Journal of Geriatric Cardiology : JGC | 2021
Typical atrial flutter from blunt cardiac injury: an atypical cause
Abstract
A trial flutter (AFL) is a detrimental cardiac arrhythmia caused by multiple pathologic conditions. Certain unsuspecting cases, however, may be an inciting factor. Among them is blunt cardiac injury (BCI), characterized by nonpenetrating mediastinal trauma, leading to arrhythmias due to myocardial tissue injury. AFL is a rare sequela of BCI that has seldom been reported. We present a case of a healthy 50-year-old lady who was incidentally diagnosed with AFL in the setting of BCI. A 50-year-old lady with a past medical history of hypertension presented after a motor vehicle accident. Driving at roughly 30 miles per hour, she suddenly swerved into a tree to avoid hitting a dog, which resulted in airbag deployment and a transient loss of consciousness. She was hemodynamically stable, anxious, and complained of chest wall tenderness, headache, and palpitations. Physical exam revealed tachypnea, tachycardia with a regular rhythm, soft abdomen, and seatbelt signs on the left neck, left and right breasts, and right upper abdomen. A trauma survey, including a whole-body computed tomography scan, confirmed the absence of significant injury. Surprisingly, she had a regular tachycardia with a rate of 150 beats per minute. Electrocardiogram (ECG) displayed a 2:1 AFL suggestive of typical counterclockwise conduction (Figure 1). Workup with chest imaging, complete blood count, electrolytes, cardiac biomarkers, thyroid-stimulating hormone, and toxicology panel was normal. She did not have any congenital, cardiac, or pulmonary diseases, and her family history was unremarkable. She had only been on extended-release Nifedipine for hypertension and did not take any other medications or recreational drugs. Transthoracic echocardiography demonstrated a normal global systolic function with no structural abnormalities. The patient was started on Metoprolol Tartrate for rate control and Apixaban for a CHA2DS2-VASc of 2. The next day, the patient still had intermittent palpitations and chest wall tenderness without significant distress, but later spontaneously converted back to normal sinus rhythm (Figure 2). The electrophysiology team evaluated her, and she underwent a cavotricuspid isthmus ablation with a bidirectional block. She was discharged home on apixaban in stable conditions with scheduled follow-up. Typical AFL is a tachyarrhythmia identified by rapid atrial depolarizations from an overactive macroreentrant circuit that traverses the cavotricuspid isthmus. It commonly involves a counterclockwise circuit rotation around the tricuspid valve, contrasted to the rare clockwise direction. Typical counterclockwise AFL is characterized by a regular atrial rate of around 300 beats per minute, seen as sawtooth atrial âFâ waves with a negative deflection in the inferior leads and a positive deflection in lead V1, followed by a regular ventricular rate of around 150 beats per minute when there is 2:1 atrioventricular conduction. Symptoms include dyspnea, palpitations, lightheadedness, chest pain, and anxiety. Complications may be syncope, heart failure, myocardial ischemia, and systemic Journal of Geriatric Cardiology