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Variations of cardiac rate and hemodynamic criteria of rejection
Insights
Heart rate variations do not significantly impact hemodynamic markers of rejection in heart transplant dogs. Serial studies comparing intrinsic and paced heart rates confirmed consistent rejection criteria regardless of rate changes.
Area of Science:
- Cardiovascular Physiology
- Transplantation Immunology
Background:
- Heart rate is a critical factor influencing hemodynamic parameters.
- Assessing hemodynamic criteria for rejection after cardiac transplantation requires understanding the impact of heart rate variations.
Purpose of the Study:
- To investigate the effect of heart rate variations on hemodynamic criteria of rejection post-cardiac transplantation.
- To determine if intrinsic versus paced heart rates alter the detection of rejection.
Main Methods:
- Serial hemodynamic assessments were performed in 11 homotransplanted dogs.
- Studies were conducted at intrinsic heart rate and a paced atrial rate of 150 beats/min.
- Cardiac index, stroke volume, peak velocity, acceleration, stroke power, and stroke work were analyzed across three postoperative phases (II, III, and IV).
Main Results:
- Hemodynamic parameter patterns showed similarity between intrinsic and paced atrial rates.
- No significant differences in rejection criteria were observed due to heart rate manipulation.
- Phase II (2-3 days post-transplant) served as a baseline for comparison with rejection phases III (4-5 days) and IV (6-7 days).
Conclusions:
- Heart rate variation does not significantly influence the hemodynamic criteria used to assess cardiac allograft rejection.
- Hemodynamic monitoring for rejection can be reliably performed across different heart rates.
Abstract:
Since heart rate influences the values of many hemodynamic parameters, the authors have examined the effect of heart rate variations noted after cardiac transplantation on the hemodynamic criteria of rejection. They have undertaken serial studies at intrinsic rate and at a paced atrial rate of 150 beats/min in 11 resting homotransplanted dogs. The authors analysed cardiac index, stroke volume, peak velocity, acceleration, stroke power and stroke work. Results at intrinsic and paced atrial rates were compared during each of three phases of postoperative evolution: phase II (2 to 3 days after transplantation), phase III (4 to 5 days) and phase IV (6 to 7 days postoperatively). Phase II, being the period of maximum recovery, served as a baseline for comparing the cardiac parameters in phases III (the initial phase of rejection) and phase IV (24 hours before death). The authors found that the patterns of change were similar at intrinsic and paced atrial rates and concluded that heart rate variation does not significantly influence the hemodynamic criteria of rejection.