Jons Christian, Thomsen Poul Erik Bloch
Gentofte University Hospital, Niels Andersens Vej 65, 2900, Copenhagen, Denmark,
Curr Treat Options Cardiovasc Med. 2012 Feb;14(1):39-49. doi: 10.1007/s11936-011-0163-4.
Using an implantable cardiac monitor (ICM) in patients with acute myocardial infarction (MI) allows continuous electrocardiogram monitoring and provides a much more detailed picture of the incidence of brady- and tachyarrhythmias than conventional follow-up. The CARISMA study was the first to use the ICM in post-MI patients with moderate to severe left ventricular systolic dysfunction. Atrial fibrillation (AF) events lasting longer than 30 s were associated with an almost threefold increase in the risk of major cardiac events. This confirms the current definition of clinically significant AF episodes, as patients with episodes of shorter duration were not at increased risk. The association of AF to progressive heart failure, reinfarction, and cardiovascular death underlines the need for an intensive follow-up of post-MI patients with new-onset AF in order to reveal underlying causes of AF such as progressive left ventricular dysfunction or myocardial ischemia. Asymptomatic, especially nightly, bradycardia episodes including high-degree 2°-3° atrioventricular (AV) block, sinus bradycardia, and sinus arrest were frequently documented by ICM in the CARISMA study. Ten percent of patients experienced high-degree 2°-3° AV block, of which the main part was nightly and asymptomatic, and 50% of all cardiovascular deaths occurred in this group, most from severe heart failure. Therefore, in post-MI patients with paroxysmal high-degree AV block, pacemaker implantation should be done, and in the case of left ventricular dysfunction (LVEF ≤ 35%), an implantable cardioverter defibrillator/cardiac resynchronization therapy defibrillator (ICD/CRT-D) may be indicated. Nonsustained ventricular tachycardia (VT) is very frequent in post-MI patients, and in the CARISMA study, high-risk patients with nonsustained VT were implanted with an ICD. Furthermore, in 10% of the patients, the ICM recorded nonsustained VT episodes of ≥ 16 beats per minute, resulting in a twofold increase in the risk for cardiac death. Thus, patients with nonsustained VT should undergo careful investigation, and we recommend a repeat echocardiography and electrophysiological stimulation in these patients. Patients with sustained VT or VF should receive an ICD.
在急性心肌梗死（MI）患者中使用植入式心脏监测器（ICM）可实现连续心电图监测，与传统随访相比，能更详细地了解缓慢性和快速性心律失常的发生率。CARISMA研究是首个在中度至重度左心室收缩功能不全的心肌梗死后患者中使用ICM的研究。持续时间超过30秒的心房颤动（AF）事件与主要心脏事件风险增加近三倍相关。这证实了具有临床意义的AF发作的当前定义，因为发作持续时间较短的患者风险并未增加。AF与进行性心力衰竭、再梗死和心血管死亡之间的关联强调了对新发AF的心肌梗死后患者进行强化随访的必要性，以便揭示AF的潜在原因，如进行性左心室功能障碍或心肌缺血。在CARISMA研究中，ICM经常记录到无症状的，尤其是夜间的缓慢性心律失常发作，包括高度2°-3°房室（AV）阻滞、窦性心动过缓和窦性停搏。10%的患者发生高度2°-3°AV阻滞，其中大部分为夜间发作且无症状，所有心血管死亡中有50%发生在该组，多数死于严重心力衰竭。因此，对于阵发性高度AV阻滞的心肌梗死后患者，应植入起搏器，对于左心室功能障碍（左心室射血分数[LVEF]≤35%）的患者，可能需要植入植入式心脏复律除颤器/心脏再同步治疗除颤器（ICD/CRT-D）。非持续性室性心动过速（VT）在心肌梗死后患者中非常常见，在CARISMA研究中，有非持续性VT的高危患者植入了ICD。此外，10%的患者中，ICM记录到每分钟≥16次的非持续性VT发作，导致心脏死亡风险增加两倍。因此，非持续性VT患者应进行仔细检查，我们建议对这些患者重复进行超声心动图检查和电生理刺激。持续性VT或室颤（VF）患者应接受ICD治疗。
