Midventricular obstruction—A form of hypertrophic obstructive cardiomyopathy—and systolic anterior motion of the mitral valve

Abstract

Summary: Hypertrophic cardiomyopathy (HCM) has various manifestations with respect to the localization of the hypertrophy. In this study we report clinical, electrocardiographic (ECG), echocardiographic (echo), and hemodynamic findings in midventricular obstruction (MO), an uncommon form of hypertrophic obstructive cardiomyopathy (HOCM) in 9 patients. The prevalence of systolic anterior motion of anterior mitral leaflet (SAM) in MO, an echocardiographic diagnostic hallmark in HOCM, was another purpose of this study. All patients had complete clinical, ECG, echo, and hemodynamic workup, including left ventricular (in 4 patients simultaneous biventricular, SBVA) and coronary angiograms. All patients had dyspnea and palpitations, chest pain, 2 had syncope. In the ECG, atrial fibrillation was present in 2 , and left ventricular hypertrophy in 9 patients. Septa1 and left ventricular free wall thickening was significantly present in all patients in echo, and SAM in 1 patient. The intraventricular gradient (IVG) was 40-1 76 mmHg, in I case 40 mmHg by provocation, Brockenbrough was positive in all patients. Two patients had right ventricular IVG. A positive beta-blocking agent effect was present in 6 cases. The best localization of the obstruction was possible with SBVA and 2D-echo. We conclude that M O has all the signs of HOCM, but S A M in echocardiography is uncommon. S A M is occasionally present and is not a necessary factor to pro-

Percutaneous Myocardial Ablation for Left Mid-Ventricular Obstructive Hypertrophic Cardiomyopathy

“…Myocardial contrast echocardiography enables extension of percutaneous treatment of hypertrophic obstructive cardiomyopathy to patients with other than subaortic obstruction. Septal ablation may be useful in patients with MVO accompanying with LV outflow tract obstruction [16]. There was no evidence for SAM of the mitral valve in this patient.…”

Mid-ventricular Obstructive Hypertrophic Cardiomyopathy during Pregnancy Complicated by Preeclampsia and Acute Myocardial Infarction: A Case Report

“…In mid‐ventricular obstructive HCM, echocardiography reveals hypertrophy only in the mid portion of the left ventricle and hypertrophied papillary muscles, resulting in a systolic obstruction of the mid‐ventricle 4 . Anterior motion of the anterior mitral leaflet during systole, an echocardiographic hallmark of HCM, is uncommon in mid‐ventricular obstructive HCM 8 . Continuous‐wave Doppler echocardiography reveals high flow velocities with an abnormally high intraventricular pressure gradient across the obstruction.…”

Left Ventricular Outflow Tract Obstruction—be Prepared!

“…Instead of being pushed away from the LVOT the mitral leaflets can be dragged into and, when conditions are met for the Venturi effect, drawn towards, the intraventricular septum 20,29,31,32 . The submitral valve apparatus and ventricular septal thickening can also cause or be associated with left ventricular systolic outflow obstruction at the mid-ventricular level (MVO) 33,34 . To exclude ventricular outflow obstruction it is therefore necessary to interrogate flow by PWD starting in the mid left ventricular cavity and advancing the velocity sample box toward the aortic valve.…”