Grade 1 diastolic dysfunction is a mild problem with how the left ventricle relaxes between heartbeats. It is considered an early risk factor for heart failure, but it may improve with lifestyle changes such as weight loss and better control of blood pressure and blood sugar levels.
Before each heartbeat, the ventricles need to relax so they can fill properly with blood. When this relaxation is mildly impaired, it can gradually reduce how efficiently the heart works. If the problem becomes more severe and is not managed, diastolic dysfunction can worsen over time and eventually lead to heart failure.