Macroreentrant Atrial Tachycardia in a Left Atrium With a Prosthetic Mitral Valve (Example 1): a Reentrant Circuit Confined to the Left Atrial Roof and the Need for Reconstruction of the Entire Reentrant Circuit
This is a 67-year-old female patient who underwent mitral and aortic valve replacement with mechanical prosthesis for a postrheumatic disease. No detailed report of surgical intervention was available. She had associated systemic hypertension and diabetes. Seven years after valvular replacement, the patient began complaining of palpitations. The surface electrocardiogram showed atrial tachycardia with a cycle length of 450 ms and positive P waves in the inferior and precordial leads, while a flat/negative P wave was present in leads I and aVL (Fig. 1). At electrocardiographic monitoring, 1:1 atrioventricular conduction was frequently observed. The arrhythmia was persistent and highly symptomatic and it recurred early after electrical cardioversion, even after intravenous and oral amiodarone administration. A transthoracicechocardiogram showed normal function of the prosthetic valves, mild impairment of left ventricular function and an enlarged left atrium. The patient was on oral anticoagulation and a transesophageal echocardiogram showed no endocavitary thrombi. Since the arrhythmia was drug-refractory and highly symptomatic, an ablation procedure was planned with the expectation of a left atrial origin of the arrhythmia and the need for transseptal catheterisation in the presence of a mechanical mitral prosthetic valve.
KeywordsLeft Atrium Prosthetic Valve Mapping Catheter Leave Anterior Oblique Reentrant Circuit
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