Department of Cardiology, Tokyo Women's Medical University, Tokyo, Japan.
Department of Clinical Pharmacology and Therapeutics, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo, 105-8461, Japan.
BMC Cardiovasc Disord. 2022 Aug 16;22(1):374. doi: 10.1186/s12872-022-02811-6.
Appropriate shock therapy is associated with subsequent all-cause death in heart failure (HF) patients who receive an implantable cardioverter defibrillator (ICD) for the primary prevention of sudden cardiac death. To evaluate the impact of signal-averaged electrocardiography (SAECG) findings on appropriate shocks in prophylactic ICD patients with nonischemic systolic HF.
We studied 86 patients with nonischemic HF and a left ventricular ejection fraction ≤ 35% who underwent new ICD implantation for the primary prevention of sudden cardiac death. We excluded patients who had a previously implanted permanent pacemaker and patients who received cardiac resynchronization therapy with an ICD. SAECG was performed before implantation. Abnormal SAECG findings were defined if 2 of the following 3 conditions were identified: filtered QRS duration (fQRS) ≥ 114 ms, root-mean-square voltage during the last 40 ms of the fQRS (RMS 40) < 20 μV, and duration of the low-amplitude potentials < 40 μV (LAS 40) > 38 ms; additionally, patients with a QRS complex ≥ 120 ms who met both the RMS 40 and LAS 40 criteria were also considered to have abnormal SAECG findings. The primary outcome was the first occurrence of appropriate shock after implantation of the ICD. The secondary outcomes were the first occurrence of inappropriate shock and all-cause mortality.
Forty-two patients met the criteria for abnormal SAECG findings (49%). During a median follow-up period of 61 months, 17 patients (20%) died, 24 (28%) received appropriate shock therapy, and 19 (22%) received inappropriate shock therapy. There was a significantly higher incidence of appropriate shocks in patients with abnormal SAECG findings than in those with normal SAECG findings (log-rank test, p = 0.025). Multivariate analysis revealed that abnormal SAECG findings were independently associated with the occurrence of appropriate shock (hazard ratio 2.67, 95% confidential interval 1.14-6.26). However, abnormal SAECG findings were not related to inappropriate shock. There was no difference in the incidence of all-cause death between patients with abnormal and normal SAECG findings.
Our results suggest that abnormal SAECG findings are associated with a high probability of appropriate shocks in prophylactic ICD patients with nonischemic systolic HF.
在因心力衰竭（HF）而接受植入式心脏复律除颤器（ICD）进行原发性预防心源性猝死的患者中，适当的电击治疗与随后的全因死亡相关。评估信号平均心电图（SAECG）结果对非缺血性收缩性 HF 患者接受预防性 ICD 治疗时发生适当电击的影响。
我们研究了 86 例非缺血性 HF 患者，这些患者左心室射血分数≤35%，因原发性预防心源性猝死而接受新的 ICD 植入。我们排除了先前植入永久性起搏器的患者和接受 ICD 心脏再同步治疗的患者。在植入前进行了 SAECG。如果存在以下 3 种情况中的 2 种，则定义为异常 SAECG 发现：滤波 QRS 持续时间（fQRS）≥114 ms、fQRS 最后 40 ms 的均方根电压（RMS 40）<20 μV 和低幅度电位持续时间（LAS 40）>38 ms；此外，符合 RMS 40 和 LAS 40 标准且 QRS 波群持续时间≥120 ms 的患者也被认为具有异常 SAECG 发现。主要结局是植入 ICD 后首次发生适当电击。次要结局是首次发生不适当电击和全因死亡率。
42 名患者符合异常 SAECG 发现标准（49%）。在中位随访 61 个月期间，17 名患者（20%）死亡，24 名（28%）接受适当电击治疗，19 名（22%）接受不适当电击治疗。异常 SAECG 发现患者发生适当电击的发生率明显高于正常 SAECG 发现患者（对数秩检验，p=0.025）。多变量分析显示，异常 SAECG 发现与适当电击的发生独立相关（风险比 2.67，95%置信区间 1.14-6.26）。然而，异常 SAECG 发现与不适当电击无关。异常和正常 SAECG 发现患者的全因死亡率无差异。
我们的结果表明，在非缺血性收缩性 HF 患者接受预防性 ICD 治疗时，异常 SAECG 发现与适当电击的高发生率相关。
