The authors describe the diagnostical value of individual findings. They indicate the importance of knowledge of individual diagnostical criteria in order to be able to recognize this disease and distinguish it from idiopathic ventricular tachycardia, the prognosis of which is generally better and also the therapeutical approach less aggressive. (Fig. 6, Ref. 29).

Adult↗