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Outcome of patients with hypertrophic cardiomyopathy and a normal electrocardiogram

Christopher J McLeod1, Michael J Ackerman, Rick A Nishimura

  • 1Department of Internal Medicine/Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905, USA.

Journal of the American College of Cardiology
|July 11, 2009
PubMed

Insights

Nearly 6% of hypertrophic cardiomyopathy (HCM) patients have a normal electrocardiogram (ECG) at diagnosis. These individuals show a milder HCM form and better cardiovascular outcomes, with no cardiac deaths observed in this group.

Area of Science:

  • Cardiology
  • Genetics and Genomics
  • Internal Medicine

Background:

  • Hypertrophic cardiomyopathy (HCM) is a leading cause of sudden cardiac death in young individuals.
  • Electrocardiogram (ECG) screening is recommended for early HCM detection in athletes.
  • Clinical outcomes for HCM patients with a normal ECG require further elucidation.

Purpose of the Study:

  • To determine the frequency of HCM in patients with a normal ECG.
  • To characterize the clinical phenotype of these patients.
  • To evaluate the prognosis of HCM patients presenting with a normal ECG.

Main Methods:

  • Retrospective analysis of 135 HCM patients with a normal ECG and 2,350 with an abnormal ECG.
  • Collection of baseline characteristics and echocardiographic data.
  • Follow-up assessment of cardiac outcomes and comparison between groups.

Main Results:

  • Approximately 6% of HCM patients had a normal ECG at diagnosis.
  • Patients with a normal ECG exhibited less severe symptoms, lower gradients, and thinner septal walls.
  • Severe obstructive symptoms and need for interventions (myectomy, ICD) were more frequent in the abnormal ECG group.
  • Cardiac survival was significantly better in the normal ECG group, with zero cardiac deaths.

Conclusions:

  • A subset of HCM patients (nearly 6%) presents with a normal ECG.
  • This normal ECG-HCM group demonstrates a less severe clinical phenotype.
  • Patients with normal ECG-HCM experience superior cardiovascular outcomes.
Abstract

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