Radiofrequency ablation for cure of atrial flutter

Abstract Background: Atrial flutter is a common arrhythmia which frequently recurs after cardioversion and is relatively difficult to control with antiarrhythmic agents.
Aims: To evaluate the success rate, recurrence rate and safety of radiofrequency (RF) ablation for atrial flutter in a consecutive series of patients with drug refractory chronic or paroxysmal forms of the arrhythmia.
Methods: Electrophysiologic evaluation of atrial flutter included activation mapping with a 20 electrode halo cadieter placed around the tricuspid annulus and entrainment mapping from within the low right atrial isthmus. After confirmation of the arrhythmia mechanism with these techniques, an anatomic approach was used to create a linear lesion between the inferior tricuspid annulus and the eustachian ridge at the anterior margin of the inferior vena cava. In order to demonstrate successful ablation, mapping techniques were employed to show that bi-directional conduction block was present in the low right atrial isthmus.
Results: Successful ablation was achieved in 26/27 patients (96%). In one patient with a grossly enlarged right atrium, isthmus block could not be achieved. Of the 26 patients with successful ablation, mere has been one recurrence of typical flutter (4%) during a mean follow-up period of 5.5±2.7 months. This patient underwent a successful repeat ablation procedure. Of eight patients with documented clinical atrial fibrillation (in addition to atrial flutter) prior to the procedure, five continued to have atrial fibrillation following the ablation. There were no procedural complications and all patients had normal AV conduction at the completion of the ablation.
Conclusions: RF ablation is a highly effective and safe procedure for cure of atrial flutter. In patients with chronic or recurrent forms of atrial flutter RF ablation should be considered as a first line therapeutic option.     

A Comprehensive Geochemical Evaluation of the Water Quality of River Adyar,India

The River Adyar flows through the fault of south Chennai for about 50 Km and enters into the Bay of Bengal. This river is almost stagnant and do not carry enough water except during rainy season. Rapid industrialization and urbanization along the river course during 80s and 90s of last century has increased the pollution of the river water. The main objective of this study is to identify and assess the nature of pollution. In order to achieve this objective, necessary geochemical parameters were determined and the quality of water is evaluated using various tools, such as Wilcox diagram, USIS, Piper, sodium absorption ratio (SAR), 3D scattered diagrams, and seasonal variation diagrams. The monsoonal variations in the data matrix of the river water (River Adyar) was monitored at 33 stations for the premonsoon and postmonsoon periods during September 2005 and February 2006.     

Rasmussen syndrome of chronic focal encephalitis.

Rasmussen syndrome of chronic focal encephalitis is a relatively rare disease, which presents with epilepsia partialis continua and hemiparesis in childhood. Though first described in the 1950s it still remains somewhat of an enigma. The immunological process involved in its pathogenesis is better understood now but the exact relationship to viral infections is still unclear. Medical treatment remains disappointing while results of surgical treatment are mixed. There are emerging insights into the disease, which are reviewed and a case study of a patient with Rasmussen syndrome is presented.     

Polymorphism at codon 72 of p53, human papillomavirus,and cervical cancer in South India

PURPOSE: It has been suggested that host genetic factors play a role in human papillomavirus (HPV)-associated tumorigenesis, although the issue continues to be a focus of much debate. Previous studies have reported that a common polymorphism of the wild type p53 gene at codon 72 of exon 4 (Arg/Arg) is associated with a sevenfold increased risk of HPV-associated cancer compared to Arg/Pro and Pro/Pro polymorphisms. In vitro studies also suggested that the Arg/Arg polymorphism was much more susceptible to HPV 16 E6-mediated degradation as compared to other allelic forms. Subsequent studies published since this initial report indicated geographical differences with respect to the role of Arg/Arg polymorphism in increasing the risk of HPV-associated cervical cancer. METHODS: In this study we analyzed leukocyte DNA from a total of 421 subjects for the Arg/Arg, Arg/Pro or Pro/Pro p53 polymorphisms at various stages of the cervical tumor progression spectrum, using allele-specific PCR. All subjects were from the Thiruvananthapuram District of South India. HPV genotyping was done for all subjects using either DNA extracted from cervical biopsies or exfoliated cervical cells. All subjects were grouped on the basis of both of cyto-pathology and HPV status. RESULTS: The distribution of p53 genotypes was not significantly different in all study groups (HPV positive vs HPV negative and cases vs controls comparisons). Homozygosity for Arg/Arg was not associated with increased risk for cervical cancer. CONCLUSION: We find no evidence for any association between homozygosity for p53 arginine with either cervical dysplasia, cervical carcinoma or HPV infection in the population from South India.     

Effects of hydroquinone on retinal and vascular cells in vitro

Aim:

To explore the molecular pathophysiology that might explain the epidemiologic association between cigarette smoke and age-related macular degeneration (AMD) by examining the effects of hydroquinone (HQ), a toxic compound present in high concentration in cigarette smoke-related tar, on human retinal pigment epithelial cells (ARPE-19), rat retinal neurosensory cells (R-28), and human microvascular endothelial cells (HMVEC).

Materials and Methods:

ARPE-19, R-28, and HMVEC were treated for 24 h with four different concentrations of HQ (500 μM, 200 μM, 100 μM, 50 μM). Cell viability, caspase-3/7 activation, DNA laddering patterns, and lactate dehydrogenase (LDH) levels were analyzed.

Results:

At 50 μM HQ, R-28 cells showed a significant decrease in cell viability compared with the dimethyl sulfoxide (DMSO)-treated controls. At the 100–500 μM concentrations, all three cell lines showed significant cell death (P < 0.001). In the ARPE-19, R-28, and HMVEC cultures, the caspase-3/7 activities were not increased at any of the HQ concentration.

Conclusion:

Our findings suggest that the mechanism of cell death in all three cell lines was through non-apoptotic pathway. In addition, neuroretinal R-28 cells were more sensitive to HQ than the ARPE-19 and HMVEC cultures.     

Conscious off-pump coronary artery bypass surgery

BACKGROUND: Cardiothoracic surgery has been previously performed successfully under thoracic epidural anesthesia alone. Between October 2001 and December 2003, we performed 123 conscious off-pump coronary artery bypass surgeries using epidural anesthesia as the sole anesthetic. This technique is an alternative to cardiothoracic surgery performed under general anesthesia. Certain modifications in the technique facilitate the process. METHODS AND RESULTS: There were 24 female patients and 99 male patients with mean age of 58.6 +/- 6.2 years; 12 patients underwent repeat coronary artery bypass surgery. All the patients underwent epidural catheterization on the evening before surgery. Out of the 123 patients scheduled for coronary artery bypass graft surgery, 120 underwent off-pump coronary artery bypass graft surgery successfully; 4 patients underwent off-pump surgery via left thoracotomy and the rest through mid sternotomy. These patients received 295 grafts in all (single graft in 26 patients, double in 42 patients, triple in 35 patients, and quadruple in 20 patients). Three patients required conversion to general anesthesia and one to cardiopulmonary bypass. There was no mortality in the group. CONCLUSIONS: Our experience suggests that by modifying the surgical techniques, we can accomplish conscious coronary artery bypass surgery.