Search results for "Ar system"

Quantitative assessment of regularity and synchronization of intracardiac recordings during human atrial fibrillation

2003

This study proposes the morphology-based evaluation of the regularity (R) and the synchronization (S) of intra-atrial electrograms acquired during atrial fibrillation (AF). R is defined as the degree of repetitiveness over time of the shapes of the activation waves detected in single atrial recordings. S accounts for the simultaneous presence of morphologically similar activation waves in two atrial electrograms, and for the dispersion of the propagation delays between the two sites. Both R and S resulted unitary for normal sinus rhythm and decreased significantly moving from atrial flutter (R=0.93, S=0.88) to AF of increasing complexity class (type I AF: R=0.75, S=0.66; type II AF: R=0.32,…

An FFR CT diagnostic strategy versus usual care in patients with suspected coronary artery disease planned for invasive coronary angiography at Germa…

2017

Aim Diagnostic evaluation practices for suspected coronary artery disease (CAD) may vary between countries. Our objective was to compare a CT-derived fractional flow reserve (FFRCT) diagnostic strategy with usual care in patients with planned invasive coronary angiography (ICA) enrolled in the PLATFORM (Prospective Longitudinal Trial of FFRCT: Outcome and Resource Impacts) study at German sites. Methods Patients were divided into two consecutive observational cohorts, receiving either usual care or CT angiography (CTA)/FFRCT. The primary endpoint was the percentage of patients planned for ICA, with no obstructive CAD on ICA within 90 days. Secondary endpoints included death, myocardial infa…

Three-dimensional transesophageal echocardiography in the guide of cardiac mass biopsy

2017

Cardiac tumors are rare. Cardiovascular imaging is more important in the differential diagnosis of cardiac masses but no current noninvasive diagnostic tool has the ability to absolutely diagnose cardiac tumors. In effect cardiac biopsy remains the gold standard in the differential diagnosis. In our case we show the advantages of three-dimensional (3D) transesophageal echocardiography as a guide for cardiac biopsy. We believe that 3D TEE is ready to be used in the guide of cardiac mass biopsy. Once interventionalists become confident with 3D imaging, this technique should be used routinely during these procedures.

Angiographic co-registration of instantaneous wave-free ratio and intravascular ultrasound improves functional assessment of borderline lesions in th…

2018

Determination of myocardial perfusion and coronary flow reserve by densitometric measurements: a selective classification of regions of interest

2002

To evaluate the functional effect of a coronary artery stenosis on the dependent myocardium, digitized coronary angiograms (DCAs) were recorded. The DCAs, acquired during heart catheterization, provide information about myocardial perfusion and coronary flow reserve of areas supplied by this coronary artery. For each analysis the myocardium is separated into different regions of interest (ROIs); 16 ROIs in the distribution of the LCA and 8 ROIs for the RCA. In addition to that, the ROIs of the diseased vessels are divided into ROIs which are proximal, within and distal to the stenosis. Using a semiautomatic procedure, densograms are constructed from which the parameter rise time is calculat…

Congenitally corrected transposition of great vessels: MRI and echocardiographic appearance

1995

This paper presents the case of a 36-year-old male with congenitally corrected transposition of great vessels (CTGV). This is a rare cardiac anomaly characterized by atrioventricular and ventriculoarterial discordance, occuriing in less than 1% of all congenital heart diseases. This was diagnosed by echocardiography and MRI. The MRI findings demonstrated cardiac abnormality.

Transkranielle Dopplersonographie bei Kopf-Hals-Tumoren*

1991

Transcranial Doppler ultrasound (TCD) recording is a non-invasive diagnostic procedure for the evaluation of the cerebral collateral flow in patients, in whom therapeutic ligation or resection of the common and/or internal carotid artery is planned. Patients are first examined under resting conditions, and then under manual compression of the ipsilateral carotid artery. Since January 1989, 31 ENT and neurosurgical patients have been examined. In all patients an immediate decrease in flow velocity in the middle cerebral artery (mca) of about 25% to 90% was recorded. In 42.8% of the patients the mca flow velocity reached 90% or more of its value under normal conditions within a short period. …

Analysis of inter-atrium differences in paroxysmal and persistent atrial fibrillation using principal component analysis

2007

The pathophysiological mechanisms of atrial fibrillation (AF) are not entirely clear yet, and there is no full explanation for the development and evolution of the arrhythmia. The goal of this study is to find inter-atrium differences in electrophysiological behavior between persistent and paroxysmal AF. The database analyzed contains intra-cardiac records from 14 patients with paroxysmal AF and 10 with persistent AF. Dominant frequency and sample entropy measurements showed that in the paroxysmal group there was a left-to-right gradient. These differences were enhanced after the extraction of the main components with principal component analysis. These findings may be interpreted as a poss…

Ectasia and Aneurysm of the Right Coronary Artery Resulting From a Shunt to the Coronary Sinus

1998

A 65-year-old woman presented with a systolic-diastolic murmur. Further MRI investigations as well as angiography revealed an arteriovenous shunt to the coronary sinus via an enlarged right coronary artery (Figure 1A⇓ and 1B⇓). The distal part of this coronary artery was transformed to a large coronary aneurysm of such extent that the left atrium was compressed …

Solitary Myofibroma of the Bladder Trigone in a 3-Month-Old Patient: First Case Report

2016

Visceral solitary myofibromas are uncommon in childhood. We report a case of a solitary asymptomatic visceral myofibroma of the bladder trigone occurring in a 3-month-old boy. Once malignancies were ruled out by cystoscopy, radical excision was performed in order to avoid any potential impairment of bladder dynamic. Postoperative course was uneventful and patient was discharged on day 3 after surgery. After 36 months of follow-up, the patient is toilet-trained and remains well; bladder function is normal.