- Email: [email protected]
QT Dispersion: A Predictor of Coronary Artery Disease?
CSANZ 2013 Abstracts
P = 0.027). Additional adjustment for age attenuated the relationship for both CV events (HR 1.17; 95% CI: 0.69–1.98, P = 0.56) and all cause mortality (HR 1.41; 95% CI: 0.67–2.97; P = 0.36). Conclusions: In this elderly population, PWV was a marker of CV risk that was independent of traditional cardiovascular risk factors, other than age.
QT Dispersion: A Predictor of Coronary Artery Disease? B. Raman 1,∗ , R. Tavella 1,2 , V. Shekar 2 , C. Zhuang 2 , A. Som 2 , E. Ong 2 , J. Beltrame 1,2,3 1 The
Queen Elizabeth Hospital, Australia University of Adelaide, Australia 3 The Bazil Hetzel Institute of Research, Australia 2 The
Purpose: Increased QT dispersion (QTd), a reflection of heterogenous ventricular repolarisation, is associated with ventricular arrhythmias and sudden cardiac death. Recent reports suggest QTd may correlate with the degree of myocardial ischaemia. We sought to investigate the difference in QT dispersion in patients with (1) insignificant coronary artery disease (ICAD), (2) coronary artery disease (CAD) and (3) healthy controls. Methods: Retrospective analysis of the ECG’s belonging to 116 patients from three groups was performed: CAD (n = 59), ICAD (n = 37), Controls (n = 20). Obstructive CAD was defined as ≥50% stenosis of the coronary artery. ICAD was defined as stenosis <50%. Heart rate, QTc and QTd were calculated. QTd was measured as the difference between maximum and minimum QT intervals on any of the 12 leads. Results: Controls n = 20
ICAD n = 37
CAD n = 59
Age
50 ± 13
57 ± 12
62 ± 10
Controls vs ICAD p 0.05 1
Controls vs CAD p
CAD vs ICAD p
<0.01
0.05
Male gender
9 (45%)
16 (43%)
46 (78%)
0.01
<0.01
Heart rate
60 ± 6
69 ± 11
68 ± 13
<0.01
<0.01
0.65
QTc
404 ± 56
456 ± 68
459 ± 70
<0.01
<0.01
0.86
QTd
56 ± 35
79 ± 38
117 ± 56
0.02
0.02
<0.01
Conclusion: Increased QTd was more common in CAD compared to ICAD suggesting an association with the degree of ischaemia. A greater QTd in CAD and ICAD compared to controls may explain a potential mechanism behind ventricular arrhythmias in these patients. http://dx.doi.org/10.1016/j.hlc.2013.05.056
Relationship Between Central Arterial Pressure, Exercise and Fitness Level in Stable Coronary Artery Disease A. Lin 1,∗ , A. Lowe 2 , K. Sidhu 1 , J. Maddison 2 , A. Kerr 3 , R. Stewart 1
Rawstom 2 , R.
1 Green Lane Cardiovascular Services, Auckland, New Zealand
University, Auckland, New Zealand Hospital, Auckland, New Zealand
3 Middlemore
55
Characteristic N (%) or mean ± SD
56
2 Auckland
http://dx.doi.org/10.1016/j.hlc.2013.05.055
S25
Background: Augmentation of central arterial pressure increases cardiovascular risk, and interventions which lower pressure augmentation may reduce risk. It is not known whether greater physical fitness is associated with reduced central pressure augmentation. Methods: In 173 patients (140 males, age 61 ± 9 years) with stable coronary artery disease (CAD), central augmentation pressure (cAP) and augmentation index (cAI) were measured by Pulsecor R6.5 at rest and after treadmill exercise. Aerobic capacity was determined by measuring maximal oxygen consumption (VO2max) using the Moxus metabolic cart (AEI Technologies). Results: Both cAP and cAI at rest were associated with age (+10 years, cAP 3.1, 95%CI, 1.9 to 4.2 mmHg, p < 0.0001) and height (+10 cm, cAP −2.9, CI −4.4 to −1.5 mmHg, p < 0.0001). There was no association between cAI or cAP at rest and VO2max after adjusting for age and height (for VO2max + 1 mL/kg/m2 , cAP 0.1, CI −0.08 to 0.28 mmHg, p = 0.26; cAI 0.3%, CI −0.03 to 0.6%, p = 0.08). Mean cAP decreased from 10.2 ± SD 7.7 at rest to 8.4 ± 6.5 immediately after exercise, 6.4 ± 6.0 five minutes, and 5.2 ± 3.7 mmHg ten minutes after exercise (p < 0.0001). Mean cAI decreased from 27 ± 13% at rest to 18 ± 10% immediately after exercise, 20 ± 11% five minutes, and 19 ± 10% after ten minutes (p < 0.0001). Both cAP and cAI decreased more during recovery in patients who exercised to a higher level as indicated by VO2max (p < 0.001). Conclusion: In CAD patients, increased physical fitness was not associated with central pressure augmentation at rest but was associated with a larger reduction in pressure augmentation after exercise. http://dx.doi.org/10.1016/j.hlc.2013.05.057 57 Retinal Artery Flicker Provocation and Digital Reactive Hyperaemia (Endopat® ) for the Assessment of Arterial Endothelial Function in Patients with Type-2-Diabetes Mellitus A. Lal ∗ The University of Sydney, Australia Background: Flicker provocation stimulates endothelial-mediated vasodilation in retinal arteries. The purpose of this study was to compare retinal artery flicker with digital reactive hyperaemia (Endopat® ) for the assessment of endothelial function in patients with and without type-2 diabetes mellitus (T2DM).
ABSTRACTS
Heart, Lung and Circulation 2013;22:S1–S125
P = 0.027). Additional adjustment for age attenuated the relationship for both CV events (HR 1.17; 95% CI: 0.69–1.98, P = 0.56) and all cause mortality (HR 1.41; 95% CI: 0.67–2.97; P = 0.36). Conclusions: In this elderly population, PWV was a marker of CV risk that was independent of traditional cardiovascular risk factors, other than age.
QT Dispersion: A Predictor of Coronary Artery Disease? B. Raman 1,∗ , R. Tavella 1,2 , V. Shekar 2 , C. Zhuang 2 , A. Som 2 , E. Ong 2 , J. Beltrame 1,2,3 1 The
Queen Elizabeth Hospital, Australia University of Adelaide, Australia 3 The Bazil Hetzel Institute of Research, Australia 2 The
Purpose: Increased QT dispersion (QTd), a reflection of heterogenous ventricular repolarisation, is associated with ventricular arrhythmias and sudden cardiac death. Recent reports suggest QTd may correlate with the degree of myocardial ischaemia. We sought to investigate the difference in QT dispersion in patients with (1) insignificant coronary artery disease (ICAD), (2) coronary artery disease (CAD) and (3) healthy controls. Methods: Retrospective analysis of the ECG’s belonging to 116 patients from three groups was performed: CAD (n = 59), ICAD (n = 37), Controls (n = 20). Obstructive CAD was defined as ≥50% stenosis of the coronary artery. ICAD was defined as stenosis <50%. Heart rate, QTc and QTd were calculated. QTd was measured as the difference between maximum and minimum QT intervals on any of the 12 leads. Results: Controls n = 20
ICAD n = 37
CAD n = 59
Age
50 ± 13
57 ± 12
62 ± 10
Controls vs ICAD p 0.05 1
Controls vs CAD p
CAD vs ICAD p
<0.01
0.05
Male gender
9 (45%)
16 (43%)
46 (78%)
0.01
<0.01
Heart rate
60 ± 6
69 ± 11
68 ± 13
<0.01
<0.01
0.65
QTc
404 ± 56
456 ± 68
459 ± 70
<0.01
<0.01
0.86
QTd
56 ± 35
79 ± 38
117 ± 56
0.02
0.02
<0.01
Conclusion: Increased QTd was more common in CAD compared to ICAD suggesting an association with the degree of ischaemia. A greater QTd in CAD and ICAD compared to controls may explain a potential mechanism behind ventricular arrhythmias in these patients. http://dx.doi.org/10.1016/j.hlc.2013.05.056
Relationship Between Central Arterial Pressure, Exercise and Fitness Level in Stable Coronary Artery Disease A. Lin 1,∗ , A. Lowe 2 , K. Sidhu 1 , J. Maddison 2 , A. Kerr 3 , R. Stewart 1
Rawstom 2 , R.
1 Green Lane Cardiovascular Services, Auckland, New Zealand
University, Auckland, New Zealand Hospital, Auckland, New Zealand
3 Middlemore
55
Characteristic N (%) or mean ± SD
56
2 Auckland
http://dx.doi.org/10.1016/j.hlc.2013.05.055
S25
Background: Augmentation of central arterial pressure increases cardiovascular risk, and interventions which lower pressure augmentation may reduce risk. It is not known whether greater physical fitness is associated with reduced central pressure augmentation. Methods: In 173 patients (140 males, age 61 ± 9 years) with stable coronary artery disease (CAD), central augmentation pressure (cAP) and augmentation index (cAI) were measured by Pulsecor R6.5 at rest and after treadmill exercise. Aerobic capacity was determined by measuring maximal oxygen consumption (VO2max) using the Moxus metabolic cart (AEI Technologies). Results: Both cAP and cAI at rest were associated with age (+10 years, cAP 3.1, 95%CI, 1.9 to 4.2 mmHg, p < 0.0001) and height (+10 cm, cAP −2.9, CI −4.4 to −1.5 mmHg, p < 0.0001). There was no association between cAI or cAP at rest and VO2max after adjusting for age and height (for VO2max + 1 mL/kg/m2 , cAP 0.1, CI −0.08 to 0.28 mmHg, p = 0.26; cAI 0.3%, CI −0.03 to 0.6%, p = 0.08). Mean cAP decreased from 10.2 ± SD 7.7 at rest to 8.4 ± 6.5 immediately after exercise, 6.4 ± 6.0 five minutes, and 5.2 ± 3.7 mmHg ten minutes after exercise (p < 0.0001). Mean cAI decreased from 27 ± 13% at rest to 18 ± 10% immediately after exercise, 20 ± 11% five minutes, and 19 ± 10% after ten minutes (p < 0.0001). Both cAP and cAI decreased more during recovery in patients who exercised to a higher level as indicated by VO2max (p < 0.001). Conclusion: In CAD patients, increased physical fitness was not associated with central pressure augmentation at rest but was associated with a larger reduction in pressure augmentation after exercise. http://dx.doi.org/10.1016/j.hlc.2013.05.057 57 Retinal Artery Flicker Provocation and Digital Reactive Hyperaemia (Endopat® ) for the Assessment of Arterial Endothelial Function in Patients with Type-2-Diabetes Mellitus A. Lal ∗ The University of Sydney, Australia Background: Flicker provocation stimulates endothelial-mediated vasodilation in retinal arteries. The purpose of this study was to compare retinal artery flicker with digital reactive hyperaemia (Endopat® ) for the assessment of endothelial function in patients with and without type-2 diabetes mellitus (T2DM).
ABSTRACTS
Heart, Lung and Circulation 2013;22:S1–S125