Diastolic heart failure. Paroxysmal or chronic?

Heart failure with preserved systolic function is considered by some to be synonymous with diastolic heart failure (DHF). Although recent epidemiological studies have suggested that DHF constitutes 30-50% of all patients with heart failure, many cardiologists dealing with ambulant heart failure patients on a daily basis find that the vast majority of heart failure patients have systolic dysfunction. What could be the reasons for this? Referral bias and varying diagnostic thresholds and interpretation of results could be one important reason. Heart failure with preserved systolic function comprises a heterogeneous group of conditions: whilst some patients may truly have DHF, others may have heart failure due to subtle systolic dysfunction (noted on tissue Doppler imaging of the left ventricular long axis). Other patients actually have pulmonary disease, obesity or ischaemic heart disease, and have their symptoms attributed to 'diastolic heart failure' on the basis of 'abnormal' mitral diastolic flow indices that may, in fact, simply reflect aging. True DHF may be much less prevalent than suggested. A further possibility is that heart failure in patients with diastolic dysfunction might be paroxysmal rather than chronic. This group of patients may present predominantly to acute units like accident and emergency, coronary care units and intensive care units and are, therefore unlikely to figure prominently in the usual outpatient population of chronic systolic left ventricular dysfunction.