Most common myocardial disorder in obesity – Cardiology MCQ – Answer
Most common myocardial disorder in obesity – Correct answer: b) Heart failure with preserved ejection fraction
Most common myocardial disorder in obesity is heart failure with preserved ejection fraction . This is mostly due to reduced distensibility of the left ventricle causing left ventricular diastolic dysfunction and heart failure with preserved ejection fraction (HFpEF). On the other way round, obesity is common in those with HFpEF .
In obesity, due to reduced distensibility of the left ventricle, even slight increase in filling leads to disproportionate increase in filling pressures. This is thought to be due to proportionately lower microvasculature and increase in fibrosis, directly driven by adiposity. Amount of myocardial fibrosis is directly related to diastolic filling, functional capacity and outcomes .
High output heart failure occurs only in the morbidly obese with volume overload. They have markedly enlarged ventricles and elevated natriuretic peptides with glomerular hyperfiltration . Still obesity contributed to 31% of cases in this data of 15 year experience on high output heart failure from Mayo Clinic catheterization laboratory.