Long-term outcomes of index cryoballoon ablation or point-by-point radiofrequency ablation in patients with atrial fibrillation and systolic heart failure.

Catheter ablation is an established effective approach for the treatment of atrial fibrillation (AF) in patients with heart failure, however, the role of cryoablation in this setting is unclear. Procedural success and left ventricular systolic dysfunction (LVEF) improvement in patients with LVEF ≤ 45% undergoing index catheter ablation with cryoablation were evaluated. Freedom from AF recurrence was seen in 43% rising to 59% following repeat procedure. There were significant improvements in LVEF and functional status at long-term follow-up. Results were comparable to a contemporaneous cohort of heart failure patients undergoing index ablation with radiofrequency ablation. Cryoablation is an effective first-line AF ablation approach in the setting of heart failure.

Outcome of ACHD patients with non-inducible versus inducible IART undergoing cavo-tricuspid isthmus ablation: the role of empiric ablation.

PURPOSE: Catheter ablation for supraventricular tachycardia (SVT) in adults with congenital heart disease (ACHD) is an important therapeutic option. Cavo-tricuspid isthmus (CTI)-dependent intraatrial re-entrant tachycardia (IART) is common. However, induction of sustained tachycardia at the time of ablation is not always possible. We hypothesised that performing an empiric CTI line in case of non-inducibility leads to good outcomes. Long-term outcomes of empiric versus entrained CTI ablation in ACHD patients were examined. METHODS: Retrospective, single-centre, case-control study over 7 years. Arrhythmia-free survival after empiric versus entrained CTI ablation was compared. RESULTS: Eighty-seven CTI ablations were performed in 85 ACHD patients between 2010 and 2017. The mean age of the cohort was 43 years and 48% were male. Underlying aetiology included ASD (31%), VSD (11.4%), AVSD (9.1%), AVR (4.8%), Fallot's (18.4%), Ebstein's (2.3%), Fontan's palliation (9.2%) and atrial switch (13.8%). CTI-dependent IART was entrained in 59 patients whereas it was non-inducible in 28. The latter had an empiric CTI ablation. Forty-three percent of procedures were performed under general anaesthesia. There were no reported procedural complications. There was no significant difference in the mean procedure or fluoroscopy times between the groups (empiric vs entrained CTI; 169.1 vs 183.3 and 28.1 vs 19.9 min). Arrhythmia-free survival was 64.3% versus 72.8% (p value 0.44) in the empiric and entrained groups at 21 months follow-up. CONCLUSIONS: Long-term outcomes after empiric and entrained CTI ablation for IART in ACHD patients are comparable. This is a safe and effective therapeutic option. In the case of non-inducibility of IART, an empiric CTI line should be considered in this cohort.

Impact of attributed audit on procedural performance in cardiac electrophysiology catheter laboratory.

PURPOSE: Audit has played a key role in monitoring and improving clinical practice. However, audit often fails to drive change as summative institutional data alone may be insufficient to do so. We hypothesised that the practice of attributed audit, wherein each individual's procedural performance is presented will have a greater impact on clinical practice. This hypothesis was tested in an observational study evaluating improvement in fluoroscopy times for AF ablation. METHODS: Retrospective analyses of fluoroscopy times in AF ablations at the Barts Heart Centre (BHC) from 2012-2017. Fluoroscopy times were compared pre- and post- the introduction of attributed audit in 2012 at St Bartholomew's Hospital (SBH). In order to test the hypothesis, this concept was introduced to a second group of experienced operators from the Heart Hospital (HH) as part of a merger of the two institutions in 2015 and change in fluoroscopy times recorded. RESULTS: A significant drop in fluoroscopy times (33.3 ± 9.14 to 8.95 ± 2.50, p < 0.0001) from 2012-2014 was noted after the introduction of attributed audit. At the time of merger, a significant difference in fluoroscopy times between operators from the two centres was seen in 2015. Each operator's procedural performance was shared openly at the audit meeting. Subsequent audits showed a steady decrease in fluoroscopy times for each operator with the fluoroscopy time (min, mean±SD) decreasing from 13.29 ± 7.3 in 2015 to 8.84 ± 4.8 (p < 0.0001) in 2017 across the entire group. CONCLUSIONS: Systematic improvement in fluoroscopy times for AF ablation procedures was noted byevaluating individual operators' performance. Attributing data to physicians in attributed audit can promptsignificant improvement and hence should be adopted in clinical practice.

Moderate sedation in cardiac electrophysiology laboratory: a retrospective safety analysis.

OBJECTIVE: Cardiac electrophysiology (EP) procedures can be performed under moderate sedation without the direct involvement of an anaesthetist. However, concerns have been raised over the safety of this approach. This study examines the use of a standardised nurse-led physician-directed sedation protocol for EP procedures to determine the safety of moderate sedation administered by non-anaesthesia personnel who have been trained in sedation techniques. METHODS AND RESULTS: Consecutive EP procedures done under moderate sedation over 12 years at our institution were evaluated. Serious adverse events were defined as (i) procedural death related to sedation; (ii) intubation and ventilation; and (iii) hypotension requiring inotropic support. Reversal of sedation constituted a minor adverse event. Up to 7117 procedures were included. These comprised ablations (55%), devices (43%) and other procedures (2%). A majority of patients were men with a mean age of 61±10 years. 99.98% of procedures were completed successfully without sedation-related serious adverse events. Two patients (0.02%) required anaesthetic support for intubation. Sedation was reversed in 1.2% of procedures with less than 1% requiring reversal because of persistent drop in oxygen saturation, hypoventilation or markedly reduced level of consciousness. There was no significant difference in the patient characteristics, mean doses of sedative agents and procedure types in the group requiring reversal of sedation when compared with the whole cohort. CONCLUSIONS: Our study demonstrates that nurse-led, physician-directed moderate sedation is safe. Anaesthesia services are not required routinely for invasive cardiac EP procedures and should be available on a need basis.

Epicardial catheter ablation for ventricular tachycardia on uninterrupted warfarin: A safe approach for those with a strong indication for peri-procedural anticoagulation?

BACKGROUND: Current guidelines for epicardial catheter ablation for ventricular tachycardia (VT) advocate that epicardial access is avoided in anticoagulated patients and should be performed prior to heparinisation. Recent studies have shown that epicardial access may be safe in heparinised patients. However, no data exist for patients on oral anticoagulants. We investigated the safety of obtaining epicardial access on uninterrupted warfarin. METHODS: A prospective registry of patients undergoing epicardial VT ablation over two years was analysed. Consecutive patients in whom epicardial access was attempted were included. All patients were heparinised prior to epicardial access with a target activated clotting time (ACT) of 300-350s. Patients who had procedures performed on uninterrupted warfarin (in addition to heparin) were compared to those not taking an oral anticoagulant. RESULTS: 46 patients were included of which 13 were taking warfarin. There was no significant difference in clinical and procedural characteristics (except INR and AF) between the two groups. Epicardial access was achieved in all patients. There were no deaths and no patients required surgery. A higher proportion of patients in the warfarin group had a drop in haemoglobin of >2g/dL compared to the no-warfarin group (38.5% versus 27.3%, p=0.74) and delayed pericardial drain removal (7.8% versus 3.03%, p=0.47). There was no difference in overall procedural complication rate. No patients required warfarin reversal or blood transfusion. CONCLUSION: Epicardial access can be achieved safely and effectively in patients' anticoagulated with warfarin and heparinised with therapeutic ACT. This may be an attractive option for patients with a high stroke risk.

Telomere shortening and telomerase activity in ischaemic cardiomyopathy patients - Potential markers of ventricular arrhythmia.

BACKGROUND: Implantable cardioverter defibrillators (ICDs) reduce mortality in patients with ischaemic cardiomyopathy at high risk of ventricular arrhythmias (VA). However, the current indication for ICD prescription needs improvement. Telomere and telomerase in leucocytes have been shown to associate with biological ageing and pathogenesis of cardiovascular diseases. We hypothesised that leucocyte telomere length, load-of-short telomeres and/or telomerase activity are associated with VA occurrence in ischaemic cardiomyopathy patients. METHODS AND RESULTS: 90 ischaemic cardiomyopathy patients with primary prevention ICDs were recruited. 35 had received appropriate therapy from the ICD for potentially-fatal VA while the remaining 55 patients had not. No significant differences in baseline demographic data relevant to telomere biology were seen between the two groups. There was no significant difference in the age and sex adjusted mean telomere length analysed by qPCR between the groups (p=0.88). In contrast, the load-of-short telomeres assessed by Universal-STELA method and telomerase activity by TRAP assay were both higher in patients who had appropriate ICD therapy and were significantly associated with incidence of ICD therapy (p=0.02, p=0.02). ROC analyses demonstrated that the sensitivity and specificity of these telomere dynamics in predicting potentially-fatal VA was higher than the current gold-standard - left ventricular ejection fraction (AUC 0.82 versus 0.47). CONCLUSION: The load-of-short telomeres and telomerase activity had a significant association with ICD therapy (for VA) in ischaemic cardiomyopathy patients. These biomarkers should be tested in prospective studies to assess their clinical utility in predicting VA after myocardial infarction and guiding primary prevention ICD prescription.

A randomized single-blind controlled trial of letrozole as a low-cost IVF protocol in women with poor ovarian response: a preliminary report.

BACKGROUND: Use of letrozole, a selective inhibitor of aromatase, reduces the gonadotrophin dose required to induce follicular maturation. We evaluated whether incorporation of letrozole could be an effective low-cost IVF protocol for poor responders. METHODS: A randomized, controlled, single-blind trial was conducted in the Assisted Reproduction Unit, Institute of Reproductive Medicine, Kolkata, India. Thirty-eight women with a history of poor ovarian response to gonadotrophins were recruited. Thirteen women (Let-FSH group) received letrozole 2.5 mg daily from day 3-7, and recombinant FSH (rFSH) 75 IU/day on days 3 and 8; and 25 women (GnRH-ag-FSH group) underwent long GnRH agonist protocol and stimulated with rFSH (300-450 IU/day). Ovulation was triggered by 10,000 IU of HCG followed by IVF-embryo transfer. The main outcome measures were total dose of rFSH (IU/cycle), terminal estradiol (E2) (pg/ml), numbers of follicles, oocytes retrieved and transferable embryo, endometrial thickness (mm), and pregnancy rate. RESULTS: Compared with the GnRH-ag-FSH group (2865 +/- 228 IU), the Let-FSH group (150 +/- 0 IU) received a significantly (P < 0.001) lower total dose of FSH. Except for terminal E2, which was significantly higher (P < 0.001) in the GnRH-ag-FSH group (380 +/- 46 pg/ml) than the Let-FSH group (227 +/- 45 pg/ml), the treatment outcomes in all other respects, including pregnancy rate, were statistically comparable. CONCLUSIONS: Adjunctive use of letrozole may form an effective means of low-cost IVF protocol in poorly responding women.

Reduced de-etiolation of hypocotyl growth in a tomato mutant is associated with hypersensitivity to, and high endogenous levels of, abscisic acid.

A recessive single gene mutant, 7B-1, in tomato was originally selected for its photoperiod-dependent male sterility. The 7B-1 mutant also has some pleiotropic effects including reduced light-induced inhibition, i.e. de-etiolation, of the hypocotyl in long days (LD), increased seed size and weight, and reduced transpiration rate. These traits led us to investigate the sensitivity of 7B-1 to exogenous hormones and the interaction of these responses with daylength. In LD, but not in short days (SD), 7B-1 was more sensitive than wild-type (WT) to exogenous abscisic acid (ABA) for inhibition of seed germination, root elongation and transpiration rate. 7B-1 mutant also exhibited reduced responses to exogenous gibberellin (GA(3)) for hypocotyl elongation, and to inhibitors of GA biosynthesis for seed germination and root and hypocotyl elongation. 7B-1 hypocotyls contained a higher level of endogenous ABA than WT in both photoperiods, although ABA levels were higher in LD than in SD. In contrast, growth-active GAs, i.e. GA(1), GA(3) and GA(4), and IAA were low in the mutant hypocotyls. The 7B-1 mutant appears to be an ABA-overproducer, and the photoperiod-regulated ABA levels may be responsible for the hypersensitivity of the mutant to exogenous ABA.

Frequent amplification of C-erbB2 (HER-2/Neu) oncogene in cervical carcinoma as detected by non-fluorescence in situ hybridization technique on paraffin sections.

Sixty primary untreated squamous cell carcinomas were studied for C-erbB2 gene amplification by non-fluorescence in situ hybridization technique. Amplified tumour cells showed intranuclear dark brown, often paired signals under light microscopy. Twenty-two out of 60 tumours (36.6%) showed signs of amplification of different degree (+ to +). Considerable heterogeneity of C-erbB2 amplification per cell was seen within each amplified tumour. The proportion of amplified cells ranged between 10 and 90% in these tumours. The arrangement of C-erbB2 in clusters in most amplified tumours suggests that C-erbB2 amplification occurs intrachromosomally. No significant difference in the frequency of amplification was observed according to clinical stage or the histological patterns of the tumours. The results of the present study showed frequent amplification of C-erbB2 in cervical carcinoma on paraffin sections. This technique was found to be more sensitive than the Southern blot technique which could detect amplification in 14% of the tumours of the same cohort.

Acquisition of competence for shoot regeneration in leaf discs ofSaintpaufla ionantha xconfusa hybrids (African violet) cultured in vitro.

Leaf discs fromSaintpaulia ionantha xconfusa hybrids (African violet) were transferred between basal medium (BM) containing no hormones and shoot-inducing medium (SIM) containing 2.0 mg 1-1 indole acetic acid and 0.08 mg l-1 6-benzylaminopurine to determine whether there is a "window" of competence for shoot regeneration. Leaf discs precultured on BM prior to transfer to SIM formed buds 3 days earlier than the controls (leaf discs not precultured) regardless of whether the discs were placed upside down or right side up on the medium. This suggests that cultured leaf cells were not competent for shoot induction during the first 3 days of culture. Leaf discs cultured right side up (abaxial surface to the medium) did not form buds on BM alone, unlike discs cultured upside down. Leaf disc survival was affected by a delay in hormonal exposure, but surviving leaf discs produced as many shoots as control leaf discs. This suggests that in the absence of exogenous plant hormones, cellular competence to regenerate shoots is not lost in excised leaf discs of African violet.

Histological changes associated with acquisition of competence for shoot regeneration in leaf discs ofSaintpaufla ionantha xconfusa hybrid (African violet) cultured in vitro.

In leaf discs ofSaintpaulia ionantha xconfusa hybrid (cv. Virginia) cultured on shoot-inducing medium, periclinal divisions were initiated in epidermal cells 3-5 days after explant isolation. This timing coincided with the time for competence acquisition determined in tissue-transfer experiments. Some of the daughter cells from periclinal divisions formed the target cells which divided both anticlinally and periclinally to form cell division centers (meristemoids), precursors of adventitious shoots. The target cells were not morphologically distinct from other epidermal cells at the light microscope level. It is suggested that the periclinal divisions in epidermal cells represent the dedifferentiation phase during which target (competent) cells are formed. Once the cells have acquired the ability to divide periclinally, both dedifferentiation and shoot induction occur in the presence of exogenous plant hormones.

Benzylaminopurine induces phenocopies of floral meristem and organ identity mutants in wild-type Arabidopsis plants.

Arabidopsis thaliana (L.) Heynh. has been used as a model system to investigate the regulatory genes that control and coordinate the determination, differentiation and morphogenesis of the floral meristem and floral organs. We show here that benzylaminopurine (BAP), a cytokinin, influences flower development in Arabidopsis and induces partial phenocopies of known floral homeotic mutants. Application of BAP to wild-type inflorescences at three developmental stages results in: (i) increase in floral organ number; (ii) formation of abnormal floral organs and (iii) induction of secondary floral buds in the axils of sepals. These abnormalities resemble the phenotypes of mutants, clv1 (increase in organ number), ap1, ap2, ap3 (abnormal floral organs) and ap1 (secondary floral buds in the axils of first-whorl organs). In addition, BAP induces secondary floral buds in the axils of perianth members of ap2-6, ap3-1 and ag mutants, and accentuates the phenotype of the ap2-1 mutant to resemble the ap2-6 mutant. These observations suggest that exogenous BAP suppresses the normal functioning of the genes for floral meristem identity and thereby affects flower development and the later stages of floral organ differentiation.

Pollen selection for Alternaria resistance in oilseed brassicas: responses of pollen grains and leaves to a toxin of A. brassicae.

The effects of destruxin B, a host-specific toxin of Alternaria brassicae that causes black spot disease in oilseed brassicas, were studied on in vitro pollen germination and pollen-tube growth of Brassica campestris var "brown sarson", B. juncea, B. napus cvs "Westar" and "Cresor", B. nigra and Sinapis alba. Pollen grains of B. nigra, B. juncea and B. campestris were the most sensitive and those of S. alba the least sensitive to the toxin. Effects of the toxin were also studied on the leaves of these species, and the degree of sensitivity of leaves of different species was comparable to that of their pollen grains. The results on the responses of pollen grains as well as leaves to the toxin are in agreement with the degree of susceptibility/resistance of these species to A. brassicae reported in the literature, indicating that the genes imparting susceptibility/restistance are expressed in the pollen, a prerequisite for pollen selection. Results are also presented which show that the toxin fed to the cut end of isolated inflorescence axis is readily taken up by the developing pollen and results in the inhibition of germination of susceptible pollen. This technique offers a simple and effective method for application of selection pressure to eliminate pollen grains susceptible to the toxin from effecting fertilization.

Protein analysis during the ontogeny of normal and male sterile stamenless-2 mutant stamens of tomato (Lycopersicon esculentum Mill.).

The levels and synthesis of proteins during the ontogeny of normal and male sterile stamenless-2 (sl-2/sl-2) mutant stamens of tomato (Lycopersicon esculentum) were examined. The mutant stamens contained low levels of soluble protein which were related to reduction in protein synthesis. The mutant stamens, however, possessed many polypeptides similar to the normal and synthesized a 53-kd polypeptide at stages when there are abnormalities in tapetum development. The mutant stamens also possessed a 23-kd and some low molecular weight polypeptides that were considered as degradative proteins. Normal stamens exhibited the synthesis of many polypeptides not found in the mutant, from microspore mother cell to the preanthesis stages. In addition, at the time of pollen maturation there was a greater synthesis of several polypeptides, particularly those of 42 and 37 kd. Although the causative mechanisms of male sterility in the sl-2/sl-2 mutant are not known, the synthesis, and the lack, of specific polypeptides reported here appears to be associated with pollen degeneration.

Polyamines and Flower Development in the Male Sterile Stamenless-2 Mutant of Tomato (Lycopersicon esculentum Mill.) : I. Level of Polyamines and Their Biosynthesis in Normal and Mutant Flowers.

The levels of free putrescine, spermidine, and spermine, and the activities of ornithine decarboxylase and s-adenosylmethionine decarboxylase were determined in the floral organs of the normal and a male sterile stamenless-2 (sl-2/sl-2) mutant of tomato (Lycopersicon esculentum Mill.). Under the intermediate temperature regime, all mutant floral organs possessed significantly higher levels of polyamines and enzyme activities than their normal counterparts. In the low temperature-reverted mutant stamens, the polyamine levels and the activity of PA biosynthetic enzymes were not significantly different from the normal. It is suggested that the abnormal stamen development in the sl-2/sl-2 mutant is, in part, related to elevated levels of endogenous PAs.

Polyamines and Flower Development in the Male Sterile Stamenless-2 Mutant of Tomato (Lycopersicon esculentum Mill.) : II. Effects of Polyamines and Their Biosynthetic Inhibitors on the Development of Normal and Mutant Floral Buds Cultured in Vitro.

The floral organs of the male sterile stamenless-2 (sl-2/sl-2) mutant of tomato (Lycopersicon esculentum Mill.) contain significantly higher level of polyamines than those of the normal (R Rastogi, VK Sawhney [1990] Plant Physiol 93: 439-445). The effects of putrescine, spermidine and spermine, and three different inhibitors of polyamine biosynthesis on the in vitro development of floral buds of the normal and sl-2/sl-2 mutant were studied. The polyamines were inhibitory to the in vitro growth and development of both the normal and mutant floral buds and they induced abnormal stamen development in normal flowers. The inhibitors of polyamine biosynthesis also inhibited the growth and development of floral organs of the two genotypes, but the normal flowers showed greater sensitivity than the mutant. The inhibitors also promoted the formation of normal-looking pollen in stamens of some mutant flowers. The effect of the inhibitors on polyamine levels was not determined. The polyamine-induced abnormal stamen development in the normal, and the inhibitor-induced production of normal-looking pollen in mutant flowers support the suggestion that the elevated polyamine levels contribute to abnormal stamen development in the sl-2/sl-2 mutant of tomato.