Beta-blocker therapy for dynamic left-ventricular outflow tract obstruction.
BACKGROUND
In a small but significant group of elderly patients who present with breathlessness, dynamic left-ventricular outflow tract obstruction (DLVOTO) may be responsible for symptom generation. The aim of our study was to investigate the effect of beta-blockade on ventricular physiology and symptoms in patients with DLVOTO.


METHODS
We performed a pilot study in 15 patients (age 76+/-10 years, mean+/-S.D., 14 female) with symptoms of exercise intolerance (New York Heart Association, NYHA, class 2.7+/-0.5). All patients had normal resting left ventricular (LV) systolic function together with DLVOTO based on the presence of basal septal hypertrophy and the development of high outflow tract velocities on stress echocardiography. All were commenced on oral atenolol (mean dose 45+/-19 mg), but this could not be tolerated in four patients due to a deterioration in clinical status.


RESULTS
In the remaining 11 patients who could tolerate atenolol therapy, the rate pressure product was significantly lower (23%, P=0.028) and there was a marked reduction in LV outflow tract velocity (23%, P=0.001) following beta-blockade. Patient symptoms improved significantly following atenolol therapy, with a reduction in mean NYHA class from 2.8+/-0.4 to 1.5+/-0.5 (P<0.0001).


CONCLUSIONS
Beta-blockade may represent a beneficial therapeutic approach in selected patients with DLVOTO as identified by stress echocardiography.
Al-Nasser
Faisal
F
Department of Clinical Cardiology, National Heart and Lung Institute, Imperial College School of Medicine, Dovehouse Street, London SW3 6LY, UK.
Duncan
Alison
A
Sharma
Rakesh
R
O'Sullivan
Christine
C
Coats
Andrew J S
AJ
Anker
Stefan D
SD
Henein
Michael Y
MY
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D000369:Aged, 80 and over; D001262:Atenolol / Q000627:therapeutic use*; D001783:Blood Flow Velocity / Q000187:drug effects / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D025401:Echocardiography, Stress / Q000187:drug effects*; D017079:Exercise Tolerance / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D010865:Pilot Projects; D016277:Ventricular Function, Left / Q000187:drug effects / Q000502:physiology; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology
D000319:Adrenergic beta-Antagonists; D001262:Atenolol