Étude électrophysiologique par voie transœsophagienne chez des enfants de moins de 11 ans, non sédatés, ayant un syndrome de Wolff-Parkinson-White

The electrophysiological evaluation of Wolff-Parkinson-White syndrome (WPW) is recommended in children aged more than five years to detect a risk of life-threatening arrhythmia. The purposes of the study were to determine the feasibility of transesophageal EPS in a child between six and 10 years in out-patient clinic.

Methods

Electrophysiological study (EPS) was indicated in 22 children, aged six to 10 years, with a manifest WPW either for no documented tachycardia (n = 7), unexplained dizziness (n = 2) or for a sportive authorization in 10 asymptomatic children. Two of the last children had a history of permanent tachycardia after the birth but were asymptomatic since the age of one year without drugs.

Results

EPS was performed in all children. The main difficulty lied in passing the catheter through the mouth. Programmed stimulation at cycle length of 380 ms was performed in all children to avoid high rates of pacing when the conduction through the accessory pathway (AP) and normal AV system was evaluated. Isoproterenol was not required in five children, because they developed a catecholaminergic sinus tachycardia. The AP refractory period was determined in all children between 200 and 270 ms. Orthodromic reentrant tachycardia (RT) was induced in 11 children, three asymptomatic children (27%), seven complaining of tachycardia and one with syncope. Rapid antidromic tachycardia was induced in this last child with dizziness. Atrial fibrillation was never induced.

Conclusions

Esophageal EPS can be performed without sedation in a young child six to 10-year-old with a shortened protocol of stimulation, which was capable to clearly evaluate the WPW-related risks.     

Apport de l’IRM cardiaque dans l’évaluation initiale et le suivi des myocardites mimant un syndrome coronaire aigu : à propos d’une série de 43 patients

Aims

The diagnosis of acute myocarditis is complex, especially when the clinical presentation mimics an acute coronary syndrome. This condition may promote the progression to dilated cardiomyopathy and the occurrence of severe arrhythmias. A reassessment integrating a cardiac MRI at three months after the acute episode could help identify patients with a poor prognosis.

Patients and results

This prospective series of 43 consecutive patients hospitalised for acute myocarditis included 36 men and seven women, with a mean age of 32 years, with no indication of heart failure. All patients presented elevated levels of troponin I. Echocardiography showed moderate left ventricular dysfunction in six cases and segmental wall motion abnormalities in 22 cases. After gadolinium injection, a subepicardial late enhancement was observed in 39 cases. Three months after the acute episode, all patients were asymptomatic. The echocardiography and laboratory tests were normal. In 23 cases, the MRI showed persistence of the late enhancement without segmental wall motion abnormality. After a mean follow-up of three years, one patient was lost to follow-up and only one suffered a heart failure revealing a dilated cardiomyopathy complicated by ventricular arrhythmias.

Conclusion

On admission, the subepicardial localisation of late enhancement in the cardiac MRI is reliable criteria for the diagnosis of acute myocarditis, enabling to rule out an acute coronary syndrome. During follow-up, the persistence of late enhancement has no impact on prognosis. In this series, after a mean follow-up of three years, it was not associated with clinical or paraclinical abnormalities, except in one patient.     

Résultats à court et long terme du remplacement valvulaire mitral par prothèse mécanique à bille et à ailettes (à propos d’une série de 236 patients consécutifs avec un suivi moyen de 11 ans)

Objectives

To study the early and late results of mitral valve replacement (MVR) by Starr-Edwards caged-ball and bileaflet mechanical prosthesis.

Material and methods

We retrospectively analyzed 236 MVR performed in 236 patients: 127 by Starr-Edwards prosthesis (group 1) and 109 by bileaflet prosthesis (group 2).

Results

During the early period (30 days), the mortality rate was higher in group 1 (6.3 % vs 1.8 %; p = 0.0001), while hemorrhagic, thromboembolic and infectious complications were comparable in the two groups. In the late period (> 30 days) and with an average follow-up of 11.5 ± 5.7 years, mortality was higher in group 1 (9.4 % vs 4.6 %; p < 0.0001). The same was true for thromboembolic complications (20.8 % vs 6.4 %; p < 0.0001), hemorrhagic complications (13.4 % vs 7.3 %; p = 0.02), infectious complications (3.1 % vs 0.9 %; p = 0.02) and cardiac complications that were not due to the prosthesis (32.3 % vs 14.7 %; p = 0.02). The hemodynamic profile of the bileaflet prostheses was better than that of the Starr-Edwards prostheses (average functional prosthetic surface area was 2.37 ± 0.44 cm² and average pressure gradient was 5.6 ± 1.1 mmHg vs 2.04 ± 0.52 cm² and 7.6 ± 4.9 mmHg).

Conclusion

Our work confirms the superiority of bileaflet mechanical prostheses, with rates of early and late mortality, thromboembolic and hemorrhagic complications lower than those of the Starr-Edwards prostheses in more than 11 years of follow-up. However, one should not forget that the prevention of infective endocarditis, good observance of oral anticoagulant treatment and early surgery before left ventricular dysfunction occurs remain the best guarantee a good result of the MVR.