Abstract
Background: Myocardial oxygenation is impaired in patients with hypertrophic cardiomyopathy (G+LVH+) and gene positive patients without hypertrophy (G+LVH-). Whether this is the initiating step prior to development of hypertrophy or abnormalities in left ventricle relaxation is unknown, and the relationship between abnormalities of echocardiographic speckle tracking strain and myocardial oxygenation has not been examined.
Method: A total of 43 patients (12 G+LVH+, 13 G+LVH -, 11 gene negative (G-) and 7 normal volunteers (NV)), underwent 2D transthoracic echocardiography for assessment of diastolic function and speckle tracking strain, and Cardiovascular
Magnetic Resonance (CMR) imaging for assessment of ventricular volumes, mass and blood oxygen level dependent (BOLD) imaging with vasodilator stress.
Results: Reduced myocardial oxygenation was seen in patients with LVH (-4±10%) when compared to G+LVH-, p=0.05; G-, p=0.001, NV, p=0.002). A blunted BOLD response to stress was seen in patients expressing the G+LVH- patients (4±8%), when compared to gene negative controls (14±13%, p=0.02). G+LVH+ patients exhibited abnormal diastolic function including lower E prime (E’), higher E to E’ ratio (E:E’) and greater left atrial area in contrast to the G+LVH- group who all had normal values for these indices. However, there
were no differences in diastolic function between the G+LVHand G- group (p=0.2). Reduced global longitudinal strain (GLS) and regional strain was detected in the G+LVH+ group compared with all other groups (G+LVH-, p=0.05; G-, p=0.01; NV p=0.03). There were no differences in GLS and regional
strain between the G+LVH- group and the G- (p=0.7) and control groups (p=0.9).
Conclusion: A blunted myocardial oxygenation response to vasodilator stress precedes changes in LV strain, wall thickness or diastolic function. Changes in BOLD signal intensity may be a surrogate marker for preclinical hypertrophic
cardiomyopathy and lead to development of preventative strategies.
Method: A total of 43 patients (12 G+LVH+, 13 G+LVH -, 11 gene negative (G-) and 7 normal volunteers (NV)), underwent 2D transthoracic echocardiography for assessment of diastolic function and speckle tracking strain, and Cardiovascular
Magnetic Resonance (CMR) imaging for assessment of ventricular volumes, mass and blood oxygen level dependent (BOLD) imaging with vasodilator stress.
Results: Reduced myocardial oxygenation was seen in patients with LVH (-4±10%) when compared to G+LVH-, p=0.05; G-, p=0.001, NV, p=0.002). A blunted BOLD response to stress was seen in patients expressing the G+LVH- patients (4±8%), when compared to gene negative controls (14±13%, p=0.02). G+LVH+ patients exhibited abnormal diastolic function including lower E prime (E’), higher E to E’ ratio (E:E’) and greater left atrial area in contrast to the G+LVH- group who all had normal values for these indices. However, there
were no differences in diastolic function between the G+LVHand G- group (p=0.2). Reduced global longitudinal strain (GLS) and regional strain was detected in the G+LVH+ group compared with all other groups (G+LVH-, p=0.05; G-, p=0.01; NV p=0.03). There were no differences in GLS and regional
strain between the G+LVH- group and the G- (p=0.7) and control groups (p=0.9).
Conclusion: A blunted myocardial oxygenation response to vasodilator stress precedes changes in LV strain, wall thickness or diastolic function. Changes in BOLD signal intensity may be a surrogate marker for preclinical hypertrophic
cardiomyopathy and lead to development of preventative strategies.
| Original language | English |
|---|---|
| Journal | Heart Lung and Circulation |
| Volume | 25 |
| Issue number | Supplement 2 |
| Publication status | Published or Issued - 2016 |
| Event | Cardiac Society of Australia and New Zealand ASM 2016 - Adelaide Convention Centre, Adelaide, Australia Duration: 4 Aug 2016 → 7 Aug 2016 |