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Biomedical subjects

J S Varma

Publications and source records attributed to J S Varma.

65 records · Page 4Linked to original sources
PubMed1982

Subacute pulmonary hypertension and systemic tumour embolism from cervical cancer.

Venous tumour embolization is not unusual in malignant disease (1-3) usually in the form of individual cells or small clumps. Malignant cells in the pulmonary vasculature are therefore not an uncommon finding, especially in patients with abdominal neoplasms (4-7). Arterial emboli from a malignant tumour are, however, rare (8, 9), particularly peripheral ones (9, 10) and those sufficiently large to cause organ infarction. An unusual case of pulmonary and widespread systemic tumour embolization from carcinoma of the cervix is described in which systemic dissemination of tumour emboli had apparently resulted from transpulmonary passage, without the development of pulmonary metastases.

Aged↗
PubMedDate not supplied

Autonomic influences on colorectal motility and pelvic surgery.

The nervous control of the motility of the human distal bowel was investigated by two physiological studies of electrical stimulation of sacral parasympathetic outflow in patients with high spinal injuries and in patients with intractable constipation following pelvic surgery. Identical and reproducible motility responses of the left colon, rectum, and anal sphincters were obtained by sequential electrical stimulation of anterior sacral roots S2, S3, and S4 in patients with spinal injury. S2 stimulation provoked isolated low-pressure colorectal contractions. S3 stimulation initiated frequency-dependent high-pressure colorectal motor activity which appeared peristaltic and was enhanced with repetitive stimuli. S4 stimulation increased colonic and rectal tone. Quantitative responses were maximal at the splenic flexure and rectum. Pelvic floor activity was stimulated in increasing magnitude from S2 to S4. These results of distal bowel motility were achieved by an implanted Brindley stimulator. A newer generation of externally active stimulators are envisaged for the control of lower bowel in fecal incontinence. Women with intractable constipation following hysterectomy had significantly increased rectal volume and compliance together with deficits of rectal sensory function. Following stimulation with Prostigmine (neostigmine) a colorectal motility gradient was paradoxically reversed in the patients following hysterectomy, thus constituting a functional obstruction. Denervation supersensitivity was demonstrable in 2 patients tested with carbachol provocation. These findings suggest dysfunction in the autonomic innervation of the hindgut in some patients following hysterectomy.

Adult↗
PubMedDate not supplied

A cardiac evoked response algorithm providing automatic threshold tracking for continuous capture verification: a single-center prospective study.

BACKGROUND: The AutoCapture algorithm as implemented in Regency and Microny pacemakers (Pacesetter Inc., Sylmar, CA, USA) provides beat-by-beat monitoring of capture based on proper detection of the evoked response, provides high output back-up pulse when loss of capture occurs, performs periodic threshold evaluations and acquires the capture threshold data in a time-based event counter for later retrieval. The safety and efficacy of this algorithm was prospectively evaluated at a tertiary care hospital of north India. METHODS AND RESULTS: Fifty-four patients (38 males, mean age 66+/-13 years) received a ventricular pacemaker model Regency SC+ with low polarization bipolar lead for high-grade atrioventricular block (n=42) and sick sinus syndrome (n=12). Evoked response and polarization signal were assessed initially at 24 hours postimplant, and follow-up measurements were systematically conducted at week 1 and months 1, 3 and 6. Further evaluation of eligible patients was performed at 6-monthly intervals. Lead implantation parameters were optimum in all patients. At 6 months, the algorithm was functional in 51 patients. The pacing threshold increased to 0.89+/-0.36 V (p<0.001) in the first month and stabilized thereafter. Significant saving of energy was accomplished by a constant output safety margin of 0.3 V instead of the traditional 100%. While the evoked response signal remained stable throughout the study period, the potential signal increased significantly from 0.6+/-0.7 mV to 1.0+/-0.6 mV (p<0.001) in the first month and remained steady subsequently. Back-up pacing in the event of exit block was confirmed in all 25 patients who underwent a 24-hour Holter test. Based on the suggested sense margins, ventricular undersensing was observed in 7 (28%) patients, the majority of whom had competitive cardiac rhythms. An elderly patient with pneumonic illness succumbed to pulmonary embolism at 6 months. CONCLUSIONS: This large single-center experience on AutoCapture demonstrates the success of this algorithm in low-energy ventricular pacing without compromising the patient's safety.

Adolescent↗