The heart in scleroderma: noninvasive assessment

Area of Science:

• Cardiovascular Medicine
• Rheumatology
• Pathology

Background:

• Scleroderma frequently involves myocardial fibrosis, detectable postmortem in up to 80% of patients.
• Many scleroderma patients exhibit normal cardiovascular examinations, masking underlying cardiac issues.
• Subclinical myocardial fibrosis contributes to cardiac dysfunction in scleroderma.

Purpose of the Study:

• To investigate isometric handgrip exercise as a noninvasive method for detecting subclinical left ventricular fibrosis in scleroderma.
• To correlate exercise-induced cardiovascular responses with immunohistological findings of myocardial fibrosis.

Main Methods:

• Compared 15 scleroderma patients (AHA criteria) with 15 age/sex-matched controls using isometric handgrip exercise.
• Assessed heart rate response, systolic and diastolic time intervals (pre-ejection period/ejection time ratio, isovolumic relaxation time).
• Performed immunohistological staining for collagen types I-V in cardiac muscle biopsies.

Main Results:

• Scleroderma patients showed a depressed heart rate response (p<0.05) and abnormal systolic/diastolic time intervals.
• A decreased pre-ejection period/ejection time ratio (p<0.05) and prolonged isovolumic relaxation time were observed in scleroderma patients.
• Immunohistology revealed excess collagen types I, III, and IV in cardiac muscle, supporting fibrosis.

Conclusions:

• Isometric handgrip exercise can unmask subclinical left ventricular fibrosis in scleroderma.
• Abnormal cardiovascular responses during isometric exercise indicate impaired left ventricular contractility and stiffness.
• Immunopathological findings confirm the presence of myocardial fibrosis in patients without overt cardiac disease.