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2020년 제 71차 대한내과학회 추계학술대회
￭S-197 ￭ PRKAG2 Syndrome presenting Wide QRS
Tachycardia mimicking Hypertrophic Cardiomyopathy: A case report
인하대학교병원 내과 이기정, 최성환, 백용수
PRKAG2 syndrome caused by a mutation of gene which is responsible for glycogen storage dysfunction is characterized by left ventricular hypertrophy mimicking hypertrophic cardiomyopathy (HCMP), ventricular pre-excitation, supraventricular tachyarrhythmias and conduction abnormalities leading to heart block or sudden cardiac death (SCD). A 22-year-old male visited our emergency department (ED) due to palpitation and dizziness. The patient was previously diagnosed with Wolff-Parkinson-White (WPW) syndrome 11 years ago at another hospital but failed to achieve successful ablation of an accessory pathway and was lost from regular follow up. 12 lead ECG taken in ED showed very fast wide QRS tachycardia with hemodynamic instability. (Figure 1A.) Synchronized 100J cardioversion shock was applied, and sinus rhythm was successfully restored with pre-excitation delta wave noted on resting ECG.
Initial laboratory results were as follows: white blood cells(WBCs), 15560 /mm3; C-reactive protein, 0.04mg/dL; hemoglobin, 16.1 g/dL; platelet 275X103 /uL; Creatinine kinase 85 IU/L; CK-MB, 5.1 ng/mL; troponin-I <0.100ng/mL ; NT-proBNP 192 pg/mL.
Transthoracic echocardiogram (TTE) revealed concentric hypertrophy of LV wall similar to HCMP (Figure 1B). The result of electrophysiology study revealed that this clinical wide QRS tachycardia was atrial tachycardia (AT) originating from coronary ostium (Figure 1C). After several radiofrequency catheter ablations under the 3D mapping system, AT was not more induced (Figure 1D).
However, after a few days, he returned to our ED with Wide QRS tachycardia. The parents of the patient denied any familial cardiac disease history. The culmination of clinical cardiac manifestations leads to suspect whether the genetic mutation was the underlying factor. Genetic testing was done with PRKAG2 gene being positive responsible for encoding the regulatory gamma 2 subunit of adenosine monophosphate-activated protein kinase. Beta-blocker was prescribed and due to high incidence of sudden cardiac death in PRKAG2 patients, implantable cardioverter defibrillator (ICD) implantation is scheduled for primary prevention of SCD.
