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Mechanism of decreased sensitivity of dobutamine associated left ventricular wall motion analyses for appreciating inducible ischemia in older adults.

Vasu S, Little WC, Morgan TM, Stacey RB, Ntim WO, Hamilton C, Thohan V, Chiles C, Hundley WG - J Cardiovasc Magn Reson (2015)

Bottom Line: Dobutamine associated left ventricular (LV) wall motion analyses exhibit reduced sensitivity for detecting inducible ischemia in individuals with increased LV wall thickness.During dobutamine stress testing, elderly patients experience increased LV concentricity and declines in LV preload and myocardial oxygen demand, all of which are associated with an absence of inducible LV WMAs indicative of myocardial ischemia.These findings provide insight as to why dobutamine associated wall motion analyses exhibit reduced sensitivity for identifying inducible ischemia in elderly.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal medicine, Section on Cardiology, Wake Forest School of Medicine, Winston Salem, North Carolina, 27157, USA. svasu@wakehealth.edu.

ABSTRACT

Background: Dobutamine associated left ventricular (LV) wall motion analyses exhibit reduced sensitivity for detecting inducible ischemia in individuals with increased LV wall thickness. This study was performed to better understand the mechanism of this reduced sensitivity in the elderly who often manifest increased LV wall thickness and risk factors for coronary artery disease.

Methods: During dobutamine cardiovascular magnetic resonance (DCMR) stress testing, we assessed rate pressure product (RPP), aortic pulse wave velocity (PWV), LV myocardial oxygen demand (pressure volume area, PVA, mass, volumes, concentricity, and the presence of wall motion abnormalities (WMA) and first pass gadolinium enhanced perfusion defects (PDs) indicative of ischemia in 278 consecutively recruited individuals aged 69 ± 8 years with pre-existing or known risk factors for coronary artery disease. Each variable was assessed independently by personnel blinded to participant identifiers and analyses of other DCMR or hemodynamic variables.

Results: Participants were 80% white, 90% hypertensive, 43% diabetic and 55% men. With dobutamine, 60% of the participants who exhibited PDs had no inducible WMA. Among these participants, myocardial oxygen demand was lower than that observed in those who had both wall motion and perfusion abnormalities suggestive of ischemia (p = 0.03). Relative to those with PDs and inducible WMAs, myocardial oxygen demand remained different in these individuals with PDs without an inducible WMA after accounting for LV afterload and contractility (p = 0.02 and 0.03 respectively), but not after accounting for either LV stress related end diastolic volume index (LV preload) or resting concentricity (p = 0.31-0.71).

Conclusions: During dobutamine stress testing, elderly patients experience increased LV concentricity and declines in LV preload and myocardial oxygen demand, all of which are associated with an absence of inducible LV WMAs indicative of myocardial ischemia. These findings provide insight as to why dobutamine associated wall motion analyses exhibit reduced sensitivity for identifying inducible ischemia in elderly.

Trial registration: This study was registered with Clinicaltrials.gov (NCT00542503).

No MeSH data available.


Related in: MedlinePlus

Concordance between left ventricular wall motion abnormalities and perfusion defects indicative of inducible myocardial ischemia. Cine white blood imaging end-diastolic (left panel) and end-systolic (middle panel) frames from slice position acquired in the apex of the left ventricle at peak dobutamine and atropine infusion administered to achieve >80% of the maximum predicted heart rate response for age. The white arrows indicate a wall motion abnormality in the inferoseptum as manifest by incomplete LV cavity obliteration at peak stress. In the right panel, a first pass gadolinium enhanced perfusion image also acquired at peak stress is displayed. The yellow arrows indicate a hypoperfused region of the LV myocardium consistent with inducible ischemia. In this case there was concordance of the wall motion and perfusion analyses both indicating inducible ischemia.
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Fig2: Concordance between left ventricular wall motion abnormalities and perfusion defects indicative of inducible myocardial ischemia. Cine white blood imaging end-diastolic (left panel) and end-systolic (middle panel) frames from slice position acquired in the apex of the left ventricle at peak dobutamine and atropine infusion administered to achieve >80% of the maximum predicted heart rate response for age. The white arrows indicate a wall motion abnormality in the inferoseptum as manifest by incomplete LV cavity obliteration at peak stress. In the right panel, a first pass gadolinium enhanced perfusion image also acquired at peak stress is displayed. The yellow arrows indicate a hypoperfused region of the LV myocardium consistent with inducible ischemia. In this case there was concordance of the wall motion and perfusion analyses both indicating inducible ischemia.

Mentions: Forty-six participants exhibited a PD indicative of ischemia. Of the 46 subjects with PDs, 18 had corresponding inducible LV WMAs (Group III) [13]. The remaining 28 exhibited a PD but no WMA (Group II). No participants experienced an inducible LVWMA without a CMR perfusion defect. The presence of a DCMR inducible LVWMA exhibited a sensitivity of 39% and a specificity of 100% for the detection of a PD consistent with inducible LV myocardial ischemia. Example cases from participants with concordance and discordance between WMA and PDs are shown in Figures 1 and 2.Figure 2


Mechanism of decreased sensitivity of dobutamine associated left ventricular wall motion analyses for appreciating inducible ischemia in older adults.

Vasu S, Little WC, Morgan TM, Stacey RB, Ntim WO, Hamilton C, Thohan V, Chiles C, Hundley WG - J Cardiovasc Magn Reson (2015)

Concordance between left ventricular wall motion abnormalities and perfusion defects indicative of inducible myocardial ischemia. Cine white blood imaging end-diastolic (left panel) and end-systolic (middle panel) frames from slice position acquired in the apex of the left ventricle at peak dobutamine and atropine infusion administered to achieve >80% of the maximum predicted heart rate response for age. The white arrows indicate a wall motion abnormality in the inferoseptum as manifest by incomplete LV cavity obliteration at peak stress. In the right panel, a first pass gadolinium enhanced perfusion image also acquired at peak stress is displayed. The yellow arrows indicate a hypoperfused region of the LV myocardium consistent with inducible ischemia. In this case there was concordance of the wall motion and perfusion analyses both indicating inducible ischemia.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4389511&req=5

Fig2: Concordance between left ventricular wall motion abnormalities and perfusion defects indicative of inducible myocardial ischemia. Cine white blood imaging end-diastolic (left panel) and end-systolic (middle panel) frames from slice position acquired in the apex of the left ventricle at peak dobutamine and atropine infusion administered to achieve >80% of the maximum predicted heart rate response for age. The white arrows indicate a wall motion abnormality in the inferoseptum as manifest by incomplete LV cavity obliteration at peak stress. In the right panel, a first pass gadolinium enhanced perfusion image also acquired at peak stress is displayed. The yellow arrows indicate a hypoperfused region of the LV myocardium consistent with inducible ischemia. In this case there was concordance of the wall motion and perfusion analyses both indicating inducible ischemia.
Mentions: Forty-six participants exhibited a PD indicative of ischemia. Of the 46 subjects with PDs, 18 had corresponding inducible LV WMAs (Group III) [13]. The remaining 28 exhibited a PD but no WMA (Group II). No participants experienced an inducible LVWMA without a CMR perfusion defect. The presence of a DCMR inducible LVWMA exhibited a sensitivity of 39% and a specificity of 100% for the detection of a PD consistent with inducible LV myocardial ischemia. Example cases from participants with concordance and discordance between WMA and PDs are shown in Figures 1 and 2.Figure 2

Bottom Line: Dobutamine associated left ventricular (LV) wall motion analyses exhibit reduced sensitivity for detecting inducible ischemia in individuals with increased LV wall thickness.During dobutamine stress testing, elderly patients experience increased LV concentricity and declines in LV preload and myocardial oxygen demand, all of which are associated with an absence of inducible LV WMAs indicative of myocardial ischemia.These findings provide insight as to why dobutamine associated wall motion analyses exhibit reduced sensitivity for identifying inducible ischemia in elderly.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal medicine, Section on Cardiology, Wake Forest School of Medicine, Winston Salem, North Carolina, 27157, USA. svasu@wakehealth.edu.

ABSTRACT

Background: Dobutamine associated left ventricular (LV) wall motion analyses exhibit reduced sensitivity for detecting inducible ischemia in individuals with increased LV wall thickness. This study was performed to better understand the mechanism of this reduced sensitivity in the elderly who often manifest increased LV wall thickness and risk factors for coronary artery disease.

Methods: During dobutamine cardiovascular magnetic resonance (DCMR) stress testing, we assessed rate pressure product (RPP), aortic pulse wave velocity (PWV), LV myocardial oxygen demand (pressure volume area, PVA, mass, volumes, concentricity, and the presence of wall motion abnormalities (WMA) and first pass gadolinium enhanced perfusion defects (PDs) indicative of ischemia in 278 consecutively recruited individuals aged 69 ± 8 years with pre-existing or known risk factors for coronary artery disease. Each variable was assessed independently by personnel blinded to participant identifiers and analyses of other DCMR or hemodynamic variables.

Results: Participants were 80% white, 90% hypertensive, 43% diabetic and 55% men. With dobutamine, 60% of the participants who exhibited PDs had no inducible WMA. Among these participants, myocardial oxygen demand was lower than that observed in those who had both wall motion and perfusion abnormalities suggestive of ischemia (p = 0.03). Relative to those with PDs and inducible WMAs, myocardial oxygen demand remained different in these individuals with PDs without an inducible WMA after accounting for LV afterload and contractility (p = 0.02 and 0.03 respectively), but not after accounting for either LV stress related end diastolic volume index (LV preload) or resting concentricity (p = 0.31-0.71).

Conclusions: During dobutamine stress testing, elderly patients experience increased LV concentricity and declines in LV preload and myocardial oxygen demand, all of which are associated with an absence of inducible LV WMAs indicative of myocardial ischemia. These findings provide insight as to why dobutamine associated wall motion analyses exhibit reduced sensitivity for identifying inducible ischemia in elderly.

Trial registration: This study was registered with Clinicaltrials.gov (NCT00542503).

No MeSH data available.


Related in: MedlinePlus