ARRHYTHMIAS IN HYPERTROPHIC CARDIOMYOPATHY

心源性猝死（SCD）和晕厥是心脏病患者常见的并发症。 肥厚型心肌病（HCM）患者。我们先前已经表明 在HCM患者中， 电生理学（EP）研究中的室性心动过速（VT）， 心脏骤停（SCA）和晕厥病史。获得更好的 理解HCM中SCA和晕厥的机制 我们对20例患者进行了详细的血流动力学和EP评估， 心脏骤停存活者（N=30）和HCM伴晕厥患者（N=55）。我们 还评估了胺碘酮（N=32）和植入式 除颤器（AICD，N=25）预防SCD，以及双腔（DDD）的作用 起搏器以缓解左心室梗阻引起的症状（N=10）。 五种机制解释了所有HCM患者的SCA， 事件：1）VT，2）左侧血液流出严重阻塞 心室，3）心脏中度增加引起的心肌缺血 率（以前未认识到的影响年轻HCM患者的综合征），4）和 导致严重低血压的房性心动过速，和5）心动过缓。 与晕厥相关的因素有：1）严重梗阻 诱发室性心动过速。两个变量独立预测 随后的SCO：1）先前SCA的历史和2）VT的诱导， EP研究。经验性胺碘酮治疗，报告可预防HCM中的SCD 霍尔特心动过速10例，其中3例中8例合并SCD 开始药物治疗的月数-几乎所有VT患者 霍尔特。EP研究显示胺碘酮经常加重传导 在大多数HCM患者中，这些问题是预防性的。值得注意的是， 胺碘酮促进VT诱导的患者更可能 随后，体验SCD。AICD装置，大大减少了 随后的SCD（平均随访期; 14个月）。DDD起搏器减少 梗阻，并导致8/10例患者的症状改善， 否则就需要做心脏手术

Sudden cardiac death (SCD) and syncope are frequent complications in patients with hypertrophic cardiomyopathy (HCM). We have previously shown that in HCM patients, a strong association exists between inducibility of ventricular tachycardia (VT) at electrophysiologic (EP) studies and a history of sudden cardiac arrest (SCA) and syncope. To obtain a better understanding of the mechanisms responsible for SCA and syncope in HCM patients, we performed detailed hemodynamic and EP assessment of sudden cardiac arrest survivors (N=30) and HCM patients with syncope (N=55). We also assessed the utility of amiodarone (N=32) and of the implantable defibrillator (AICD, N=25) to prevent SCD, and role of dual chamber (DDD) pacemakers to relieve symptoms due to left ventricular obstruction (N=10). Five mechanisms explained SCA in all the HCM patients presented with this event: 1) VT, 2) severe obstruction to the outflow of blood in the left ventricle, 3) myocardial ischemia induced by moderate increases in heart rate (previously unrecognized syndrome affecting young HCM patients), 4) an atrial tachycardia resulting in severe hypotension, and 5) bradycardia. Factors that were associated with syncope were 1) significant obstruction and inducibility of VT at EP studies. Two variables independently predicted subsequent SCO: 1) a history of previous SCA and 2) inducibility of VT at EP studies. Empiric amiodarone therapy, reported to prevent SCD in HCM patients with VT Holter, was associated with SCD in 8 patients within 3 months of initiation of drug therapy - nearly all in patients with VT on Holter. EP studies showed that amiodarone frequently aggravated conduction problems and in most HCM patients was proarrhythmic. Notably, symptomatic patients in whom amiodarone facilitated VT induction were more likely to experience SCD subsequently. The AICD device, significantly reduced subsequent SCD (mean follow-up period; 14 months). DDD pacemakers reduced obstruction and resulted in symptomatic improvement in 8/10 patients who would otherwise have needed cardiac surgery.