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Biomedical subjects

I A Kraft

Publications and source records attributed to I A Kraft.

At least 19 recordsLinked to original sources
PubMed1977

Functional independence of donor and recipient cardiac tissues of single and double heart transplant patients revealed by chronobiology.

3 total (single) and 1 double-heart-transplant patients were studied for temporal changes in the electrical events of cardiac function. Results of statistical analyses document the existence of circadian rhythms in the donor and recipient P--P or R--R intervals. However, for 1 total-heart-transplant patient studied at intervals during the year following implant and the double-heart-transplant patient 5 mth after surgery, the period (tau) of the rhythm in the P--P or R--R interval of the recipient tissue deviated greatly from that of 24.0 h. For the total-heart-transplant patient studied 1 mth prior to death, the tau was 32.3 h; for the double-heart-transplant patient, the tau was 29.0 h. In both patients, the donor heart tissue continued to exhibit a 24-h rhythm. These findings imply that changes in tau for the rhythm in P--P or R--R interval may reflect aspects of disrupted physiologic, feedback, regulatory mechanisms or perhaps graft rejection. Although additional study is required, the possibility that alteration in tau is associated with rejection is intriguing since if documented, then the noninvasive monitoring of ECG and subsequent analysis of data for significant deviations of tau from 24.0 h will be useful as an additional tool for monitoring host tolerance for the heart implant.

Bed Rest↗
PubMed1975

A common factor in the MMPI scales of married couples.

Using canonical analysis, a common factor in the MMPI scales of husbands and wives was found. The Sc, Pd, and Hs scales for both the husbands and the wives contributed heavily to the relationship. Other scales contributing to the correlation between the personality components of the pairs were F, Hy Pt, and Si for the husbands and Pa for the wives. The results were interpreted as indicating areas of homogeneity and heterogeneity in the personalities of married couples.

Anxiety↗
PubMed1975

Circadian rhythmicity in heart rate and duration of cardiac cycle (P-P interval) in donor and recipient cardiac tissue of heart homograft patients.

Chronobiologic analyses of data collected during one or more continuous 72-hr spans from 3 heart-transplant patients adhering at diurnal activity (0700-2230) and nocturnal rest (2230-0700) reveal statistically significant circadian rhythmicity in the P-P time interval of recipients (P-P)R and the donor (P-P)D, as well as in the reciprocal measure of the latter, the heart rate. The circadian acrophase for (P-P)D and (P-P)R differ slightly (the 95% confidence arcs overlap). For the group, the acrophases for (P-P)D and heart rate at 0344 (2056 to 0528) and 1656 (0940 to 2100) agree in anti-phase, as expected. For 1 patient studied during 3 separate occasions -1,5 and 12 months post-transplant--the period of the rhythm for the (P-P)R time interval progressively elongated from 23.7 hr (1 month post-transplant) to 26.1 hour (5 months post-transplant) and finally to 32.3 hr (12 months post-transplant and 4 months prior to death) while the (P-P)D remained around 24.0 hr (range 23.8 to 24.6 hr). Change in the rhythm's period in (P-P)R may reflect events associated with rejection, continuing necrosis of cardiac tissue and/or medications, among others.

Circadian Rhythm↗
PubMed1970

Circadian rhythms in human heart homograft.

The electrocardiogram and cardiotachogram of a patient with a human heart transplant has been recorded for 72 hours. Within the donor P-QRS-T complex, one can identify the P waves emanating from residual sinoatrial heart tissue of the recipient. The recipient P waves are independent of the donor complexes. A clear circadian rhythm (23.4 hours) in heart rate is maintained for both donor and recipient tissue, the donor complexes preceding by a phase shift of 135 minutes the complexes of the recipient heart tissue. Both tissues display clear morning and evening minimum and maximum rates paralleling activity and lighting cycles.

Circadian Rhythm↗