22 Inter-field strength agreement of left ventricular strain and strain rate using Tissue Tracking and AI derived global longitudinal shortening

Noninvasive measurements of myocardial strain and strain rate by speckle tracking echocardiography correlate to cardiac contractile state but also to load, which may weaken their value as indices of inotropy. In a porcine model, we investigated the influence of acute dynamic preload reductions on left ventricular strain and strain rate and their relation to the pressure-conductance catheter-derived preload recruitable stroke work (PRSW) and peak positive first derivative of left ventricular pressure (LV-dP/d tmax). Speckle tracking strain and strain rate in the longitudinal, circumferential, and radial directions were measured during acute dynamic reductions of end-diastolic volume during three different myocardial inotropic states. Both strain and strain rate were sensitive to unloading of the left ventricle ( P < 0.001), but the load dependency for strain rate was modest compared with strain. Changes in longitudinal and circumferential strain correlated more strongly to changes in end-diastolic volume ( r = −0.86 and r = −0.72) than did radial strain ( r = 0.35). Longitudinal, circumferential, and radial strain significantly correlated with LV-dP/d tmax ( r = −0.53, r = −0.46, and r = 0.86), whereas only radial strain correlated with PRSW ( r = 0.55). Strain rate in the longitudinal, circumferential and radial direction significantly correlated with both PRSW ( r = −0.64, r = −0.58, and r = 0.74) and LV-dP/d tmax ( r = −0.95, r = −0.70, and r = 0.85). In conclusion, the speckle tracking echocardiography-derived strain rate is more robust to dynamic ventricular unloading than strain. Longitudinal and circumferential strain could not predict load-independent contractility. Strain rates, and especially in the radial direction, are good predictors of preload-independent inotropic markers derived from conductance catheter.

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Left ventricular strain and strain rates are decreased in children with normal fractional shortening after exposure to anthracycline chemotherapy

Cardiology in the Young ◽

10.1017/s1047951113001182 ◽

2013 ◽

Vol 24 (5) ◽

pp. 854-865 ◽

Cited By ~ 16

Author(s):

Thomas J. Moon ◽

Shelley D. Miyamoto ◽

Adel K. Younoszai ◽

Bruce F. Landeck

Keyword(s):

Strain Rate ◽

Cancer Patients ◽

Chemotherapeutic Agents ◽

Left Ventricular ◽

Paediatric Cancer ◽

Left Ventricular Strain ◽

Left Ventricular Deformation ◽

Diastolic Strain Rate ◽

Strain And Strain Rate ◽

Fractional Shortening

AbstractBackgroundAnthracycline chemotherapeutic agents carry the well-recognised risk of cardiotoxicity. Previous methods to evaluate cardiac function are useful, but have significant limitations. We sought to determine the left ventricular strain and strain rate of paediatric cancer patients with normal fractional shortening treated with anthracyclines using the latest ultrasound feature-tracking technology.Patients and methodsEchocardiograms on cancer patients before anthracycline exposure and following completion of treatment were retrospectively analysed using Velocity Vector Imaging software in the circumferential and longitudinal planes. The same analysis was performed on matched controls. Only patients with a fractional shortening ≥28% were included.ResultsIn all, 71 patients were identified with an age at diagnosis of 10.5 ± 4.7 years. The time from diagnosis to follow-up was 3.9 ± 4.0 years and the cumulative anthracycline dose was 356 ± 106 mg/m2. Following anthracycline exposure, paediatric cancer patients had a higher heart rate and a lower longitudinal strain, longitudinal diastolic strain rate, circumferential strain, and circumferential systolic and diastolic strain rate when compared with controls. Diastolic strain rate showed the greatest percent difference following anthracycline exposure versus controls.ConclusionDespite having a normal fractional shortening, children exposed to anthracyclines have subclinical derangement of their left ventricular deformation as measured by decreases in strain and strain rate in both the circumferential and longitudinal axis. In particular, there was a profound decrease in diastolic strain rate following anthracycline exposure compared with controls. Whether the decline of strain or strain rate can predict future risk of developing cardiomyopathy requires further investigation.

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