Coronary haemodynamics in left ventricular hypertrophy.
BACKGROUND
Left ventricular hypertrophy is associated with an increased risk of cardiovascular morbidity and mortality. Previous studies have shown that patients with left ventricular hypertrophy develop electrocardiographic changes and left ventricular dysfunction during acute hypotension, and suggest that the lower end of autoregulation may be shifted upwards.


OBJECTIVE
To measure coronary blood flow (velocity) and flow reserve during acute hypotension in patients with left ventricular hypertrophy.


METHODS
Eight patients with atypical chest pain and seven with hypertensive left ventricular hypertrophy; all with angiographically normal epicardial vessels.


METHODS
Tertiary referral centre.


METHODS
The physiological range of blood pressure was determined by previous ambulatory monitoring. Left ventricular mass was determined by echocardiography. At cardiac catheterisation, left coronary blood flow velocity was measured using a Judkins style Doppler tipped catheter. During acute hypotension with sodium nitroprusside, coronary blood flow velocity was recorded at rest and during maximal hyperaemia induced by intracoronary injection of adenosine. Quantitative coronary angiography was performed manually.


RESULTS
For both groups coronary blood flow velocity remained relatively constant over a range of physiological diastolic blood pressures and showed a steep relation with diastolic blood pressure during maximal hyperaemia with intracoronary adenosine. Absolute coronary blood flow (calculated from quantitative angiographic data), standardised for left ventricular mass, showed reduced flow in the hypertensive group at rest and during maximal vasodilatation.


CONCLUSIONS
The results are consistent with an inadequate blood supply to the hypertrophied heart, but no upward shift of the lower end of the autoregulatory range was observed.
Wallbridge
D R
DR
Department of Medical Cardiology, Royal Infirmary, Glasgow.
Cobbe
S M
SM
D000241:Adenosine; D001783:Blood Flow Velocity; D001794:Blood Pressure; D006328:Cardiac Catheterization; D017023:Coronary Angiography; D003326:Coronary Circulation; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000503:physiopathology*; D007022:Hypotension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009599:Nitroprusside; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D009599:Nitroprusside; D000241:Adenosine