Imaging of left ventricular outflow tract obstruction in hypertrophic cardiomyopathy.

PURPOSE OF REVIEW: The current article reviews obstructive forms of hypertrophic cardiomyopathy and associated morphologic cardiac abnormalities. It focuses on echocardiographic imaging of the left ventricular (LV) outflow tract obstruction, its evaluation, prognostication, and differentiation from other conditions mimicking obstructive hypertrophic cardiomyopathy. RECENT FINDINGS: Symptomatic patients with LV outflow tract (LVOT) gradients at least 50 mmHg on maximally tolerated medical therapy are candidates for advanced therapies. Resting echocardiography may only identify 30% of patients with obstructive physiology. Provocative maneuvers are essential for symptomatic patients with hypertrophic cardiomyopathy (HCM). Exercise echocardiography is recommended if they fail to provoke a gradient. Although dynamic LV tract obstruction is seen with obstructive HCM, it is not specific to this condition and exists in other physiologic and pathophysiologic states. Careful clinical evaluation and imaging techniques aid in the differentiation of HCM from these conditions. SUMMARY: Imaging plays an integral role in the diagnosis, prognosis, and risk stratification of HCM patients. Newer imaging technologies, including 3D transthoracic echocardiography, 3D transesophageal, speckle-derived 2D strain, and cardiac MRI, allow for a better hemodynamic understanding of systolic anterior motion and LV tract obstruction. Evolving techniques, that is, artificial intelligence, will undoubtedly further increase diagnostic capabilities. Newer medical therapies are available with the hope that this will lead to better patient management.

Degenerative Mitral Stenosis-Diagnostic Challenges and Future Directions.

Determining the severity of stenosis in degenerative mitral stenosis (DMS) is fraught with challenges. Neither a high trans-mitral gradient nor a small valve area calculation is sufficiently diagnostic for DMS due to variable left atrial and left ventricular compliance in the setting of diastolic dysfunction, and the variable flow seen in patients with chronic kidney disease (i.e., high flow state) and elderly women (low flow state). Three-dimensional measurement of mitral valve area may be underestimated due to shadowing from basal calcium, and mitral valve annulus (MVA) by continuity equation (CEQ) or dimensionless mitral valve index can be erroneous in the presence of significant regurgitation of left-sided valves. The proposed dimensionless mitral stenosis index (DMSI) can be an easy echocardiographic tool to use in daily practice but needs further validation and is limited in the setting of significant regurgitation of left sided valves. Mean trans-mitral gradients > 8 mmHg and pulmonary artery pressure > 50 mmHg are independent predictors of mortality in those with MVA < 1.5 cm 2 derived by CEQ. In patients who have symptoms that are out of proportion to the degree of stenosis reported, exercise stress testing may help determine the physiologic effects of the stenotic valve. A combination of MVA by CEQ or DMSI and mean transmitral gradient at a given left ventricle stroke volume (flow) should be evaluated in larger studies.

Dimensionless index of the mitral valve for evaluation of degenerative mitral stenosis.

PURPOSE: Degenerative mitral stenosis (DMS) is an increasingly recognized cause of mitral stenosis. The goal of this study was to compare echocardiographic differences between DMS and rheumatic mitral stenosis (RMS), identify echocardiographic variables reflective of DMS severity, and propose a dimensionless mitral stenosis index (DMSI) for assessment of DMS severity. METHODS: This is a single-center, retrospective cohort study. We included patients with at least mild MS and a mean transmitral pressure gradient (TMPG) ≥4 mm Hg. Mitral valve area by the continuity equation (MVACEQ ) was used as an independent reference. The DMSI was calculated as follows: DMSI = VTILVOT / VTIMV. All-cause mortality data were collected retrospectively. RESULTS: A total of 64 patients with DMS and 24 patients with RMS were identified. MVACEQ was larger in patients with DMS (1.43 ± 0.4 cm2 ) than RMS (0.9 ± 0.3 cm2 ) by ~0.5 cm2 (P = <.001), and mean TMPG was lower in the DMS group (6.0 ± 2 vs 7.9 ± 3 mm Hg, P = .003). A DMSI of ≤0.50 and ≤0.351 was associated with MVACEQ ≤1.5 and MVACEQ ≤1.0 cm2 (P < .001), respectively. With the progression of DMS from severe to very severe, there was a significant drop in DMSI. There was a nonsignificant trend toward worse survival in patients with MVACEQ ≤1.0 cm2 and DMSI ≤0.35, suggesting severe stenosis severity. CONCLUSION: Our results show that TMPG correlates poorly with MVA in patients with DMS. Proposed DMSI may serve as a simple echocardiographic indicator of hemodynamically significant DMS.

Impact of appropriate use criteria for transesophageal echocardiograms on clinically meaningful care.

INTRODUCTION: The aim of this study was to evaluate appropriateness of transesophageal echocardiography (TEE) studies based on 2011 Appropriate Use Criteria (AUC) for Echocardiography and its impact on patient management. METHODS AND RESULTS: In a retrospective analysis of 100 inpatient TEEs, 85% of the TEEs ordered were determined to be appropriate, 9% were inappropriate, and 6% were uncertain. Inter-observer differences in the determination of AUC were seen in 24% of the studies, requiring a senior-level cardiologist to make the final determination of AUC score. The variance in interpretation by experts is concerning for how that might translate into differences in clinical practice. Of all TEEs, only 63% led to an active change in care, including changes in medications or procedures, while 37% did not. We found a statistically significant difference between cardiologists' and non-cardiologists' orders for TEE having an impact on patient's clinical care (41% vs 22%, respectively, P < 0.05) (Table ). While not statistically significant, a trend toward clinical change was observed in the appropriate vs inappropriate TEEs (70% vs 44%, respectively, P = 0.06). CONCLUSION: Ideally, the role of a diagnostic cardiovascular imaging test, such as a TEE, is to influence clinical care, if it is ordered appropriately on the right patient. While the AUC guides clinicians on the appropriate use of cardiovascular imaging, it is broadly written and offers room for interpretation to encompass variety of clinical scenarios. Clinical care paths that utilize AUC and standardize use of multidisciplinary institutional resources offer opportunity for optimal clinical impact and patient care.

Development and Implementation of a Quality Improvement Process for Echocardiographic Laboratory Accreditation.

We describe our process for quality improvement (QI) for a 3-year accreditation cycle in echocardiography by the Intersocietal Accreditation Commission (IAC) for a large group practice. Echocardiographic laboratory accreditation by the IAC was introduced in 1996, which is not required but could impact reimbursement. To ensure high-quality patient care and community recognition as a facility committed to providing high-quality echocardiographic services, we applied for IAC accreditation in 2010. Currently, there is little published data regarding the IAC process to meet echocardiography standards. We describe our approach for developing a multicampus QI process for echocardiographic laboratory accreditation during the 3-year cycle of accreditation by the IAC. We developed a quarterly review assessing (1) the variability of the interpretations, (2) the quality of the examinations, (3) a correlation of echocardiographic studies with other imaging modalities, (4) the timely completion of reports, (5) procedure volume, (6) maintenance of Continuing Medical Education credits by faculty, and (7) meeting Appropriate Use Criteria. We developed and implemented a multicampus process for QI during the 3-year accreditation cycle by the IAC for Echocardiography. We documented both the process and the achievement of those metrics by the Echocardiography Laboratories at the Ochsner Medical Institutions. We found the QI process using IAC standards to be a continuous educational experience for our Echocardiography Laboratory physicians and staff. We offer our process as an example and guide for other echocardiography laboratories who wish to apply for such accreditation or reaccreditation.

Risk assessment and management of anthracycline and HER2 receptor inhibitor-induced cardiomyopathy.

With the advent and increased use of chemotherapeutic agents and radiation therapy, cancer survival rates have increased. With increased survival, both acute and chronic cardiotoxic adverse effects have emerged. The growing need for managing the treatment of individuals with chemotherapy-induced cardiotoxicity has led to the formation of cardio-oncology programs throughout the United States. These programs concentrate on many aspects of cardiac disease in the oncology patient. Of these, the cardiotoxic effects (particularly cardiomyopathy) of anthracyclines and HER2 receptor inhibitors are a large focus of cardio-oncology practice. Despite the increasing availability of these programs, no consensus guidelines have been established to provide a framework for treating these patients. This review describes the initial evaluation, risk assessment, and management of individuals receiving anthracycline and HER2 receptor inhibitor therapy for cardiomyopathy. These recommendations are supported by the current literature in this field.

Multimodality imaging of hypertrophic cardiomyopathy.

The diagnosis and management of hypertrophic cardiomyopathy (HCM) requires multimodality imaging. Transthoracic echocardiogram (TTE) remains the first-line imaging modality to diagnose HCM identifying morphology and obstruction, which includes left ventricular outflow obstruction, midcavitary obstruction and systolic anterior motion. Cardiac magnetic resonance imaging (CMR) can adjudicate equivocal cases, rule out alternative diagnoses and evaluate for risk factors of sudden cardiac death. Imaging with TTE or transesophageal echocardiogram can also guide alcohol septal ablation or surgical myectomy respectively. Furthermore, TTE can guide medical management of these patients by following peak gradients. Thus, multimodality imaging in HCM is crucial throughout the course of these patients' care.

A Practical Approach to Echocardiographic Imaging in Patients With Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is frequently unrecognized or misdiagnosed. The recently published consensus recommendations from the American Society of Echocardiography provided recommendations for the utilization of multimodality imaging in the care of patients with HCM. This document provides an additional practical framework for optimal image and measurement acquisition and guidance on how to tailor the echocardiography examination for individuals with HCM. It also provides resources for physicians and sonographers to use to develop HCM imaging protocols.

Prosthesis-patient mismatch following aortic and mitral valves replacement - A comprehensive review.

Prothesis-patient mismatch (PPM) occurs when there is a mismatch between the effective orifice area (EOA) of the prosthetic valve and the required cardiac output to meet the need of the patient's body surface area (BSA). The clinical threshold for PPM occurs when the indexed effective orifice area (iEOA) is ≤0.65 cm2/m2 for the aortic valve prosthesis, and ≤ 1.20 cm2/m2 for the mitral valve prosthesis. The wide variation of reported incidence of PPM is most likely attributed to the variation in the methods of calculating iEOA [(for e.g., using continuity equation across the prosthesis versus using projected EOA (generated by the industry)]. Newer generation mechanical valves have shown less PPM than older generation, and stentless bioprosthesis have less PPM than stented prosthesis. Long-term clinical outcome of PPM is associated with adverse cardiovascular events especially in the presence of pre-existing left ventricle dysfunction or with concomitant procedure such as coronary artery bypass graft surgery. Strategies to mitigate the risk of PPM such as aortic root replacement in patients with the small aortic annulus should be utilized. Accurate assessment of the patient's annular size and indexing the effective orifice area (EOA) of the prosthesis to patient's BSA at the time of prosthesis implantation are important steps to preventing future PPM.

Watchman FLX Implantation for Challenging Left Atrial Appendage Anatomy: Case-Based Discussion.

Left atrial appendage (LAA) occlusion devices provided an acceptable and valid alternative to anticoagulation among patients with atrial fibrillation who carry high bleeding risk. Watchman device is non-inferior to oral anticoagulation to prevent cerebrovascular accidents. The presence of a longer distal portion of the older generation Watchman led to exclusion of patients with prohibitive anatomy of the LAA such as chicken-wing morphology or shallow LAA. Watchman FLX provides a wider range of sizes and can be implanted with complex anatomy or shallow LAA. In the case series, we discuss 3 patients with challenging LAA anatomy that underwent successful Watchman FLX implantation.

Recommendations for Multimodality Cardiovascular Imaging of Patients with Hypertrophic Cardiomyopathy: An Update from the American Society of Echocardiography, in Collaboration with the American Society of Nuclear Cardiology, the Society for Cardiovascular Magnetic Resonance, and the Society of Cardiovascular Computed Tomography.

Hypertrophic cardiomyopathy (HCM) is defined by the presence of left ventricular hypertrophy in the absence of other potentially causative cardiac, systemic, syndromic, or metabolic diseases. Symptoms can be related to a range of pathophysiologic mechanisms including left ventricular outflow tract obstruction with or without significant mitral regurgitation, diastolic dysfunction with heart failure with preserved and heart failure with reduced ejection fraction, autonomic dysfunction, ischemia, and arrhythmias. Appropriate understanding and utilization of multimodality imaging is fundamental to accurate diagnosis as well as longitudinal care of patients with HCM. Resting and stress imaging provide comprehensive and complementary information to help clarify mechanism(s) responsible for symptoms such that appropriate and timely treatment strategies may be implemented. Advanced imaging is relied upon to guide certain treatment options including septal reduction therapy and mitral valve repair. Using both clinical and imaging parameters, enhanced algorithms for sudden cardiac death risk stratification facilitate selection of HCM patients most likely to benefit from implantable cardioverter-defibrillators.

Role of Transesophageal Echocardiography in Patients with Ischemic Stroke.

Acute ischemic stroke is a condition with considerable mortality and morbidity. When used appropriately, Transesophageal Echocardiography (TEE) can be an incredibly useful tool to identify potential causes of stroke and guide management. The crucial distinction in this modality lies in separating common incidental findings from those likely to have contributed to ischemic stroke. Furthermore, the management of identified intracardiac causes varies widely from open surgery to antiplatelet therapy. This review seeks to discuss the role of TEE in identifying common etiologies of cardioembolic stroke, review the clinical entities, and the highlight the most recent management recommendations.

Prognostic Implications of Left Ventricular Hypertrophy.

Left ventricular hypertrophy (LVH) was one of the earliest studied echocardiographic characteristics of the left ventricle. As the myriad of measurable metrics has multiplied over recent years, this reliable and relevant variable can often be overlooked. In this paper, we discuss appropriate techniques for accurate analysis, underlying pathophysiology, and the contributions from various risk factors. The prognostic implications of LVH on stroke, serious arrhythmias, and sudden cardiac death are reviewed. Finally, we examine the effect of therapy to reduce LVH and the resultant clinical outcomes.

Echocardiographic Assessment of Degenerative Mitral Stenosis: A Diagnostic Challenge of an Emerging Cardiac Disease.

Degenerative mitral stenosis (DMS) is characterized by decreased mitral valve (MV) orifice area and increased transmitral pressure gradient due to chronic noninflammatory degeneration and subsequent calcification of the fibrous mitral annulus and the MV leaflets. The "true" prevalence of DMS in the general population is unknown. DMS predominantly affects elderly individuals, many of whom have multiple other comorbidities. Transcatheter MV replacement techniques, although their long-term outcomes are yet to be tested, have been gaining popularity and may emerge as more effective and relatively safer treatment option for patients with DMS. Echocardiography is the primary imaging modality for evaluation of DMS and related hemodynamic abnormalities such as increased transmitral pressure gradient and pulmonary arterial pressure. Classic echocardiographic techniques used for evaluation of mitral stenosis (pressure half time, proximal isovelocity surface area, continuity equation, and MV area planimetry) lack validation for DMS. Direct planimetry with 3-dimensional echocardiography and color flow Doppler is a reasonable technique for determining MV area in DMS. Cardiac computed tomography is an essential tool for planning potential interventions or surgeries for DMS. This article reviews the current concepts on mitral annular calcification and its role in DMS. We then discuss the epidemiology, natural history, differential diagnosis, mechanisms, and echocardiographic assessment of DMS.

Current Perspectives on Left Ventricular Geometry in Systemic Hypertension.

Hypertension (HTN) is a global health problem and a leading risk factor for cardiovascular disease (CVD) morbidity and mortality. The hemodynamic overload from HTN causes left ventricular (LV) remodeling, which usually manifests as distinct alterations in LV geometry, such as concentric remodeling or concentric and eccentric LV hypertrophy (LVH). In addition to being a common target organ response to HTN, LV geometric abnormalities are well-known independent risk factors for CVD. Because of their prognostic implications and quantifiable nature, changes in LV geometric parameters have commonly been included as an outcome in anti-HTN drug trials. The purpose of this paper is to review the relationship between HTN and LV geometric changes with a focus on (1) diagnostic approach, (2) epidemiology, (3) pathophysiology, (4) prognostic effect and (5) LV response to anti-HTN therapy and its impact on CVD risk reduction.

Prediction of All-Cause Mortality by the Left Atrial Volume Index in Patients With Normal Left Ventricular Filling Pressure and Preserved Ejection Fraction.

OBJECTIVE: To describe the prevalence of left atrial (LA) enlargement (LAE) and its association with all-cause mortality in 10,719 patients with an early diastolic transmitral flow velocity (E) to early diastolic mitral annular velocity (e') ratio-determined normal left ventricular (LV) filling pressure and preserved LV ejection fraction (LVEF). METHODS: We evaluated 10,719 patients (deceased patients: n = 479; mean [SD] age, 65 [14] years; 60% male; surviving patients: n = 10,240; mean (SD) age, 54 (16) years; 48% male) with estimated normal LV filling pressure (E/e' ratio ≤ 8) and preserved LVEF (≥ 50%) to determine the impact of LA volume index (LAVi) on all-cause mortality during a mean (SD) follow-up of 2.2 (1.0) years. RESULTS: In the univariate analysis, with every milliliter per square meter increase in LAVi, all-cause mortality risk increased by 3% (hazard ratio [HR], 1.03; 95% CI, 1.02-1.04; P < .001). After adjusting for covariates, LAVi (as a continuous variable) was an independent predictor of all-cause mortality (HR, 1.015; 95% CI, 1.005-1.026; P = .01). When LAVi was assessed as a categorical variable with normal LAVi (≤ 28 mL/m(2)) as the reference group, moderate LAVi (34-39 mL/m(2)) and severe LAVi (≥ 40 mL/m(2)) were independent predictors of all-cause mortality (HR, 1.34; 95% CI, 1.01-1.79; P = .04; and HR, 1.65; 95% CI, 1.18-2.29; P = .003, respectively). CONCLUSION: LAE was independently associated with an increased risk of all-cause mortality in our large cohort of 10,719 patients with normal LV filling pressure and preserved LVEF.

Overview of transesophageal echocardiography for the chest physician.

Transesophageal echocardiography (TEE) is a growing technology that is frequently utilized in the critical care setting by intensivists, surgeons, anesthesiologists as well as specialists in cardiovascular diseases. The clinical application of TEE continues to emerge, and the indications and diagnostic utility of this technology as currently available are summarized in this review.

Is a Full Digital Echocardiography Laboratory Feasible for Routine Daily Use?

To determine the feasibility and accuracy of digital echocardiography for routine interpretation of two-dimensional and Doppler echocardiography, we studied 93 consecutive patients chosen at random from our daily workload. The parameters studied included cavity sizes, biventricular regional and global systolic and diastolic function, valvular structure and function, and presence or absence of pericardial disease. The results were first interpreted using quad screen, digital format cine loops. These results were then compared with the results obtained from reviewing the video-tape images. Seventy-nine patients (87%) showed complete concordance between the digital system and video tape. Among the 1156 echocardiographic parameters/measurements examined in all patients, a 99% concordance rate (normal vs abnormal) was found. Disagreements between the digital system and video tape in the patients undergoing two-dimensional/Doppler exams included mitral valve prolapse in 3, mild valvular insufficiency in 5, a small pleural effusion in 2, and a wall-motion abnormality in 3 patients. In conclusion, the use of digital technology for evaluation of routine echocardiograms appears to compare favorably with the interpretation of images using the conventional video tape. (ECHOCARDIOGRAPHY, Volume 13, September 1996)

Myxosarcoma: a rare primary cardiac tumor.

We describe the case of a patient with myxosarcoma of the left ventricle, a very rare type of primary cardiac sarcoma, who presented with features of acute pericarditis and discuss the management of this condition.