Left ventricular systolic dysfunction during exercise and dobutamine stress in patients with hypertrophic

K Okeie1, M Shimizu, H Yoshio

  • 1Second Department of Internal Medicine, School of Medicine, Kanazawa University, Japan. yonken1@med.kanazawa-u.ac.jp

Insights

Stress testing revealed that half of hypertrophic cardiomyopathy (HCM) patients experience exercise-induced systolic dysfunction. These patients often show regional wall motion abnormalities in hypertrophied segments, highlighting a key characteristic of HCM.

Area of Science:

  • Cardiology
  • Cardiovascular Physiology
  • Medical Imaging

Background:

  • Myocardial ischemia and diastolic dysfunction are known complications in hypertrophic cardiomyopathy (HCM).
  • A hypothesis posits that transient myocardial ischemia during stress can precipitate left ventricular systolic dysfunction in HCM patients.

Purpose of the Study:

  • To characterize stress-induced left ventricular systolic dysfunction in patients diagnosed with hypertrophic cardiomyopathy (HCM).

Main Methods:

  • 39 patients with HCM (no resting obstruction or coronary artery disease) were studied.
  • Left ventricular function was assessed using a ventricular function monitor (VEST) during exercise and dobutamine stress echocardiography (DSE).
  • Left ventricular ejection fraction (LVEF) and regional wall motion were analyzed from echocardiographic images.

Main Results:

  • A significant correlation (r=0.643, p<0.0001) was found between LVEF changes during exercise and dobutamine stress.
  • 17 patients (44%) exhibited a decrease in LVEF >5% during peak exercise (group II), indicating systolic dysfunction.
  • Regional wall motion abnormalities were more prevalent in hypertrophied segments and significantly correlated with LVEF response during stress (p<0.0001).

Conclusions:

  • Approximately 50% of patients with HCM experience exercise-induced systolic dysfunction.
  • In affected patients, regional wall motion abnormalities are frequently observed in hypertrophied myocardial segments.
Abstract

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