An 18 Year Old Man Who Presented With Typical AV Nodal Reentrant Tachycardia and Pulmonary Embolus After Blunt Chest Trauma

Abstract

INTRODUCTION: Paroxysmal supraventricular tachycardia (PSVT) following blunt cardiac injury (BCI) is rare but reported in the literature. AV nodal reentrant tachycardia (AVNRT) is the commonest form of PSVT encountered in clinical practice. We present a unique case of AVNRT after a blunt chest trauma with concomitant pulmonary embolism. CASE PRESENTATION: An 18 year-old Hispanic man with no significant past medical history presented to the emergency room with two hours of palpitations after sustaining a hard blow to the left mid-sternum while playing basketball. Patient reported a presyncopal episode lasting less than one minute immediately after the blunt trauma followed by unremitting palpitations and worsening mid-sternal chest pain and dyspnea on exertion. On presentation he was in mild distress, complaining only of palpitations. His heart rate was 210 beats per minute and blood pressure was 100/45 mmHg. EKG showed SVT. Adenosine was given and he converted to normal sinus rhythm with symptom resolution. Serum troponin I peaked to 3.30 ng/mL and plasma D-Dimer Assay was elevated at 1244 ng/mL. Chest radiography showed no pathology. Echocardiogram showed mildly enlarged right ventricle. CT Angiogram of the chest showed acute right lower lobe lobar and segmental pulmonary embolus without pulmonary infarct. The patient is without risk factors for cardiopulmonary disease or clotting disorders and lower extremity venous duplex was negative for deep vein thrombosis. Patient was inducible into typical AVNRT at a rate of 200-210 beats per minute on electrophysiological study. He underwent successful radiofrequency ablation and was no longer inducible into SVT. The patient remained asymptomatic and was discharged on oral anticoagulation. DISCUSSION: BCI is a risk factor for cardiac dysrhythmia (1). It is hypothesized that the reentrant rhythm was triggered by premature ectopic beats resulting from the blunt cardiac trauma. In the setting of dual AV nodal physiology, an ectopic beat was able to initiate sustained AVNRT (2). Thromboembolism after BCI has been reported previously (3). We hypothesize that the blunt cardiac trauma also predisposed the patient to an in situ thrombus which embolized to the pulmonary artery branches. This case of blunt chest trauma causing typical AVNRT and PE is to the best of our knowledge the first of its kind reported in the literature. CONCLUSIONS: This case illustrates two unusual sequelae of blunt chest trauma- pulmonary embolus and sustained AV nodal reentrant tachycardia.