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Biomedical subjects

B Singh

Publications and source records attributed to B Singh.

1,131 records · Page 63Linked to original sources
PubMedDate not supplied

Anatomic considerations in relation to the mandibular nerve block.

OBJECTIVES: To determine the length of needle that should be advanced beyond the distance to the lateral pterygoid plate to reach the mandibular nerve. METHODS: The study was conducted on patients and skulls. PATIENT STUDY: Distances from the skin at midpoint of the zygomatic arch to lateral pterygoid plate and to the point where mandibular nerve paraesthesia occurred were measured in 74 patients having mandibular nerve block for treatment of neuralgic pain. Osteologic study: Distances from the midpoint of the zygomatic arch to lateral pterygoid plate and to a probe inserted vertically into the foramen ovale were measured in 76 dry skulls. RESULTS: Patient study: The distance to the point where mandibular nerve paraesthesia occurred was more than that to lateral pterygoid plate by 0.07 cm on right and 0.11 cm on left. Osteologic study: The distance to the probe in the foramen ovale (representing mandibular nerve) was less than the distance to lateral pterygoid plate by 0.08 cm on the right and 0.07 cm on the left. CONCLUSIONS: There is no osteologic basis to advance the needle beyond the distance to the lateral pterygoid plate to reach mandibular nerve. However, because the needle may contact the nerve at variable points rather than the shortest distance to the nerve, the needle may be advanced by 0.07 cm on the right and 0.11 cm on the left side in patients. This increase is much less than that indicated in the standard textbooks. Therefore, while performing mandibular nerve block, we suggest caution in advancing the needle beyond the distance to lateral pterygoid plate.

Adult↗
PubMedDate not supplied

Transcatheter ablation of ventricular tachycardia arising from right ventricular outflow tract.

Two patients with recurrent episodes of symptomatic, sustained monomorphic ventricular tachycardia (VT) resistant to medical therapy underwent catheter ablation for the relief of VT. One patient had arrhythmogenic right ventricular dysplasia while the other had no structural heart disease. The VT had left bundle branch block morphology with normal axis in both the patients. The cycle length during VT was 260 msec and 270 msec respectively. Site for ablation was guided by pacemapping and the target site was identified in the right ventricular outflow tract in both the patients. Two cathodal shocks of 200 J in the first patient and one shock of 200 J in the second patient resulted in abolition of the arrhythmia. At repeat electrophysiologic testing at 7 days in the first patient and at 8 months in the second, VT was not inducible despite three extrastimuli from two right ventricular sites. Over a follow up of 24 and 26 months respectively, there has been no recurrence without any antiarrhythmic therapy. There were no acute or long term complications. In conclusion, catheter ablation offers a cure in patients with right ventricular tachycardia resistant to antiarrhythmic drugs.

Adult↗
PubMedDate not supplied

Radiofrequency ablation of idiopathic ventricular tachycardia.

Eleven patients (9 male, 2 female) with ventricular tachycardia (VT) and structurally normal heart underwent radiofrequency (RF) ablation of VT focus. The detailed electrophysiological mapping localized the VT focus in the left ventricular (LV) apicoseptal region in 5, LV posteroseptal region in 2, right ventricular (RV) outflow tract in 2 and RV midseptal and inflow regions in one patient each. The technique of endocardial activation mapping during VT, pacemapping and the presence of His-Purkinje potential (for LV focus) were used to identify the precise site of delivery of RF energy. The procedure was successful in 9 patients. There was no complication. The mean fluoroscopic time was 45 +/- 21 (range 20-120) minutes. RF ablation is effective and may be considered as therapy of choice for patients with ventricular tachycardia and normal heart.

Adolescent↗
PubMedDate not supplied

In-hospital results of radiofrequency ablation of supraventricular tachycardia.

Two hundred and one consecutive patients with symptomatic paroxysmal supraventricular tachycardia (PSVT) underwent a diagnostic electrophysiological test and catheter ablation with radiofrequency (RF) current. In 102 (51%) patients, the mechanism of PSVT was found to be atrioventricular nodal reentry (AVNRT, typical in 101, atypical in 1). Atrioventricular reentrant tachycardia (AVRT) involving accessory pathway was present in 94 (47%) and ectopic atrial tachycardia in 5 patients. A successful outcome was achieved in 100 of 102 patients (98%) with AVNRT and in 85 of 94 patients (90%) with AVRT. The anatomical approach was used for ablation in patients with AVNRT. The focus was ablated in 4 patients with ectopic atrial tachycardia whereas it was modified in the remaining one patient. Procedure-related complications occurred in 4 patients (2 AVNRT, 2 AVRT). One patient each developed haemothorax, pericardial effusion, mitral valve endocarditis and high-grade AV block requiring permanent pacemaker implantation. The electrode and ablation catheters were repeatedly used after ethylene oxide sterilisation to reduce the cost of the procedure. RF ablation is an effective, safe and curative modality of treatment for patients with symptomatic PSVT due to AVNRT and AVRT. The experience with this modality in patients with ectopic atrial tachycardia is limited.

Adolescent↗
PubMedDate not supplied

Analysis of local electrograms at successful and unsuccessful sites for slow pathway ablation of atrioventricular nodal reentrant tachycardia.

Anatomic and electrogram approaches have been described for ablation of slow pathway in patients with atrioventricular nodal tachycardia. The purpose of this study was to identify parameters to predict successful slow pathway ablation using the anatomic approach. Local electrograms at successful and unsuccessful sites were compared in 36 patients undergoing slow pathway ablation using anatomic approach. A total of 208 local electrograms were studied. Fragmented atrial electrogram was seen in 24/36 (67%) of successful and in 46/172 (26%) of unsuccessful sites (p < 0.001). The sensitivity, specificity and positive and negative predictive values of fragmented atrial electrogram were 67, 73, 34 and 91 percent respectively. A slow pathway potential was noted in three of successful sites. There was no difference in the atrial to ventricular amplitude ratio in these sites. In conclusion, fragmentation of atrial electrogram and presence of possible slow pathway potential are seen more often at successful than at unsuccessful sites. In our opinion, while using an anatomic approach for slow pathway ablation, an analysis of local electrogram may help in identifying the proper site and avoiding unnecessary radiofrequency energy delivery.

Adult↗
PubMedDate not supplied

Medication-induced gingival enlargement: a clinical review.

This review discusses the etiology and treatment of gingival hyperplasia. It cites evidence that medications such as phenytoin, an anticonvulsant; cyclosporine, an immunosuppressant; and numerous calcium channel blocking agents have been shown clinically and histologically to produce analogous gingival enlargements. A multiphasic approach to treating disfiguring gingival hyperplasia through mechanical and chemical plaque control, in conjunction with the surgical removal of the hyperplastic tissue, is discussed.

Anticonvulsants↗
PubMedDate not supplied

Congenital anomalies of domestic fowl: seven cases.

In 13,483 necropsies of domestic fowl, six anomalies were recorded: bifurcation of the metasternum, duplication of the ileum, pancreas divisum (partial), vesica fellea occulta, aplasia of the left cecum, and aplasia of the right kidney (2 cases).

Animals↗
PubMedDate not supplied

Malignant gastroparesis and outlet obstruction in carcinoma gall bladder.

INTRODUCTION: Malignant gastroparesis and mechanical gastric outlet obstruction are two major accompaniments of advanced upper abdominal malignancies. The incidence of such problems has not been well documented in patients of carcinoma gall bladder. The aim of this study was to determine the incidence of gastric outlet problems in patients of carcinoma gall bladder and correlate them with clinical presentation. The role of prophylactic gastrojejunostomy (GJ) and its postoperative outcome was also evaluated. PATIENTS AND METHODS: Thirty seven patients of carcinoma gall bladder were prospectively studied. Twenty five patients underwent radio labelled solid meal gastric emptying study and eleven of these underwent prophylactic GJ and followup gastric emptying study in early postoperative period. RESULTS: Mechanical gastric outlet obstruction was seen in 10 (27%) patients. Delayed gastric emptying on scintigraphic study was found in 10 (40%) of remaining patients (n = 25). Only 6 (60%) of these patients were actually symptomatic. All patients who had delayed gastric emptying also had an advanced disease. No correlation was found between delayed gastric emptying and presence of jaundice and/or serum levels of bilirubin. Prophylactic GJ had 18% postoperative morbidity as compared to 28.5% for therapeutic GJ done during the same period. Oral feed were started latest by 11th postoperative day. Prophylactic GJ did not affect gastric emptying patterns in early postoperative period. CONCLUSION: Mechanical gastric outlet obstruction was present in 27% patients. Delayed gastric emptying was seen in 40% of remaining patients with carcinoma gall bladder. Delayed gastric emptying correlated well with symptoms of gastric stasis and the stage of disease. Functioning of gastrojejunostomy was not fully dependent on presence or absence of malignant gastroparesis.

Carcinoma↗
PubMedDate not supplied

Outcomes of primary stenting for acute myocardial infarction.

Primary coronary stenting is being increasingly used in patients undergoing primary coronary angioplasty for acute myocardial infarction. In this prospective study we analysed our experience of direct angioplasty in 76 patients with acute myocardial infarction of whom 65 received intracoronary stents using high pressure deployment (> or = 12 atm) with adjunctive aspirin and ticlopidine therapy but without coumadin. All patients underwent pre-discharge angiography. Stent implantation was successful in all patients. Stent thrombosis was not seen in any patient. However, TIMI grade 3 flow was obtained in only 58 (89.2%) patients with evidence of slow-flow present in the remaining seven patients. Pre-discharge angiograms showed no-stent thrombosis but five out of the seven (71%) patients with slow-flow phenomenon persisted to have slow-flow. These patients had lower left ventricular ejection fraction as compared to patients with TIMI 3 flow at pre-discharge angiography (27.5 +/- 10.2% vs 42.1 +/- 15.2%; p < 0.001) and a high mortality (2 out of 7) within 30 days. Primary stenting is safe and feasible in the majority of patients with good short-term outcome. But persistent slow-flow phenomenon with adverse clinical outcome is seen in a small but significant number of patients.

Adult↗