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Biomedical subjects

A Fieldman

Publications and source records attributed to A Fieldman.

29 records · Page 2Linked to original sources
PubMed1980

Bedside pulmonary angiography utilizing an existing Swan-Ganz catheter.

A single view, wedge, pulmonary angiogram was performed at bedside in nine patients using a Swan-Ganz catheter which had been inserted previously for other indications. Criteria for consideration of a bedside study were as follows: (1) a clinical suspicion of significant, acute pulmonary embolism; (2) the inability or inadvisability of transferring the patient for definitive studies; and (3) a Swan-Ganz catheter in situ. Seven of the nine patients subsequently died. Of five patients who underwent necropsy, three positive studies and one negative, were confirmed. No post-mortem evidence for embolism could be demonstrated in one patient with a positive study. Of the two patients who survived, one negative study was confirmed with a negative radionuclide perfusion lung scan. There was no morbidity or mortality associated with the procedure. These data suggest that this technique is safe and has a role in the early diagnosis of significant pulmonary embolism in selected critically ill patient.

Adolescent↗
PubMed1979

Gas pocket causing pacemaker malfunction.

Pacemaker malfunction was attributed to the increase in impedance to current flow caused by a pocket of air separating the anodal contact plate of a unipolar generator from the overlying skin. Lack of capture was noted 20 hours after implantation. The malfunction was permanently corrected by bedside aspiration of the gas with a sterile syringe.

Air↗
PubMed1978

Phantom pacemaker programming.

Spurious or "phantom" programming of programmable pacemakers may occur as the result of two phenomena. One is change in rate and/or output of the generator from an anomalous source (dysprogramming); the other is a generator response different from that intended and set on the conventional programmer (misprogramming). In either case, the result is a nuisance, at best. Conceivably, at worst, an irreversible subthreshold output could be induced. Despite wide usage of such devices, neither event has been reported. In the routine follow-up of 95 implanted Cordis Omni-Stanicor generators, we have observed three instances of dysprogramming upon application of a magnet commonly used to induce the asynchronous mode. Subsequent in vitro studies revealed magnetically induced programming reed switch vibration in 9 of 6,680 units, which could account for the in vivo observations. We also describe many instances of misprogramming, attributable, in most cases, to a faulty programmer emission count. In this series, none of the anomalies was clinically detrimental. However, anyone involved in pacemaker follow-up should be alerted to the existence of these potentially hazardous phenomena.

Cardiac Pacing, Artificial↗
PubMed1978

Clicks due to Swan-Ganz catheter.

Nonejection systolic and diastolic clicks appeared when a Swan-Ganz catheter was positioned in the proximal portion of the right pulmonary artery. The clicks disappeared on inflation of the catheter's balloon. Initial impressions included secondary prolapse of the mitral leaflets, an accentuated third heart sound, and the exposure of an occult opening snap. These high-frequency sounds are thought to be generated by the forward and backward movement of the catheter against either the proximal portion of the pulmonary artery or the right ventricular outflow tract or by a whipping action of the catheter itself.

Cardiac Catheterization↗
PubMedDate not supplied

The effect of quinidine sulfate on QRS duration and QT and systolic time intervals in man.

QRS duration, QT interval, total electromechanical systole (QS(2)), left ventricular ejection time (LVET), and preejection period (PEP) were determined in five male and two female healthy volunteers in a fasting state at hourly intervals for 7 hours during a control period and after administration of 400 mg quinidine sulfate. Changes of QRS duration (delta QRS) and rate-corrected QT interval (delta QTc) were calculated before and after quinidine. Deviations of measured QS(2), LVET, and PEP from the normal were calculated as the differences between the observed interval and those predicted from the normal regression equation. The effect of quinidine on systolic time intervals (delta QS(2), delta LVET, DELTA PEP) were expressed as the differences between the deviations from the normal regression equation during the control period and after the drug administration. After quinidine sulfate delta QRS, delta LVET, delta PEP, and delta PEP, delta LVET were slight and inconsistent. However, delta QTc and delta QS(2) were significant (at P is less than 0.05 or better) from the first hour to the 7th hour and from the 2nd hour to the 5th hour, respectively. The mean maximum delta QTc was 44.8 milliseconds and delta QS(2) was 29.9 milliseconds. The significant changes of QTc and QS(2) seemed to occur at the plasma level range of 0.75-1.9 mug/ml. This study indicates that of the various systolic time interval measurements obtained after quinidine administration, the changes of QT interval and QS(2) are most significant and that these changes seem to occur even at low plasma levels.

Adult↗