Extraction of Chronic Pacing Lead and Angioplasty for Complete Superior Baffle Obstruction in Complex Congenital Heart Disease

Laser lead extraction in adult patients with congenital heart disease is safe and effective. Baffle angioplasty for obstruction in patients with a Mustard procedure is well established. We describe a unique combined interventional and electrophysiological approach on a patient with superior baffle obstruction. This technique utilized the channel created after extracting the chronic pacing lead to cross the obstruction and stent angioplasty of the superior baffle.     

Disposition and Metabolism of [14C]Dibenzo[c,g]carbazole Aerosols in Rats after Inhalation

Disposition and Metabolism of [^l4C]Dibenzo[c,g]carbazole Aerosolsin Rats after Inhalation. Bond, J. A. Ayres, P. H., Medinsky,M. A., Cheng, Y. S., Hirshfield, D., and McClellan, R. O. (1986).Fundam Appl Toxicol. 7, 76-85. Dibenzo[c.£]carbazole (DBC)is a nitrogen-containing polycyclic aromatic hydrocarbon thathas been detected in tobacco tars, industrial oils, and dieselengine exhaust fumes. DBC is carcinogenic in respiratory tracttissue of hamsters and in lungs, kidneys, and livers of mice.The purpose of this research was to determine the respiratorytract deposition, distribution in tissues, metabolism, and excretionof DBC in rats after inhalation. Rats were exposed nose-onlyto 1.1 or 13 Mg [¹⁴C]DBC/liter air for 60 min. Activity medianaerodynamic diameters for the two concentrations of DBC rangedfrom 0.7 to 0.8 pm. Unne. feces, and selected tissues were collectedfor various times after exposure. The fractional depositionfor the 1.1 and 13 ug/liter exposure concentrations was similar,13 and 16%, respectively. The dominant route of excretion of¹⁴C following exposure to either concentration of DBC was thefeces, accounting for approximately 95% of the total 14C eliminated.Half-time for fecal excretion was 20 ± 6 hr (x ±SE). Gastrointestinal absorption of [I4C]DBC was 43%. Radioactivitywas widely distributed to all tissues examined, with the respiratorytract (lung, trachea, larynx, and nasal turbinates), upper gastrointestinaltract (stomach and small intestine), the liver, and the adrenalscontaining the highest concentrations of [I4C]DBC equivalentswithin 1 hr after exposure. At both concentrations of DBC tested,clearance of I4C from tissues was rapid, with approximately60 to 98% of the initial tissue burden being cleared with half-timesranging from 1 to 16 hr. The remaining 2 to 40% in the tissueswas cleared with half-times that ranged from 1.5 to 14 days.Several metabolites were detected in the urine and feces, noneof which appeared to be either glucuronide or sulfate conjugates.Small quantities of [I4C]DBC were detected in the urine, althoughquantities were less than 1% of the initial respiratory tractburden of [I4C]DBC. The results from this research indicatethat DBC was rapidly absorbed from the lungs and translocatedto many tissues. Prior to elimination, primarily in the feces,DBC was extensively metabolized There appeared to be no effectof exposure concentration on the toxicokinetics of inhaled DBC.     

Influence of Propranolol on the Ventricular Depolarization Gradient

Sensing of the ventricular depolarization gradient (VDG) has recently been used as The basis of a closed-loop rate responsive pacemaker. Factors influencing this aspect of the evoked response have not been fully evaluated although previous reports have suggested that sympathetic stimulation and circulating catecholamines are primarily responsible for the observed changes during stress and exercise. In five patients (Table I), four males and one female (mean age 60.4 ± 20.1 years) implanted with the Prism pacemaker, the pacing response to exercise and tilting was assessed before and after the infusion of propranolol. There was an increase in the pacing rate in all patients during the infusion of the drug (mean 27 ± 12.9 beats/min) suggestive of a direct drug effect on the VDG. The rate control parameter (RCP) of the pacemaker, the numerical equivalent of the VDG, was significantly different after the administration of propranolol (P < 0.01). However, exercise performance and pacing rate behavior were not different after beta blockade. The pacing rate increase observed when tilting patients to the supine position was not altered by propranolol. Out date suggest that factors other than adrenergic stimulation may be of importance in affecting the ventricular evoked response and accordingly the rate adaptation of the Prism pacemaker.     

Computer-Enhanced Mapping of Activation Sequences in the Surgical Treatment of Supraventricular Arrhythmias

Surgical treatment of accessory pathways and ectopic foci requires accurate information on the physical locations of the arrhythmogenic substrates. AJthough electrophysiology studies during cardiac catheterization frequently provide accurate and reliable data, the physical locations of the sites to be ablated must be verified in situ by electrical activity mapping. We have developed a microcomputer-based system that facilitates creation of electrical activity maps, supplanting the manual method formerly used. Signals produced by mapping and reference electrodes, as well as cardiac diagrams with grid coordinates and times, are presented on a monitor in formats that are easily interpreted by the surgeon and cardiologist. The system is rapid, accurate, and reliable, and has reduced the time required to localize conduction abnormalities from 30 to 45 minutes for the manual method, down to an average of 12 minutes per case. The system is simple to operate, requiring only minimal training. All of the components of the system are commercially available; no specialized hardware is required.     

Endothelial dysfunction:EDCF revisited

Endothelial cells can initiate contraction(constriction)of the vascular smooth muscle cells that surround them.Such endothelium-dependent,acute increases in contractile tone can be due to the withdrawal of the production of nitric oxide,to the production of vasoconstrictor peptides(angiotensin II,endothelin-1),to the formation of oxygen-derived free radicals(superoxide anions)and/or the release of vasoconstrictor metabolites of arachidonic acid.The latter have been termed endothelium-derived contracting factor(EDCF)as they can contribute to moment-to-moment changes in contractile activity of the underlying vascular smooth muscle cells.To judge from animal experiments,EDCF-mediated responses are exacerbated when the production of nitric oxide is impaired as well as by aging,spontaneous hypertension and diabetes.To judge from human studies,they contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive patients.Since EDCF causes vasoconstriction by activation of the TP-receptors on the vascular smooth muscle cells,selective antagonists at these receptors prevent endothelium-dependent contractions,and curtail the endothelial dysfunction in hypertension and diabetes.     

Patterns of benzylpiperazine/trifluoromethylphenylpiperazine party pill use and adverse effects in a population sample in New Zealand

Introduction and Aims . A large legal market for party pills containing benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP) developed in New Zealand after 2004. The use of these party pills has been associated with adverse health effects. The purpose of this paper was to assess a general population sample of party pill users to investigate the relationship between (1) patterns of use of BZP/TFMPP party pills and concurrent use of other drug types, and (2) adverse side effects from BZP/TFMPP party pill use. Design . A national household survey of the use of BZP/TFMPP party pills was conducted using a computer‐assisted telephone interviewing (CATI) facility. The quantity of BZP and TFMPP in each brand of party pill was obtained from the National Poisons Centre. Multiple logistic regression analysis was used to identify independent predictors of having experienced adverse side effects from party pills. Results . The mean quantity of BZP/TFMPP taken on an occasion of greatest use was 533 mg (median 400 mg, range 43 – 2500 mg). Being female, using cannabis and other drugs concurrently with BZP/TFMPP party pills, taking large quantities of party pills in a single session and taking 5‐hydroxytryptophan (5‐HTP) recovery pills at the same time as party pills were independent predictors of having experienced an adverse problem from party pills. Conclusions . Females may be at greater risk of experiencing problems from BZP/TFMPP party pills due to their smaller physical size. Taking 5‐HTP ‘recovery’ pills with party pills may increase the risk of adverse effects as both substances increase users' levels of serotonin.