Management of Atrial Fibrillation in Hypertrophic Cardiomyopathy

Abstract

C ase Presentation:A 38-year-old man with hypertrophic cardiomyopathy (HCM) was referred for management of intermittent palpitations and exertional dyspnea with routine activities despite escalated β-blocker therapy. His initial examination was notable for a regular pulse at 72 bpm and harsh systolic murmur that increased with the Valsalva maneuver. A 12-lead electrocardiography revealed sinus rhythm with increased QRS voltage, repolarization abnormalities, and a QTc of 430 milliseconds. Echocardiography was notable for severe asymmetrical hypertrophy (septal thickness, 22 mm), normal systolic function, severe outflow tract obstruction (70 mm Hg), and left atrial (LA) enlargement. A 24-hour Holter monitor detected 6 minutes of rapid atrial fibrillation (AF) that coincided with his palpitations. Therapy was recommended with warfarin to prevent stroke and with disopyramide to minimize outflow tract obstruction and frequency of AF. IntroductionHCM, which affects 0.2% of the population, is an important cause of heart failure and is the leading cause of nonviolent sudden death in the young. Traditionally defined as left ventricular hypertrophy that develops in the absence of abnormal hemodynamics, it is caused by dominant mutations in sarcomere genes.1 Prevention of sudden death and management of left ventricular outflow tract obstruction (LVOTO) have been the primary focus of HCM clinical research and management since its original descriptions. However, AF is more prevalent than either sudden death or medically refractory obstruction and is the most common sustained arrhythmia in HCM.2 The combination of HCM and AF is associated with a markedly increased risk of stroke, overall mortality, and heart failure. This Clinician Update focuses on the epidemiology, pathophysiology, and clinical management of AF in patients with HCM. AF Prevalence and DetectionAF represents the most common sustained arrhythmia in both the general and HCM populations. In the general population, AF prevalence increases progressively with age and occurs predominantly in patients >60 years of age.3 Beyond age, established risk factors for developing AF include male sex, hypertension, and obesity.3The recognition of a hereditary component has led to the discovery of predisposing genetic variants for AF. 4AF in patients with HCM appears to be 4-to 6-fold more common than in the general population, with a reported prevalence between 18% and 28% (Table 1). 2,[5][6][7][8] In light of the high prevalence of AF in HCM, the American Heart Association, American College of Cardiology, and European Society of Cardiology have included recommendations for AF screening in their contemporary practice guidelines (Table 2).9,10 The European Society of Cardiology guidelines advise that 48-hour ambulatory ECG monitoring should be performed (Class IIA recommendation) every 6 to 12 months in patients with LA anterior-posterior diameter ≥45 mm. 10 The 2011 American College of Cardiology/ American Heart Association guidelines are less stringent, stating that 24-hour a...

Апікальна Гіпертрофічна Кардіоміопатія. Клінічний Випадок І Огляд Літератури

“…Появление аритмий, как правило, утяжеля-ет клиническую картину и во многом определяет прогноз заболевания -увеличивает риск развития инсульта, общую смертность и способствует про-грессированию сердечной недостаточности (СН) [39]. У больных с АГКМП высокий риск развития фибрилляции предсердий, пароксизмальной пред-сердной тахикардии, желудочковых нарушений ритма (желудочковой тахикардии или фибрилляции желудочков) [5,22,28,60]…”

“…Однако до сих пор не ясно: увеличивается ли ЛП перед появлением ФП или его дилатация носит вторичный к аритмии характер [39]. Рассматрива-ют несколько причин, ответственных за увеличение ЛП.…”

“…При этом не рекомендуется при-менять шкалу CHA2-DS2-VASC для оценки риска тромбоэмболических осложнений [39], так как при ГКМП она не обеспечивает эффективную страти-фикацию риска [29]. Новые антикоагулянты -пря-мой ингибитор тромбина (дабигатран) и прямые ингибиторы фактора Ха (ривароксабан и апикса-бан) -могут применяться у пациентов ГКМП с ФП [27,37].…”

Surgical management of atrial fibrillation at the time of septal myectomy

“…This results in varying degrees of associated secondary mitral regurgitation (i.e., AF secondary to structural heart disease). Additional potential reasons for developing AF are atrial sarcomeric myopathy or acquired risk factors such as hypertension (1).…”

Catheter ablation for atrial fibrillation in patients with hypertrophic cardiomyopathy

“…Atrial fibrillation (AF) is a well-recognised comorbidity in patients with hypertrophic cardiomyopathy (HCM), occurring in about 25% of patients 1. It is associated with increased mortality and worse heart failure symptoms, especially if there is concomitant outflow tract obstruction,2 and can be markedly debilitating in some individuals.…”