Case 1
A 61-year-old man repeatedly visited our emergency room (ER) for dyspnea of New York Heart Association (NYHA) class III, which had first developed four months ago. Heart failure with preserved ejection fraction (HFpEF) and persistent AF were diagnosed. He had a history of hypothyroidism and cerebral infarction. His electrocardiogram (ECG) showed AF with an SVR rhythm (Figure 1A-a). Transthoracic echocardiography (TTE) showed left ventricular ejection fraction (LVEF) of 70%, left atrial (LA) diameter of 39 mm, E/E‘ ratio of 31, moderate aortic regurgitation and mild pulmonary hypertension. Coronary angiography (CAG) revealed minimal coronary artery disease (CAD). A 24-hour Holter tracing demonstrated persistent AF with a mean HR of 42 bpm (minimum 33 bpm, maximum 64 bpm), and non-sustained ventricular tachycardia (NSVT) of up to 5 beats (Figure 2A). His medications included atorvastatin, furosemide, indapamide, levothyroxine, perindopril, spironolactone, trimetazidine, and warfarin. Despite decongestive treatment with an increase in diuretics, his dyspnea did not improve. Therefore, electrical cardioversion was attempted to improve his symptoms. AF was terminated by electrical cardioversion, but junctional rhythm under 40 bpm persisted (Figure 1A-b). Finally, a permanent pacemaker of the DDDR type was implanted without any complications. However, after the procedure, the patient abruptly lost consciousness and the pulse was not palpable during transfer of the patient to the intensive care unit. The ECG monitor showed asystole. Cardiopulmonary resuscitation (CPR) and intubation were performed immediately. The rhythm strip in the pacemaker showed sustained VT, which had degenerated to VF (Figure 3A). Although his pacing rhythm was restored by CPR and repeated defibrillation under the support of extracorporeal membrane oxygenation, he eventually deteriorated and died the next day due to intractable heart failure.