Effects of Atrio-ventricular Delay and Interventricular Delay on Continuous left Atrial Pressure and Waveforms in Ambulant Heart Failure Patients: A Novel Method for Cardiac Resynchronisation Therapy Optimization

Abstract

(62% in week one and 67% in week two), atrial arrhythmia (114% and 89%) and heart failure (44% and 67%). There was a dramatic surge of stress cardiomyopathy, especially following the second earthquake (none in 2009, six cases in the first two weeks following the 2010 earthquake and 24 cases in the first week of the 2011 earthquake). More data are currently been gathered and analysed following the 2011 earthquake. Conclusion: We have demonstrated significant increases in acute cardiology admissions following both earthquakes. This finding has important implications for future disaster planning. may be helpful for CRT optimisation. We evaluated the effect of changes in atrio-ventricular delay (AVD) and inter-ventricular delay (VVD) on LAP and its waveform morphology using a novel implantable LAP sensor. Methods: Eight ambulant patients (age 66± 12 yrs, EF 30± 10%) implanted with separate CRT-D and a new LAP monitoring system (PROMOTETM RF and HeartPODTM ISL, both from St. Jude Medical) underwent CRT optimization with echocardiographic guidance including transmitral and left ventricular outflow tract Doppler indices. LAP and intracardiac electrogramswere recorded at eight AVDs and five VVDs. Each LAP recording was 20 seconds long and was band-pass filtered to remove both high-frequency noise and respiration artifact. QRStriggered ensemble average waveforms were calculated for each recording and plotted to evaluate the effects of the different AVDs and VVDs on the LAP waveform. Results: Mean LAPs were lower in the more optimal echocardiography guided settings. All patients exhibited a dramatic response in waveform morphology to the changes in AVD (see figure) with the c-wave moving progressively into the a-wave and producing large cannon a-waves with shorter, less optimal AVD. VVD changes produced a less dramatic effect on LAP morphology. The effects were consistent between patients, with individual patient signals correlating closely with the mean population signal r= 0.80± 0.14. doi:10.1016/j.hlc.2011.03.019 Effects of Atrio-ventricular Delay and Interventricular Delay on Continuous left Atrial Pressure and Waveforms in Ambulant Heart Failure Patients: A Novel Method for Cardiac Resynchronisation Therapy Optimization W. Chan1,∗, A. Blomqvist 2, I. Melton1, K. Noren2, R.I. Crozier 1, Troughton1 1 Christchurch Hospital, New Zealand 2 St. Jude Medical AB, Sweden Background: Left atrial pressure (LAP) is sensitive to cardiac resynchronisation therapy (CRT) device settings and Conclusion: LAP and its waveformmorphology are sensitive to the effects of AVD and VVD in a consistent manner across patients. Further investigation of the role of LAP in CRT interval optimisation is warranted. A B S T R A C T S Heart, Lung and Circulation 379 2011;20:376–419 Abstracts