Lack of diastolic reserve in patients with heart failure and normal ejection fraction.

Background: The genesis of symptoms in patients with heart failure (HF) and normal ejection fraction (HFNEF) is unclear. Most investigations of HFNEF have focused on cardiac function at rest although most of these patients are breathless only on exercise. Stress-induced impairment in systolic or diastolic function could result in these symptoms.

The effect of pharmacological stress on intraventricular dyssynchrony in left ventricular systolic dysfunction.

Background: Cardiac resynchronisation therapy (CRT) improves symptoms and exercise capacity in many patients with heart failure (HF) who have left ventricular systolic dysfunction (LVSD) and markers of dyssynchrony. LV dyssynchrony is conventionally measured at rest but the symptoms of heart failure occur predominantly on exercise. Induction or exacerbation of dyssynchrony during stress might identify additional patients who could benefit from CRT.