Department of Cardiology, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China.
Department of Cardiology, Shanghai East Hospital, Shanghai Tongji University School of Medicine, Shanghai, China.
BMC Cardiovasc Disord. 2020 Jun 23;20(1):306. doi: 10.1186/s12872-020-01592-0.
Apical hypertrophic cardiomyopathy (ApHCM) is a phenotypic variant of nonobstructive HCM. ApHCM is characterized by left ventricular hypertrophy involve the distal apex. The electrocardiographic character of ApHCM can mimic non-ST elevation acute coronary syndrome (NSTEACS), triggering a series of studies and treatments that may be unnecessary. This study aimed to clarify the electrocardiogram (ECG) differences between the two diseases.
Initial ECG recordings of 41 patients with ApHCM and 72 patients with NSTEACS were analyzed retrospectively. We analyzed the voltage of negative T (neg T) and R wave, the change of ST-segment as well as the number of leads with neg T wave in the 12-lead ECGs.
Across the 12-lead ECGs, the magnitude of R wave significantly differed between ApHCM and NSTEACS in 10 leads excluding leads aVR and V1. ApHCM was associated with a greater maximal amplitude of R wave in lead V5 (3.13 ± 1.08 vs. 1.38 ± 0.73 mV, P < 0.001). The magnitude of T wave significantly differed between ApHCM and NSTEACS in 10 leads excluding leads II and V1. ApHCM was associated with a greater maximal amplitude of neg T wave in lead V4 (0.85 ± 0.69 vs. 0.35 ± 0.23 mV, P < 0.001). The frequency of giant neg T (1mv or more) wave was higher in ApHCM (36.5% vs. 0%, P < 0.001). The magnitude of ST-segment deviation significantly differed between ApHCM and NSTEACS in 10 leads excluding leads aVF and V2. ApHCM was associated with a greater maximal amplitude of ST-segment depression in lead V5 (0.19 ± 0.07 vs. 0.03 ± 0.06 mV, P < 0.001). The number of leads with neg T wave also differed between ApHCM and NSTEACS (6.75 ± 1.42 vs. 6.08 ± 1.51, P = 0.046). The sum of R wave in lead V5, neg T wave in lead V6 and ST-segment depression in lead V4 > 2.585 mV identified ApHCM with 90.2% sensibility and 87.5% specificity, representing the highest diagnostic accuracy.
Compared with NSTEACS patients, ApHCM patients presented higher R and neg T wave voltage as well as a greater ST-segment depression in the 12-lead ECG. The ECG characteristics can help to differentiate ApHCM from NSTEACS in clinical setting.
心尖肥厚型心肌病（Apical hypertrophic cardiomyopathy，ApHCM）是一种非梗阻性肥厚型心肌病的表型变异。ApHCM 的特征是左心室肥厚累及心尖远端。ApHCM 的心电图特征可模拟非 ST 段抬高型急性冠脉综合征（non-ST elevation acute coronary syndrome，NSTEACS），从而引发一系列可能不必要的研究和治疗。本研究旨在阐明这两种疾病的心电图差异。
回顾性分析 41 例 ApHCM 患者和 72 例 NSTEACS 患者的初始心电图记录。我们分析了负 T 波（neg T）和 R 波电压、ST 段变化以及 12 导联心电图中具有 neg T 波的导联数量。
在 12 导联心电图中，ApHCM 与 NSTEACS 在除 aVR 和 V1 导联外的 10 个导联的 R 波幅度存在显著差异。ApHCM 与 V5 导联的 R 波最大振幅更大（3.13±1.08 比 1.38±0.73 mV，P<0.001）。在除 II 和 V1 导联外的 10 个导联中，ApHCM 与 NSTEACS 的 T 波幅度存在显著差异。ApHCM 与 V4 导联的最大 neg T 波振幅更大（0.85±0.69 比 0.35±0.23 mV，P<0.001）。在 ApHCM 中，巨大 neg T（1 mV 或更高）波的频率更高（36.5%比 0%，P<0.001）。在除 aVF 和 V2 导联外的 10 个导联中，ApHCM 与 NSTEACS 的 ST 段偏移幅度存在显著差异。ApHCM 与 V5 导联的 ST 段压低最大振幅更大（0.19±0.07 比 0.03±0.06 mV，P<0.001）。具有 neg T 波的导联数量也存在差异（6.75±1.42 比 6.08±1.51，P=0.046）。V5 导联的 R 波、V6 导联的 neg T 波和 V4 导联的 ST 段压低之和>2.585 mV 可识别 ApHCM，其敏感性为 90.2%，特异性为 87.5%，代表了最高的诊断准确性。
与 NSTEACS 患者相比，ApHCM 患者在 12 导联心电图中表现出更高的 R 波和 neg T 波电压以及更大的 ST 段压低。心电图特征有助于在临床环境中区分 ApHCM 和 NSTEACS。
