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Tissue Doppler imaging in hypertrophic cardiomyopathy: impact of intraventricular obstruction on longitudinal left
Nuno Cardim1, Diogo Torres, Humberto Morais
1Serviço de Cardiologia do Hospital Pulido Valente, Lisboa. corclinica@clix.pt
Insights
Tissue Doppler imaging reveals that obstructive hypertrophic cardiomyopathy patients exhibit similar longitudinal systolic and diastolic dysfunction as non-obstructive forms. Left atrial dysfunction is more severe in obstructive cases, with specific annular sides aiding pseudonormalization identification.
Area of Science:
- Cardiology
- Echocardiography
- Cardiovascular Imaging
Background:
- Non-obstructive hypertrophic cardiomyopathy (HCM) demonstrates significant mitral annular systolic and diastolic dysfunction.
- Obstructive HCM presents complex pathophysiological interactions, complicating conventional echocardiographic assessment.
- Tissue Doppler imaging (TDI) is crucial for evaluating myocardial function in HCM.
Purpose of the Study:
- To investigate longitudinal left ventricular function using TDI in obstructive HCM.
- To compare TDI-derived parameters between obstructive and non-obstructive HCM.
- To assess the influence of dynamic intraventricular obstruction on cardiac function parameters.
Main Methods:
- Pulsed TDI of the mitral annulus (septal, lateral, inferior, anterior) was performed in 26 obstructive HCM and 23 non-obstructive HCM patients.
- Analysis included velocities, time intervals, and integrals for systolic (s) and diastolic (e, a) waves.
- Heterogeneity and asynchrony indexes were calculated and compared between groups and with conventional Doppler data.
Main Results:
- Obstructive HCM showed preserved annular relations but longer isovolumic contraction time and PEP/LVET compared to non-obstructive forms.
- Diastolic function parameters (rapid filling velocities/integrals) were similar, though atrial contraction velocity/integral were lower in obstructive HCM.
- No significant difference in most TDI parameters was observed, suggesting relative load independence.
Conclusions:
- Dynamic intraventricular obstruction in HCM does not significantly alter most annular TDI parameters.
- Longitudinal systolic and diastolic function (velocities, time intervals) are comparably impaired in both obstructive and non-obstructive HCM.
- Left atrial dysfunction is more pronounced in obstructive HCM, and specific annular segments are key for identifying pseudonormalization.
Background:
In non-obstructive hypertrophic cardiomyopathy, tissue Doppler imaging of the mitral annulus shows severe systolic and diastolic dysfunction, with marked heterogeneity and asynchrony. In obstructive forms, the complexity of pathophysiological interactions makes conventional echocardiographic functional assessment extremely difficult and complex.
Objective:
To study longitudinal left ventricular function with tissue Doppler imaging in the obstructive forms of hypertrophic cardiomyopathy.
Methods:
Twenty-six patients with hypertrophic obstructive cardiomyopathy and 23 patients with the non-obstructive form of the disease, matched by age, were studied with pulsed tissue Doppler imaging of the 4 sides of the mitral annulus (septal, lateral, inferior, anterior) in 4 and 2 chamber views. In each wave (systolic-s, rapid filling-e, atrial contraction-a) we analyzed velocities, time intervals and velocity-time integrals, as well as heterogeneity and asynchrony indexes. Data were compared between the different sides in each group, between groups and with conventional Doppler data.
Results:
In contrast to the non-obstructive forms, patients with intraventricular obstruction showed: Systolic function: similar velocities and integrals, the relations between the different sides of the annulus usually being preserved; longer isovolumic contraction time, time to peak s and PEP/LVET. Diastolic function: similar rapid filling and e/a velocities and integrals, lower atrial contraction velocity and integral, similar number of sides with e/a higher than or equal to 1 on the lateral and inferior side of the annulus; similar diastolic time intervals, except diastolic time.
Conclusions:
This study shows that the presence of dynamic intraventricular obstruction and the loading conditions of obstructive forms of hypertrophic cardiomyopathy do not significantly influence most annular tissue Doppler imaging parameters, showing the relative load independence of the technique. So, in obstructive hypertrophic cardiomyopathy patients: 1--Longitudinal systolic function (velocities) is similar to the non-obstructive forms--longitudinal systolic dysfunction. 2--Longitudinal diastolic function (velocities and time intervals) is similar to the non-obstructive forms--longitudinal diastolic dysfunction. 3--Left atrial dysfunction is more severe than in non-obstructive forms. 4--The inferior and lateral sides of the annulus should be those selected in order to identify pseudonormalization of the transmitral flow.