Search results for "electrocardiography"
showing 10 items of 419 documents
Nonlinear coupling is absent in acute myocardial patients but not healthy subjects.
2008
We investigated whether autonomic nervous system imbalance imposed by pharmacological blockades and associated with acute myocardial infarction (AMI) is manifested as modifications of the nonlinear interactions in heart rate variability signal using a statistically based bispectrum method. The statistically based bispectrum method is an ideal approach for identifying nonlinear couplings in a system and overcomes the previous limitation of determining in an ad hoc way the presence of such interactions. Using the improved bispectrum method, we found significant nonlinear interactions in healthy young subjects, which were abolished by the administration of atropine but were still present afte…
Comparison of contrast-enhanced MR angiography to intraarterial digital subtraction angiography for evaluation of peripheral arterial occlusive disea…
2010
Purpose To evaluate the efficacy and safety of 0.1 mmol/kg gadodiamide administration for contrast-enhanced magnetic resonance angiography (CE-MRA) in detecting hemodynamically relevant main stenosis (ie, ≥50% or occlusion) of aortoiliac arteries. Materials and Methods In a multicenter, phase 3, controlled study, patients with suspected or proven peripheral arterial occlusive disease (PAOD) underwent CE-MRA with administration of gadodiamide. Intraarterial digital subtraction angiography (IA-DSA) was used as the reference. The study was approved by all Institutional Review Boards or Institutional Ethic Committees prior to commencement of patient recruitment and written informed consent was …
Supraventricular arrhythmias in noncompaction of left ventricle: Is this a frequent complication?
2008
Background: Isolated left ventricular noncompaction is the result of incomplete myocardial morphogenesis, leading to persistence of the embryonic myocardium. The condition is recognised by an excessively prominent trabecular meshwork and deep intertrabecular recesses of the left ventricle. Whether these intertrabecular recesses are a favorable substrate for supraventricular arrhythmias is unclear, even if the incidence of chronic heart failure seems to be high. Results: We evaluated a continuous series of 238 patients affected by noncompaction. In 4 cases the patients reported palpitations and in 4 an episode of syncope. Periodic holter monitoring was performed every 6 months for 4 years. O…
Ventricular tachycardia in non-compaction of left ventricle: Is this a frequent complication?
2007
Background: Isolated left ventricular non-compaction is the result of incomplete myocardial morphogenesis, leading to persistence of the embryonic myocardium. The condition is recognized by an excessively prominent trabecular meshwork and deep intertrabecular recesses of the left ventricle. Whether these intertrabecular recesses are a favorable substrate for ventricular arrhythmias is unclear. Some reports have found that the fatal ventricular arrhythmias may occur in approximately half of the patients. In this report we investigated about this association. Methods and Results: In total we evaluated a continuous series of 238 patients affected by non-compaction. Periodic Holter monitoring w…
Lateralization of directional brain-heart information transfer during visual emotional elicitation
2019
Previous studies have characterized the physiological interactions between central nervous system (brain) and peripheral cardiovascular system (heart) during affective elicitation in healthy subjects; however, questions related to the directionality of this functional interplay have been gaining less attention from the scientific community. Here, we explore brain-heart interactions during visual emotional elicitation in healthy subjects using measures of Granger causality (GC), a widely used descriptor of causal influences between two dynamical systems. The proposed approach inferences causality between instantaneous cardiovagal dynamics estimated from inhomogeneous point-process models of…
Circulatory response to volume expansion and transjugular intrahepatic portosystemic shunt in refractory ascites: Relationship with diastolic dysfunc…
2015
Abstract Background Cirrhotic cardiomyopathy may lead to heart failure in stressful circumstances, such as after transjugular intrahepatic portosystemic shunt (TIPS) placement. Aim To examine whether acute volume expansion predicts haemodynamic changes after TIPS and elicits signs of impending heart failure. Methods We prospectively evaluated refractory ascites patients (group A) and compensated cirrhotics (group B), who underwent echocardiography, NT-proBNP measurement, and heart catheterization before and after volume load; group A repeated measurements after TIPS. Results 15 patients in group A (80% male; 54 ± 12.4 years) and 8 in group B (100% male; 56 ± 6.2 years) were enrolled. Echoca…
Habituation and recovery of a slow negative wave of the event-related brain potential.
2002
This study is concerned with the question of whether the late, slow negative wave 2 (SNW2) component of the event-related brain potential is a component of the orienting response (OR). As habituation of the SNW2 would be an argument for such a link with the OR, it was investigated using a variant of the classical repetition/change paradigm. Results supported major claims to be made for a component of the OR: the amplitude of the vertex SNW2 exhibited roughly the typical exponential decline with repeated stimulations (six numeric verbal stimuli presented seriatim in an ascending order) and responded incrementally to a change, at least in a narrow time slot, i.e. it exhibited partial recovery…
[Cardiac arrhythmias in hypertensive subjects with and without left ventricular hypertrophy compared to the circadian profile of the blood pressure].
1990
To evaluate possible correlations between cardiac arrhythmias and circadian pattern of blood pressure (BP) and of heart rate (HR), we studied 2 groups of 20 males with stable arterial hypertension of mild to moderate entity, with (Group I) or without (Group II) left ventricular hypertrophy (LVH). In patients with LVH the mean age (56 vs 46 years), the duration of the hypertensive state (48.1 vs 15.7 months), the thickening of interventricular septum (IVS; 13.7 vs 9.6 mm) and of the posterior wall of the left ventricle (13.2 vs 9.2 mm) and the mass of LV (149.8 vs 99.7 g/m2) were significantly greater (p less than 0.01). On the contrary, the 2 groups did not show significant differences conc…
Non invasive evaluation of endothelial function in patients with Anderson-Fabry disease.
2005
AIM: Fabry's disease is an X-linked recessive abnormality of glycosphingolipid metabolism. Increased levels of endothelial prothrombotic factors have recently been demonstrated in Fabry's disease, whereas endothelial function has not been studied using high resolution ultrasound. METHODS: We enrolled 6 patients (4 male, 2 female; mean age, 37 years) and 12 sex matched control subjects (mean age, 37 years). Patients' exclusion criteria included a prior history of cardiac disease, diabetes and treated or untreated hypertension. Patients underwent: anamnesis, physical examination, EKG, 2-dimensional echocardiography with tissue Doppler, measurement of body weight and height, blood pressure. Bi…
Genome-Wide Association Studies of the PR Interval in African Americans.
2011
The PR interval on the electrocardiogram reflects atrial and atrioventricular nodal conduction time. The PR interval is heritable, provides important information about arrhythmia risk, and has been suggested to differ among human races. Genome-wide association (GWA) studies have identified common genetic determinants of the PR interval in individuals of European and Asian ancestry, but there is a general paucity of GWA studies in individuals of African ancestry. We performed GWA studies in African American individuals from four cohorts (n = 6,247) to identify genetic variants associated with PR interval duration. Genotyping was performed using the Affymetrix 6.0 microarray. Imputation was p…