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Subclinical Systolic Dysfunction Following Chest Radiation Therapy Detected by Strain Imaging
S50
Abstracts CSANZ Abstracts 2011
ABSTRACTS
control sheep. Using linear regression with stepwise entry of significantly correlated variables, weight was predictive of RA fibrosis (P < 0.001) whereas LA pressure and atrial inflammation were each predictive of LA fibrosis (P < 0.001 and P = 0.008, respectively). Weight and total myocardial mass were each predictive of total atrial fibrosis burden (P < 0.001 and P = 0.018, respectively). In this model of weight gain and obesity; weight, LA hypertension, LA inflammation and total myocardial mass were individually predictive of either regional or global atrial fibrosis burden. This provides insights into mechanisms by which obesity may promote AF. doi:10.1016/j.hlc.2011.05.125 123 Sex Differences in Functional Response of Hypertrophic Cardiomyocytes to Simulated Ischaemic Insult C. Curl ∗ , T. Harding, J. Bell, S. Harrap, L. Delbridge University of Melbourne, Australia Sex differences in ischaemic heart disease have been documented, with most experimental evidence derived from intact heart studies. Limited investigations of cardiomyocyte function have been undertaken. The aim of this study was to investigate sex differences in the responses of hypertrophic cardiomyocytes to a simulated ischemic insult. Cardiomyocytes were isolated by collagenase digestion from hearts of adult (age 12–16 weeks) Hypertrophic Heart Rat (HHR) and Normal Heart Rat (NHR) inbred strains. Hypertrophic Heart Rat myocytes were significantly longer than NHR myocytes (male 138.4 ± 7.5 m vs 114.8 ± 6.6 m; female 127.9 ± 5.1 m vs 107.7 ± 4.4 m). Single myocyte contractility was measured by edge detection microscopy and Ca2+ levels tracked by microfluorimetry (IonOptix) in Fura2-AM loaded cells. Myocyte basal performance was monitored for 5 minutes under normoxia (4 Hz, 2.0 mM Ca2+ , 37 ◦ C) prior to 20 minutes simulated ischemia (0 mM glucose, pH 6.8, 10 mM lactate, N2 saturation) followed by 30 minutes simulated normoxic reperfusion. Under basal conditions both male and female HHR displayed hypercontractility when compared to NHR controls (% shortening: 4.95 ± 0.9 vs 3.38 ± 0.8; 5.93 ± 0.8 vs 3.04 ± 0.4). A similar pattern of difference was observed for Ca2+ transient amplitudes. After ischaemia and reperfusion the NHR female myocytes regained diastolic length and returned to basal shortening state (within 95%). In contrast, myocytes of all other groups exhibited rebound shortening increases relative to basal state (NHR male 187%, HHR female 123%, HHR male 142%). Thus the ischaemic resilience of female myocytes is lost when hypertrophy is present, and more closely resembles a male pattern of contractile and Ca2+ handling dysfunction. doi:10.1016/j.hlc.2011.05.126
Heart, Lung and Circulation 2011;20S:S1–S155
124 Subclinical Systolic Dysfunction Following Chest Radiation Therapy Detected by Strain Imaging Q. Lo 1,∗ , L. Hee 2 , V. Batumalai 2 , C. Delaney 2 , D. Lonergan 2 , L. Thomas 2
Allman 2 , G.
1 University 2 Liverpool
of New South Wales, Australia Hospital, Sydney, Australia
Background: Long term cardiac effects are documented after chest radiation (RT); however, its acute effects are not well characterised. Aim: We sought to evaluate acute changes in LV systolic function following chest RT by serial echocardiograms. Methods: Serial transthoracic echocardiograms (at baseline, during acute phase RT and at six weeks post RT) were performed on 20 women with left sided breast cancer post surgery undergoing only RT (mean dose 60 Gy) to the left chest. Conventional indices of LV ejection fraction (LVEF), tissue Doppler S velocity, strain (S) parameters were measured. Results: Although LV end diastolic (p < 0.001) and end systolic volumes (p < 0.003) increased, no change was observed in LVEF or serial S velocity by repeated measures ANOVA to examine within patient differences. However, global longitudinal peak systolic S (p < 0.003) was significantly reduced on serial measurement. Parameter
Baseline
LVEDV (ml) LVESV (ml) LVEF (%) S velocity (cm/s) Peak longitudinal S (%)
56.4 20.2 64 6.7 −20.4
± ± ± ± ±
8.8 4.1 5 1 2.4
During RT 58.2 21.9 63 6.8 −19.4
± ± ± ± ±
9.1 5.9 4 1.3 2.8
6 wks post RT
p value
± ± ± ± ±
p < 0.001 p < 0.003 NS NS p < 0.003
65.5 23.6 64 6.7 −18.8
10.9 4.4 5 1.4 2.4
Conclusions: Acute effects from left sided RT, that may include the heart in the field, are evident using strain measurements but are not evident using traditional measures. The long term clinical implication of reduction in strain parameters in these patients needs to be determined. doi:10.1016/j.hlc.2011.05.127 125 The Return of the Normal Heart: Cardiac Amyloidosis Regression After Bone Marrow Transplantation G. Scalia 1,∗ , J. Bashford 2 , B. Fitzgerald 1 1 Heart
Care Partners, Australia Oncology Clinics of Australia, Australia
2 Haematology
Purpose: Amyloidosis results in a median survival of 12 months, reducing to five months with cardiac infiltration. Bone marrow transplantation (BMT) has been shown to dramatically improve survival when haematologic remission is obtained. Our group had noticed that some patients with cardiac amyloidosis had return to normal function as assessed by echocardiography. Methods: Of 269 patients with BMT for amyloidosis, 30 (11.2%) had cardiac amyloidosis (thick walls, diastolic dysfunction, dilated atria and/or small pericardial effusions).
Abstracts CSANZ Abstracts 2011
ABSTRACTS
control sheep. Using linear regression with stepwise entry of significantly correlated variables, weight was predictive of RA fibrosis (P < 0.001) whereas LA pressure and atrial inflammation were each predictive of LA fibrosis (P < 0.001 and P = 0.008, respectively). Weight and total myocardial mass were each predictive of total atrial fibrosis burden (P < 0.001 and P = 0.018, respectively). In this model of weight gain and obesity; weight, LA hypertension, LA inflammation and total myocardial mass were individually predictive of either regional or global atrial fibrosis burden. This provides insights into mechanisms by which obesity may promote AF. doi:10.1016/j.hlc.2011.05.125 123 Sex Differences in Functional Response of Hypertrophic Cardiomyocytes to Simulated Ischaemic Insult C. Curl ∗ , T. Harding, J. Bell, S. Harrap, L. Delbridge University of Melbourne, Australia Sex differences in ischaemic heart disease have been documented, with most experimental evidence derived from intact heart studies. Limited investigations of cardiomyocyte function have been undertaken. The aim of this study was to investigate sex differences in the responses of hypertrophic cardiomyocytes to a simulated ischemic insult. Cardiomyocytes were isolated by collagenase digestion from hearts of adult (age 12–16 weeks) Hypertrophic Heart Rat (HHR) and Normal Heart Rat (NHR) inbred strains. Hypertrophic Heart Rat myocytes were significantly longer than NHR myocytes (male 138.4 ± 7.5 m vs 114.8 ± 6.6 m; female 127.9 ± 5.1 m vs 107.7 ± 4.4 m). Single myocyte contractility was measured by edge detection microscopy and Ca2+ levels tracked by microfluorimetry (IonOptix) in Fura2-AM loaded cells. Myocyte basal performance was monitored for 5 minutes under normoxia (4 Hz, 2.0 mM Ca2+ , 37 ◦ C) prior to 20 minutes simulated ischemia (0 mM glucose, pH 6.8, 10 mM lactate, N2 saturation) followed by 30 minutes simulated normoxic reperfusion. Under basal conditions both male and female HHR displayed hypercontractility when compared to NHR controls (% shortening: 4.95 ± 0.9 vs 3.38 ± 0.8; 5.93 ± 0.8 vs 3.04 ± 0.4). A similar pattern of difference was observed for Ca2+ transient amplitudes. After ischaemia and reperfusion the NHR female myocytes regained diastolic length and returned to basal shortening state (within 95%). In contrast, myocytes of all other groups exhibited rebound shortening increases relative to basal state (NHR male 187%, HHR female 123%, HHR male 142%). Thus the ischaemic resilience of female myocytes is lost when hypertrophy is present, and more closely resembles a male pattern of contractile and Ca2+ handling dysfunction. doi:10.1016/j.hlc.2011.05.126
Heart, Lung and Circulation 2011;20S:S1–S155
124 Subclinical Systolic Dysfunction Following Chest Radiation Therapy Detected by Strain Imaging Q. Lo 1,∗ , L. Hee 2 , V. Batumalai 2 , C. Delaney 2 , D. Lonergan 2 , L. Thomas 2
Allman 2 , G.
1 University 2 Liverpool
of New South Wales, Australia Hospital, Sydney, Australia
Background: Long term cardiac effects are documented after chest radiation (RT); however, its acute effects are not well characterised. Aim: We sought to evaluate acute changes in LV systolic function following chest RT by serial echocardiograms. Methods: Serial transthoracic echocardiograms (at baseline, during acute phase RT and at six weeks post RT) were performed on 20 women with left sided breast cancer post surgery undergoing only RT (mean dose 60 Gy) to the left chest. Conventional indices of LV ejection fraction (LVEF), tissue Doppler S velocity, strain (S) parameters were measured. Results: Although LV end diastolic (p < 0.001) and end systolic volumes (p < 0.003) increased, no change was observed in LVEF or serial S velocity by repeated measures ANOVA to examine within patient differences. However, global longitudinal peak systolic S (p < 0.003) was significantly reduced on serial measurement. Parameter
Baseline
LVEDV (ml) LVESV (ml) LVEF (%) S velocity (cm/s) Peak longitudinal S (%)
56.4 20.2 64 6.7 −20.4
± ± ± ± ±
8.8 4.1 5 1 2.4
During RT 58.2 21.9 63 6.8 −19.4
± ± ± ± ±
9.1 5.9 4 1.3 2.8
6 wks post RT
p value
± ± ± ± ±
p < 0.001 p < 0.003 NS NS p < 0.003
65.5 23.6 64 6.7 −18.8
10.9 4.4 5 1.4 2.4
Conclusions: Acute effects from left sided RT, that may include the heart in the field, are evident using strain measurements but are not evident using traditional measures. The long term clinical implication of reduction in strain parameters in these patients needs to be determined. doi:10.1016/j.hlc.2011.05.127 125 The Return of the Normal Heart: Cardiac Amyloidosis Regression After Bone Marrow Transplantation G. Scalia 1,∗ , J. Bashford 2 , B. Fitzgerald 1 1 Heart
Care Partners, Australia Oncology Clinics of Australia, Australia
2 Haematology
Purpose: Amyloidosis results in a median survival of 12 months, reducing to five months with cardiac infiltration. Bone marrow transplantation (BMT) has been shown to dramatically improve survival when haematologic remission is obtained. Our group had noticed that some patients with cardiac amyloidosis had return to normal function as assessed by echocardiography. Methods: Of 269 patients with BMT for amyloidosis, 30 (11.2%) had cardiac amyloidosis (thick walls, diastolic dysfunction, dilated atria and/or small pericardial effusions).