Scleroderma - Systemic Sclerosis (SSc)
Scleroderma
  A systemic disease with multiple organ involvement.
  Cardiac manifestations of SSc can affect all structures of the heart and may result in pericardial disease, arrhythmias, conduction system abnormalities, direct myocardial disease such as myositis, cardiac failure, cardiac fibrosis, coronary artery diseases and rarely, primary valvular involvement.
  An abnormal ECG is present in approximately 50% of patients with SSc and is considered an independent predictor of mortality.
ECG findings in Scleroderma
  Nonspecific ST-T wave abnormalities (12.1%): significantly associated with elevated right ventricular systolic pressure on echocardiogram.
  Septal infarction pattern (10%): related to abnormal perfusion in the septum and anteroseptal wall in the absence of extramural coronary artery disease (probably due to underlying myocardial fibrosis).
  First-degree atrioventricular block (8%): significantly associated with elevated right ventricular systolic pressure on echocardiogram.
  Complete right bundle branch block with or without left anterior hemiblock (2.6%). It has been suggested that right bundle branch block (RBBB) is an independent predictor of mortality, and should be considered a marker of disease severity in SSc (possibly because that RBBB is either a surrogate for primary cardiac involvement [myocardial fibrosis] or undiagnosed pulmonary hypertension in SSc patients).
  Second- and third-degree atrioventricular block (<2%)
  Left bundle branch block (LBBB) (1%)
  QTc prolongation
  Increased number of Ventricular ExtraSystoles on Holter recordings.
References
  Rheumatology 2014;53:1172-1177. The Scleroderma Clinical Trial Consortium (SCTC) Cardiac Subcommittee
  Ann Intern Med 1981;94:38-40.
  Am J Med 1988;84:1007-1015.
  PLoS One 2013 Oct 31;8(10):e78808.
  Scand J Rheumatol 2014;43:221-225.

ECG 1. Third degree (complete) AV block in a 68 years-old woman with Systemic Sclerosis (Scleroderma).
Multidetector CT coronary angiography showed normal coronary arteries.
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The ECG above has been used with the permission of Anatolian Journal of Cardiology and AVES Publishing.

ECG 2. The ECG above belongs to a 54 years-old woman.
She has had Scleroderma for almost 8 years.
Left bundle branch block pattern is seen. Limb leads show low voltage.
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ECG 3. The ECG above belongs to a woman with Scleroderma and pulmonary hypertension.
PR interval prolongation (first-degree AV block) and P wave widening (140 milliseconds, interatrial block) are seen.
Right bundle branch block is seen. The tall R wave in V1 is suggestive of right ventricular hypertrophy.
Dr. Peter Kukla has donated the above ECG to our website.
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