Usefulness of ECG to differentiate apical hypertrophic cardiomyopathy from non-ST elevation acute coronary syndrome

BMC Cardiovasc Disord. 2020 Jun 23;20(1):306. doi: 10.1186/s12872-020-01592-0.

Abstract

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Keywords: Apical hypertrophic cardiomyopathy; Electrocardiogram; Non-ST elevation acute coronary syndrome.

MeSH terms

  • Action Potentials*
  • Acute Coronary Syndrome / diagnosis*
  • Acute Coronary Syndrome / physiopathology
  • Aged
  • Aged, 80 and over
  • Cardiomyopathy, Hypertrophic / diagnosis*
  • Cardiomyopathy, Hypertrophic / physiopathology
  • Diagnosis, Differential
  • Electrocardiography*
  • Female
  • Heart Rate*
  • Humans
  • Male
  • Middle Aged
  • Non-ST Elevated Myocardial Infarction / diagnosis*
  • Non-ST Elevated Myocardial Infarction / physiopathology
  • Predictive Value of Tests
  • Retrospective Studies