Effects of the HeartMate II left ventricular assist device as observed by serial echocardiography.

BACKGROUND: The HeartMate II is the most frequently used left ventricular assist device (LVAD) in patients with end-stage heart failure. There is a paucity of data regarding its longitudinal cardiac effects, particularly that on diastole. METHODS: This retrospective study was an evaluation of echocardiograms preoperatively and at 3, 6, and 12 months postoperatively in patients with a HeartMate II. Measurements included left ventricle (LV) dimensions, ejection fraction (EF), right ventricle (RV) size and function, parameters of diastolic function, and an analysis of mitral regurgitation (MR), tricuspid regurgitation (TR), aortic insufficiency (AI), and aortic valve thickening. RESULTS: Forty-seven patients were evaluated. LV dimensions decreased but EF, RV size, and RV function were unchanged. Right ventricular systolic pressure (RVSP) and diastolic parameters including mitral inflow E/A, deceleration time (DT), pulmonary vein inflow, left atrial size, and overall diastolic grade improved. LV relaxation measured by tissue Doppler (e') was unchanged and the E/e' ratio was also unchanged. Regarding valve function, MR decreased, TR was unchanged, and the aortic valve became increasingly thickened with increased AI severity. CONCLUSIONS: The HeartMate II unloads the LV as shown by decreased LV size, decreased MR, reduced RVSP, and improved patterns of mitral inflow. However, neither systolic function nor diastolic relaxation improves in this cohort. RV size and function also remain unchanged. The aortic valve shows increased thickening and AI likely from valve leaflet fusion. These results provide detailed functional and hemodynamic information regarding the longitudinal effects of the HeartMate II.

Classification of left ventricular diastolic function using American Society of Echocardiography Guidelines: agreement among echocardiographers.

Guidelines for assessing diastolic function by echocardiography are continually being updated. Our ability to use available guidelines effectively has not been completely investigated. Six trained echocardiographers were asked to interpret 105 echocardiograms using current American Society of Echocardiography (ASE) algorithms for interpretation of diastolic grade and estimation of left atrial (LA) pressure. Diastolic grade was categorized as normal, mild, moderate, or severe dysfunction. The presence or absence of elevated LA pressure was determined using a second ASE algorithm. As a reference comparison for level of agreement, left ventricular ejection fraction was visually determined. By the ASE algorithm, 29 subjects (28%) met all measurement criteria in their assigned grade and 57 subjects (55%) met all or all but one criterion of their assigned grade. Of the 45 subjects (43%) for whom the guidelines disagreed by more than 1 criterion, the readers debated between normal and moderate dysfunction in 22% or mild and moderate diastolic dysfunction in 31%. Percent inter-reader agreement and kappa values were 76% (0.7) for determining diastolic grade, 84% (0.67) for determining elevated LA pressure, and 84% (0.67) for estimation of ejection fraction, the reference standard. For all subjects, if multiple echocardiographic criteria failed to fit into the proposed guidelines, agreement fell to 66% (0.58) for determining diastolic grade and 74% (0.48) for determining LA pressure. There is reasonable agreement estimating diastolic grade and LA pressure using current guidelines. Further refinements in the definition of mild and moderate dysfunction may improve agreement.

Decreased cardiac functional reserve in heart failure with preserved systolic function.

BACKGROUND: Heart failure in patients with preserved left ventricular systolic function (HFpEF) is a prevalent disease characterized by exercise intolerance with poorly understood pathophysiology. We hypothesized that recruitable contractility is impaired in HFpEF, accounting for the appearance of symptoms with exertion. METHODS AND RESULTS: Echocardiographic analysis of myocardial performance was performed at baseline and after a modified dobutamine protocol (max dose 16 µg/kg/min) in participants with known HFpEF and age- and gender-matched controls. The primary outcome variable was change in contractile reserve, measured as a change in ejection fraction (EF). Recruitable contractility was decreased in HFpEF participants compared with control subjects (HFpEF 0.4 ± 1.9% vs control 19.0 ± 1.4%; P < .001). During dobutamine infusion, velocities increased in control participants but remained unchanged in the HFpEF group, yielding a significant difference between groups (P < .05) for both longitudinal displacement and velocity. CONCLUSIONS: Patients with HFpEF have an impaired contractile response to adrenergic stimulation. The blunted response to adrenergic stimulation in the HFpEF group suggests that these patients may be unable to respond to periods of increased cardiac demand. This inability to increase contractility appropriately suggests abnormalities of systolic function in this disease and may contribute to exertional intolerance in HFpEF.

Three-dimensional echocardiography and mitral valve disease.

Three-dimensional echocardiography is a growing imaging modality, particularly for the evaluation of mitral valve pathology. Functional anatomy in disease states such as mitral regurgitation and stenosis as well as prosthetic valves can be effectively studied, offering superior knowledge to treating physicians. Additionally, three-dimensional echocardiography has the ability to help guide operative and percutaneous interventions, allowing for improved patient outcomes and advancement of clinical research. Continued experience with three-dimensional echocardiography will further our knowledge of the mitral valve and refine current indications for cardiovascular imaging.

Cardiac computed tomography and quadricuspid aortic valve: a case report.

A quadricuspid aortic valve is rare and often incidentally found by echocardiography, surgically, or on post mortem examination. Aortic regurgitation is common and if severe enough can lead to symptoms of dyspnea. We report a case of a quadricuspid aortic valve, which was found by cardiac multidetector computed tomography during a pre-operative assessment for severe aortic regurgitation.

Diagnosis and management of stage a heart failure.

Reduction of the monetary and societal costs of the heart failure epidemic can best be achieved by prevention of new heart failure cases. To effectively prevent heart failure, patients at risk must be identified and treated. The American College of Cardiology/American Heart Association Guidelines for Evaluation and Management of Chronic Heart Failure in the Adult define the stage A heart failure patient as one with identified risk factors for heart failure, particularly coronary heart disease, hypertension, and diabetes, but no evidence of cardiovascular damage. In this review, the authors discuss the commonly recognized, as well as some less commonly recognized, risk factors that define the stage A patient. The authors also discuss data demonstrating that risk factor modification can reduce heart failure incidence. Given the size of the population at risk, through increased awareness of heart failure risk and aggressive treatment, health care providers can critically impact this public health concern.

Effects of Obstructive Sleep Apnea and Obesity on Cardiac Remodeling: The Wisconsin Sleep Cohort Study.

STUDY OBJECTIVES: To characterize the prospective associations of obstructive sleep apnea (OSA) with future echocardiographic measures of adverse cardiac remodeling. METHODS: This was a prospective long-term observational study. Participants had overnight polysomnography followed by transthoracic echocardiography a mean (standard deviation) of 18.0 (3.7) y later. OSA was characterized by the apnea-hypopnea index (AHI, events/hour). Echocardiography was used to assess left ventricular (LV) systolic and diastolic function and mass, left atrial volume and pressure, cardiac output, systemic vascular resistance, and right ventricular (RV) systolic function, size, and hemodynamics. Multivariate regression models estimated associations between log10(AHI+1) and future echocardiographic findings. A secondary analysis looked at oxygen desaturation indices and future echocardiographic findings. RESULTS: At entry, the 601 participants were mean (standard deviation) 47 (8) y old (47% female). After adjustment for age, sex, and body mass index, baseline log10(AHI+1) was associated significantly with future reduced LV ejection fraction and tricuspid annular plane systolic excursion (TAPSE) ≤ 15 mm. After further adjustment for cardiovascular risk factors, participants with higher baseline log10(AHI+1) had lower future LV ejection fraction (ß = -1.35 [standard error = 0.6]/log10(AHI+1), P = 0.03) and higher odds of TAPSE ≤ 15 mm (odds ratio = 6.3/log10(AHI+1), 95% confidence interval = 1.3-30.5, P = 0.02). SaO2 desaturation indices were associated independently with LV mass, LV wall thickness, and RV area (all P < 0.03). CONCLUSIONS: OSA is associated independently with decreasing LV systolic function and with reduced RV function. Echocardiographic measures of adverse cardiac remodeling are strongly associated with OSA but are confounded by obesity. Hypoxia may be a stimulus for hypertrophy in individuals with OSA.