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Biomedical subjects

J W Calvin

Publications and source records attributed to J W Calvin.

5 recordsLinked to original sources
PubMed1978

Intraoperative pacemaker electrical testing.

To determine the clinical value of intraoperative pacemaker system electrical testing, the results of 200 consecutive pacemaker procedures (95 ventricular and 6 atrial primary implantations, 88 generator replacements, and 11 system revisions) were reviewed. The rationale and technique of testing maneuvers are described, including the use of a compact pacing system analyzer wrapped and used on the sterile operating field.

Electricity↗
PubMed1976

Permanent atrial pacing. Epicardial approach - "pinch-on" electrodes.

Atrial pacing, while recognized to have therapeutic indications, has not been easily accomplished because there have been no simple and reliable electrodes available. A short parasternal mediastinotomy provides sufficient exposure for easy application of "pinch-on" electrodes to the presenting fold of the right atrium. Special attention is given to the recording of electrical indexes of the pulse generator and electrodes (voltage threshold, calculated impedance, and intrinsic amplitude of the P wave) with testing apparatus, most of which is conveniently brought to the operative table. Less than ideal results are not accepted, and immediate replacement of the electrodes into adjacent areas of the atrial myocardium is performed with ease. Five patients have tolerated the procedure without complication. These electrodes and this operative procedure have proved to have been successful over a six-month term of observation.

Aged↗
PubMed1976

Perfusion lung scan patterns in 100 patients with bronchogenic carcinoma.

The relationship between size of the perfusion defect as seen by perfusion lung scan (PLS) and size of the mass lesion as seen radiologically was correlated with the presence of regional adenopathy in 100 consecutive patients with bronchogenic carcinoma. All patients underwent scanning before open thoracotomy or mediastinotomy and had histologic documentation of the disease. Each perfusion lung scan was classified as follows: (1) perfusion defect larger than the mass lesion. (2) perfusion defect of the same size as the mass lesion, or (3) no focal defect seen. Among patients with a larger perfusion defect 84 per cent were found to have regional lymph node involvements, whereas among patients in whom a larger defect was not present only 23 per cent had such extensions of the disease.

Adult↗