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.

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.

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.

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.

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.

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.

Metabolic parameters derived from cardiopulmonary stress testing for prediction of prognosis in patients with heart failure: the ochsner experience.

Cardiopulmonary parameters, particularly peak oxygen consumption, have proven utility in prognostic stratification for patients with heart failure. These have been typically corrected for total body weight as opposed to lean body mass (LBM). For practical purposes, fat consumes virtually no oxygen and receives minimal perfusion. Based on this rationale and on observations from previous studies, several investigations conducted at the Ochsner Clinic Foundation have assessed the prognostic value of metabolic parameters when corrected for LBM. Three studies reviewed in this discussion consistently found greater prognostic value for LBM-corrected parameters, especially peak oxygen consumption and oxygen pulse. These findings lead to a strong recommendation for LBM correction of cardiopulmonary exercise stress test-derived parameters for more accurate prognostic stratification in patients with heart failure, especially in the obese population. Other centers have studied additional parameters such as the ventilation to carbon dioxide production slope, oxygen uptake efficiency slope, and partial pressure of end-tidal carbon dioxide during exercise and rest. In multiple studies, these ventilation-dependent parameters have shown prognostic superiority compared with the standard peak oxygen consumption even when obtained from submaximal exercise data. However, no study to our knowledge has compared these parameters with LBM-adjusted values as described herein. The prognostic validity of cardiopulmonary exercise stress test-derived parameters requires further investigation in patients treated with ß-blockers.

Impact of left ventricular geometry on prognosis-a review of ochsner studies.

We review data from epidemiologic and population-based studies that demonstrate the impact of abnormal left ventricular geometric patterns, including both concentric remodeling and left ventricular hypertrophy, on major cardiovascular morbidity and mortality. We also review studies from Ochsner Clinic Foundation that assessed the impact of various left ventricular geometric patterns on overall cardiovascular prognosis, especially all-cause mortality.

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.

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.

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)

Benefits of Cardiac Rehabilitation and Exercise Training in Older Persons.

Despite the well-proved benefits of cardiac rehabilitation and exercise training, older persons are frequently not referred to or vigorously encouraged to pursue this therapy after major coronary heart disease (CHD) events. Therefore, we determined the effects of this therapy on plasma lipids, indices of obesity, and exercise capacity in older CHD patients compared with the benefits obtained in a younger cohort. At baseline, the older persons had lower body mass indices (BMI), triglycerides levels, and estimated metabolic equivalent (METs), and the elderly had higher levels of high-density lipoprotein cholesterol (HDL-C). Most other parameters were statistically similar in the older and younger patients. After cardiac rehabilitation, the elderly had significant improvements in METs, BMI, percent body fat, HDL-C, and low-density lipoprotein cholesterol (LDL-C)/HDL-C but not in total cholesterol or LDL-C. However, improvements in all of these parameters were statistically similar in older and younger patients. We conclude that despite baseline differences, improvements in exercise capacity, obesity indices, and lipid levels were statistically similar in older and younger patients enrolled in formal, phase II, cardiac rehabilitation and exercise training programs. Therefore, our data emphasized that the elderly should not be categorically denied the benefits of vigorous secondary CHD prevention, including formal cardiac rehabilitation and exercise training programs.