Contribution of mitral valve leaflet length and septal wall thickness to outflow tract obstruction in patients with hypertrophic cardiomyopathy.

We sought to examine whether elongation of the mitral valve leaflets in patients with hypertrophic cardiomyopathy (HCM) is synergistic to septal wall thickness (SWT) in the development of left ventricular outflow tract obstruction (LVOTO). HCM is a common genetic cardiac disease characterized by asymmetric septal hypertrophy and predisposition towards LVOTO. It has been reported that elongation of the mitral valve leaflets may be a primary phenotypic feature and contribute to LVOTO. However, the relative contribution of this finding versus SWT has not been studied. 152 patients (76 with HCM and 76 non-diseased age, race and BSA-matched controls) and 18 young, healthy volunteers were studied. SWT and the anterior mitral valve leaflet length (AMVLL) were measured using cine MRI. The combined contribution of these variables (SWT × AMVLL) was described as the Septal Anterior Leaflet Product (SALP). Peak LVOT pressure gradient was determined by Doppler interrogation and defined as "obstructive" if ≥ 30 mmHg. Patients with HCM were confirmed to have increased AMVLL compared with controls and volunteers (p < 0.01). Among HCM patients, both SWT and SALP were significantly higher in patients with LVOTO (N = 17) versus without. SALP showed modest improvement in predictive accuracy for LVOTO (AUC = 0.81) among the HCM population versus SWT alone (AUC = 0.77). However, in isolated patients this variable identified patients with LVOTO despite modest SWT. Elongation of the AMVLL is a primary phenotypic feature of HCM. While incremental contributions to LVOTO appear modest at a population level, specific patients may have dominant contribution to LVOTO. The combined marker of SALP allows for maintained identification of such patients despite modest increases in SWT.

Association of Bicuspid aortic valve morphology and aortic root dimensions: a substudy of the aortic stenosis progression observation measuring effects of rosuvastatin (ASTRONOMER) study.

BACKGROUND: Bicuspid aortic valve (BAV) is the leading cause of aortic stenosis in patients younger than the age of 50. A classification scheme of BAVs is based upon leaflet orientation: Type I (fusion of right and left coronary cusps) and Type II (fusion of right and noncoronary cusps). The correlation between BAV leaflet orientation and aortic root pathology however remains ill defined. OBJECTIVE: The objective was to describe a potential relationship between BAV leaflet morphology and aortic root measurements in the ASTRONOMER study, a multicenter study to assess the effect of rosuvastatin on the progression of AS. METHODS: BAV morphology was classified as Type I or Type II orientation based on the parasternal short-axis view. Echo measurements including left ventricular and aortic root dimensions were obtained. RESULTS: The study population included 89 patients (56 +/- 11 years; 44 males). There were 63 patients with Type I and 26 patients with Type II BAV. Baseline demographics, hemodynamics, and left heart dimensions were similar between both groups. Patients with Type I BAV had larger aortic annulus and ascending root dimensions compared to those patients with Type II BAV (P < 0.05). CONCLUSION: In patients with mild to moderate aortic stenosis due to a BAV, the presence of Type I valve orientation was associated with significantly greater aortic root parameters compared to Type II valve orientation.

Association of mitral annular calcification and aortic valve morphology: a substudy of the aortic stenosis progression observation measuring effects of rosuvastatin (ASTRONOMER) study.

AIMS: Mitral annular calcification (MAC) is characterized by calcium and lipid deposition in the annular fibrosa of the mitral valve. Although individuals with MAC are at increased risk of cardiovascular events, little is known about the significance of this finding in patients with concurrent aortic stenosis (AS). The aim of this study was to describe the association of baseline MAC and aortic valve morphology in asymptomatic patients enrolled in the ASTRONOMER study, a multicentre study to assess the effect of Rosuvastatin on the progression of AS. METHODS AND RESULTS: At baseline, transthoracic echocardiography was performed with two-dimensional and Doppler imaging following a standardized protocol. Echo measurements including left ventricular (LV) dimensions and aortic root dimensions were obtained according to the ASE recommendations. MAC was identified by bright echoes at the base of the mitral leaflets or annulus on 2D imaging, and aortic valve calcification by visualization of bright echoes on the aortic valve leaflets. The degree of calcification was semi-quantitated from absent to severe. The study population included 219 patients (57 +/- 14 years; 129 males), divided into two pre-specified categories; bicuspid (n = 133) and tricuspid (n = 86) aortic valves. Baseline LV dimensions, aortic valve haemodynamics, and cholesterol profiles were similar between the two groups at baseline. Individuals with tricuspid aortic valves were older, more hypertensive, with higher degrees of MAC and AV calcification (P < 0.001). The higher degree of MAC persisted in patients with tricuspid AV after adjustment for age and systolic blood pressure (P = 0.004). CONCLUSION: In patients with asymptomatic mild to moderate AS, MAC is more prevalent in those individuals with tricuspid AV, independent of age, and systolic blood pressure. Whether the degree of MAC may be a surrogate for atherosclerosis, and predict the subset of patients who will respond to statin therapy in preventing the progression of AS, remains to be determined.

Clinical usefulness of tissue Doppler imaging in patients with mild to moderate aortic stenosis: a substudy of the aortic stenosis progression observation measuring effects of rosuvastatin study.

OBJECTIVE: Although impaired diastolic function is common in aortic stenosis (AS), little is known about the clinical usefulness of tissue Doppler imaging (TDI) to detect diastolic dysfunction in patients with mild to moderate AS. The objective was to describe both conventional and TDI measurements of diastolic function in asymptomatic patients enrolled in the Aortic Stenosis Progression Observation Measuring Effects of Rosuvastatin study, a multicenter study to assess the effect of rosuvastatin on the progression of AS. METHODS: Baseline echocardiography measurements, including left ventricular interventricular septal thickness, posterior wall thickness, cavity dimensions, and ejection fraction were obtained. Conventional Doppler indices, including peak early (E) and late (A) transmitral velocities, E/A ratio, and E-wave deceleration time, were measured from spectral Doppler. Tissue Doppler measurements, including early (E') and late (A') velocities of the lateral annulus, were determined, and E/E' was calculated. RESULTS: The study population included 172 patients (aged 57 +/- 13 years; 73 were female) divided into three categories of AS severity on the basis of peak velocity at baseline (group I: 2.5-3.0 m/s; group II: 3.1-3.5 m/s; group III; 3.6-4.0 m/s). Baseline hemodynamics, left ventricular dimensions, and conventional diastolic functional parameters were similar among all 3 groups. In patients with greater severity of AS, the lateral E' was lower and the E/E' (as an estimate of increased left ventricular end-diastolic pressure) was higher (P <.05). CONCLUSION: In patients with mild to moderate asymptomatic AS, TDI measures of diastolic function are abnormal and related to the severity of AS. These findings may help to predict the future development of symptoms in this population.

Guidelines for the provision of echocardiography in Canada: recommendations of a joint Canadian Cardiovascular Society/Canadian Society of Echocardiography Consensus Panel.

Recognizing the central role of echocardiographic examinations in the assessment of most cardiac disorders and the need to ensure the provision of these services in a highly reliable, timely, economical and safe manner, the Canadian Cardiovascular Society and Canadian Society of Echocardiography undertook a comprehensive review of all aspects influencing the provision of echocardiographic services in Canada. Five regional panels were established to develop preliminary recommendations in the five component areas, which included the echocardiographic examination, the echocardiographic laboratory and report, the physician, the sonographer and indications for examinations. Membership in the panels was structured to recognize the regional professional diversity of individuals involved in the provision of echocardiography. In addition, a focus group of cardiac sonograhers was recruited to review aspects of the document impacting on sonographer responsibilities and qualification. The document is intended to be used as a comprehensive and practical reference for all of those involved in the provision of echocardiography in Canada.