Atrial and Ventric ular Arrhythmias in H y p e r t rop h i c C a rd i o m y o p a t h y Kartik R. Kumar, MBBS, Swati N. Mandleywala, MBBS, Mark S. Link, MD* KEYWORDS Arrhythmias Atrial fibrillation Ventricular fibrillation Hypertrophic cardiomyopathy Risk factors Electrophysiology
KEY POINTS
INTRODUCTION Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disease caused by mutations in genes coding for cardiac sarcomeres. HCM is the most common inherited heart disease, with a prevalence of 0.2% or 1 in 500 persons.1 There are multiple genetic variants that cause pleomorphic disease characterized by myocardial disarray and myocardial hypertrophy. Throughout the history of understanding this disease, we have come to learn that these patients are at an increased risk of atrial and ventricular arrhythmias and these contribute to the prognosis and mortality of the disease.2
ATRIAL FIBRILLATION Atrial fibrillation (AF) is the most common arrhythmia in patients with HCM. A landmark
2001 study3 evaluated 480 patients with HCM with a mean follow-up of 9.1 years and found the prevalence of AF to be 22%. More recently, in 2009 a study in Japan 4 evaluated 261 patients with HCM and found that 74 (28%) patients had documented paroxysmal AF (PAF) or chronic AF at registration, and a 2014 systematic review5 including several larger studies concluded an overall prevalence of 22.45%. AF is an important prognostic indicator in patients with HCM, because these patients are typically at a higher New York Heart Association (NYHA) functional class and have a poorer outcome. This subgroup of patients with HCM are at an increased risk of cardiovascular morbidity and mortality in the form of thromboembolic events, heart failure, and sudden death.6 A large cohort study including 293 patients with
The authors have nothing to disclose. Department of Cardiology, Tufts Medical Center, 800 Washington Street, Boston, MA 02111, USA * Corresponding author. Box #197, 800 Washington Street, Boston, MA 02111. E-mail address: [email protected] Card Electrophysiol Clin - (2015) -–http://dx.doi.org/10.1016/j.ccep.2015.03.002 1877-9182/15/$ – see front matter Ó 2015 Elsevier Inc. All rights reserved.
cardiacEP.theclinics.com
Atrial fibrillation (AF) is common finding in patients with hypertrophic cardiomyopathy (HCM) and contributes to poor outcomes as a result of the progression and exacerbation of heart failure in addition to the innate morbidity of AF. Ventricular tachycardia and fibrillation are life threatening, with the 5 most common risk factors being: Left ventricular hypertrophy Personal history of unexplained syncope Family history of sudden cardiac death Nonsustained ventricular tachycardia Abnormal blood pressure response to exercise Management of AF in HCM is often difficult, and the risk of systemic thromboembolism is high. Ventricular arrhythmias are best managed with implantable cardioverter defibrillator implantation.
2
Kumar et al HCM with a median follow-up of 6 years found that 50 patients developed heart failure, of whom 32 (64%) had AF as a contributor. In addition, 18 of the 50 patients with heart failure who had died and on whom autopsy was performed, 5 had presence of thrombi in the left atrium (LA). All 5 of these hearts were in patients with HCM suffering from AF.7 In 158 patients with HCM with AF and 496 patients with HCM without AF followed up for 4.2 2.8 years, AF was associated with an increased risk for all-cause death (P 5 .001), cardiovascular death (P
KEY POINTS
INTRODUCTION Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disease caused by mutations in genes coding for cardiac sarcomeres. HCM is the most common inherited heart disease, with a prevalence of 0.2% or 1 in 500 persons.1 There are multiple genetic variants that cause pleomorphic disease characterized by myocardial disarray and myocardial hypertrophy. Throughout the history of understanding this disease, we have come to learn that these patients are at an increased risk of atrial and ventricular arrhythmias and these contribute to the prognosis and mortality of the disease.2
ATRIAL FIBRILLATION Atrial fibrillation (AF) is the most common arrhythmia in patients with HCM. A landmark
2001 study3 evaluated 480 patients with HCM with a mean follow-up of 9.1 years and found the prevalence of AF to be 22%. More recently, in 2009 a study in Japan 4 evaluated 261 patients with HCM and found that 74 (28%) patients had documented paroxysmal AF (PAF) or chronic AF at registration, and a 2014 systematic review5 including several larger studies concluded an overall prevalence of 22.45%. AF is an important prognostic indicator in patients with HCM, because these patients are typically at a higher New York Heart Association (NYHA) functional class and have a poorer outcome. This subgroup of patients with HCM are at an increased risk of cardiovascular morbidity and mortality in the form of thromboembolic events, heart failure, and sudden death.6 A large cohort study including 293 patients with
The authors have nothing to disclose. Department of Cardiology, Tufts Medical Center, 800 Washington Street, Boston, MA 02111, USA * Corresponding author. Box #197, 800 Washington Street, Boston, MA 02111. E-mail address: [email protected] Card Electrophysiol Clin - (2015) -–http://dx.doi.org/10.1016/j.ccep.2015.03.002 1877-9182/15/$ – see front matter Ó 2015 Elsevier Inc. All rights reserved.
cardiacEP.theclinics.com
Atrial fibrillation (AF) is common finding in patients with hypertrophic cardiomyopathy (HCM) and contributes to poor outcomes as a result of the progression and exacerbation of heart failure in addition to the innate morbidity of AF. Ventricular tachycardia and fibrillation are life threatening, with the 5 most common risk factors being: Left ventricular hypertrophy Personal history of unexplained syncope Family history of sudden cardiac death Nonsustained ventricular tachycardia Abnormal blood pressure response to exercise Management of AF in HCM is often difficult, and the risk of systemic thromboembolism is high. Ventricular arrhythmias are best managed with implantable cardioverter defibrillator implantation.
2
Kumar et al HCM with a median follow-up of 6 years found that 50 patients developed heart failure, of whom 32 (64%) had AF as a contributor. In addition, 18 of the 50 patients with heart failure who had died and on whom autopsy was performed, 5 had presence of thrombi in the left atrium (LA). All 5 of these hearts were in patients with HCM suffering from AF.7 In 158 patients with HCM with AF and 496 patients with HCM without AF followed up for 4.2 2.8 years, AF was associated with an increased risk for all-cause death (P 5 .001), cardiovascular death (P
