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Amyotrophic Lateral Sclerosis and Pseudo-infarct Pattern on the Electrocardiogram

      To the Editor:

      Case Report

      We report an interesting and unusual case of a 45-year-old man with recent diagnosis of amyotrophic lateral sclerosis diagnosed 8 months prior and a pseudo-infarct pattern on the electrocardiogram (ECG). This patient presented to our hospital complaining of a 2-month history of intermittent chest pain and shortness of breath associated with palpitations and anxiety. This chest pain onset was at rest, described as pressure-like sensation, of moderate intensity, and worse when lying in bed. The chest pain was located in the left retrosternal area and associated with shortness of breath and anxiety. Further evaluation in the Emergency Department disclosed an otherwise hemodynamically stable patient with normal vital signs and normal laboratory results, including complete metabolic profile and complete blood count. Initial cardiac work-up during this hospitalization showed an interesting 12-lead ECG demonstrating normal sinus rhythm and prominent inferior Q waves suggestive of an old inferior infarct (Figure 1). These Q waves in inferior leads were a new finding when compared with his previous ECG in 2009 (Figure 2).
      Figure thumbnail gr1
      Figure 1Electrocardiogram showing T-wave inversions and Q waves in leads III and AVF.
      Further cardiac studies showed normal cardiac enzymes, normal 2-dimensional echocardiogram, and a normal ventilation/perfusion scan to rule out pulmonary embolism. Upon further questioning, the patient revealed having a similar episode of chest pain in the recent past for which he underwent a cardiac angiogram at an outside facility. This coronary angiogram disclosed normal coronary anatomy (Figure 3). This is a third case report describing an abnormal ECG finding among patients with amyotrophic lateral sclerosis.
      Figure thumbnail gr3
      Figure 3Normal coronary angiogram. AP cranial view showing normal left main (LM) and left anterior descending coronary artery (LAD) and left circumflex coronary artery (LCx). AP caudal view showing normal LM, LAD and LCx. RAO caudal view showing normal LM, LAD, LCx. LAO cranial view showing normal right dominant right coronary artery (RCA).

      Discussion

      Patients with amyotrophic lateral sclerosis can display cardiac parasympathetic and sympathetic alterations with relative sympathetic predominance predisposing hypertensive crisis, sudden cardiac death, and cardiovascular collapse, leading to a decrease in life expectancy.
      • Pavlovic S.
      • Stevic Z.
      • Milovanovic B.
      • et al.
      Impairment of cardiac autonomic control in patients with amyotrophic lateral sclerosis.
      Furthermore, amyotrophic lateral sclerosis can produce QT-segment prolongation, leading to an increased risk for sudden cardiac death, apparently due to loss of the intermediolateral nucleus of the upper thoracic spinal cord.
      • Asai H.
      • Hirano M.
      • Udaka F.
      • et al.
      Sympathetic disturbances increase risk of sudden cardiac arrest in sporadic ALS.
      In addition to all these pathophysiological findings seen in these patients, in recent years there have been reports of electrocardiographic abnormalities resembling acute myocardial infarctions. As described by Li et al,
      • Li A.H.
      • Hsu K.L.
      • Liau C.S.
      • et al.
      Amyotrophic lateral sclerosis with a ‘pseudo-infarction’ pattern on the electrocardiograph. A case report.
      a patient presented with an ST elevation and biphasic T waves in the precordial leads in the setting of normal cardiac studies. Similarly, Zhang et al
      • Zhang J.
      • Yang S.W.
      • Wang Z.
      • et al.
      Pseudo-ischaemic ECG in a patient with amyotrophic lateral sclerosis surviving for a decade.
      described a patient who presented with T-wave inversions in all leads, resembling an ischemic event. To date, there is no clear involved mechanism that explains these ECG manifestations; nevertheless, these disturbances in the autonomic function in this patient population are possibly due to a degenerative process, leading to anatomical and metabolic disarrangements.
      Moreover, these cardiovascular abnormalities also can be precipitated by chronic myocardial hypoxia, leading to apoptosis or necrosis and cell release of troponin, as recently described in a patient with amyotrophic lateral sclerosis with normal coronary angiogram.
      • Von Lueder T.G.
      • Melsom M.N.
      • Atar D.
      • Agewall S.
      Amyotrophic lateral sclerosis, a novel rare cause of elevated plasma troponin T levels.
      Thus, we present a case of a patient with Q waves in the inferior leads on ECG with normal anatomy. We can conclude that disarrangements of the autonomic nervous system lead to pseudo-infarct patterns on ECG in patients with amyotrophic lateral sclerosis.

      References

        • Pavlovic S.
        • Stevic Z.
        • Milovanovic B.
        • et al.
        Impairment of cardiac autonomic control in patients with amyotrophic lateral sclerosis.
        Amyotroph Lateral Scler. 2010; 11: 272-276
        • Asai H.
        • Hirano M.
        • Udaka F.
        • et al.
        Sympathetic disturbances increase risk of sudden cardiac arrest in sporadic ALS.
        J Neurol Sci. 2007; 254: 78-83
        • Li A.H.
        • Hsu K.L.
        • Liau C.S.
        • et al.
        Amyotrophic lateral sclerosis with a ‘pseudo-infarction’ pattern on the electrocardiograph. A case report.
        Cardiology. 2000; 93: 133-136
        • Zhang J.
        • Yang S.W.
        • Wang Z.
        • et al.
        Pseudo-ischaemic ECG in a patient with amyotrophic lateral sclerosis surviving for a decade.
        BMJ Case Rep. 2012 Feb 25; 2012
        • Von Lueder T.G.
        • Melsom M.N.
        • Atar D.
        • Agewall S.
        Amyotrophic lateral sclerosis, a novel rare cause of elevated plasma troponin T levels.
        Clin Lab. 2011; 57: 615-618