Search PubMedSearch

Biomedical subjects

D I Roitman

Publications and source records attributed to D I Roitman.

6 recordsLinked to original sources

A quantitative technical quality assay method for electrocardiograms.

A method is presented for quantitative assessment of ECG technical quality to permit sensitive detection of performance trends of individual technicians or entire ECG laboratories. The common flaws in ECG recording technic are those which introduce ultra-low frequency artifact or baseline shift, powerline artifact, myographic and intermediate frequency artifact, clipping of waveforms, disconnection or reversal of electrodes and general faults of protocol adherence. Procedures for quantitating these attributes are presented and explained in order to arrive at a mean figure of merit for each ECG recording. Use of such a method can aid ECG technicians' understanding of the important features of tracing quality and provide an objective basis for the recognition of outstanding performance, on one hand, or the need for remedial training, on the other.

Electrocardiography

A controlled study of a new ECG electrode system.

A newly marketed resting ECG electrode system was compared with conventional metal suction and plate electrodes, electrode cream and patient cable. Two experienced technicians were given special training in the use of the new electrode, electrolyte and patient cable system and alternated daily in using new and conventional equipment. Nearly equal numbers of perfect-scoring ECGs were recorded with each system, attesting to the impartiality of the technicians. A total of 1,062 ECGs were evaluated, 554 with the new system and 508 with the conventional one. ECG tracings were evaluated by electrocardiographers unaware of which system was used for each. A quantitative scoring system was used to measure the technical quality of each tracing in terms of baseline drift, powerline artifact and myographic plus miscellaneous artifacts. The new system received mean scores of 2.33, 3.08, and 2.72, respectively, while the conventional electrodes received scores of 2.56, 3.03 and 2.79. We concluded that the two types of electrodes produced ECGs of essentially equal quality.

Electrocardiography

Interesting approaches to the diagnosis of angina pectoris.

Twelve different approaches to laboratory diagnosis of angina pectoris are reviewed here. They employ no fewer than seven different means of intentionally provoking a disparity between myocardial requirement and supply: dynamic exercise, hypoxia, prandial stress, raised systemic vascular resistance, paced tachycardia, mental stress, and exposure to normal environment. Of these, only dynamic exercise and the diverse combinations of stresses in the normal environment are capable of altering the heart's oxygen requirement-supply ratio threefold or more, accounting for the successful results from tests using these means of stress. The reviewed tests use three different means of detecting myocardial ischemia provoked by stress: electrocardiography to indicate impaired ventricular repolarization, indirect graphic records sensitive to impairment of mechanical ventricular function, and detection of insufficient myocardial perfusion patterns by radioactive tracer. The latter approach is particularly appealing because it directly reflects the pathophysiologic anomaly of interest. It should be remembered, however, that the basic differences in these methods of detecting ischemia make them complementary to each other and encourage their use in combination for improved diagnostic sensitivity.

Angina Pectoris