PubMed Health⌕ Search

Biomedical subjects

S Carerj

Publications and source records attributed to S Carerj.

At least 19 recordsLinked to original sources
PubMed2003

Tilt-induced pseudosyncope.

Using the head-up tilt test (HUTT) we evaluated 986 consecutive patients affected by unexplained syncope. In 266 patients the test induced bradycardia and/or hypotension resulting in syncope or presyncope, thus allowing a diagnosis of neurally mediated syncope. In three other patients (0.3% of the entire population and 1% of the all positive tests) HUTT provoked loss of consciousness despite no significant change in heart rate and/or blood pressure. In all three cases unconsciousness was prolonged and no pathological finding was present except lack of response. This phenomenon has been defined as 'pseudosyncope' and related to psychiatric illness. Pseudosyncope induced by HUTT reproduced the clinical events, so the test outcome was considered a true positive response. Our experience suggests that HUTT may contribute to the recognition of psychiatric disorder in some patients affected by unexplained syncope.

Adolescent↗
PubMed2003

[Thrombo-embolic risk evaluation in patients with atrial fibrillation. Role of echocardiography].

Atrial fibrillation (AF) is the most common observed cardiac arrhythmia and is the most frequent condition associated with thromboembolic events in patients with or without mitral valve disease. The source of cardiac emboli is the left atrium, the left atrial appendage or, less frequently, the left ventricle. Emboli may also originate from aortic atherosclerotic plaques. It is important to identify patients at risk in order to perform the appropriate therapy. Risk stratification is multiparametric, being based on clinical, laboratory, and echocardiographic data. Several trials have pointed out the role of echocardiography in the evaluation of anatomic and functional parameters associated with thromboembolic risk. Transthoracic echocardiography (TTE) does not provide sufficient information regarding posterior cardiac structures, being its sensitivity in detecting thrombi relatively low (33-72%). Transesophageal echocardiography (TEE) in contrast, has an almost 100% sensitivity; this technique is, therefore, mandatory in patients with AF for an adequate prevention of thromboembolism. The echocardiographic information joined with clinical features allow to stratify, in a proper way, the risk of every single patient.

Atrial Fibrillation↗
PubMed2002

[Pathophysiology of congestive heart failure].

Pathophysiology of congestive heart failure (CHF) has undergone a remarkable evolution during the last two decades. CHF is now regarded especially as a neurohormonal disease and not only as a cardiocirculatory impairment. Many studies have emphasized that an abnormal neuroendocrine activation precedes the development of clinically recognized heart failure and plays an important pathogenetic role in progression of this disease. In patients with CHF, moreover, circulating levels of some neurohormonal factors have an independent negative prognostic value. More recently immunological and molecular biology studies have also demonstrated the negative effects exerted by some cytokines and by apoptosis. Correction of neurohormonal disorder is the rationale of therapeutical approach to patients with CHF and appears the only way to significantly decrease mortality. In this review the role of neuroendocrine activation in the pathophysiology of CHF is analyzed.

Angiotensin II↗
PubMed2002

[Detection of left ventricular endocardial border with tissue harmonic imaging].

BACKGROUND: Ultrasonic wave propagation in human tissues is not linear. As a consequence, harmonic waves, whose frequency is a multiple (harmonic) of the emitted frequency, are generated. Tissue Harmonic Imaging (THI) processes only the second harmonic frequency in order to improve the signal-to-noise ratio of the received signal. The study was aimed at investigating the impact of THI on the detection of the Left Ventricular (LV) endocardial border. Attention was paid to determine which LV walls were analysed more clearly with THI rather than with conventional Fundamental Frequency Imaging (FFI). METHODS: We compared the FFI and the THI visualization of the 16 LV segments and of the 6 LV walls in 30 consecutive patients by scoring the images as bad, sufficient or good. The equipment used was a GE Vingmed System Five (Orten, Norway). RESULTS: Images were good in 85% of segments explored with THI, whereas FFI provided good images in 47% of segments (p<0.001). From the apical window, visualization of the apex, lateral wall and anterior wall significantly improved with THI; using the parasternal approach, imaging of posterior wall was definitely better with THI than with FFI. CONCLUSIONS: THI enhances both endocardial visualization and global image quality. Tech-nical development, however, increases the diagnostic possibilities of echocardiography but does not substitute the operator's experience.

Echocardiography↗
PubMed2001

QRS complex voltage changes associated with supraventricular tachycardia.

INTRODUCTION: The aim of this study was to evaluate the changes in ventricular complex voltage associated with narrow QRS supraventricular tachycardia (SVT). METHODS AND RESULTS: One hundred forty-five patients undergoing catheter ablation for SVT, 85 with AV nodal reentrant tachycardia (AVNRT) and 60 with AV reentrant tachycardia (AVRT) due to a concealed accessory pathway, were studied. Four consecutive tachycardia beats and four consecutive sinus beats were analyzed, excluding the last tachycardia complex and the first sinus one. For each of the 12 leads, the QRS complex voltage was measured, and the results of four beats were averaged both in SVT and in sinus rhythm (SR). The sum (sigma) of the QRS voltages measured in the 12 leads during SVT (sigmaSVT) and SR (sigmaSR) were calculated, as well as the QRS axis during SVT and SR. QRS complex voltage was significantly increased during SVT, with respect to SR, in leads II, III, aVR, aVF, and V2 to V6. In addition, sigmaSVT was significantly greater than sigmaSR. Only lead V1 showed a significant voltage decrease during SVT. These voltage changes were almost identical in patients with AVNRT and patients with AVRT. No relationship was found between tachycardia rate and QRS voltage variation. The QRS axis showed a significant shift during SVT, from 55.8 degrees to 64.5 degrees. CONCLUSION: QRS voltage increase occurs in reentrant SVT, independent of the underlying reentrant circuit. The phenomenon likely depends on tachycardia-related reduced ventricular filling. This could result in displacement of the heart in such a way that the left ventricle becomes closer to the precordial electrodes (proximity effect). Alternatively, decreased intracavitary blood mass could diminish the intracardiac short-circuiting of potentials, resulting in augmented transmission of cardiac vectors to the body surface.

Adolescent↗
PubMed2001

Advanced A-V block with apparent A-V junctional escape complexes because of dual A-V nodal pathways.

We report a patient with second degree A-V block in whom several sinus impulses were conducted over the slow A-V nodal pathway, resulting in P-R intervals so prolonged to suggest a diagnosis of intermittent advanced A-V block with A-V junctional escape complexes. However, the "escape" cycles were markedly irregular, and moreover, "escape" complexes often occurred with R-R cycles shorter than those ended by conducted sinus beats. These observations suggested that no escape mechanism was present. The marked variability of P-R intervals was a manifestation of dual A-V nodal pathways: short P-R intervals expressed conduction over the fast pathway, whereas long P-R intervals corresponded to sinus impulses conducted over the slow pathway.

Aged↗
PubMed2001

[The second tissue harmonic signal: from physics principles to clinical application].

The second harmonic signals received from organs are due to the non linear properties of tissue which cause distortion of the transmitted signal and are not primarily caused by the transmission of a harmonic frequency. The velocity of ultrasound propagation depends on the density of the insonified material. During the compression phase, the tissue becomes denser, and the ultrasound waves travel faster through the tissue than during the rarefaction phase; the compression phase tends to overtake the rarefaction phase. The ultrasound waveform thus, undergoes a distortion that becomes greater as the distance from the transducer increases. Due to these effects, the tissue tends to generate harmonics and hence shifts energy from the fundamental to the harmonic bands. There are several reasons why harmonic tissue imaging increases the signal-to-noise ratio and facilitates interpretation. In technically difficult patients, there is often a diffuse haze due to distortion of the transmitted beam by shallow surface layers or to reverberations between the skin and ribs. These distortions and reverberations consist almost entirely of ultrasound energy at the fundamental frequency. When the returned signal is filtered at the harmonic so as to reject the fundamental frequency, the clutter and haze are removed and the image becomes more clear and defined. A further reason for the decrease in artifacts and clutter is the side-lobe level reduction in the second harmonic beam. Thus, harmonic beams are narrower and have lower side-lobe levels than fundamental ones. There are several clinical applications of harmonic tissue imaging. These include the correct definition of endocardial borders resulting in an improved assessment of left ventricular function at rest as well as during stress testing, the delineation of the left atrial appendage, the detection of atrial right to left shunting, and left atrial spontaneous echo contrast. Moreover, improved endocardial visualization leads to better endocardial tracking with acoustic quantification and to more segments being interpretable with the anatomic M-mode.

Acoustics↗
PubMed2000

[Cardiologic diagnosis of pulmonary embolism: echocardiography].

Pulmonary embolism (PE) represents the third more frequent cardiovascular disease following the acute coronary artery disease and stroke. The most important predisposing clinical condition for PE is represented by the deep-vein thrombosis. The clinical diagnosis of PE has a very low accuracy; so the clinical suspect has to be necessarily directed towards the performance of diagnostic procedures. Among the most used procedures, the echocardiography has a diagnostic role but also a prognostic one. Moreover, it offers precious informations useful to perform the most suitable treatment. The echocardiography features which suggest the presence of pulmonary embolism are: right ventricle and atrium dilatation, right ventricular hypokinesia, systolic flattening of the interventricular septum, tricuspid regurgitation, pulmonary artery dilatation, disappearance or reduction of the inspiratory collapse of the inferior vena cava and presence of eventual embolic sources. According to the involvement degree of right ventricular function, it is generally possible to identify a different survival. The subgroup of patients with moderate or severe right ventricular dysfunction shows a high in hospital and within 1 year death rate. For this reason the right ventricular dysfunction degree together with the hemodynamic stability, are the most important parameters in the therapeutic choice. If there is no right ventricular dysfunction a treatment with heparin is indicated. In presence of right ventricular dysfunction and hemodynamic instability, the thrombolytic treatment is necessary. If the patient is hemodynamically stable, a transesophageal echocardiography is recommended; in case of central thrombosis the thrombolytic therapy or surgery are needed, while if no embolic material is shown the heparin treatment is advisable.

Aged↗
PubMed1994

[Does aortic insufficiency influence Doppler-derived calculation of the valvular area in patients with mitral stenosis?].

BACKGROUND: The evaluation of mitral valve area (MVA) in patients with mitral stenosis represents the main purpose of any diagnostic method, provided that MVA is a key parameter to indicate the need for valve surgery. The aim of this study was to assess whether the presence of aortic regurgitation associated with mitral stenosis affects the MVA measurement by left atrial pressure half time (PHT). METHODS: Eighty-nine patients with mitral valve stenosis (68 females and 21 males, mean age 53.6 +/- 12.1 years), were studied. Fourty-eight patients (36 females and 12 males) had a concomitant aortic regurgitation (AR group), whereas 41 patients (32 females and 9 males) did not reflect any aortic valve involvement (no-AR group). Aortic regurgitation was graded on the basis of color flow analysis. The majority of patients had a slight to moderate regurgitation. MVA determination was carried out using both Hatle formula (220/PHT) and planimetric measurement in parasternal short axis view. RESULTS: Statistical analysis demonstrated a good correlation between the 2 MVA measurement in both groups (IA group: r = 0.9, p < 0.0001, SSE = 0.21 cm2, y = 0.91x + 0.05; no-IA group r = 0.92, p < 0.0001, SSE = 0.22 cm2, y = 0.92x + 0.04). The concomitant aortic valve disease did not affect in any way the MVA measurement by means of the PHT method. CONCLUSIONS: The Doppler derived method appears to be reliable for estimating the mitral valve area in patients with mitral stenosis even in the presence of aortic regurgitation.

Adult↗
PubMed1993

[Role of transesophageal echography in the study of embolism of cardiac origin].

In the total population, cerebrovascular ischemic diseases account for 0.2-0.3% cases per year, and in the 20-40% of them it is possible to recognize a cardioembolic mechanism. The cardiological examination in patients with stroke is, therefore, aimed at detecting cardiac sources of emboli (left atrial, valvular, and ventricular thrombosis, atherosclerotic plaques of ascending aorta), and at identifying the cardiovascular disease directly or indirectly associated with ischemic stroke. Transesophageal echocardiography (TEE) is particularly suitable for this purpose, due to the proximity of the transducer to the posterior cardiac structures and to its better resolution. Many recent reports have demonstrated that TEE not only improves the recognition of known cardioembolic diseases (intracardiac thrombi, mitral stenosis, valvular prosthesis thrombosis, endocardial infectious diseases), but is also the most reliable non invasive technique suitable to detect atherosclerotic lesions of the ascending aorta. Furthermore, TEE allowed to recognize new anatomic and functional abnormalities, such as left atrial spontaneous echo contrast, atrial septal aneurysm, patent foramen ovale, frequently associated with stroke. Noteworthy, TEE is the only technique suitable for functional and anatomic evaluation of the left atrial appendage. The Authors studied by TEE the functional properties of left atrial appendage in patients with severe mitral stenosis with or without atrial fibrillation, as compared to patients with left atrial thrombosis. Results showed that fractional shortening of left appendage was greatly reduced, at the same extent in the 3 groups, demonstrating that abnormalities in left atrial appendage emptying could be a risk factor for atrial thrombosis. In order to compare TEE with the transthoracic 2D-echo for the detection of cardioembolic sources, the Authors studied 63 patients with ischemic stroke. TEE revealed a possible cardioembolic source in 70% of younger patients and in 50% of patients older than 45 years. These abnormalities were detected by TEE respectively in 10% and in 1.8% of cases. These data are in agreement with many other reports in literature, and suggest the usefulness of TEE in the evaluation of patients with ischemic stroke and no evidence of severe atherosclerotic cerebrovascular disease, in contrast to the poor role of TEE. Another important field is the prevention of stroke in patients at high risk of cardioembolic events. The role of TEE before and immediately after cardioversion in patients with atrial fibrillation has been recently studied by several papers. Cardioversion was proved at low risk of stroke when TEE did not show left atrial or left appendage thrombosis. Therefore, the transesophageal approach identifies patients needing prolonged anticoagulation (roughly 20%), avoiding an undue, potentially dangerous therapy.

Adult↗
PubMed1991

Pseudo pre-excitation with concertina effect in idioventricular tachycardia.

The concertina effect is a phenomenon where the QRS complexes reflect alternating phases of gradual widening and narrowing. This is most commonly due to ventricular pre-excitation, and the changes in QRS morphology are due to variability of the ventricular zone that undergoes pre-excitation. This presentation reflects a case where the concertina effect is due to an idioventricular tachycardia at a rate nearly identical to the sinus rate. Variable degrees of ventricular fusion therefore occur, and the concertina effect ensues, in relation to slight variations of the sinus cycle.

Electrocardiography↗
PubMed1991

[Evaluation of the kinetics of MB creatine kinase in patients undergoing systemic thrombolytic therapy].

This study was aimed to evaluate if the time-course of creatinkinase MB in acute myocardial infarction (AMI) is influenced by therapy and which index, derived from the enzymatic curve, is the most reliable marker of successful coronary artery recanalization. We studied the enzymatic curves in 38 patients with transmural myocardial infarction, 19 treated with streptokinase (SK) and 19 with tissue plasminogen activator (rtPA). Blood samples were obtained every 2 hours for the first 12 hours and every 6 hours until the level of serum CK returned to baseline. Three indexes were calculated: peak serum enzyme level, time to peak enzyme level and maximal enzyme rise velocity. Time to peak did not differ significantly between SK and rtPA groups. Peak levels were significantly higher (414 +/- 40 vs 249 +/- 33; p = 0.004) in rtPA groups, as well as maximal enzyme rise velocity (1.7 +/- 0.4 vs 0.8 +/- 0.1; p = 0.02). However, infarct size evaluated by the total release of CK-MB in 28 patients was greater in rtPA group (10949 +/- 1097 vs 6346 +/- 869; p = 0.002). These findings suggest that differences in peak level and in maximal velocity of rise observed between SK and rtPA are due to differences in infarct size and not to a different recanalization rate. Thus, enzymatic estimate of infarct size significantly correlates to peak enzyme (r = 0.894, p less than 0.001), and to maximal rise velocity (r = 0.518, p = 0.007) but not to time to peak (r = 0.208, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Creatine Kinase↗
PubMed1989

Trifascicular block with asynchronous intraventricular recovery and "supernormal" AV conduction.

The authors present a case of trifascicular block: complete right bundle branch block, tachycardia-dependent left anterior hemiblock, and bradycardia-dependent left posterior hemiblock. There is, in addition, a complicating independent AV junctional rhythm that is in most instances not affected by the conducted sinus impulses. Occasionally, however, this focus is discharged by very early sinus impulses that are unexpectedly conducted to the ventricles (a manifestation of "supernormal" conduction). A complex electrocardiographic pattern results from the interplay of the aforementioned mechanisms.

Atrioventricular Node↗