Serial changes of L wave according to heart rates in a heart failure patient with persistent atrial fibrillation

Mid-diastolic forward flow velocity of transmitral flow (L wave) is known as a marker of diastolic dysfunction and is occasionally observed in patients with fluid retention, low heart rate, and atrial fibrillation (AF). However, how hemodynamic condition affects L wave is still unknown. An 81-year-old woman who underwent implantation of a DDD pacemaker due to complete atrioventricular block 38 years previously suffered from congestive heart failure and was admitted to our hospital. At the time of admission, electrocardiogram showed new-onset AF resulting in mode switch to VVI, and echocardiography showed a giant L wave. At the mid-term of the treatment, AF was converted to sinus rhythm resulting in mode switch to DDD, and pacemaker check-up was performed at pre- and post-cardioversion. During the pacemaker check-ups, L wave was assessed in various pacing rates. As pacing rate was increased, L wave altered according to heart rates and disappeared at 85 bpm in VVI with AF, whereas at 75 bpm in DDD. Through the treatment, L wave got smaller as fluid retention was improved and finally disappeared at the time of discharge. This case suggests that L wave is highly variable and affected by fluid volume, heart rate, and heart rhythm. < Learning objective: Although L wave is known as a marker of diastolic dysfunction and occasionally observed in patients with high left ventricular filling pressure, low heart rate, and atrial fibrillation, how hemodynamics affects L wave is still unknown. In this case, it was observed that L wave is highly variable in the therapeutic process of heart failure and affected by fluid volume, heart rate, and heart rhythm. L wave potentially can be a useful indicator to evaluate treatment efficacy for heart failure.>