Introduction: Heart Failure with preserved ejection fraction (HFpEF) is a highly prevalent condition for which no pharmacologic therapy is available. Diastolic dysfunction is thought to be central to its pathophysiology. Organic nitrates have pharmacologic effects on preload, afterload and myocardial contraction/relaxation that may favourably influence ventricular filling. However, the effect of sublingual nitro-glycerine (NTG) on diastolic parameters in this population has not been studied. We aimed to assess the effect of NTG on intraventricular pressure gradients (IVPG) and other measures of diastolic function.

Methods: Colour M-mode Doppler (CMM) is a non-invasive ultrasound technique used to obtain left ventricular (LV) blood flow velocities during early filling and to calculate IVPG. CMM recordings of 20 patients (HFpEF) at rest and after the administration of 0.4 mg of NTG were obtained and processed. Average values of the parameters were calculated and compared (Wilconox test) at rest and after NTG.

Results: NTG induced a non-significant increase in early diastolic IVPG (p=0.286) due to a reduction in the early diastolic convective component (p=0.026). Similarly, the early diastolic reversal convective component was reduced (p=0.009). In contrast, the late diastolic IVPG was increased (p=0.017), due to an increased inertial component (p=0.034). There was a reduction in peak E wave velocity (p=0.004), E wave acceleration (p=0.003) and deceleration (p=0), while the acceleration time (p=0.034) and the heart rate (HR) (p=0.016) increased.

Conclusion: Organic nitrates exert effects on diastolic filling in HFpEF: increased HR and myocardial contractility and decreased peak E-wave velocity possibly related to a preload reduction.