Dobutamine stress echocardiography in hypertrophic cardiomyopathy.
OBJECTIVE
Myocardial ischemia in the absence of coronary artery disease is common in patients with hypertrophic cardiomyopathy (HCM). Dobutamine stress echocardiography (DSE) induces left ventricular (LV) new wall motion abnormalities (NWMA) in some patients with HCM. We evaluated the effects of dobutamine on LV performance and hemodynamics in HCM.


RESULTS
Eighteen patients with non-obstructive HCM underwent DSE. Dobutamine was administered at dosages of 5, 10, 20, 30 and 40 microg/kg/min with increments at intervals of 3 min. Seven patients developed NWMA, whereas the other 11 did not. During DSE, heart rate increased significantly more in NWMA patients,whereas LV outflow tract gradient (OTG) increased significantly and similarly in both groups. At peak dobutamine dose, NWMA patients had a significant increase in LV end-systolic diameter and volume and a significant decrease in LV fractional shortening and ejection fraction. Posterior wall thickening increased significantly, whereas septal thickening did not increase throughout DSE in both groups.


CONCLUSIONS
In a subgroup of patients with HCM, DSE induces NWMA, associated with a greater increase in heart rate, irrespective of LVOTG. NWMA induce a depression of global LV systolic performance. The septum shows no contractile reserve, regardless of NWMA. These phenomena may be the result of induction of ischemia and/or impaired LV systolic function due to fast heart rate.
Losi
Maria Angela
MA
Department of Clinical Medicine, Cardiovascular and Immunological Sciences, Federico II University of Naples, Via Pansini 5, IT-80131 Naples, Italy. losi@unina.it
Betocchi
Sandro
S
Aversa
Mariano
M
Lombardi
Raffaella
R
Miranda
Marianna
M
Cacace
Alessandra
A
Ciampi
Quirino
Q
Tocchetti
Carlo Gabriele
CG
Guida
Adriana
A
Chiariello
Massimo
M
D000318:Adrenergic beta-Agonists / Q000008:administration & dosage / Q000009:adverse effects; D000328:Adult; D000787:Angina Pectoris / Q000139:chemically induced; D001794:Blood Pressure / Q000187:drug effects; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis* / Q000503:physiopathology; D004280:Dobutamine / Q000008:administration & dosage / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D025401:Echocardiography, Stress; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006346:Heart Septum / Q000187:drug effects / Q000503:physiopathology; D006352:Heart Ventricles / Q000187:drug effects / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D013318:Stroke Volume / Q000187:drug effects; D017180:Tachycardia, Ventricular / Q000139:chemically induced; D016277:Ventricular Function, Left / Q000187:drug effects
D000318:Adrenergic beta-Agonists; D004280:Dobutamine