OBJECTIVES This study characterizes left ventricular outflow tract (LVOT) gradient variability in patients with hypertrophic cardiomyopathy (HCM) during cardiac catheterization. BACKGROUND Management of HCM is directed by the presence and magnitude of LVOT obstruction. The magnitude and clinical impact of spontaneous variability during a single cardiac catheterization has not been described. ...

BACKGROUND AND OBJECTIVES Prior studies indicate that up to 35% of cases of severe aortic stenosis (AS) have paradoxical low flow, low gradient despite preserved left ventricular ejection fraction (LVEF). However, error in left ventricular outflow tract (LVOT) diameter may lead to misclassification. Herein, we determined whether measurement of LVOT diameter by transesophageal echocardiography (...

BACKGROUND While implications of myocardial fibrosis on left ventricular (LV) function at rest have been studied in hypertrophic cardiomyopathy (HCM), the pathophysiological consequences on dynamic LV outflow tract (LVOT) gradient have so far not been investigated in detail. OBJECTIVE To evaluate the influence of myocardial fibrosis, detected by MRI as late-gadolinium enhancement (LGE), on LV...

BACKGROUND Improvement in the left ventricular outflow tract (LVOT) gradient has been used as a means of assessing response to therapy in patients with hypertrophic obstructive cardiomyopathy (HOCM). To our knowledge, no data exist regarding the spontaneous day-to-day variability of the LVOT gradient in patients with HOCM. Defining the magnitude of such variability is critical to properly under...

Various treatment modalities have been introduced to reduce the subaortic pressure gradient in patients with obstructive hypertrophic cardiomyopathy, including pacemaker insertion. Complete ventricular capture during pacing is essential and requires optimization of the atrioventricular interval (AVI). In this study, a protocol using echocardiographic examination assessing the changes in the lef...

Obstructive Hypertrophic Cardiomyopathy: Pathogenesis of the Obstruction In most patients, the hypertrophy develops initially in the septum and extends to the free walls, often giving a picture of concentric hypertrophy. In '25% of patients with familial hypertrophic cardiomyopathy (FHCM), asymmetrical septal hypertrophy leads to a highly variable pressure gradient between the apical left ventr...

BACKGROUND In patients with aortic stenosis (AS), precise assessment of severity is critical for treatment decisions. Estimation of aortic valve area (AVA) with transthoracic echocardiographic (TTE)-continuity equation (CE) assumes a circular left ventricular outflow tract (LVOT). We evaluated incremental utility of 3D multidetector computed tomography (MDCT) over TTE assessment of AS severity....

An echocardiogram performed on a 72-year–old man with exertional dyspnea revealed asymmetrical septal hypertrophy (maximum thickness, 1.8 mm) and turbulent flow in the left ventricular outflow tract (LVOT; Movie I in the onlineonly Data Supplement) with a resting gradient of 62 mm Hg and a peak provoked gradient of 166 mm Hg after Valsalva maneuver (Figure, A and B), consistent with hypertrophi...