Giovanni Di Salvo, MD, PhD, MSc, FESC
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Traditionally, cardiac ultrasound has quantified regional myocardial function by combining visual analysis of wall motion with the measurement of wall thickening and thinning.
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Visual assessment of wall motion and thickening requires extensive training and remains highly subjective.
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The eye has been shown to have limitations in assessing the timing of the complex changes in regional myocardial deformation that occur in differing ischemic substrates.
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Kvitting showed that healthy individuals can neither reliably visualize nor time regional mechanical events when they occur at a time interval of less than 90 ms.
•Contractility •Pre-Load •After-Load
Strain Rate Imaging
Regional Strain Rate Rate at which myocardial deformation occurs
Strain Imaging
Regional Strain integral Total ammount of deformation
40% strain 1s
40% strain 2s
SR = 0.4s-1
SR = 0.2s-1
Strain Rate Imaging
•While TDI during parabolic flight was feasible in 100% subjects, RT3DE was feasible in 36/40 subjects (90%). •Preload dependence was confirmed for systolic and diastolic velocities, and peak systolic strain, while strain rates were preload independent, probably reflecting intrinsic myocardial properties.
Caiani EG et al. Respiratory Physiology & Neurobiology 169S (2009) S6–S9
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Because of adaptive remodeling of the left ventricle, patients can remain asymptomatic or minimally symptomatic for prolonged periods, even in the presence of severe valvular disease.
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STE improves the yield of routine 2D echocardiography in valvular heart diseases by providing insights into the pattern of adaptive remodeling and detecting the presence of subclinical cardiac dysfunction.
Over a median follow-up of 2.1 (inter-quartile range: 1.8–2.4) years, there were 20 deaths and 101 patients recorded a MACE
GLS > -15%
MAVG > 40 mmHg
EF <50%
Symptoms
GLS > -16%
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In recent years, aortic regurgitation (AR) has increased in the pediatric population because of the expanded use of new surgical and hemodynamic procedures.
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Conventional echocardiographic parameters, LV dimensions and the LV ejection fraction, have limitations in predicting early LV dysfunction.
On multivariate analysis, performed entering the jet area/LV outflow tract area ratio, E/Em ratio, and average LV longitudinal strain as potential variables, the only significant risk factor for progressive AR was average LV longitudinal strain (p 0.04, coefficient 0.73, SE 0.37)
GLS > -19.5%
Predict Post-operative LV dysfunction
Strain and Atrial Fibrillation
LA Volume vs Fibrosis and AF Recurrence
Courtesy by V. Delgado and G. Bax
Follow-up at 4 years (mean duration: 52,5 Âą 3,1 months)
101 (standard ECG or 24-h Holter ECG)
Asymptomatic MS patients
Atrial Fibrillation
3 pts paroxysmal
20 pts (20%)
17 pts persistent
MS patients with AF vs without AF during 4-year follow-up
Atrial 2D Strain 16±5%
MS pts with AF
P < 0,0001
21±4%
MS pts without AF
Results
Follow-up: 4 years
ATRIAL FIBRILLATION
Multivariate Analysis
Age PHT mitral Area Left Atrial Volume Left Atrial 2D Strain
P < 0,01 Coeff: 0,43 SE= 0,098
Atrial 2D Strain Peak systolic average
Cut off = 17,4% Instead no other significant associations were evidenced among the other parameters and AF occurrence
Results
Follow-up: 4 years ROC Analysis
area under the ROC curve of 0.761 (SE, 0.085; 95% CI, 0.587 to 0.888, P= 0.002)
Kaplan Meier
55,5 versus 42,4 months, respectively
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There is clear indication to surgically or percutaneously treat MS in symptomatic patients.
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For the asymptomatic ones, there is agreement to treat only in the presence of pulmonary hypertension.
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These patients may feel asymptomatic for years and often present only a gradual decrease in their activity.
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So a diagnostic tool, capable to evaluate which asymptomatic patients are at risk of adverse events, may be very useful.
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53 pts (mild to moderate rheumatic MS) Adverse outcome: symptoms/hospitalization AF valvular surgery or percutaneous commissurotomy
Results MS Patients + Events vs. MS Patients -Events
Results LEFT ATRIAL STRAIN RATE IN MS PATIENTS 2 S-1
Adverse events
4 S-1
Without adverse events
In multivariate analysis including:
Age, LA maximal volume, MV area at PHT, LA SR average.
The best predictor of events was:
• the LA peak systolic SR average (P < 0.04; coefficient: 0.113; SE: 0.055). In ROC analysis, a cut-off value of 1.69 s1 (sensitivity of 88%, specificity of 80.6%, AUC ROC curve of 0.852).
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We believe that the further implementation of deformation imaging could lead to a more accurate definition of surgical timing, allowing patients with VHD to undergo surgery before the occurrence of irreversible myocardial damage.
Atrial myocardial deformation imaging may be of great help in assessing atrial function in MS patients, their implementation in the clinical setting may improve the surgical timing and their management. This technique has the potential to managing MS patients â&#x20AC;&#x153;individuallyâ&#x20AC;?.