Hypertrophic cardiomyopathy: Part 1 - Introduction, pathology and pathophysiology

Abstract

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease with many genotype and phenotype variations. Earlier terminologies, hypertrophic obstructive cardiomyopathy and idiopathic hypertrophic sub-aortic stenosis are no longer used to describe this entity. Patients present with or without left ventricular outflow tract (LVOT) obstruction. Resting or provocative LVOT obstruction occurs in 70% of patients and is the most common cause of heart failure. The pathology and pathophysiology of HCM includes hypertrophy of the left ventricle with or without right ventricular hypertrophy, systolic anterior motion of mitral valve, dynamic and mechanical LVOT obstruction, mitral regurgitation, diastolic dysfunction, myocardial ischemia, and fibrosis. Thorough understanding of pathology and pathophysiology is important for anesthetic and surgical management.

Apical hypertrophic cardiomyopathy, a review of presentation, pathophysiology, diagnosis and natural course of the disease

“…32 The key histological feature of HCM is myocyte and myofibrillar disarray. 33 Myocyte hypertrophy with nuclear enlargement and hyperchromasia is also seen. 34 Dysplasia of small arteries seen as medial and intimal smooth muscle proliferation with luminal narrowing can also develop.…”

“…(Bangladesh Heart Journal 2016; 31 (1) : [29][30][31][32][33][34][35][36] Apical hypertrophic cardiomyopathy mimics and the role of other imaging modalities As mentioned a TTE although often the first line imaging modality can be non-diagnostic for AHCM especially if the apex is not fully visualized. Furthermore apical thrombus, Loefflers endocarditis, LV aneurysm, LV non compaction, and endomyocardial fibrosis may give a similar echocardiographic appearance on TTE to AHCM.…”

Hypertrophic cardiomyopathy part II - Anesthetic and surgical considerations

“…[27] Intraoperative Transesophageal Echocardiography [ Table 1] Two-dimensional TEE assessment Confi rmation of diagnosis Hypertrophic cardiomyopathy is usually diagnosed when the LV wall thickness exceed >15 mm in any myocardial segment without any other apparent cause. [5] The symptomatic patients have septal wall thickness exceeding 20 mm. The typical pattern of ventricular thickening is asymmetric hypertrophy rather than uniform concentric hypertrophy and usually involves the basal and mid anterior wall.…”

“…The typical pattern of ventricular thickening is asymmetric hypertrophy rather than uniform concentric hypertrophy and usually involves the basal and mid anterior wall. [5] The involvement of basal septum can be appreciated in the mid-esophageal (ME) 5-chamber view or ME long-axis view (MELAX). The LVH and the wall thickness can also be assessed in the trans-gastric (TG) short axis views; [28] the LV walls are greatly hypertrophied and there is near obliteration of the ventricular cavity during systole.…”

“…Recently, minimally invasive left atrial approach for septal myectomy was described by Mohr et al [4] Earlier, we had reviewed the pathology and pathophysiology of HCM and indications for surgery. [5] Preoperative workup The aim of preoperative evaluation is to identify patients with obstructive physiology primary modality for screening and diagnosis of HCM. [9] Comprehensive TTE should document the points shown in Table 1.…”