{'fraction_non_alphanumeric': 0.024793388429752067, 'fraction_numerical': 0.009535918626827717, 'mean_word_length': 5.030651340996169, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Cardiac conduction disturbances in mixed connective tissue disease.

BACKGROUND
Myocardial involvement occurs in about 20% of patients with mixed connective tissue disease. The purpose of this study was to determine the prevalence of conduction disturbances, their association with other manifestations of the disease.


OBJECTIVE
Determine the prevalence of cardiac conduction disturbances in patients with mixed connective tissue disease attended in an institute in Mexico City and their relation with other manifestations of the disease.


METHODS
One hundred thirteen patients admitted to the Institute with a diagnosis of mixed connective tissue disease were divided into those with conduction disturbances (n = 23) and those without (n = 90). Over a mean follow-up of 10.2 +/- 7.8 years, clinical course, treatment, duration of the disease, types of conduction disturbances and systemic alterations were examined.


RESULTS
There was an overwhelming predominance of women in both groups. Conduction disturbances occurred in about 20% of the patients with mixed connective tissue disease and that was not possible to find significant differences in the outcome of them. As could be expected a significant difference between the two groups was QRS axis, related to anterior hemiblock, the most common conduction alteration observed. During the follow-up one patient death in-group A, but none in group B.


CONCLUSION
Conduction disturbances were present in 20%; in agree with other authors in the literature. However, did not participate in the outcome of the disease.