Supraventricular arrhythmia before and after surgical closure of atrial septal defects: spectrum, prognosis and management.

UNLABELLED: Supraventricular arrhythmias are often observed in patients before and after atrial septal defect repair. Although several papers report different incidences of sustained supraventricular arrhythmias, postoperative 'incisional' macroreentrant tachycardias have not been systematically investigated. METHODS: We reviewed 136 consecutive patients (79 female, 57 male, mean age 36.8+/-17.8 years) who underwent atrial septal defect repair at our institutions between January 1990 and January 1999. Coexisting valve disease requiring surgical intervention was noted in 13 patients (9.5%). The mean follow-up period was 78.8+/-30.1 months. RESULTS: Sustained supraventricular arrhythmias occurred in 12 patients (8.8%) before surgery (atrial fibrillation in 11 patients). Using multivariate analysis the occurrence of arrhythmia significantly correlated with the presence of coexisting heart disease (P< 0.001) and age at surgery (P=0.011) After surgery sustained supraventricular arrhythmias were recorded in 16 patients (11.7%). Eleven of them had atrial fibrillation, permanent in 8 cases, 4 'incisional' macroreentrant atrial tachycardia and 1 atrioventricular re-entry tachycardia. There was a significant correlation between pre and postoperative arrhythmia (P< 0.001). Two of the 4 patients with macroreentrant atrial tachycardia underwent successful radiofrequency catheter ablation, whereas the arrhythmia was controlled medically in the remaining 2 patients. CONCLUSIONS: Atrial fibrillation remains the most frequent form of arrhythmia before and after surgical closure of atrial septal defects in adulthood, and relates to age at the time of repair and coexisting heart disease. Incisional macroreentrant atrial tachycardia is an identifiable, albeit less common, form of tachycardia, which can be treated by transcatheter ablation.

Screening for primary aldosteronism with a logistic multivariate discriminant analysis.

OBJECTIVE: Primary aldosteronism (PA) is the most common endocrine cause of curable hypertension, but no single test unequivocally identifies it. Accordingly, we investigated the usefulness of a logistic multivariate discriminant analysis (MDA) approach for PA screening. DESIGN: Generation of a logistic MDA function based on retrospective analysis of biochemical tests in a large cohort of referred patients with/without confirmed Conn's adenoma (CA), followed by prospective validation of the model. PATIENTS: We investigated 574 selected hypertensives: 206 (32 with and 174 without CA) retrospectively, 48 (with a 13% prevalence of CA) prospectively for the validation of the model, and 320 referred hypertensives (with a 3.4% prevalence of CA) similarly evaluated. Patients were referred to a specialised centre for hypertension (4th Clinica Medica--University of Padua) and to a department of Internal Medicine of a regional hospital (Reggio Emilia). MEASUREMENTS: In all patients we measured several demographic and biochemical variables and performed a captopril test. A stepwise analysis of variance, based on a model fitted with several different variables, identified baseline (sALDO) and captopril-suppressed plasma aldosterone (cALDO), supine plasma renin activity (sPRA) and K+ as the most informative. Therefore, two models of logistic MDA with sPRA, K+, and either sALDO (model A) or cALDO (model B) were developed and used. ROC analysis was also performed to assess the optimal cut-off values. RESULTS: The model B of MDA provided the best performance and identified CA with 100% sensitivity and 81% accuracy. When used prospectively it showed 100% sensitivity, both in the Padua (88% accuracy) and in the Reggio Emilia series (90% accuracy). However, at both institutions most patients with idiopathic hyperaldosteronism (IHA) were also detected. CONCLUSIONS: Thus, although developed from patients with confirmed Conn's adenoma, a strategy based on multivariate discriminant analysis can be used prospectively for accurate screening for primary aldosteronism. Furthermore, it was proven to be accurate and applicable to patients tested with similar modalities at a different institution. Although this approach did not provide a clear-cut discrimination of Conn's adenoma from idiopathic hyperaldosteronism, it may avoid unnecessary and costly further testing in patients with a low probability of primary aldosteronism.