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Subclinical cardiac dysfunction in acromegaly: evidence for a specific disease of heart muscle
E A Rodrigues1, M P Caruana, A Lahiri
1Department of Cardiology, Northwick Park Hospital, Harrow.
Insights
Acromegaly patients often have heart muscle disease, not just hypertension or coronary issues. This study found subclinical diastolic dysfunction in acromegaly, suggesting a specific cardiac impact.
Area of Science:
- Cardiology
- Endocrinology
Background:
- Acromegaly is linked to higher cardiac morbidity and mortality.
- The exact cause remains unclear: increased hypertension/coronary heart disease or a specific heart muscle disease.
Purpose of the Study:
- To investigate cardiac abnormalities in acromegaly patients using non-invasive techniques.
- To determine if acromegaly causes a specific heart muscle disease, particularly affecting diastolic function.
Main Methods:
- Studied 34 acromegaly patients using echocardiography, Holter monitoring, and Thallium-201 scans.
- Compared cardiac function in 19 acromegaly patients (without other cardiac causes) to 22 age-matched controls.
Main Results:
- Elevated left ventricular mass (68%) and hypertrophy (48%) were common.
- Ventricular arrhythmias (38%) and coronary heart disease (24%) were observed.
- Acromegaly patients showed impaired left ventricular diastolic function compared to controls, independent of left ventricular mass.
Conclusions:
- Evidence of subclinical cardiac diastolic dysfunction in acromegaly suggests a specific heart muscle disease.
- Hypertension may exacerbate diastolic abnormalities in acromegalic patients.
- Findings support the hypothesis of a distinct cardiomyopathy in acromegaly.
Abstract:
Acromegaly is associated with an increased cardiac morbidity and mortality, but it is not clear whether this is the result of increased incidence of hypertension and coronary heart disease or of a specific disease of heart muscle. Thirty four acromegalic patients were studied by non-invasive techniques. Seven of these patients had raised plasma concentrations of growth hormone at the time of study; three were newly diagnosed and had not received any treatment. Hypertension was present in nine (26%) but only three (9%) had electrocardiographic left ventricular hypertrophy. Echocardiography showed ventricular hypertrophy in 12 (48%) and increased left ventricular mass in 17 (68%) patients. Holter monitoring detected important ventricular arrhythmias in 14 patients. Thallium-201 scanning showed evidence for coronary heart disease in eight patients. Systolic time intervals were normal except when there was coexistent ischaemic heart disease. A comparison between 19 acromegalic patients with no other detectable cause of heart disease and 22 age matched controls showed appreciably abnormal left ventricular diastolic function in the group with acromegaly. The abnormalities shown did not correlate with left ventricular mass or wall thickness. There was no difference in diastolic function between patients with active acromegaly and those with treated acromegaly. Hypertensive acromegalic patients had worse diastolic function than hypertensive controls, suggesting that hypertension may further impair the left ventricular diastolic abnormality in acromegaly. This is the first study to find evidence of subclinical cardiac diastolic dysfunction in acromegaly and it supports the suggestion that there is a specific disease of heart muscle in acromegaly.