Power Modulation Echocardiography to Detect and Quantify Myocardial Scar.

BACKGROUND: Myocardial scar correlates with clinical outcomes. Traditionally, late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) is used to detect and quantify scar. In this prospective study using LGE CMR as reference, the authors hypothesized that nonlinear ultrasound imaging, namely, power modulation, can detect and quantify myocardial scar in selected patients with previous myocardial infarction. In addition, given the different histopathology between ischemic and nonischemic scar, a further aim was to test the diagnostic performance of this echocardiographic technique in unselected consecutive individuals with ischemic and nonischemic LGE or no LGE on CMR. METHODS: Seventy-one patients with previous myocardial infarction underwent power modulation echocardiography following CMR imaging (group A). Subsequently, 101 consecutive patients with or without LGE on CMR, including individuals with nonischemic LGE, were scanned using power modulation echocardiography (group B). RESULTS: In group A, echocardiography detected myocardial scar in all 71 patients, with good scar volume agreement with CMR (bias = -1.9 cm3; limits of agreement [LOA], -8.0 to 4.2 cm3). On a per-segment basis, sensitivity was 82%, specificity 97%, and accuracy 92%. Sensitivity was higher in the inferior and posterior segments and lower in the anterior and lateral walls. In group B, on a per-subject basis, the sensitivity of echocardiography was 62% (91% for ischemic and 30% for nonischemic LGE), with specificity and accuracy of 89% and 72%, respectively. The bias for scar volume between modalities was 5.9 cm3, with LOA of 34.6 to 22.9 cm3 (bias = -1.9 cm3 [LOA, -11.4 to 7.6 cm3] for ischemic LGE, and bias = 18.9 cm3 [LOA, -67.4 to 29.7.6 cm3] for nonischemic LGE). CONCLUSIONS: Power modulation echocardiography can detect myocardial scar in both selected and unselected individuals with previous myocardial infarction and has good agreement for scar volume quantification with CMR. In an unselected cohort with nonischemic LGE, sensitivity is low.

Unexpected finding after aortic arch operation: a left ventricular pseudoaneurysm - Who is the culprit?

We present a case of a 61-year-old female who, after undergoing frozen elephant trunk surgery, was found to have an unexpected left ventricular pseudoaneurysm on transthoracic echocardiogram. The pseudoaneurysm was caused by the left ventricular vent catheter constantly impinging the LV wall of the beating heart during surgery. Contrast echocardiography, cardiac magnetic resonance imaging and computed tomography (CT) imaging confirmed the diagnosis and served for follow-up demonstrating the narrow neck and outpouching structure on the apical lateral wall. The patient remains asymptomatic two years after the operation and is being followed up with echocardiography and CT imaging.

Association between ethnicity and degree of improvement in cardiac function following initiation of sacubitril/valsartan.

AIMS: The aim of this study was to determine the degree of short-term improvement in left ventricular ejection fraction (LVEF), haemodynamics, NT-proBNP and quality of life following initiation of sacubitril/valsartan in black patients when compared with white patients. METHODS: This was a retrospective, observational, single-centre, hypothesis-generating study of patients with symptomatic heart failure and reduced ejection fraction (HFrEF) treated with guideline recommended therapy, who were transitioned from an ACE inhibitor (ACE-I) or angiotensin receptor blocker (ARB) to sacubitril/valsartan. RESULTS: Our analysis included 83 patients (mean age 57 years) with echocardiography performed before and after transition from ACE-I/ARB to sacubitril/valsartan, after excluding patients with concomitant Cardiac resynchronization therapy implantation. Overall, sacubitril/valsartan was associated with LVEF improvement from 28.8% ±â€Š0.7 to 32.0% ±â€Š1.1% (P = 0.0002), but no reverse remodelling was observed. The association with LVEF improvement was only observed in white patients (n = 46, P = 0.0006), but not in black patients (n = 37, P = 0.1728), and appeared to be associated with reduced blood pressure (baseline vs. 2-week blood pressure 116.5 ±â€Š13.9 vs. 109.4 ±â€Š14.3 mmHg, respectively, in white patients, P = 0.0449). Fifteen patients (18.1%) became ineligible for primary prevention Implantable cardioverter defibrillator implantation. CONCLUSION: Sacubitril/valsartan was associated with improved LVEF, NT-proBNP concentrations and quality of life in patients with symptomatic HFrEF on guideline recommended therapy. However, in our cohort, improvement of LVEF and quality of life might be attenuated in black patients, which warrants further investigation.

The Impact of Vendor-Specific Ultrasound Beam-Forming and Processing Techniques on the Visualization of In Vitro Experimental "Scar": Implications for Myocardial Scar Imaging Using Two-Dimensional and Three-Dimensional Echocardiography.

BACKGROUND: Myocardial scar appears brighter compared with normal myocardium on echocardiography because of differences in tissue characteristics. The aim of this study was to test how different ultrasound pulse characteristics affect the brightness contrast (i.e., contrast ratio [CR]) between tissues of different acoustic properties, as well as the accuracy of assessing tissue volume. METHODS: An experimental in vitro "scar" model was created using overheated and raw pieces of commercially available bovine muscle. Two-dimensional and three-dimensional ultrasound scanning of the model was performed using combinations of ultrasound pulse characteristics: ultrasound frequency, harmonics, pulse amplitude, steady pulse (SP) emission, power modulation (PM), and pulse inversion modalities. RESULTS: On both two-dimensional and three-dimensional imaging, the CR between the "scar" and its adjacent tissue was higher when PM was used. PM, as well as SP ultrasound imaging, provided good "scar" volume quantification. When tested on 10 "scars" of different size and shape, PM resulted in lower bias (-9.7 vs 54.2 mm3) and narrower limits of agreement (-168.6 to 149.2 mm3 vs -296.0 to 404.4 mm3, P = .03). The interobserver variability for "scar" volume was better with PM (intraclass correlation coefficient = 0.901 vs 0.815). Two-dimensional and three-dimensional echocardiography with PM and SP was performed on 15 individuals with myocardial scar secondary to infarction. The CR was higher on PM imaging. Using cardiac magnetic resonance as a reference, quantification of myocardial scar volume showed better agreement when PM was used (bias, -645 mm3; limits of agreement, -3,158 to 1,868 mm3) as opposed to SP (bias, -1,138 mm3; limits of agreement, -5,510 to 3,233 mm3). CONCLUSIONS: The PM modality increased the CR between tissues with different acoustic properties in an experimental in vitro "scar" model while allowing accurate quantification of "scar" volume. By applying the in vitro findings to humans, PM resulted in higher CR between scarred and healthy myocardium, providing better scar volume quantification than SP compared with cardiac magnetic resonance.