Quantitative divergence of the bacterial root microbiota in Arabidopsis thaliana relatives.

Plants host at the contact zone with soil a distinctive root-associated bacterial microbiota believed to function in plant nutrition and health. We investigated the diversity of the root microbiota within a phylogenetic framework of hosts: three Arabidopsis thaliana ecotypes along with its sister species Arabidopsis halleri and Arabidopsis lyrata, as well as Cardamine hirsuta, which diverged from the former ∼ 35 Mya. We surveyed their microbiota under controlled environmental conditions and of A.

[Intermittent pre-excitation after adenosine administration].

We describe a case of 2:1 intermittent preexcitation after adenosine administration in a patient with an accessory pathway that did not show preexcitation on the basal ECG. We review the mechanisms involved that explain this event and the possible utility of adenosine to show accessory pathways that do not show preexcitation on the ECG.

[Image of pseudocapture caused by micro-dislodgment of the electrode in a VDD pacemaker].

The new AV sequential pacemakers have improved the suitability for the election of the best pacing mode for each patient. The complexity of the systems may mask some dysfunctions. In the presented case, a failure to capture due to micro-dislodgment, may have been missed in a simple pacemaker control, because of the combination of several factors: the presence of normal AV conduction at that moment, the concordance between the pacemaker stimulus and the conducted QRS complex and the similar morphology of the conducted and paced QRS complex.

[Peritoneal migration of defibrillator implanted behind the rectus abdominis].

Automatic Implantable Cardioverter Defibrillator (AICD) has become a therapeutic option to malignant ventricular tachyarrhythmias. Its bulky device responds for discomfort and the likelihood of generator extrusion or migration, when implanted under the subcutaneous tissue. Among alternative sites, pre-peritoneal location has several advantages but hides its own risks.

[Complications associated with nonfunctioning pacemaker electrodes retained within the cardiovascular system].

Introduction And Objective: The aim of the present study was to evaluate the complications in patients with functionless pacing leads retained in the cardiovascular system.

Patients And Methods: We retrospectively studied 39 patients: 31 underwent surgery for electrical or mechanical failure (group I) and eight for cutaneous pocket infection (group II). The follow-up was 45 +/- 34 months.

[Mechanisms favoring and triggering atrial fibrillation].

Many experimental and clinical studies have demonstrated that it is possible to trigger atrial fibrillation (AF) by vagal stimulation which reduces and disperses the atrial refractory periods and decreases the threshold of fibrillation. In order to induce fibrillation, it is necessary to deliver a stimulation near to the refractory period. It has also been shown that, in these conditions, there is a delay in atrial conduction.

Recovery of sinus node function after pacemaker implant for sinus node disease following cardiac transplantation.

In a 4-year interval, 3/55 (7.8%) heart transplant recipients developed (greater than 4 weeks) severe sinus node dysfunction. An epicardial ventricular pacemaker was implanted at 90, 40, and 38 days after operation.

Ventricular fibrillation in the Wolff-Parkinson-White syndrome.

Ventricular fibrillation (VF) is a well-known but rare complication of the Wolff-Parkinson-White syndrome (WPW). Clinical and electrophysiological data of 23 patients with spontaneous VF were compared with data from 100 consecutive patients with WPW without VF but with symptomatic supraventricular tachycardia. The 23 patients were collected in a multicentre retrospective study in seven European centres.

Study of the evolution of masked bifascicular block.

Masked bifascicular block (MBB) (absent or minimal S in I and VL, high R in Vi and AQRS approximately -60 degrees) is a rare condition. We have found 16 such cases in the last 12 years, thirteen male and three female, mean age 70 +/- 9 years. The conventional electrocardiogram was tabulated and the clinical features and evolution of the patients were followed over 39.

Interatrial conduction block and retrograde activation of the left atrium and paroxysmal supraventricular tachyarrhythmia.

We studied 16 patients with electrocardiographic evidence of advanced interatrial block and retrograde activation of the left atrium (P greater than or equal to 0.12 s, and diphasic (+/-) P waves in leads II, III, and VF). Eight patients had valvular heart disease, four had dilated cardiomyopathy and four had other forms of heart disease.

[Electrophysiologic characteristics of the transplanted heart].

The electrophysiologic characteristics of the denervated human heart were assessed in 20 cardiac transplants recipient from the Cardiology Department, at the Hospital of San Pablo, Barcelona, Spain. We studied the donor and the recipient sinus node function at rest and exercise test. Holter recording of 24 hours was performed in a few cases.

[Use of temporary pacemaker programming in VVT mode for the treatment of recurrent ventricular tachycardia].

This is a report of a 59-year-old man with a Björk aortic prosthetic valve and mitral commissurotomy with left ventricular dysfunction and recurrent ventricular tachycardia (VT) in spite of antiarrhythmic therapy with amiodarone. Serial electrophysiologic studies were performed using standard ventricular extrastimulation technique. During these studies, sustained VT was induced and terminated by programmable extrastimulus pacing.

Concealed atrial electrical activity.

In the following paragraphs we describe a case diagnosed clinically and haemodynamically as a cardiomyopathy. Atrial flutter which was not in evidence in the standard ECG was diagnosed by the use of a new technique of amplification and filtering of special surface leads (T.A.

True aneurysm of the main pulmonary artery: surgical correction.

A 23-year-old man who underwent surgical correction of a true pulmonary artery aneurysm is presented. Pathological features and the different surgical alternatives for treatment of this lesion are discussed.