Apparent Acute Reversible Right Ventricular Pacing‐Induced Left Ventricular Dysfunction

Apparent Acute Reversible Right Ventricular Pacing‐Induced Left Ventricular Dysfunction . We report the case of a 70‐year‐old Caucasian male with a dual chamber (right atrium/right ventricle) pacemaker implanted for sinus node dysfunction and not pacemaker (PM) dependent who was found to have an apparent acute worsening of left ventricular (LV) function with right ventricular (RV) apical pacing caused by the mode switch to VVI pacing as battery depletion occurred. LV dysfunction resolved immediately with RV pacing turned off. To our knowledge, this is the first report of this phenomenon. (J Cardiovasc Electrophysiol, Vol. 24, pp. 224‐226, February 2013)     

Inhaled corticosteroids increase the risk of oropharyngeal colonization by Streptococcus pneumoniae in children with asthma

Background and objective: Recent studies have raised concerns about the link between use of inhaled corticosteroids (ICS) and risk of pneumonia in patients with chronic obstructive pulmonary disease. This cross‐sectional study aimed to investigate the association between ICS and oropharyngeal colonization by Streptococcus pneumoniae (S. pneumoniae) among children (up to 18 years old) with asthma. Methods: Two age‐matched groups of patients were consecutively recruited: (i) exposed group: children who had persistent asthma and were being treated with daily ICS for at least 30 days and (ii) non‐exposed group: children who had asthma and were not being treated with ICS at study entry. Oropharyngeal specimens from the tonsillar area and posterior pharyngeal wall were collected. S. pneumoniae was identified according to National Committee for Clinical Laboratory Standards recommendations. Results: A total of 200 consecutive patients were recruited and 192 (96 in each group) were included in the analysis. In the exposed group, the mean daily dose of ICS was 400 µg of beclomethasone or equivalent and the mean duration of treatment was 8.6 months. The prevalence of oropharyngeal colonization by S. pneumoniae was higher in the exposed group compared with the non‐exposed group (27.1% vs 8.3%, P = 0.001). After adjusting for potential confounders, use of ICS was an independent risk factor for oropharyngeal carriage of S. pneumoniae, with an adjusted prevalence ratio of 3.75 (95% confidence interval: 1.72–8.18, P = 0.001). Conclusions: Regular use of ICS is associated with an increased risk of having oropharyngeal colonization by S. pneumoniae in children with asthma.     

Toward an Implantable Wireless Cardiac Monitoring Platform Integrated with an FDA-Approved Cardiovascular Stent

Continuous monitoring of blood pressure from a minimally invasive device in the pulmonary artery can serve as a diagnostic and early warning system for cardiac health. The foremost challenge in such a device is the wireless transfer of data and power from within the blood vessel to an external device while maintaining unrestricted flow through the artery. We present a miniaturized system, which is attached to the outer surface of a regular or drug-eluting FDA-approved stent. When expanded, the stent maintains a patent vessel lumen while allowing contact between the electronic sensors and the blood supply. The stent-based antenna can be used for both wireless telemetry and power transfer for the implanted electronics. Using the stent platform as both a radiating antenna and a structural support allows us to take advantage of an FDA-approved device whose safety and surgical procedure are well established. The electronics package has been reduced to an area of less than 1 mm², with a thickness under 300 μm. A minimally invasive implantation procedure allows the delivery of the stent-based implant in nearly any major vessel of the body. This article describes an initial prototype with two stents configured as a single dipole, a 2.4-GHz transmitter microchip, and a battery, and validates transcutaneous transmission through ex vivo and in vivo porcine studies. The results demonstrate the feasibility of a stent-based wireless platform for continuous monitoring of blood pressure.     

INFLUENCE OF REGULAR ALCOHOL CONSUMPTION ON URICAEMIA IN UNSELECTED HEALTHY INDIVIDUALS

We analysed serum uric acid concentrations in a group of healthymale and female volunteers in Córdoba (Spain) possessingvarying nutritional habits, in order to correlate them withtheir usual alcohol intake as measured according to a protocolized,blind dietary questionnaire. There was no significant correlationbetween the serum uric acid and the amount of alcohol regularlydrunk by either male or female individuals. These results suggestthat a moderate alcohol intake has no effect on uricaemia inhealthy individuals.     

Rate Adaptive Dual Chamber Pacing: Inappropriate Rate Response due to Pseudomalfunction of the QT Biosensor

Inappropriate tachycardias may be observed in patients with DDDR pacemakers equipped with an activity sensor and a QT sensor due erroneous T wave sensing, provoked by drug treatment that prolongs cardiac repolarization.     

Observations on Mechanisms of Circus Movement Tachycardia in the Wolff-Parkinson-White Syndrome. Role of Different Tachycardia Circuits and Sites of Block in Maintenance of Tachycardia

Different mechanisms of block of impulse propagation in several re-entrant circuits resulted in a major discordance between the "echo-zone" and the "tachycardia-zone" in a patient with intermittent Wolff-Parkinson-White syndrome, dual atrioventricular nodal pathways, and bundle branch re-entry. This case illustrates the delicate balance in electrophysiological properties required between the tissues incorporated in a re-entrant circuit to initiate and sustain the arrhythmia. It also shows how the presence of several reentrant pathways can lead to refractoriness in the circuit responsible for the circus movement tachycardia.