Hypertrophic nonobstructive cardiomyopathy as a cause of severe restrictive physiology

and revealed signs of restrictive physiology without intraventricular dynamic obstruction (fig. 2, table 1). However, the PApressure was only mildly elevated and the ventricular diastolic pressure showed a subtle dipplateau pattern (square root sign). Aggressive treatment with diuretics typically decreases filling pressures (preload) acutely, as confirmed by the low absolute LV and RV end-diastolic pressures, and affects recognition of the typical restrictive pressure tracings. We therefore performed an intravenous fluid challenge with 500 ml of NaCl 0.9% over approximately 10 minutes. The fluid challenge provoked an increase in systolic RV pressure from 36 mm Hg to 57 mm Hg (fig. 3), confirming a significant preload increase (probably more representative of this patient’s usual clinical condition). The typical “M or W” pattern of restriction became more obvious on the RA pressure A 66-year-old woman with a family history of hypertrophic cardiomyopathy (HCM) presented with severeprogressive exertional dyspnoea. She had recently complained of palpitations corresponding to atrial fibrillation on the ECG.A transthoracic echocardiogram (TTE) showed nonobstructive, slightly asymmetrical left ventricular hypertrophy (septum and posterior wall thickness respectively measured at 20 and 15 mm). Left ventricular (LV) cavity and ejection fraction (70%) were normal, but both atria were enlarged (fig. 1A). Diastolic function assessment was suggestive of restrictive physiology (fig. 1B). The patient did not improve despite successful cardioversion and intensive medical therapy with maximally-tolerated doses of beta-blockers and verapamil. She was then referred to the catheterisation laboratory to undergo left and right heart catheterisation and coronary angiography after aggressive forced diuresis with intravenous diuretics. The coronary angiogram did not show significant coronary artery disease (narrowing <30%). Right heart, pulmonary artery (PA), left atrial (via trans-septal approach) and left heart catheterisations were performed Hypertrophic nonobstructive cardiomyopathy as a cause of severe restrictive physiology