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Lateral Sites (lateral + site)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

Is the Left Ventricular Lateral Wall the Best Lead Implantation Site for Cardiac Resynchronization Therapy?

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1p2 2003
MAURIZIO GASPARINI
GASPARINI, M., et al.: Is the Left Ventricular Lateral Wall the Best Lead Implantation Site for Cardiac Resynchronization Therapy?Short-term hemodynamic studies consistently report greater effects of cardiac resynchronization therapy (CRT) in patients stimulated from a LV lateral coronary sinus tributary (CST) compared to a septal site. The aim of the study was to compare the long-term efficacy of CRT when performed from different LV stimulation sites. From October 1999 to April 2002, 158 patients (mean age 65 years, mean LVEF 0.29, mean QRS width 174 ms) underwent successful CRT, from the anterior (A) CST in 21 patients, the anterolateral (AL) CST in 37 patients, the lateral (L) CST in 57 patients, the posterolateral (PL) CST in 40 patients, and the middle cardiac vein (MCV) CST in 3 patients. NYHA functional class, 6-minute walk test, and echocardiographic measurements were examined at baseline, and at 3, 6, and 12 months. Comparisons were made among all pacing sites or between lateral and septal sites by grouping AL + L + PL CST as lateral site (134 patients, 85%) and A + MC CST as septal site (24 patients, 15%). In patients stimulated from lateral sites, LVEF increased from 0.30 to 0.39(P < 0.0001), 6-minute walk test from 323 to 458 m(P < 0.0001), and the proportion of NYHA Class III,IV patients decreased from 82% to 10%(P < 0.0001). In patients stimulated from septal sites, LVEF increased from 0.28 to 0.41(P < 0.0001), 6-minute walk test from 314 to 494 m(P < 0.0001), and the proportion of NYHA Class III,IV patients decreased from 75% to 23%(P < 0.0001). A significant improvement in cardiac function and increase in exercise capacity were observed over time regardless of the LV stimulation sites, either considered singly or grouped as lateral versus septal sites. (PACE 2003; 26[Pt. II]:162,168) [source]

Comparison between aortic annulus motion and mitral annulus motion obtained using echocardiography

CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 5 2006
K. Emilsson
Summary Earlier studies have shown that the aortic root, in analogy with the mitral annulus, moves towards the left ventricular apex during systole. However, there are no earlier studies comparing the amplitude of the aortic annulus motion (AAM) with that of the mitral annulus (MAM), which was the main aim of the study. Another aim was to study the intra- and interobserver reproducibility (IIOR) of measuring AAM with M-mode and 2-D echocardiography as it is not obvious which of the methods that should be used. Twenty-one healthy subjects were examined by echocardiography. AAM and MAM were measured at different sites. IIOR was measured in 10 of the subjects. There was no significant difference between average AAM (15·3 ± 1·5 mm) and average MAM (15·6 ± 1·5 mm) and there was a rather good agreement between the variables. There was also no significant difference between AAM at the septal site (16·3 ± 2 mm) and average MAM, but a significant difference between AAM at the lateral site (14·2 ± 1·6 mm) and average MAM (P<0·001) and between the both sites of measuring AAM (P<0·001). The significant difference between the two sites of measuring AAM may have anatomical reasons but may also depend on difficulties in measuring AAM at the septal site where it has lower reproducibility than at the lateral site. IIOR of measuring AAM was good when using M-mode but poor when using 2-D echocardiography and AAM should preferably be measured using M-mode and not using 2-D echocardiography. [source]

Idiopathic Left Ventricular Tachycardia Originating from the Mitral Annulus

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2005
KOJI KUMAGAI M.D.
Background: Radiofrequency catheter ablation (RFCA) can eliminate most idiopathic repetitive monomorphic ventricular tachycardias (RMVTs) originating from the right and left ventricular outflow tracts (RVOT, LVOT). Here, we describe the electrophysiological (EP) findings of a new variant of RMVT originating from the mitral annulus (MAVT). Methods and Results: MAVT was identified in 35 patients out of 72 consecutive left ventricular RMVTs from May 2000 to June 2004. All patients underwent an EP study and RFCA. The sites of origin of the MAVT were grouped into four groups according to the successful ablation sites around the mitral annulus. Group I included the anterior sites (n = 11), group II the anterolateral sites (n = 9), group III the lateral sites (n = 6), and group IV the posterior sites (n = 9). The MAVTs were a wide QRS tachycardia with a delta wave-like beginning of the QRS complex. The transitional zone of the R wave occurred between V1-V2 in all cases. The 12-lead electrocardiogram (ECG) pattern might reflect the site of the origin of MAVTs around the mitral annulus. We proposed an algorithm for predicting the site of the focus and the tactics needed for successful RFCA of the MAVT. Conclusions: We described the EP findings of the new variant of RMVT, MAVT. Most MAVTs could be eliminated by RF applications to the endocardial mitral annulus using our proposed tactics. [source]

Is the Left Ventricular Lateral Wall the Best Lead Implantation Site for Cardiac Resynchronization Therapy?

Organization of tectopontine terminals within the pontine nuclei of the rat and their spatial relationship to terminals from the visual and somatosensory cortex

THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 3 2005
Cornelius Schwarz
Abstract We investigated the spatial relationship of axonal and dendritic structures in the rat pontine nuclei (PN), which transfer visual signals from the superior colliculus (SC) and visual cortex (A17) to the cerebellum. Double anterograde tracing (DiI and DiAsp) from different sites in the SC showed that the tectal retinotopy of visual signals is largely lost in the PN. Whereas axon terminals from lateral sites in the SC were confined to a single terminal field close to the cerebral peduncle, medial sites in the SC projected to an additional dorsolateral one. On the other hand, axon terminals originating from the two structures occupy close but, nevertheless, totally nonoverlapping terminal fields within the PN. Furthermore, a quantitative analysis of the dendritic trees of intracellularly filled identified pontine projection neurons showed that the dendritic fields were confined to either the SC or the A17 terminal fields and never extended into both. We also investigated the projections carrying cortical somatosensory inputs to the PN as these signals are known to converge with tectal ones in the cerebellum. However, terminals originating in the whisker representation of the primary somatosensory cortex and in the SC were located in segregated pontine compartments as well. Our results, therefore, point to a possible pontocerebellar mapping rule: Functionally related signals, commonly destined for common cerebellar target zones but residing in different afferent locations, may be kept segregated on the level of the PN and converge only later at specific sites in the granular layer of cerebellar cortex. J. Comp. Neurol. 484:283,298, 2005. © 2005 Wiley-Liss, Inc. [source]