Table 1 Clinical modulators of dynamic left ventricular outflow tract obstruction
Obstruction augmentedObstruction diminished
Decrease preloadIncrease preload
Short filling period (fast heart rate)Long filling period
Hypovolaemia/dehydration/diuresisVolume repletion
ValsalvaLeg raise
Squat-to-standStand-to-squat
Warm environmentCool environment
Postprandial state
Decrease afterloadIncrease afterload
VasodilatorsVasoconstrictors
Increase contractilityDecrease contractility
Positive inotropesNegative inotropes