FOCUS ISSUE: HYPERTROPHIC CARDIOMYOPATHY: CLINICAL RESEARCH
Outcome of Patients With Hypertrophic Cardiomyopathy and a Normal Electrocardiogram
Christopher J. McLeod, MB, ChB, PhD,
Michael J. Ackerman, MD, PhD,
Rick A. Nishimura, MD,
A. Jamil Tajik, MD,
Bernard J. Gersh, MB, ChB, DPhil and
Steve R. Ommen, MD*
Department of Internal Medicine/Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
Manuscript received October 10, 2008;
revised manuscript received February 23, 2009,
accepted February 23, 2009.
* Reprint requests and correspondence: Dr. Steve R. Ommen, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905 (Email: ommen.steve{at}mayo.edu).
Objectives: This study sought to clarify the frequency, clinical phenotype, and prognosis of those patients with hypertrophic cardiomyopathy (HCM) who present with a normal electrocardiogram (ECG).
Background: Hypertrophic cardiomyopathy is the most common cause of sudden death in young people. Screening advocates have recommended a 12-lead ECG for the early detection of HCM in athletes, yet the clinical outcomes of those presenting with a normal ECG remains to be fully delineated.
Methods: Baseline characteristic and echocardiographic data were collected on all patients with HCM who initially presented to our institution with a diagnostic echocardiogram but a normal ECG. Follow-up was obtained and compared with the prognosis of HCM patients who presented with abnormal ECGs.
Results: We compared 135 HCM patients with a normal ECG with 2,350 HCM patients with an abnormal ECG. The latter group was more likely to have worse symptoms, have higher gradients, and a greater degree of septal wall thickness than the patients with a normal ECG. Severe obstructive symptoms requiring surgical myectomy and implantation of an implantable cardioverter-defibrillator were more common in patients with abnormal ECGs. Cardiac survival was significantly better in the group with a normal ECG at presentation—none of these patients had a cardiac death at follow-up.
Conclusions: Almost 6% of patients presenting with demonstrable echocardiographic evidence of HCM had a normal ECG at the time of diagnosis. This subset of patients with normal ECG-HCM appears to exhibit a less severe phenotype with better cardiovascular outcomes.
Key Words: hypertrophic cardiomyopathy • electrocardiography • outcomes • screening
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Abbreviations and Acronyms
| | ECG = electrocardiogram | | HCM = hypertrophic cardiomyopathy |
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Inside This Issue
J. Am. Coll. Cardiol. 2009 54: A24.
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