Evaluation of the JT and corrected JT intervals as a new ECG method for monitoring doxorubicin cardiotoxicity in the dog

Early Diagnosis of Problems Related to the Self-Organization of the Cardiovascular System Based on the Interplay between RR and JT Cardiac Intervals

The dynamics of the collapse of complexity observable in the performance of the cardiovascular system during the stress test is investigated in this paper. For this purpose, the interplay between the RR and JT cardiac intervals is measured and assessed for each participant. This case study involves a modest sample size of eight individuals with normal and elevated blood pressure. Although it is anticipated that the interaction between the RR and JT intervals is rather complex during the stress test, the existence of interpretable time delays between those cardiac intervals is demonstrated using the time delayed patterns algorithm. The assessment of the cardiovascular mobilization taking place during the stress test is also an integral part of this study. The velocity of adaptation index Ad and the newly formulated modified adaptation index Ar (computed only for the recovery phase) are used to quantify the healthy mobilization of the cardiovascular system for each participant. The time frequency analysis of the difference signal between the RR and JT intervals is used to quantify the collapse of complexity around the load termination point. Finally, a semi-gauge indication tool is constructed to assess the overall goodness of the self-organization of the cardiovascular system during the stress test.

Treatment with DAV for advanced-stage hemangiosarcoma in dogs

Hemangiosarcoma (HSA) is an aggressive disease that is fairly common in the dog. The authors evaluated a doxorubicin, dacarbazine, and vincristine (DAV) combination protocol in dogs with nonresectable stage II and stage III HSA. Twenty-four dogs were enrolled in this prospective, phase 2 study. Doxorubicin and dacarbazine were administered on day 1 while vincristine was administered on days 8 and 15. The protocol was repeated every 21 days for a maximum of six cycles or until disease progression. Toxicity and efficacy were assessed by clinical and laboratory evaluation and by questionnaires completed by the owners. Of the 24 included dogs, 19 were evaluable for response. The response rate (including five complete responses and four partial responses) was 47.4%. Median time to tumor progression was 101 days and median overall survival was 125 days. Significant toxicities were noted, including 41 high-grade hematologic and 12 high-grade gastrointestinal toxic events. Five dogs discontinued treatment due to chemotherapy-related toxicities, but no treatment-related deaths occurred. Multivariate analysis identified patient age (relative risk [RR], 2.3, P=0.049) to be negatively associated with time to progression whereas dacarbazine dose reductions (RR, 0.06, P=0.031) were positively associated with time to progression. Dacarbazine dose reduction was the sole factor positively associated with overall survival (RR, 0.28, P=0.015). In conclusion, the DAV combination appears to offer clinical responses and may prolong survival in dogs with advanced-stage HSA.