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Atrial Fibrillation Ablation Leads to reverse Remodelling of Cardiac Chambers: A Cardiac Magnetic Resonance Study
S20
Heart, Lung and Circulation 2009;18S:S1–S286
Abstracts
ABSTRACTS
Methods: 518 interpretable images were available from the data sets of 52 patients (31 male, 21 female, mean age 61 years). CT data was reconstructed for 10 phases of the cardiac cycle and retrospectively analysed to establish a mean coronary sinus (CS) area for each cardiac phase. Logistic regression was used to determine the correlates of maximal CS area. Results: There was marked inter-individual variation in CS area (mean 81.8 mm2 , SD 33.6 mm2 ) and the maximal mean area occurred at 40% of the cardiac cycle (99.2 mm2 , SD 40.3 mm2 ). The ratio of the maximum to minimum area can partition responses dichotomously into a phasic or non-phasic response. Increasing age and male gender were associated with higher probability of non-phasic variability (logistic regression: age p = 2.61 × 10−13 , male p = 4.85 × 10−7 ). The interval between 30% and 50% of the cardiac cycle represented maximal CS area in 79% of cases. Increasing age and non-phasic variability were associated with a lower probability of the maximal area occurring within the 30–50% interval (logistic regression: age p = 2 × 10−16 , non-phasic variability p < 0.002). Conclusions: Maximal mean CS area occurs in the systolic phases of the cardiac cycle. CS area demonstrates less phasic variation in males and decreases with age. This translates into a lower probability of maximal CS area occurring within the 30–50% interval, particularly after age 70 years. This is relevant to deciding the appropriate reconstruction intervals in prospectively gated scans. doi:10.1016/j.hlc.2009.05.041 40 ATRIAL FIBRILLATION ABLATION LEADS TO REVERSE REMODELLING OF CARDIAC CHAMBERS: A CARDIAC MAGNETIC RESONANCE STUDY P. Molaee, K.S.L. Teo, P. Kuklik, S.G. Worthley, P. Sanders Cardiovascular Research Centre, Department of Cardiology, Royal Adelaide Hospital and the Disciplines of Medicine and Physiology, University of Adelaide, Adelaide, Australia Background: Atrial fibrillation (AF) is associated with tachycardia mediated remodelling of the atria and ventricles. The long-term effects of AF ablation on the cardiac chambers have not been fully established. Methods: 31 patients (21 M, age 60.0 ± 7.9 year; 23 paroxysmal) undergoing AF ablation had cardiac magnetic resonance imaging (1.5 T), in sinus rhythm, at baseline and 12 months post-ablation. Ablation comprised circumferential pulmonary vein isolation in all, with substrate modification (linear ± complex fractionated atrial electrogram ablation) in patients with AF episodes >48 h, largest left atrial (LA) size >57 mm or structural heart disease. Steady state free precession cine images were acquired, and chamber volumes were calculated using Simpson’s rule. Results: 81% of this cohort was in sinus rhythm without the use of antiarrhythmic drugs at 12 months post procedure. Table 1 presents changes in cardiac chamber size and function at baseline and 12 months.
Table 1. Maximum LA volume (mL) LA ejection fraction (%) Maximum right atrial volume (mL) LV end-diastolic volume (mL) LV ejection fraction (%) LV mass (g) RV end-diastolic volume (mL) RV ejection fraction (%)
Pre-ablation
Post-ablation
P value
102.5 ± 34.5
91.0 ± 27.7
0.002
46.2 ± 7.2
40.2 ± 7.8
0.003
97.4 ± 35.0
85.1 ± 24.4
0.002
153.2 ± 37.2
137.0 ± 36.3
<0.0001
73.9 ± 7.9
74.4 ± 7.3
0.71
129.0 ± 35.8 181.9 ± 53.8
121.8 ± 35.1 159.2 ± 42.4
0.019 <0.0001
52.5 ± 11.3
57.4 ± 9.9
0.021
Conclusion: AF ablation results in a significant reduction in atrial and ventricular volumes, LV mass, and improvement in ventricular function at long term follow up. Interestingly, the reduction in size of the right atrium, where ablation had not been performed, implicates a possible role for reverse remodelling following AF ablation. doi:10.1016/j.hlc.2009.05.042 41 AUTOMATED TWO-DIMENSIONAL SPECKLE TRACKING STRAIN IMAGING FOR CORONARY ARTERY DISEASE IN PATIENTS UNDERGOING DOBUTAMINE ECHOCARDIOGRAPHY Arnod C.T. Ng 2 , Phuong Pham 1 , Jane Vidaic 1 , Christine Allman 1 , Melissa Leung 1 , Liza Thomas 1 , Dominic Leung 1 1 Liverpool 2 Leiden
Hospital, Liverpool, NSW, Australia University Medical Centre, Leiden, The Netherlands
Background: Wall motion analysis during dobutamine stress echocardiogram (DSE) is subjective resulting in significant inter-observer variability. We studied the feasibility and accuracy of automated radial, circumferential and longitudinal strain analyses with two-dimensional speckle tracking (2DST) and the value of evaluating LV dyssynchrony in detecting significant coronary disease during DSE. Methods: Radial, circumferential and longitudinal LV strain were studied during DSE in 40 patients (aged 62.7 ± 9.5 years, 25 men) who later underwent invasive coronary angiography. LV dyssynchrony was measured as the maximum delay in times to peak LV strain normalized to the RR interval. Significant coronary stenosis was defined by quantitative coronary angiography as ≥50% diameter stenosis (n = 25). Results: Combined analysis of peak strain of the three orthogonal axes had the highest diagnostic accuracy compared with expert visual assessment and analysis of each individual plane. LV radial, circumferential and longitudinal strain dyssynchrony increased with higher heart rates,
Heart, Lung and Circulation 2009;18S:S1–S286
Abstracts
ABSTRACTS
Methods: 518 interpretable images were available from the data sets of 52 patients (31 male, 21 female, mean age 61 years). CT data was reconstructed for 10 phases of the cardiac cycle and retrospectively analysed to establish a mean coronary sinus (CS) area for each cardiac phase. Logistic regression was used to determine the correlates of maximal CS area. Results: There was marked inter-individual variation in CS area (mean 81.8 mm2 , SD 33.6 mm2 ) and the maximal mean area occurred at 40% of the cardiac cycle (99.2 mm2 , SD 40.3 mm2 ). The ratio of the maximum to minimum area can partition responses dichotomously into a phasic or non-phasic response. Increasing age and male gender were associated with higher probability of non-phasic variability (logistic regression: age p = 2.61 × 10−13 , male p = 4.85 × 10−7 ). The interval between 30% and 50% of the cardiac cycle represented maximal CS area in 79% of cases. Increasing age and non-phasic variability were associated with a lower probability of the maximal area occurring within the 30–50% interval (logistic regression: age p = 2 × 10−16 , non-phasic variability p < 0.002). Conclusions: Maximal mean CS area occurs in the systolic phases of the cardiac cycle. CS area demonstrates less phasic variation in males and decreases with age. This translates into a lower probability of maximal CS area occurring within the 30–50% interval, particularly after age 70 years. This is relevant to deciding the appropriate reconstruction intervals in prospectively gated scans. doi:10.1016/j.hlc.2009.05.041 40 ATRIAL FIBRILLATION ABLATION LEADS TO REVERSE REMODELLING OF CARDIAC CHAMBERS: A CARDIAC MAGNETIC RESONANCE STUDY P. Molaee, K.S.L. Teo, P. Kuklik, S.G. Worthley, P. Sanders Cardiovascular Research Centre, Department of Cardiology, Royal Adelaide Hospital and the Disciplines of Medicine and Physiology, University of Adelaide, Adelaide, Australia Background: Atrial fibrillation (AF) is associated with tachycardia mediated remodelling of the atria and ventricles. The long-term effects of AF ablation on the cardiac chambers have not been fully established. Methods: 31 patients (21 M, age 60.0 ± 7.9 year; 23 paroxysmal) undergoing AF ablation had cardiac magnetic resonance imaging (1.5 T), in sinus rhythm, at baseline and 12 months post-ablation. Ablation comprised circumferential pulmonary vein isolation in all, with substrate modification (linear ± complex fractionated atrial electrogram ablation) in patients with AF episodes >48 h, largest left atrial (LA) size >57 mm or structural heart disease. Steady state free precession cine images were acquired, and chamber volumes were calculated using Simpson’s rule. Results: 81% of this cohort was in sinus rhythm without the use of antiarrhythmic drugs at 12 months post procedure. Table 1 presents changes in cardiac chamber size and function at baseline and 12 months.
Table 1. Maximum LA volume (mL) LA ejection fraction (%) Maximum right atrial volume (mL) LV end-diastolic volume (mL) LV ejection fraction (%) LV mass (g) RV end-diastolic volume (mL) RV ejection fraction (%)
Pre-ablation
Post-ablation
P value
102.5 ± 34.5
91.0 ± 27.7
0.002
46.2 ± 7.2
40.2 ± 7.8
0.003
97.4 ± 35.0
85.1 ± 24.4
0.002
153.2 ± 37.2
137.0 ± 36.3
<0.0001
73.9 ± 7.9
74.4 ± 7.3
0.71
129.0 ± 35.8 181.9 ± 53.8
121.8 ± 35.1 159.2 ± 42.4
0.019 <0.0001
52.5 ± 11.3
57.4 ± 9.9
0.021
Conclusion: AF ablation results in a significant reduction in atrial and ventricular volumes, LV mass, and improvement in ventricular function at long term follow up. Interestingly, the reduction in size of the right atrium, where ablation had not been performed, implicates a possible role for reverse remodelling following AF ablation. doi:10.1016/j.hlc.2009.05.042 41 AUTOMATED TWO-DIMENSIONAL SPECKLE TRACKING STRAIN IMAGING FOR CORONARY ARTERY DISEASE IN PATIENTS UNDERGOING DOBUTAMINE ECHOCARDIOGRAPHY Arnod C.T. Ng 2 , Phuong Pham 1 , Jane Vidaic 1 , Christine Allman 1 , Melissa Leung 1 , Liza Thomas 1 , Dominic Leung 1 1 Liverpool 2 Leiden
Hospital, Liverpool, NSW, Australia University Medical Centre, Leiden, The Netherlands
Background: Wall motion analysis during dobutamine stress echocardiogram (DSE) is subjective resulting in significant inter-observer variability. We studied the feasibility and accuracy of automated radial, circumferential and longitudinal strain analyses with two-dimensional speckle tracking (2DST) and the value of evaluating LV dyssynchrony in detecting significant coronary disease during DSE. Methods: Radial, circumferential and longitudinal LV strain were studied during DSE in 40 patients (aged 62.7 ± 9.5 years, 25 men) who later underwent invasive coronary angiography. LV dyssynchrony was measured as the maximum delay in times to peak LV strain normalized to the RR interval. Significant coronary stenosis was defined by quantitative coronary angiography as ≥50% diameter stenosis (n = 25). Results: Combined analysis of peak strain of the three orthogonal axes had the highest diagnostic accuracy compared with expert visual assessment and analysis of each individual plane. LV radial, circumferential and longitudinal strain dyssynchrony increased with higher heart rates,