868 research outputs found

    Bidirectional ventricular tachycardia in cardiac sarcoidosis.

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    A 73-year-old man with history of pulmonary sarcoidosis was found to have runs of non-sustained bidirectional ventricular tachycardia (BVT) with two different QRS morphologies on a Holter monitor. Cardiac magnetic resonance delayed gadolinium imaging revealed a region of patchy mid-myocardial enhancement within the left ventricular basal inferolateral myocardium. An 18-fluorodeoxyglucose positron emission tomography (FDG-PET) showed increased uptake in the same area, consistent with active sarcoid, with no septal involvement. Follow-up FDG-PET one year later showed disease progression with new septal involvement. Cardiac sarcoidosis, characterized by myocardial inflammation and interstitial fibrosis that can lead to conduction system disturbance and macro re-entrant arrhythmias, should be considered in differential diagnosis of BVT. BVT may indicate septal involvement with sarcoidosis before the lesions are large enough to be detected radiologically

    Electrocardiographic Patterns of Ventricular Arrhythmias in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

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    Ventricular arrhythmias in patients with ARVD/C are common. Differentiation between idiopathic ventricular tachycardia and arrhythmogenic right ventricular dysplasia is of utmost importance. Baseline sinus rhythm electrocardiography as well as electrocardiographic differences during ventricular arrhythmias (VT or PVCs) can be helpful in differentiating the two disease states. The pathological fibrofatty myocyte replacement in ARVD/C as well as ventricular arrhythmia origin are likely responsible for these differences

    Results of Catheter Ablation of Ventricular Tachycardia Using Direct Current Shocks

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74779/1/j.1540-8159.1989.tb02654.x.pd

    Clinical and electrophysiologic characteristics of left septal atrial tachycardia

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    AbstractObjectivesIt was the purpose of this study to define the electrophysiologic (EP) identity of left septal atrial tachycardia (AT).BackgroundThe clinical and EP characteristics of this particular type of arrhythmia have not been fully described.MethodsA total of 120 patients with AT underwent invasive EP evaluation. Five patients (two men and three women; mean age 49 ± 15 years) with left septal AT were identified. Mapping of the right and left atrium was performed using conventional electrode catheters (five patients) and a three-dimensional electroanatomic mapping system (three patients) followed by radiofrequency (RF) ablation at the earliest site of local endocardial activation.ResultsFive tachycardias with a mean cycle length of 320 ± 94 ms were mapped, and the earliest endocardial electrogram occurred 22 ± 10 ms before the onset of the surface P-wave. Three left septal ATs were found to be originating from the left inferoposterior atrial septum and two from the left midseptum. During tachycardia, positive (three patients), biphasic negative-positive deflection (one patient), or isoelectric (one patient) P waves were recorded in lead V1. The inferior leads demonstrated a positive or biphasic P-wave morphology in four of five patients (80%). Four patients were given both adenosine and verapamil during AT. In three of four patients, verapamil successfully terminated AT after adenosine had failed. Adenosine successfully terminated AT in one of four patients. Successful RF ablation was performed in all patients (mean 2.2 ± 1.7 RF applications) without affecting atrioventricular conduction properties. No recurrence of AT was observed after a mean follow-up of 14 ± 8 months.ConclusionsLeft septal AT ablation is safe and effective. There was no consistent P-wave morphology associated with this particular type of AT. This arrhythmia appears to be resistant to adenosine and moderately responsive to calcium antagonists

    Randomized trial of conventional transseptal needle versus radiofrequency energy needle puncture for left atrial access (the TRAVERSE-LA study).

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    BackgroundTransseptal puncture is a critical step in achieving left atrial (LA) access for a variety of cardiac procedures. Although the mechanical Brockenbrough needle has historically been used for this procedure, a needle employing radiofrequency (RF) energy has more recently been approved for clinical use. We sought to investigate the comparative effectiveness of an RF versus conventional needle for transseptal LA access.Methods and resultsIn this prospective, single-blinded, controlled trial, 72 patients were randomized in a 1:1 fashion to an RF versus conventional (BRK-1) transseptal needle. In an intention-to-treat analysis, the primary outcome was time required for transseptal LA access. Secondary outcomes included failure of the assigned needle, visible plastic dilator shavings from needle introduction, and any procedural complication. The median transseptal puncture time was 68% shorter using the RF needle compared with the conventional needle (2.3 minutes [interquartile range {IQR}, 1.7 to 3.8 minutes] versus 7.3 minutes [IQR, 2.7 to 14.1 minutes], P = 0.005). Failure to achieve transseptal LA access with the assigned needle was less common using the RF versus conventional needle (0/36 [0%] versus 10/36 [27.8%], P < 0.001). Plastic shavings were grossly visible after needle advancement through the dilator and sheath in 0 (0%) RF needle cases and 12 (33.3%) conventional needle cases (P < 0.001). There were no differences in procedural complications (1/36 [2.8%] versus 1/36 [2.8%]).ConclusionsUse of an RF needle resulted in shorter time to transseptal LA access, less failure in achieving transseptal LA access, and fewer visible plastic shavings

    Pyridoxamine lowers kidney crystals in experimental hyperoxaluria: A potential therapy for primary hyperoxaluria

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    Pyridoxamine lowers kidney crystals in experimental hyperoxaluria: A potential therapy for primary hyperoxaluria.BackgroundPrimary hyperoxaluria is a rare genetic disorder of glyoxylate metabolism that results in overproduction of oxalate. The disease is characterized by severe calcium oxalate nephrolithiasis and nephrocalcinosis, resulting in end-stage renal disease (ESRD) early in life. Most patients eventually require dialysis and kidney transplantation, usually in combination with the replacement of the liver. Reduction of urinary oxalate levels can efficiently decrease calcium oxalate depositions; yet, no treatment is available that targets oxalate biosynthesis. In previous in vitro studies, we demonstrated that pyridoxamine can trap reactive carbonyl compounds, including intermediates of oxalate biosynthesis.MethodsThe effect of PM on urinary oxalate excretion and kidney crystal formation was determined using the ethylene glycol rat model of hyperoxaluria. Animals were given 0.75% to 0.8% ethylene glycol in drinking water to establish and maintain hyperoxaluria. After 2 weeks, pyridoxamine treatment (180mg/day/kg body weight) started and continued for an additional 2 weeks. Urinary creatinine, glycolate, oxalate, and calcium were measured along with the microscopic analysis of kidney tissues for the presence of calcium oxalate crystals.ResultsPyridoxamine treatment resulted in significantly lower (by ∼50%) levels of urinary glycolate and oxalate excretion compared to untreated hyperoxaluric animals. This was accompanied by a significant reduction in calcium oxalate crystal formation in papillary and medullary areas of the kidney.ConclusionThese results, coupled with favorable toxicity profiles of pyridoxamine in humans, show promise for therapeutic use of pyridoxamine in primary hyperoxaluria and other kidney stone diseases

    Use of P wave configuration during atrial tachycardia to predict site of origin

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    Objectives.This study sought to construct an algorithm to differentiate left atrial from right atrial tachycardia foci on the basis of surface electrocardiograms (ECGs).Background.Atrial tachycardia is an uncommon form of supraventricular tachycardia, often resistant to drug therapy.Methods.A total of 31 consecutive patients with atrial tachycardia due to either abnormal automaticity or triggered rhythm underwent detailed atrial endocardial mapping and successful radiofrequency catheter ablation of a single atrial focus. P wave configuration was analyzed from 12-lead ECGs during tachycardia during either spontaneous or pharmacologically induced atrioventricular block. P waves inscribed above the isoelectric line (TP interval) were classified as positive, below as negative, above and below (or conversely, below and above) as biphasic and flat P waves as isoelectric (0). In 17 patients the tachycardia was located in the right atrium: crista terminalis (n = 4); right atrial appendage (n = 4); lateral wall (n = 4); posteroinferior right atrium (n = 3); tricuspid annulus (n = 1); and near the coronary sinus (n = 1). In 14 patients, atrial tachycardia was located in the left atrium: at the entrance of the right (n = 6) or left (n = 4) superior pulmonary veins; left inferior pulmonary vein (n = 1); inferior left atrium (n = 1); base of left atrial appendage (n = 1); and high lateral left atrium (n = 1).Results.There were no differences in P wave vectors between sites at the right atrial lateral wall versus the right atrial appendage or between sites at the entrance of right versus left superior pulmonary veins. However, analysis of P wave configuration showed that leads aVL and V1were most helpful in distinguishing right atrial from left atrial foci. The sensitivity and specificity of using a positive or biphasic P wave in lead aVL to predict a right atrial focus was 88% and 79%, respectively. The sensitivity and specificity of a positive P wave in lead V1in predicting a left atrial focus was 93% and 88%, respectively.Conclusions.1) Analyses of surface P wave configuration proved to be reasonably good in differentiating right atrial from left atrial tachycardia foci. 2) Leads II, III and aVF were helpful in providing clues for differentiating superior from inferior foci
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