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Echocardiographic evaluation of patients with undocumented arrhythmias occurring in adults late after repair of tetralogy of Fallot.

AIMS
Arrhythmias occurring late after repair of tetralogy of Fallot (ToF) are common. Due to the risk of sudden cardiac death, attention is focused towards ventricular tachycardias (VT). The aims of this study were to determine the clinical profile of patients with known benign and malignant arrhythmias and to assess patients with palpitations without documented arrhythmias.


METHODS AND RESULTS
Fifty-two patients with prior ToF repair were included in this study (mean follow-up: 18+/-7.3 years). Echocardiographic measurements such as left ventricular ejection fraction, left and right atrial (LA and RA) diameters, left and right ventricular diameters (LVEDD and RVEDD), pulmonary and tricuspid regurgitation (TI and PI) and electrocardiographic parameters such as QRS duration, P-wave duration, P-wave dispersion were obtained and compared in patients with and without a history of palpitations. The same comparisons were performed between patients with documented supraventricular tachycardias (SVT) and VT. Twenty-seven of 52 patients had a clinical history of palpitations. The remaining 25 patients served as controls. Eleven patients had documented SVT and 6 patients had documented VT. In patients with documented SVT, the RA size and the QRS durations were significantly higher than in the controls (RA: 55.3+/-5.6 vs. 47.4+/-4.8 mm, P=0.03, QRS: 160.0+/-25.9 vs. 131.8+/-26.1 ms, P=0.01). In patients with VT, the LVEDD, LA, and QRS durations showed significantly higher values compared with the control patients (LVEDD: 53.5+/-4.7 vs. 45.6+/-6.8 mm; LA: 56.0+/-3.4 vs. 48.5+/-4.8 mm, P=0.01; QRS: 169.5+/-29.7 ms vs. 131.8+/-26.1 ms; P=0.001). The only significant differences between patients with and without palpitations were the RA size (58.2+/-3.9 vs. 50.5+/-5.2 mm, P=0.02) and the P-wave dispersion (26.8+/-15.2 vs. 16.6+/-4.3 ms, P=0.04).


CONCLUSION
Our present data suggest that undocumented arrhythmias are most likely SVTs and are associated with increased RA size.