Heart Attack Patients Need Ongoing Monitoring of Heart
Future problems of patients after a heart attack can be predicted if the heart's relaxation capacity can ben monitoried, say the researchers at The University of Auckland.
The international study shows relaxation of the heart can be used to determine the probability of further cardiac problems and associated death in heart attack patients, even in those without significant damage to their muscle or impaired pump function after a heart attack.
The first results from the study are published in the latest issue of internationally renowned journal Circulation.
"After a heart attack, many patients undergo ultrasound imaging to determine how much muscle is damaged and the overall pump function of the heart," says Dr Gillian Whalley of the Faculty of Medical and Health Sciences. "The visible damage to the cardiac muscle and the volume of blood pumped with each heart beat are normally used to determine the severity of the problem. Our research shows that the relaxation and filling of the heart can also be reduced after a heart attack and predicts which patients are at higher risk."
The Meta-analysis Research Group in Echocardiography (MeRGE) study, coordinated by the University's Cardiovascular Research Laboratory, analysed ultrasound measurements of the hearts of more than 3000 patients who had suffered heart attacks. The first results from this collaboration provide compelling evidence that all patients who suffer a heart attack should undergo ultrasound imaging, or echocardiography to assess both muscle damage and heart relaxation.
The group's research interest will soon turn to a similar study where they hope to collate data on close to 70,000 patients with chronic heart failure to determine the impact of the underlying causes of heart failure symptoms, in particular to examine the impact of pump dysfunction versus relaxation dysfunction as a primary cause for heart failure symptoms.
"These studies are a great testament to the global reputation of the University and New Zealand research," continues Associate Professor Rob Doughty. "Most studies of this type look at only a few hundred people, and it is only through this collaboration with our international colleagues that we have managed to build a sufficient data resource to make this discovery."
The MeRGE study was funded through The University of Auckland Vice-Chancellor's University Development Fund and grants from the Heart Foundation of New Zealand.