Hypertrophic Cardiomyopathy

A Practical Guide to Diagnosis and Management

Srilakshmi M. Adhyapak, V. Rao Parachuri, Srilakshmi M. Adhyapak, V. Rao Parachuri

• Publisher: CRC Press
• Year: 2020
• ISBN:
  9781000261387
• Edition: 1
• Topic: Medicina
• Subtopic: Cardiología

Hypertrophic cardiomyopathy is a disease of the cardiac muscle leading to severe debilitating symptoms with relentless progression. Medical options in treating this disease are limited to its early stages, with the disease often becoming resistant to pharmacological interventions. Hypertrophic Cardiomyopathy: A Practical Guide to Diagnosis and Management describes the various sub-types of this condition, including its unique anatomic features, with an emphasis on a therapeutic approach, encapsulating several techniques. Surgical myectomy has become the gold standard of effective treatment. This book also throws light on patient selection, newer surgical techniques, and novel image-based pre-operative planning modalities for surgical myectomy.

Key Features

• Explores the surgical aspects along with the clinical coverage of hypertrophic cardiomyopathy

• 
  
  

• Provides ready resource for practicing cardiologists, practitioners, trainees, and fellows

• 
  
  

• Covers anatomical variants, mitral valve pathology, and non-invasive pre-surgical planning with a detailed surgical video and intra-operative pictures

• 
  
  

Chapter 1

HYPERTROPHIC CARDIOMYOPATHY
An Overview

Srilakshmi M. Adhyapak

Contents

Introduction

Prevalence

Clinical Features and Presentation

Hypertrophic Cardiomyopathy Phenotypes and their Clinical Presentation

Hypertrophic Obstructive Cardiomyopathy

Non-Obstructive HCM

Apical HCM

Hypertrophic Cardiomyopathy with Preserved Left Ventricle Function and Advanced Heart Failure

Role of Imaging in HCM

Cardiac Magnetic Resonance Imaging

Risk of Sudden Cardiac Death

Predictors of Heart Failure

Exercise (Stress) Echocardiography

Metabolic (Cardiopulmonary) Testing

Biomarkers

Heart Failure Treatment in HCM

LifeStyle Measures

Drugs

Surgical Septal Myectomy

Alcohol Septal Ablation

Heart Transplantation

Genetically Based Interventions

Conclusions

References

Introduction

Prevalence

The prevalence of hypertrophic cardiomyopathy (HCM) has been reported as 1:500, with greater prevalence noted recently [1]. The earliest reports of it were largely limited to developed countries of North America and Western Europe in Caucasians, but shortly thereafter there were reports of it from Japan, which helped the compilation of a substantial literature on it in Asians [2]. With enhanced awareness and diagnostic acumen, and the development of dedicated multidisciplinary centers [1], the epidemiology of HCM has evolved to include patients from a wide variety of races, cultures, ethnicities, and both sexes – equally (see Figure 1.1). The occurrence of HCM can be attributed to spontaneous (de novo) mutations among 11 genes encoding thick and thin filament proteins of the cardiac sarcomere (most commonly the beta-myosin heavy chain and myosin-binding protein C). Estimates of the prevalence of HCM have been reported disproportionately from developed countries with advanced medical systems. An occurrence of 1:500 in the general population has been reported based on clinical expression of the disease’s phenotype, which is left ventricular hypertrophy, evidenced by imaging. A more recent higher estimate of 1:200 takes into account a broader clinical profile based on familial transmission and contemporary imaging, as well as the high frequency of pathogenic sarcomere gene mutations which are known to occur in the affected population [3].

Figure 1.1 World map showing global distribution of HCM, which is found in 122 countries in the world (shown in red). HCM = hypertrophic cardiomyopathy. With permission of B.J. Maron et al., “Global Burden of Hypertrophic Cardiomyopathy.” JACC: Heart Failure (2018) 6: 376–378.

Clinical Features and Presentation

Diagnosis of HCM is often challenging due to its phenotypic heterogeneity. In a majority of diagnosed patients, prognosis is generally favorable, with sudden cardiac death (SCD) and severe congestive heart failure occurring only in a subset of patients. Treatment is multifaceted, requiring individualized care. The clinical presentation has morphed from SCD to heart failure with the advent of implantable cardioverter defibrillators (ICD), which have substantially decreased the incidence of SCD, making heart failure increasingly prevalent [2].

Hypertrophic cardiomyopathy-related heart failure differs from heart failure by other...