Consensus and development of document for management of stabilized acute decompensated heart failure with reduced ejection fraction in India

Aim

Ensuring adherence to guideline-directed medical therapy (GDMT) is an effective strategy to reduce mortality and readmission rates for heart failure (HF). Use of a checklist is one of the best tools to ensure GDMT. The aim was to develop a consensus document with a robust checklist for stabilized acute decompensated HF patients with reduced ejection fraction. While there are multiple checklists available, an India-specific checklist that is easy to fill and validated by regional and national subject matter experts (SMEs) is required.

Methodology

A total of 25 Cardiology SMEs who consented to participate from India discussed data from literature, current evidence, international guidelines and practical experiences in two national and four regional meetings.

Results

Recommendations included HF management, treatment optimization, and patient education. The checklist should be filled at four time points- (a) transition from intensive care unit to ward, (b) at discharge, (c) 1st follow-up and (d) subsequent follow-up. The checklist is the responsibility of the consultant or the treating physician which can be delegated to a junior resident or a trained HF nurse.

Conclusion

This checklist will ensure GDMT, simplify transition of care and can be used by all doctors across India. Institutions, associations, and societies should recommend this checklist for adaptability in public and private hospital. Hospital administrations should roll out policy for adoption of checklist by ensuring patient files have the checklist at the time of discharge and encourage practice of filling it diligently during follow-up visits.

Interspecies and intraspecies interactions in social amoebae

The stable co-existence of individuals of different genotypes and reproductive division of labour within heterogeneous groups are issues of fundamental interest from the viewpoint of evolution. Cellular slime moulds are convenient organisms in which to address both issues. Strains of a species co-occur, as do different species; social groups are often genetically heterogeneous. Intra- and interspecies 1 : 1 mixes of wild isolates of Dictyostelium giganteum and D. purpureum form chimaeric aggregates, following which they segregate to varying extents. Intraspecies aggregates develop in concert and give rise to chimaeric fruiting bodies that usually contain more spores (reproductives) of one component than the other. Reproductive skew and variance in the proportion of reproductives are positively correlated. Interspecies aggregates exhibit almost complete sorting; most spores in a fruiting body come from a single species. Between strains, somatic compatibility correlates weakly with sexual compatibility. It is highest within clones, lower between strains of a species and lowest between strains of different species. Trade-offs among fitness-related traits (between compatible strains), sorting out (between incompatible strains) and avoidance (between species) appear to lie behind coexistence.

Vitamin B12-responsive severe leukoencephalopathy and autonomic dysfunction in a patient with "normal" serum B12 levels

Leukoencephalopathy and autonomic dysfunction have been described in individuals with very low serum B(12) levels (<200 pg/ml), in addition to psychiatric changes, neuropathy, dementia and subacute combined degeneration. Elevated homocysteine and methylmalonic acid levels are considered more sensitive and specific for evaluating truly functional B(12) deficiency. A previously healthy 62-year-old woman developed depression and cognitive deficits with autonomic dysfunction that progressed over the course of 5 years. The patient had progressive, severe leukoencephalopathy on multiple MRI scans over 5 years. Serum B(12) levels ranged from 267 to 447 pg/ml. Homocysteine and methylmalonic acid levels were normal. Testing for antibody to intrinsic factor was positive, consistent with pernicious anaemia. After treatment with intramuscular B(12) injections (1000 μg daily for 1 week, weekly for 6 weeks, then monthly), she made a remarkable clinical recovery but remained amnesic for major events of the last 5 years. Repeat MRI showed partial resolution of white matter changes. Serum B(12), homocysteine and methylmalonic acid levels are unreliable predictors of B(12)-responsive neurologic disorders, and should be thoroughly investigated and presumptively treated in patients with unexplained leukoencephalopathy because even long-standing deficits may be reversible.

Cytokines, matrix metalloproteases, angiogenic and growth factors in tears of normal subjects and vernal keratoconjunctivitis patients

BACKGROUND

To detect the presence of multiple mediators and growth factors in tears of vernal keratoconjunctivitis (VKC) patients with active disease using stationary phase antibody arrays.

METHODS

Tears were collected from 12 normal subjects (CT) and 24 active VKC patients. Tears were centrifuged and successively probed using three microwell plate arrays specific for: (i) cytokines: interleukin (IL)-2, IL-4, IL-5, IL-8, IL-10, IL-12, IL-13, interferon-gamma and tumour necrosis factor-alpha; (ii) growth factors: basic fibroblast growth factor (bFGF), platelet-derived growth factor, thrombopoietin, angiopoietin-2, vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), keratocyte growth factor, tissue inhibitor of metalloprotease (TIMP)-1 and heparin-binding epithelial growth factor (HB-EGF) and (iii) matrix metalloprotease (MMP)-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, MMP-13, TIMP-1 and TIMP-2.

RESULTS

Interleukin-8 signals were detected in all CT and highly detected in all VKC samples. The Th2-type cytokines, IL-4, IL-5 and IL-10 were detected only in tears of VKC patients. Signals for bFGF, HB-EGF, VEGF and HGF were detected in 41-87% of VKC samples and in few CT samples. Only TIMP-1 and TIMP-2 were found in all normal and patient tear samples, whereas MMP-1, MMP-2, MMP-3, MMP-9 and MMP-10 were highly present in all VKC samples.

CONCLUSIONS

Stationary phase antibody array methodology was useful for the screening of various cytokines, growth factors and MMPs in tears. These analyses identified in tears of VKC patients previously unreported factors including MMP-3 and MMP-10 and multiple proteases, growth factors and cytokines, which may all play an important role in the pathogenesis of conjunctival inflammation.

Calcium channel and NMDA receptor activities differentially regulate nuclear C/EBPbeta levels to control neuronal survival

Insulin-like growth factor-1 (IGF-1) promotes the survival of cerebellar granule neurons by enhancing calcium influx through L-type calcium channels, whereas NMDA receptor-mediated calcium influx can lead to excitotoxic death. Here we demonstrate that L and NMDA receptor channel activities differentially regulate the transcription factor C/EBPbeta to control neuronal survival. Specifically, we show that L channel-dependent calcium influx results in increased CaMKIV activity, which acts to decrease nuclear C/EBPbeta levels. Conversely, NMDA receptor-mediated influx rapidly elevates nuclear C/EBPbeta and induces excitotoxic death via activation of the calcium-dependent phosphatase, calcineurin. Moderate levels of AMPA receptor activity stimulate L channels to improve survival, whereas higher levels stimulate NMDA receptors and reduce neuronal survival, suggesting differential synaptic effects. Finally, N-type calcium channel activity reduces survival, potentially by increasing glutamate release. Together, these results show that the L-type calcium channel-dependent survival and NMDA receptor death pathways converge to regulate nuclear C/EBPbeta levels, which appears to be pivotal in these mechanisms.

Molecular epidemiology of oxacillin-resistant Staphylococcus aureus in Brooklyn, New York

Although oxacillin-resistant Staphylococcus aureus (ORSA) are well-established pathogens in many hospitals, the impact of infection control measures on the clonal distribution of ORSA is poorly defined. A citywide surveillance study of Staphylococcus aureus in Brooklyn, New York revealed that 36% of isolates were ORSA. Molecular typing showed that one strain (Cluster A) accounted for more than half of the isolates and was present in all 15 hospitals. In one hospital, a distinct strain (Cluster B) accounted for 20% of ORSA isolates. Infection control measures in this hospital significantly decreased the percentage of clinical isolates that belonged to Cluster B, but did not have an effect on the strain endemic to the city (Cluster A). Regional infection control strategies may need to be developed to limit the spread of the ORSA clone endemic to this area.

Effect of external ocular surgery and mode of post-operative care on plasminogen, plasmin, angiostatins and alpha(2)-macroglobulin in tears

PURPOSE

To determine whether corneal surgery and the mode of post-surgical treatment influence the distribution of plasminogen, plasmin, angiostatins and alpha(2)-macrogobulin in tear fluid.

METHODS

Subjects underwent either photorefractive keratectomy (PRK), insertion of intra-stromal corneal rings (ICR), or cataract ablation followed by insertion of an intra-ocular lens (IOL). Post-surgical treatment consisted of prophylactic use of antibiotic and anti-inflammatory agents followed either by patching for 24 hours, or covering the wounded cornea with a bandage soft contact lens. Open eye tear fluid (OTF) was obtained prior to surgery and 10 minutes after patch removal or 24 hours after surgery and thereafter with the bandage lens still in place. After centrifugation, supernatants and controls were western blot analyzed using a protocol designed to allow the simultaneous semi- quantitative detection of alpha2-macroglobulin, plasminogen, plasmin, angiostatins and interleukin-8 (IL-8).

RESULTS

No obvious differences were apparent in OTF recovered from contralateral control eyes compared to the surgical eyes in individuals who underwent PRK surgery and whose eyes were covered with a bandage contact lens. In contrast, OTF samples recovered 10 minutes after patch removal from all individuals contained elevated levels of alpha2-macroglobulin and a diverse mixture of elevated levels of plasminogen/plasmin, angiostatins and possibly a plasmin-a1-antiplasmin complex. All of these changes were seen, albeit to a lesser extent, in the patched control OTF samples. IL-8 could not be detected in any sample. The composition of the tear film returned to near normal on subsequent sampling 24 hours after patch removal.

CONCLUSIONS

Patching results in a marked increase in the concentration of various proteins which could modulate inflammation and wound healing.

Towards a closed eye model of the pre-ocular tear layer

Although the tear film has been extensively studied as it exists in the open eye state, until recently very little was known as to what happens to the tear film on eye closure. Recent studies have shown that eye closure results in a profound change in the composition, origins, turnover and physiological functions of the tear film. These changes include a shift from an inducible, neurologically controlled, lacrimal secretion containing among other proteins primarily lysozyme, lactoferrin and tear specific lipocalin, to a much slower, constitutive-type of secretion, composed almost exclusively of sIgA. This change is accompanied by the build-up of sialoglycoproteins of epithelial and goblet cell origin, the build-up and activation of complement and the build-up of serum proteins. In addition, various cytokines and proinflammatory mediators accumulate, including some which are potent inducers of angiogenesis and leukochemotaxis. The closed eye also exhibits the recruitment and activation of massive numbers of PMN cells. This results in a stagnant, closed eye layer, which is extremely rich in reactive complement products, PMN cell proteases including protease-3, elastase, capthepsin G, MMP-9 and urokinase. We have postulated that this shift represents a fundamental change in host-defense strategies from a passive-barrier defense to an active immune, inflammatory, phagocyte-mediated process and that this shift is necessitated in order to protect the cornea from entrapped microorganisms. Studies have shown that autologous cell damage is avoided in closed eye tear fluid, by the accumulation of several modulators of complement activation, which shift activation towards opsonization of entrapped microorganisms and the build-up of a wide array of antiproteases. Some of the latter are likely to arise from the ocular surface tissues. Corneal neovascularization may be avoided in part by the build-up of alpha2-macroglobulin and the conversion of plasminogen to angiostatin. It is highly probable that other bioactive protein fragments are produced in the closed eye, which contribute to homeostasis. Areas of future study are indicated.

Diurnal variations in angiostatin in human tear fluid: a possible role in prevention of corneal neovascularization

PURPOSE

Although overnight eye closure is known to result in hypoxia and release of potent angiogenic factors, even prolonged eye closure does not result in corneal neovascularization. This suggests that the closed eye tear film may contain factors that can impede neovascularization. Closed eye tear fluid is known to contain proteases capable of converting plasminogen/plasmin to angiostatin and other angiostatin-like A-chain fragments which are potent inhibitors of angiogenesis. This study was designed to characterize open and closed eye tear fluid for the presence of these entities.

METHODS

Open and closed eye tears were collected by microcapillaries from normal individuals. Tears were centrifuged and the supernatants analyzed by SDS-PAGE and western blotting. Membranes were probed with antibodies specific for the A-chain of plasmin and plasminogen and with antibodies specific for conformational domains on the smaller N terminal kringles 1-->4 and kringles 1-->3 fragments which are known angiogenesis inhibitors. Supernatants were also analyzed after fractionation by HPLC and binding to lysine sepharose 4B. The isolated fragments were identified based on size, lysine-binding capabilities, antigenic properties and by comparison with standards.

RESULTS

Open eye tear fluid from all normal individuals contained low levels of plasminogen, but no detectable antigens consistent with free A-chain or angiostatins. Tears collected after overnight eye closure contained significant amounts of plasminogen, A-chain antigen and various A-chain fragments including kringles 1-->4 and kringles 1-->3 and most likely free kringle 5, all known to have anti-angiogenesis properties. These were often present in concentrations likely to be physiologically significant. In samples collected from an atopic subject, the concentration of angiostatins in CTF increased markedly during active phases of the disease reaching levels of several ng/microl. In these instances and in similar samples obtained from other atopic individuals experiencing active reactions, angiostatin was often detectable in basal-type tear fluid.

CONCLUSION

A-chain fragments, which can inhibit angiogenesis, are often present at physiologically significant levels in human tear fluid collected after overnight eye closure. These fragments may play a role in preventing neovascularization in the hypoxic closed eye environment and may well be up regulated during inflammatory reactions.

Identification, origins and the diurnal role of the principal serine protease inhibitors in human tear fluid

PURPOSE

Previous work identified polymorphonuclear leukocyte (PMN) elastase as the major caseinolytic entity in tears collected after overnight eye closure. This study was designed to identify the principal serine protease inhibitors (serpins) in tears and to determine their function in the regulation of PMN cell proteases on eye closure.

METHODS

Reflex and closed eye tear samples were collected by microcapillary tube and centrifuged. After reflex and closed eye supernatants (R and C) were fractionated by HPLC, samples were subjected to casein zymography and reverse zymography. Western blots were utilized to screen tears and HPLC fractions for elastase, cathepsin G and proteinase-3 and to obtain semi-quantitative data on alpha 1-protease inhibitor (alp1), alpha 1-antichymotrypsin (alpha 1-Achy), secretory leukocyte protease inhibitor (SLPI), elafin and alpha 2-macroglobulin (alpha 2-M) as well as associated complexes and products. To confirm specificity of reactivity, samples were immunoprecipitated for a given protease or serpin and screened for the coprecipitation of interacting species.

RESULTS

Although R fluid contains no caseinolytic activity, it contains low levels of serpin-like activity principally in the form of SLPI (5-10 ng/microliter). Lesser amounts of alpha 2-M, alpha 1-Achy and alp1 (approximately < 1-3 ng/microliter) are also evident. C fluid is associated with very high levels of PMN cell proteases along with a approximately 5-20-fold increase in the concentrations of all of the above inhibitors. Trace levels of elafin were also detected. The concentrations of rapid reacting inhibitors exceeded that of proteases, with SLPI, alpha 1-Achy and alp1 being the principal functional entities. In atypical samples, complexes of elastase and alpha 2-M were also encountered.

CONCLUSIONS

SLPI, a known antimicrobial agent and an elastase and cathepsin G inhibitor, is the principal serpin in R fluid. C fluid is associated with a marked increase in the concentrations of an array of rapid reacting serpins capable of inhibiting all known PMN cell serine proteases. In the normal closed eye, the concentration of rapid reacting inhibitors always exceeds that of proteases with C fluid also containing a functional reserve of the slow reacting inhibitor alpha 2-M.

Polymorphonuclear leukocyte cells and elastase in tears

PURPOSE

To characterize the effects that mode of sampling and overnight eye closure have on the nature of caseinolytic activity recovered in tear fluid.

METHODS

Reflex, open and closed (R, O and C) eye tear fluids were collected by microcapillary tubes or from the inferior formix by Schirmer strip. Microcapillary collected samples were centrifuged and recovered cells cytochemically characterized and probed by immunofluorescence microscopy, or alternatively extracted in acidic PBS. Tear supernatants, pellets and Schirmer strip extracts were subjected to casein zymography or SDS-PAGE and immunoprobed for plasmin/plasminogen. To identify caseinolytic activity, samples were immunoprecipitated with antibodies to plasmin/plasminogen or to elastase, and the immunoprecipitated materials were subjected to zymographic analysis.

RESULTS

Immunoblot assays revealed R and O samples contained low levels of plasminogen (approximately 1.1 micrograms/ml) and only trace levels of plasmin (< 0.1 ng/ml). Insufficient levels of caseinolytic activity were present to allow zymographic detection. Cytochemical analysis revealed that R and O pellets consisted almost exclusively of desquamated epithelium. Immunoblot analysis revealed that C fluid was associated with an increase in plasminogen and its partial conversion to plasmin (approximately 3.2 ng/ microliter), high molecular weight covalent complexes and degradative products. Zymographic analysis disclosed much greater caseinolytic activity than could be attributed to plasmin or its cleavage products. This consisted primarily of three bands (30-26 kDa) which were identified as polymorphonuclear leukocyte (PMN) cell elastase based on size and antigenicity. This is derived from PMNs recovered from the C pellet. Elastase could also be recovered from Schirmer strips from 90% of donors, provided that the strips were extracted in sample loading buffer. The activity was restricted to the portion of the strip that had been in contact with the ocular tissue.

CONCLUSIONS

The main source of caseinolytic activity in C fluid is elastase. This arises from PMNs that undergo recruitment, activation and degranulation in the C environment. In contrast, the elastase recovered in Schirmer strip extracts is derived from intact PMNs that adhere to the strip during sample collection. This would suggest that PMN cells undergo a low level of recruitment into the open eye environment.

Diurnal variations in tear glycoproteins: evidence for an epithelial origin for the major non-reducible > or = 450 kDa sialoglycoprotein(s)

PURPOSE

To characterize the nature and origin of changes in tear glycoproteins accompanying eye closure.

METHODS

Reflex (R) and overnight closed (C) eye tears collected by capillary tubes were centrifuged with the resulting R pellets (primarily desquamated epithelial cells) and C pellets (primarily PMN and some epithelial cells) extracted in acidic PBS. Extracts and supernatants were separated by size-exclusion HPLC and/or SDS-PAGE. Gels were stained or blotted and immune- or lectin-probed. An HPLC glycoprotein fraction of > or = 450 kDa isolated from all four sources was characterized before and after partial deglycosylation, using antibodies specific to known mucin and carbohydrate epitopes. Immunofluorescence microscopy was carried out on human conjunctiva, using as probe a MAb to salivary mucin specific for a sialyl Lea epitope, which was found to cross-react specifically with the major non-reducible high molecular weight sialoglycoproteins (SGs) in tears. These SGs were immunoprecipitated and blot-probed along with tissue extracts.

RESULTS

R fluid contained minor amounts of numerous glycoproteins, including probably several of inducible lacrimal secretory origin. Results confirmed sIgA as the principal source of the intense reducible glycoprotein bands common to C fluid. Smaller amounts of free secretory component and serum glycoproteins were also visualized. The HPLC fraction (> or = 450 kDa) consisted of four major non-reducible glycoproteins. In R fluid, this fraction (< 1% total protein) consisted primarily of two entities: a 450-500 kDa SG and a larger asialoglycoprotein. The SG accounts for as much as 85% of the total protein in the R pellet extract. C fluid was associated with a selective increase in SGs and a shift in distribution to two SGs > 500 kDa. All SGs exhibited a common antigenicity reacting specifically with the MAb for the sialyl Lea epitope. SGs indistinguishable in size and antigenicity were recovered in epithelial extracts. Immunofluorescence microscopy revealed that reactivity was localized to the epithelial plasma membrane, increasing in intensity from basal to apical cells. Although these SGs exhibited some properties in common with MUC1, immunological and other data suggest a unique SG.

CONCLUSIONS

Tear glycoproteins are derived from four principal sources. In R fluid, an inducible lacrimal secretion predominates. In C fluid, a constitutive sIgA secretion predominates, augmented by a serum exudate and SGs derived at least in part from the epithelium. In R fluid and pellet extracts, the SGs consist primarily of a 450-500 kDa species that is most probably derived from the plasma membrane. Larger antigenically related SGs are prevalent in C fluid.

The effect of eye closure on protein and complement deposition on Group IV hydrogel contact lenses: relationship to tear flow dynamics

PURPOSE

This study was designed to determine the effect of overnight eye closure on the rate and composition of protein deposition on high water content ionic matrix soft contact lenses (Group IV SCLs) and to extrapolate from this data information on the probable change in the rate of reflex-type tear secretion associated with eye closure.

METHODS

Group IV SCLs were temporally sampled after equivalent periods of wear under closed eye (C) or open eye (O) conditions. Lenses were rinsed in saline and the majority of the tightly bound protein extracted at 90 degrees C in 40% urea, containing 1% SDS, 1 mM DTT, 100 mM Tris-HCl (pH 8.00). Residual protein was determined by Coomassie staining of the extracted lenses and densitometric analysis. Extracted protein was quantitated and separated by SDS-PAGE. Gels were either stained with Coomassie blue or reversibly stained with imidazole-zinc and blotted. Blots were PAS stained, or lectin and antibody probed for glycoproteins, secretory IgA (sIgA), IgG, lysozyme and complement C3. Laboratory simulated deposition studies were carried out on unworn lenses exposed to HPLC purified lysozyme.

RESULTS

The protein in the saline rinse, to a large degree mirrored the composition of tear fluid in which the lens had been residing (O or C). This would suggest that the saline wash consists of residual tear fluid and loosely adherent protein. In contrast, the urea extracts were highly homogeneous consisting primarily of lysozyme and to lesser extent lysozyme dimer. This supports the contention that the Group IV SCL functions in the eye much as cationic exchange resin selectively absorbing lysozyme. C extracts also proved relatively enriched in trace amounts of sIgA, IgG and complement C3 and its breakdown products. High levels of C3 and C3 breakdown products were specifically recovered only in the C worn lens extracts from a subject experiencing unilateral contact lens associated corneal infiltrates from the affected eye. In all subjects, markedly less protein (lysozyme) was recovered in urea extracts of lenses exposed to 7-8 h of closed eye as compared to open eye wear (0.20 +/- .08 versus 0.79 +/- .15 mg/lens (n = 6)). Temporal studies further revealed that deposition was linearly related to duration of wear during the initial phase of conditioning film formation giving rise to rate constants for lysozyme deposition of 2.2 +/- 0.29 (n = 5) and 0.20 +/- 0.06 microgram/min (n = 4) under open and closed eye conditions respectively. With further wear, deposition eventually reached a steady state. Under laboratory conditions, lysozyme was much rapidly and quantitatively removed from solution in a manner following a hyperbolic plot. This suggests that during the initial phase of deposition the rate of deposition is limited by the capacity of the tear fluid to deliver lysozyme to the lens surface under these two extremes of conditions.

CONCLUSIONS

Eye closure profoundly affects the rate of lysozyme deposition on Group IV hydrogels and the composition of minor biofilm constituents in a manner that could affect biocompatibility. Findings support the contention that eye closure results in a > 90% reduction in the rate of reflex-type tear secretion.

Initial and long-term results of percutaneous transluminal balloon angioplasty for chronic total occlusions: an analysis of 184 procedures

BACKGROUND

Coronary angioplasty, although of proven use in partial occlusion, has not been shown to be of similar benefit in chronic total occlusion.

AIMS

To assess the utility of coronary angioplasty in chronically totally occluded vessels in patients undergoing angioplasty and to determine the success of TIMI-I flow before angioplasty compared to those patients with TIMI-O flow.

METHODS

A group of 178 consecutive patients (from 1984 to 1992), who underwent angioplasty of a chronic occlusion, were analysed. There were 136 males and 42 females with a mean age of 56.9 years.

RESULTS

Initial technical success was achieved in 65%. Patients with TIMI-I flow before angioplasty had a higher chance of success (70%) compared to those with TIMI-O flow (53%), p < 0.04. During hospitalisation six patients suffered myocardial infarction (MI), two required surgery and one patient died. During a mean follow-up of 2.8 years the overall survival rate was 95% for the group as a whole. Freedom from coronary surgery was significantly greater in patients with successful angioplasty (93%) than those without (66%, p < 0.002). The above two populations also showed a significant difference in the incidence of angina (35% vs 56%, p < 0.0003). However, the incidence of MI (6% vs 5%, p > 0.5) and cardiac survival (98% vs 94%, p > 0.1) did not differ significantly in the two groups. Restenosis occurred in 63% of the 95 patients (82%) who returned for follow-up angiography. Eighteen of the 59 patients (28%) with restenosis had a reocclusion.

CONCLUSION

The success rate for angioplasty of chronic total occlusions is acceptable. Long-term clinical benefit in patients with successful angioplasty is suggested by the high freedom from angina and the lesser need for coronary surgery. No major impact on either the incidence of MI or cardiac survival was noted when patients who had coronary surgery were included, although it must be emphasised that the sample size in this study was insufficient to detect a difference in these outcome variables.

Catheter ablation of the atrioventricular node using radiofrequency energy

BACKGROUND

Catheter ablation of the atrioventricular (AV) junction using stored direct current (DC) energy from a standard DC Cardioverter defibrillator was first reported in 1982. Since then many patients have been treated using this procedure for refractory supraventricular arrhythmias, usually atrial fibrillation and flutter. Undesirable thermal effects such as barotrauma and arcing are largely responsible for complications associated with the use of DC energy. This report details our experience of catheter ablation of the AV junction using radiofrequency (RF) energy in a series of 30 consecutive patients.

METHODS

RF ablations were performed using steerable Mansfield (Webster Laboratories) 4 mm tipped electrodes and locally assembled RF energy delivery system.

RESULTS

The procedure was successful in 27/30 (90%) patients using RF energy, while three patients required DC energy to achieve successful AV junction ablation. General anaesthesia was required in nine patients, six of whom required this for cardioversion to sinus rhythm so that an adequate His Bundle spike could be recorded and three for DC ablation. Dual chamber permanent pacemakers with automatic mode switching were implanted in four patients who had paroxysmal atrial fibrillation or flutter and the remainder had ventricular rate responsive pacemakers.

CONCLUSIONS

In patients with drug refractory paroxysmal atrial fibrillation and flutter and in patients with established atrial fibrillation where control of the ventricular rate is difficult, catheter ablation of the AV junction using RF energy is a safe and effective procedure with a high success rate.

Bail-out stenting for left main coronary artery occlusion following diagnostic angiography

We report a case of acute left main coronary artery occlusion treated with stenting of the left main artery. The patient had a severe ostial left main stenosis and after diagnostic coronary angiography developed a total occlusion of the left main artery with life threatening hemodynamic consequences. Stenting of the unprotected left main coronary artery was successfully performed as a salvage procedure.

Radiofrequency catheter ablation for paroxysmal supraventricular tachycardia: a report of 135 procedures

BACKGROUND

Paroxysmal Supraventricular Tachycardia (PSVT) is a common condition which until recently has been treated with anti-arrhythmic drugs or surgery. Radiofrequency (RF) catheter ablation is a new mode of treatment which provides a cure of this condition.

AIMS

To present our early experience of RF catheter ablation for PSVT.

METHODS

One hundred and thirty-five procedures were performed in 117 patients. The diagnostic study and therapeutic catheter ablation were performed as a combined electrophysiological procedure in 74 patients (63%). In 58 patients (50%), PSVT was due to Atrio-ventricular junctional (nodal) re-entrant tachycardia (AVJRT). Twenty-five of the 58 patients underwent a fast pathway ablation while 33 had ablation of their slow pathway. The mean number of radiofrequency pulses delivered was ten for a mean duration of 25 seconds. Radiofrequency ablation of accessory pathways was attempted in 58 patients; pathways were left-sided in 29 patients, postero-septal in 21, midseptal in five, Mahaim connection in two, antero-septal in one and right free wall in one patient. One patient with incessant automatic atrial tachycardia also underwent a successful RF ablation.

RESULTS

Using RF ablation cure of PSVT was achieved in 90% of patients. Cure of AVJRT was achieved in 95% (55/58) of patients using either fast or slow pathway ablation. Only one patient required permanent pacemaker implantation for Mobitz type I AV block following fast pathway ablation. The overall success rate for ablation of accessory pathways was 85%. There is an operator learning curve for this procedure suggested by the fact that the success rate for accessory pathway ablation at first attempt was 63% in the first 29 patients and 93% in the remaining 29. There was no significant morbidity or mortality during or after the procedure. In a mean follow-up of nine months in the patients with successful ablation only two patients with AVJRT had a recurrence of documented PSVT. Both these patients had successful repeat RF ablation. Catheter ablation using radiofrequency energy is an effective and safe therapeutic option for patients with symptomatic PSVT.

Malignant ventricular arrhythmias in patients with mitral valve prolapse and mild mitral regurgitation

Mitral valve prolapse (MVP) is a common disorder that, in general, has a good prognosis. Rare occasions of sudden death have been reported in patients with MVP and it is presumed that the basis of sudden death is arrhythmic. We report seven patients with moderate to severe MVP and malignant ventricular arrhythmias. All patients had trivial to mild mitral regurgitation and normal left ventricular function. Three patients presented with syncope, two with out-of-hospital cardiac arrest, and three with recurrent palpitations and presyncope. In a mean follow-up period of 2.5 years (range 6 months to 5 years), two patients died suddenly despite successful control of their nonsustained ventricular tachycardia (VT) with sotalol as shown by ambulatory monitoring. Two patients, who had sustained VT despite antiarrhythmic drug therapy, had mitral valve surgery, however, monomorphic VT could be induced in both even after surgery. The arrhythmias in the remaining three patients are controlled on antiarrhythmic drugs. We conclude that a selected subset of patients with MVP, malignant ventricular arrhythmias, and mild mitral regurgitation are at risk of sudden death. Syncope, inferolateral repolarization changes, complex ventricular ectopy, and a markedly myxomatous valve may be pointers to higher risk of sudden death and mitral valve surgery may not provide control of ventricular arrhythmias.

Immediate and long-term results of percutaneous balloon aortic valvuloplasty: a report of 33 procedures

The purpose of this study was to evaluate the immediate and long-term clinical and haemodynamic effects of Percutaneous Balloon Aortic Valvuloplasty (PBAV). Thirty-three procedures were performed in 27 patients, 11 males and 16 females with a mean age of 72 years. The peak to peak systolic gradient across the aortic valve decreased by 52%, from 67 +/- 24 mmHg to 31 +/- 15 mmHg (p < 0.0001) and the aortic valve area increased by 35%, from 0.48 +/- 0.16 to 0.67 +/- 0.21 cm2 (p < 0.001) after PBAV. There were no procedural deaths. Minor complications occurred in seven patients. Eighty-one per cent of patients (27 procedures) showed immediate symptomatic improvement, five remained symptomatic and one died in hospital before discharge. In a mean follow-up of 17 +/- 12 months (range six to 38 months), eight patients died due to congestive cardiac failure, six underwent repeat PBAV, three died due to noncardiac causes and three had recurrent symptoms controlled on medical therapy. Event free survival at 15 months was 43%. In conclusion PBAV produces a satisfactory immediate clinical and haemodynamic result, however, considering the high rate of symptom recurrence, this procedure has a beneficial role only in short-term palliation of severely symptomatic patients who are unable to undergo aortic valve replacement.

Clinical experience with surgery for paroxysmal supraventricular tachycardia: a report of 103 cases

One-hundred-and-three patients underwent surgery for paroxysmal supraventricular tachycardia (PSVT). In eighty-three patients (81%), PSVT was due to an accessory atrioventricular pathway (Group I) and in 20 (19%) to Atrioventricular Junctional (AV nodal) Reentrant Tachycardia (AVJRT:Group II). Initial surgery successfully divided 77 of 83 accessory pathways, including 58 of 60 left free wall pathways, 12 of 15 posteroseptal pathways, six of seven right free wall pathways and one anteroseptal pathway. Twenty patients had successful surgery for AVJRT. Surgery was performed with low morbidity and no early or late mortality in either group. One patient in each group required permanent pacemaker implantation. Immediate (within one week) postoperative electrophysiological study using epicardial wires was performed in 96% of patients and repeat electrophysiological study six months later was possible in 65/103 (63%) patients. Patients with surgery for accessory pathways were followed-up for a mean 34 +/- 23 months, while those with surgery for AVJRT for a mean of 13 +/- seven months. No patient with successful surgery has had a clinical recurrence of PSVT. Thus the results indicate that surgery is a safe and curative therapy for patients with PSVT.

Single coronary artery: a report of 2 cases

An isolated single coronary artery is a rare congenital anomaly. We report 2 patients each of whom had a single coronary artery with an obstructive atherosclerotic lesion in one of its branches. In the first patient angioplasty was successfully performed using a perfusion catheter whilst in the second, the procedure was considered inappropriate as the patient had chronic total occlusion.

Closely linked lesions in a region of the X chromosome affect central and peripheral steps in gustatory processing in Drosophila

We have analyzed a set of closely linked mutations on the X chromosome of Drosophila that lead to defects in gustatory behavior. The mutations map to a small region of the X chromosome between 10E1-4. Two distinct complementation groups, gustB and gustD, map to the ends of this region. These groups show complex complementation patterns with the mutations gustC and GT-1, which also map to this region. We describe the behavioral and electrophysiological properties of the mutants. These mutations affect peripheral receptor properties as well as more central processing steps in the gustatory pathway.

HIV-2-associated AIDS in the United States. The first case

A 41-year-old woman from the Cape Verde Islands, Africa, who had been residing in the United States for 11 months was found to have human immunodeficiency virus type 2 (HIV-2)-associated acquired immunodeficiency syndrome (AIDS). Antibody to HIV-2 was found by enzyme immunoassay and was verified by radioimmunoprecipitation. The patient was being treated for pulmonary tuberculosis at the time of her admission to our institution. Further laboratory and clinical evaluation at our facility revealed depressed CD4 lymphocytes, oral candidiasis, and cryptococcal meningitis with indeterminate results on serologic testing for HIV type 1 (HIV-1). The biopsy specimen of a lesion in the right occipital lobe of the brain documented Toxoplasma gondii, indicating a clinical diagnosis of AIDS. To our knowledge, our study presents the first known patient with HIV-2-associated AIDS in the United States. Our patient provides further evidence that HIV-2 causes severe immunodeficiency and opportunistic infection. The condition should be suspected in the face of normal or repeatedly equivocal HIV-1 antibody test results in the presence of clinically documented AIDS.

HIV-2-associated AIDS in the United States. The first case

A 41-year-old woman from the Cape Verde Islands, Africa, who had been residing in the United States for 11 months was found to have human immunodeficiency virus type 2 (HIV-2)-associated acquired immunodeficiency syndrome (AIDS). Antibody to HIV-2 was found by enzyme immunoassay and was verified by radioimmunoprecipitation. The patient was being treated for pulmonary tuberculosis at the time of her admission to our institution. Further laboratory and clinical evaluation at our facility revealed depressed CD4 lymphocytes, oral candidiasis, and cryptococcal meningitis with indeterminate results on serologic testing for HIV type 1 (HIV-1). The biopsy specimen of a lesion in the right occipital lobe of the brain documented Toxoplasma gondii, indicating a clinical diagnosis of AIDS. To our knowledge, our study presents the first known patient with HIV-2-associated AIDS in the United States. Our patient provides further evidence that HIV-2 causes severe immunodeficiency and opportunistic infection. The condition should be suspected in the face of normal or repeatedly equivocal HIV-1 antibody test results in the presence of clinically documented AIDS.

Unruptured aneurysm of sinus of Valsalva: report of 2 cases

2 cases of unruptured aneurysm of the sinus of Valsalva are presented. Both the patients had involvement of the right sinus of Valsalva. One of the patients had associated systemic lupus erythematosus (SLE). Such an association has not been described in the literature. Clinical, echocardiographic and the angiographic features have been discussed and literature reviewed.

Uridine uptake inhibition as a cytotoxicity test: correlations with the Draize test

The effects of 25 xenobiotic chemicals on the uptake of [3H]-uridine by Balb/c 3T3 cells were assessed. The test compounds, which included alcohols, ethers, esters, ketones, amides, acids and a detergent, inhibited uridine uptake at concentrations lower than those required to kill the cells; thus uridine uptake inhibition is a more sensitive indicator of toxic action than is cell lethality. The concentration of agent required to induce a 50% inhibition in uridine uptake rates after 4 h of treatment was determined for each agent, and this value (UI-50) was used to rank the potency of the test agents. This ranking correlated well with published data on the chemicals' capacity to induce ocular irritation in rabbits (the Draize test). Combinations of agents with differing functional groups produced additive uridine uptake inhibitory effects, suggesting the utility of this approach for the analysis of mixtures. Cells treated with levels of agents that reduced uridine uptake by 60-80% were able to recover most of their uridine uptake capacity after refeeding, indicating that the test shares with in vivo tests the ability to demonstrate recovery from toxic insult. This uridine uptake assay system provides a quantitative and rapid method for assessing toxicity that correlates well with Draize test results.

Coronary-pulmonary artery fistula arising distal to obstructive coronary lesions

We report 2 cases of coronary-pulmonary artery fistulae (CPF) arising distal to obstructive coronary artery disease. The fistula in the first patient was in the form of a tortuous dilatation of the distal portion of the right coronary artery and opened into the right pulmonary artery. In the second case, the fistula, a plexus of vessels, arose from the left anterior descending artery and entered the left pulmonary artery. Both the fistulae were successfully ligated at the time of concurrent coronary artery bypass graft surgery.