Mid-Ventricular Obstructive Hypertrophic Cardiomyopathy Associated with an Apical Aneurysm: Evaluation of Possible Causes of Aneurysm Formation

Abstract

Mid-ventricular obstructive hypertrophic cardiomyopathy (MVOHCM) is a rare type of cardiomyopathy, associated with apical aneurysm formation in some cases. We report a patient presenting with ventricular fibrillation, an ECG with an above normal ST segment, and elevated levels of cardiac enzymes but normal coronary arteries. Left ventriculography revealed a left ventricular obstruction without apical aneurysm. There was a significant pressure gradient between the apical and basal sites of the left ventricle. Cine magnetic resonance imaging (MRI), performed on the 10th hospital day, showed asymmetric septal hypertrophy, mid-ventricular obstruction, and an apical aneurysm with a thrombus. The first evaluation by contrast-enhanced imaging showed a subendocardial perfusion defect and delayed enhancement. It was speculated that the intraventricular pressure gradient, due to mid-ventricular obstruction, triggered myocardial infarction, which subsequently resulted in apical aneurysm formation.

Successful Catheter Ablation of Hemodynamically Unstable Monomorphic Ventricular Tachycardia in a Patient with Hypertrophic Cardiomyopathy and Apical Aneurysm

“…[3][4][5][6][7][8][9][10] The presence of an apical aneurysm in HCM may be associated with a high risk of VT and adverse cardiovascular events including sudden death. [3][4][5][6][7][8][9][10] The presence of an apical aneurysm in HCM may be associated with a high risk of VT and adverse cardiovascular events including sudden death.…”

“…This report describes successful ablation of a hemodynamically unstable VT arising from within the neck of an apical aneurysm associated with mid-ventricular LV hypertrophy, in a patient with an unusual variant of HCM. [3][4][5][6][7][8][9][10] The presence of an apical aneurysm in HCM may be associated with a high risk of VT and adverse cardiovascular events including sudden death. 6 The pathophysiology of the apical aneurysm is not known, but may be related to local endocardial ischemia and replacement fibrosis.…”

Tako-tsubo, hypertrophic obstructive cardiomyopathy & muscle bridging — Separate disease entities or a single condition?

“…The onset of aneurysm in MVOHCM is usually insidious but can present acutely with complications of an established aneurysm such as thromboembolic events or ventricular arrhythmias. The pathogenesis of aneurysm in TC and MVOHCM remains unclear but is widely believed to be unrelated to coronary occlusion [3]. Myocardial bridging has also been extensively reported and is widely accepted to be a cause of angina and in some cases myocardial infarction either due to spasm or thrombosis.…”

“…It has been linked with SAM related LVOT obstruction and acute MR but is not usually considered in patients Myocardial wall stress is an important index of ventricular loading conditions and may be useful to evaluate stress-shortening (EF) or stressfiber shortening (mVCF) relationships in the LV myocardium [1][2][3]. Janz proposed a formula for estimating wall stress based on the thick-wall shell theory and a more general representation of ventricular geometry, as opposed to a sphere, cylinder, or ellipsoid [2][3][4][5]. This method has been applied for determining local afterload and preload of the myocardium, and can be clinically used for inhomogeneity of wall thickness [4][5][6][7].…”

Two Cases of Cerebral Embolism Caused by Apical Thrombi in Midventricular Obstructive Cardiomyopathy

“…We encountered and thoroughly examined two cases of stroke, possibly caused by a thrombus of akinetic apical aneurysm as possible sources of embolism. Few patients with normal left ventricular systolic performance who have never experienced stroke have demonstrated thrombus in an apical aneurysm (6). A thrombus is induced by turbulent stasis of blood flow and injured myocardial endocardium by both systolic midventricular obstruction and diastolic paradoxical jet flow (7,8) from the apex to the base of the left ventricular cavity.…”