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A simple, accurate and precise UV spectrometric method has been developed for the simultaneous determination of valsartan and hydrochlorothiazide in tablet dosage form. Spectra of valsartan and hydrochlorothiazide in methanol and water (50:50 V/V) show λ max at 250.0 nm and 271.4 nm, respectively. Valsartan and hydrochlorothiazide are subjected to various stress conditions like acid, alkali, thermal and photolytic degradation. Beer's law was obeyed in concentration range of 4-24 μg mL-1 for valsartan and 0.5-3 μg mL-1 for hydrochlorothiazide at their respective wavelengths. The proposed method was successfully applied to tablet dosage form for determination of both drugs. The percentage recovery of valsartan and hydrochlorothiazide were found to be 100.19 % and 99.51 %, respectively. A novel accurate and precise stability indicating spectroscopic method has been developed for estimation of valsartan and hydrochlorothiazide. [ABSTRACT FROM AUTHOR]

High Mg-Al granulite occurs as enclave within granite gneisses at Karimnagar, southern India, and it contains coarse granoblastic aggregates of orthopyroxene and sapphirine with minor amount of cordierite, spinel and phlogopite. An important chemical characteristic of these minerals is their extremely high MgO content and the high CrO in sapphirine and spinel. Textural analysis shows sapphirine + orthopyroxene + cordierite as the peak-metamorphic assemblage that possibly evolved though the breakdown of a spinel-bearing assemblage. Cation exchange geothermometers involving orthopyroxene, sapphirine and spinel yield temperatures of 600-800 °C with a maximum of 860 °C implying an event of high temperature (HT) metamorphism. Pseudosection analysis in the FeO-MgO-AlO-SiO chemical system shows the stability of the peak- assemblage below 6.2 kbar. Subsequently, the rock underwent hydration and cooling with the appearance of phlogopite in the assemblage. Chromium enrichment is possibly inherited from the protolith and its presence presumably stabilized sapphirine and spinel below their high-temperature stability field. The recorded Rb-Sr age of ca. 2,500 Ma in host granite gneiss marks the upper age limit of HT metamorphism. Presence of patchy, lobate grains as well as veinlets of uraninite and brannerite is also a characteristic feature of the rock. Uranium mineralization took place during the post peak metamorphic stage, sulfide mineralization represented by tiny grains and veinlets of pyrite, millerite and pentlandite coincided with, and outlasted the uranium mineralization. The U-Th-Pb chemical ages of uraninite grains suggest ca. 2,200 ± 12 Ma for the age of uranium mineralization in the granulite. Based on the field relations, it is surmised that the granulite metamorphism in the study area is older than ca. 2,500 Ma and is comparable with an event in the other parts of Eastern Dharwar Craton. It can be conceived as a widespread event in southern India. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to compare the characteristics and prevalence of late potentials (LP) in patients with nonischemic cardiomyopathy (NICM) and ischemic cardiomyopathy (ICM) etiologies and evaluate their value as targets for catheter ablation.Background: LP are frequently found in post-myocardial infarction scars and are useful ablation targets. The relative prevalence and characteristics of LP in patients with NICM is not well understood.Methods: Thirty-three patients with structural heart disease (NICM, n = 16; ICM, n = 17) referred for catheter ablation of ventricular tachycardia were studied. Electroanatomic mapping was performed endocardially (n = 33) and epicardially (n = 19). The LP were defined as low voltage electrograms (<1.5 mV) with onset after the QRS interval. Very late potentials (vLP) were defined as electrograms with onset >100 ms after the QRS.Results: We sampled an average of 564 +/- 449 points and 726 +/- 483 points in the left ventricle endocardium and epicardium, respectively. Mean total low voltage area in patients with ICM was 101 +/- 55 cm(2) and 56 +/- 33 cm(2), endocardial and epicardial, respectively, compared with NICM of 55 +/- 41 cm(2) and 53 +/- 28 cm(2), respectively. Within the total low voltage area, vLP were observed more frequently in ICM than in NICM in endocardium (4.1% vs. 1.3%; p = 0.0003) and epicardium (4.3% vs. 2.1%, p = 0.035). An LP-targeted ablation strategy was effective in ICM patients (82% nonrecurrence at 12 +/- 10 months of follow-up), whereas NICM patients had less favorable outcomes (50% at 15 +/- 13 months of follow-up).Conclusions: The contribution of scar to the electrophysiological abnormalities targeted for ablation of unstable ventricular tachycardia differs between ICM and NICM. An approach incorporating LP ablation and pace-mapping had limited success in patients with NICM compared with ICM, and alternative ablation strategies should be considered. [ABSTRACT FROM AUTHOR]

High defibrillation thresholds (DFTs) occasionally are encountered during placement of implantable cardioverter defibrillators (ICDs). There are multiple strategies to lower DFTs in such patients, including reassessment of right ventricular lead position, alteration of the shock waveform, and implantation of subcutaneous arrays. This article describes a novel technique of implanting a high-voltage lead in the azygos vein. This procedure may serve as an adjunctive approach to reduce DFTs. The anatomic location of the azygos vein posterior to the heart provides a suitable shocking vector between the right ventricular electrode, a high-voltage lead placed in the azygos vein, and the ICD can. [ABSTRACT FROM AUTHOR]

Coronary sinus cannulation and placement of left ventricular (LV) leads can be difficult. Occasionally alternative approaches are required. We report the first case of a modified transseptal LV endocardial lead placement via the left axillary vein for cardiac resynchronization. [ABSTRACT FROM AUTHOR]