INFLUENCE OF HEART-RATE, RESPIRATION AND RECIPIENT ATRIAL CONTRACTIONON PULSED WAVE TRANSMITRAL DOPPLER FLOW INDEXES IN ORTHOTOPIC HEART-TRANSPLANT RECIPIENTS

Aims The study set out to assess the relative contributions of donor h eart rate, respiration and recipient atrial contrac tion on the mean o f pulsed wave transmitral Doppler flow indices in orthotopic heart tra nsplant recipients. This would provide information on the theoretical usefulness of pacemaker synchronization of recipient atrial contractio n, as well as on the validity of certain strategies used for pulsed wa ve Dopper analysis of diastolic left ventricular function, which have excluded beats based on recipient atrial contraction timing. Methods T hirty two consecutive patients undergoing orthotopic heart transplanta tion in our centre were prospectively studied. The following Dopper in dices were analysed. peak early diastolic velocity (E) and its area un der the Doppler curve (TVIE), diastolic velocity after donor atrial co ntraction (A) and its area under the curve (TVIA), the total area unde r the curve (TVI), the isovolumic relaxation period (IVR), the diastol ic filling period, the normalized peak filling rate and the pressure h alf time. Results Only 81 out of 347 recordings (23%) allowed analysis of the recipient P wave and thus recipient atrial contraction timing, heart rate and the respiration phase in 22 patients for a total of 15 79 beats. The isovolumic relaxation period, E, pressure half time and TVIA are not influenced by donor heart rate. For the isovolumic relaxa tion period, E, TVI and TVIE, respiration contributes as much as recip ient atrial contraction timing to beat-to-beat variation. Pressure hal f time, the diastolic filling period and peak filling rate were not af fected by respiration. TVI was not affected by recipient atrial contra ction timing. Conclusion With respect to analysis of diastolic functio n: exclusion of beats based on recipient atrial contraction timing is invalid for the isovolumic relaxation period, E, TVI and TVIE, since t hese are equally influenced by respiration. Since TVI was not affected by recipient atrial contraction timing, pacemaker synchronization of donor and recipient atria is not expected to be useful in patients wit h left ventricular diastolic dysfunction.