Identification of myocardial damage in systemic sclerosis: a nuclear cardiology approach

Abstract

Myocardial involvement is an important prognostic factor in patients with systemic sclerosis, and early diagnosis and staging of the disease have been sought after. Since myocardial damage is characterized by connective tissue disease, including fibrosis and diffuse vascular lesions or microcirculation, nuclear myocardial perfusion imaging has been a promising option for evaluating myocardial damages in early stages. In addition to the conventional stress-rest perfusion imaging, the current use of quantitative electrocardiographic gated imaging has contributed to more precise evaluation of cardiac perfusion, ventricular wall motion, and diastolic function, all of which have enhanced diagnostic ability of evaluating myocardial dysfunction. Abnormal sympathetic imaging with Iodine-123 metaiodobenzylguanidine might be another option for identifying myocardial damage. This paper deals with approaches from nuclear cardiology to detect perfusion and functional abnormality as an early sign of myocardial involvement as well as possible prognostic values in patients with abnormal imaging results. The role of nuclear cardiology in the era of multiple imaging modalities is discussed.

Figure 1

A patient with SSc showing slight anteroseptal ischemia. Quantitative analyses of perfusion, defect scores, wall motion and thickening showed significant abnormality, which supported abnormality in this region (arrows). Diastolic dysfunction was observed even at resting condition as shown by the blue arrow.

Figure 2

A patient with diffuse cutaneous type with MRSS 21, showing decreased MIBG activity and rapid washout rate (33%). ¹²³I-MIBG distribution showed marked heterogeneity in both early and delayed short-axis images. Resting perfusion was normal by ^99mTc-MIBI SPECT. Adapted from [41].

Figure 3

Possible roles of cardiac imaging modalities for diagnostic work-ups and followup in SSc. Abbreviations: ECG, electrocardiography; Cath., catheterization; MRI, magnetic resonance imaging; CT, computed tomography; SPECT, single-photon emission computed tomography; PET, positron emission tomography.