Recurrent symptomatic atrial fibrillation in a patient with univascular coronary artery disease in dilated stage – ischaemic etiology or thyroid dysfunction?

Introduction: The cardiovascular risk in patients with history of myocardial infarction is known to be extremely high, especially in patients with increased left ventricle dimensions. Also, associated pathologies whose occurrence is favored by this history, like rhythm disorders, are accompanied by therapeutical aspects with a difficult to reach balance in clinical practice, including because of the frequent iatrogenic complications that may occur.
Case presentation: A 60 years old patient, hypertensive, diabetic, with a history of inferior myocardial infarction treated with thrombolysis, coronary artery disease in dilated stage (chronic occlusion RC IInd segment), with previous episodes of sustained ventricular tachycardia in May 2017 for which a cardiac defibrillator was implanted as a measure of secondary prophylaxis in the prevention of sudden cardiac death, a history of persistent atrial fibrillation electrically converted to sinus rhythm, is presented with decreased effort tolerance, shortness of breath in moderate efforts, the symptoms being aggravated in the presence of a recurrence of the atrial fibrillation. The electrocardiogram reveals atrial fibrillation with medium heart rate, old anterior myocardial infarction and nonspecific intraventricular conduction disorders. The patient was efficiently anticoagulated under antivitamin K therapy, with a low hepatocytolysis syndrome, mild thrombocytopenia, subclinical hypothyroidism (mildly elevated TSH, FT4 within normal limits) in the presence of chronic amiodarone therapy for over an year. The echocardiography showed a dilated left ventricle, with kinetic disorders in the RC territory, with mildly depre-ciated systolic function (40%), mixed moderate mitral insufficiency (degenerative and secondary to the LV dilation). The Holter ECG monitoring (under amio-darone therapy 200 mg/day and metoprolol succinate 2×50 mg/day) showed atrial fibrillation with medium heart rate, without any pauses or significant rhythm or conduction disorders. No malignant tachycardia episo-des were revealed on the ICD interrogation. During the admission, the anticoagulation therapy was continued along with the beta blockers, antiarrhythmic medicati-on, angiotensin converting enzyme inhibitors, antial-dosteronic diuretics and statins, with a favorable clinical evolution. At discharge, frequency control was cho-sen in favor of rhythm control, considering the onset of the fibrillation under antiarrhythmic therapy and, therefore, a low probability of long term persistence of the sinus rhythm after an electric conversion. Also, an endocrinologic exam was recommended considering the hypothyroidism developed under amiodarone therapy. Case particularity: The recurrence of the atrial fibrilla-tion under antiarrhythmic treatment, in a patient with old myocardial infarction treated with thrombolysis, ICD carrier as secondary prophylaxis of sudden cardiac death, with univascular coronary artery disease in dilated stage and the association of a subclinical hypothyroidism after amiodarone therapy.
Conclusions: The management of a patient with recur-rent atrial fibrillation and a history of sustained ventricular tachycardia, old myocardial infarction treated with thrombolysis, univascular coronary artery disease in dilated stage, with adverse reactions from amiodarone treatment, can often become a therapeutical challenge.

ISSN – online: 2734 – 6382
ISSN-L 1220-658X
ISSN – print: 1220-658X
The Romanian Journal of Cardiology is indexed by:
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CODE: 379
CME Credits: 10 (Romanian College of Physicians)