The addition of functional data to stress and rest perfusion images significantly improves their specificity and reduces the uncertainty in test interpretation, with a better separation of normal from abnormal studies SPECT allows the assessment of myocardial perfusion, providing evidence of associated reversible ischaemia. Using pharmacological stress (dipyridamole) with SPECT, decreased heart perfusion was observed in 82% of SSc patients.13 This technique is important in differentiating myocardial stunning from inducible ischemia or necrosis, using the endothelium-dependent vasodilating effect of dipyridamole. SPECT is considered relatively safe, inexpensive, and easy to perform. SPECT can be applied in scintigraphy with thallium-201 and with perfusion markers like Tc-99m. We recommend performance of SPECT as a baseline exam even in asymptomatic patients.
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Explore This IssueMay 2009
2) Coronary angiography: Coronary angiography offers the most accurate visualization of the coronary arteries and remains the gold standard when a stenotic coronary lesion is suspected. Angiography is not recommended for screening asymptomatic patients.14
A 53-year-old SSc patient with esophageal and muscle involvement (weakness, elevated CK) developed dyspnea on exertion. Pulmonary function tests and high-resolution computed chest tomography were normal. Cardiac color-Doppler echocardiography PAP was normal, but a left ventricular asynergy with normal ejection fraction (56%) was detected. Cardiac scintigraphy demonstrated an apical–septal area of inducible ischemia. Coronary angiography was performed demonstrating a slow contrast washout representing a microcirculation pathology with no occlusions of the extramural coronary arteries. Cardiac Holter showed the presence of 7.567 monomorphic ventricular extrasystolic beats with 237 pairs and 13 runs of bigeminy despite antiarrhythmic drug (amiodarone) therapy (see Figure 2, p. 17). For this reason, an intracardiac defibrillator (ICD) was implanted.
Six months later, the analysis of the ICD showed that it has been activated with deliverance of four shocks to stop episodes of malignant ventricular tachycardia. This case shows that a prompt diagnosis of arrhythmia and the implantation of an ICD can prevent sudden cardiac death in an SSc patient and this clearly illustrates the value of a comprehensive diagnostic work-up and the benefits of an aggressive patient management.
Pericardial Piece of the Puzzle
Pericardial effusion is a harbinger of a poor prognosis and is more frequent in patients with the diffuse subset of the disease.15,16 Pericardial effusion is also a useful predictor of scleroderma renal crisis.17 In autopsy studies, SSc patients commonly have asymptomatic pericardial abnormalities with a prevalence estimated from 33% to 72%. Recently, it has been reported that pericardial abnormalities are associated with echocardiographically defined pulmonary arterial hypertension (PAH).18
1) Echocardiography: Echocardiography is the most widely used imaging technique in the evaluation of suspected pericardial disease. Transthoracic echocardiography represents the gold standard for diagnosis of pericardial abnormalities, demonstrating the location and amount of even minimal pericardial effusion. The echocardiogaphic features of pericardial effusion are the pericardial layer separation with an echo-free space and the decrease in the parietal pericardial motion.