A high proportion of incident MIs remains clinically unrecognized. As a history of MI is associated with an increased risk of repeat cardiovascular complications, our data suggest a need for periodical electrocardiographic screening to recognize (prevalent) infarctions and to install effective preventive treatment in those aged 55 and older.

No abstract

Objective: To investigate whether the orientation of the electrical T-axis and the spatial QRS-T angle provide independent diagnostic and prognostic information in patients presenting with acute chest pain. Methods: Patients with symptoms suggestive of acute cardiac pathology, who were seen by a general practitioner and for whom a prehospital electrocardiogram (ECG) was recorded by the ambulance service between 1992 and 1994 were investigated. The ECGs (n = 2,261) for our study population were stored for off-line analysis by the Modular ECG Analysis System. QRS- and T-axes were computed from the reconstructed vectorcardiographic X, Y and Z leads. During the year 2000, a follow-up of the entire cohort was performed, and the vital status of the patients was determined via the civil registrar’s office. Cox multivariable regression analyses were performed to evaluate the relation between the orientation of the T-axis, the spatial QRS-T angle and long-term mortality. Results: An abnormal orientation of the T-axis and the spatial QRS-T angle were associated with an increased likelihood of cardiac diseases and an increased risk of all-cause mortality during short- and long-term follow-up. Conclusions: We conclude that the frontal T-axis and the spatial QRS-T angle are important determinants of diagnosis and prognosis in patients presenting with acute chest pain. The reintroduction of vectorcardiography in routine clinical practice might therefore be reconsidered.

In addition to the classical Vκ-Jκ, Vκ-κ deleting element (Kde), and intron-Kde gene rearrangements, atypical recombinations involving Jκ recombination signal sequence (RSS) or intronRSS elements can occur in the Igκ (IGK) locus, as observed in human B cell malignancies. In-depth analysis revealed that atypical JκRSS-intronRSS, Vκ-intronRSS, and JκRSS-Kde recombinations not only occur in B cell malignancies, but rather reflect physiological gene rearrangements present in normal human B cells as well. Excision circle analysis and recombination substrate assays can discriminate between single-step vs multistep rearrangements. Using this combined approach, we unraveled that the atypical Vκ-intronRSS and JκRSS-Kde pseudohybrid joints most probably result from ongoing recombination following an initial aberrant JκRSS-intronRSS signal joint formation. Based on our observations in normal and malignant human B cells, a model is presented to describe the sequential (classical and atypical) recombination events in the human IGK locus and their estimated relative frequencies (0.2–1.0 vs <0.03). The initial JκRSS-intronRSS signal joint formation (except for Jκ1RSS-intronRSS) might be a side event of an active V(D)J recombination mechanism, but the subsequent formation of Vκ-intronRSS and JκRSS-Kde pseudohybrid joints can represent an alternative pathway for IGK allele inactivation and allelic exclusion, in addition to classical Cκ deletions. Although usage of this alternative pathway is limited, it seems essential for inactivation of those IGK alleles that have undergone initial aberrant recombinations, which might otherwise hamper selection of functional Ig L chain proteins.