Mid-diastolic mitral flow vectors in complete atrioventricular block

Excerpt

An 81-year-old man who was treated for prostate cancer was referred to our department because of bradycardia. He had a 1-month history of shortness of breath. A 12-lead electrocardiogram (ECG) showed complete atrioventricular (AV) block. His blood pressure was 165/78 mmHg and pulse rate was 38 beats/min. Results of blood sampling were normal. A transthoracic echocardiogram revealed normal left ventricular (LV) wall thickness (interventricular septal thickness, 8 mm; LV posterior wall thickness, 8 mm) and normal LV systolic function (LV end-diastolic dimension, 39 mm; LV end-systolic dimension, 22 mm; LV ejection fraction, 76 %). A color-coded 2-dimensional echocardiogram showed no significant valvular disease. During mid-diastole, mitral forward and regurgitant flows were intermittently observed (Fig. 1). Color-coded M-mode echocardiography also showed intermittent mitral forward and regurgitant flows (Fig. 2). Simultaneous ECG recording indicated a relationship between the timing of the P wave and the T wave and the direction of mid-diastolic flow. Mid-diastolic mitral inflow was observed when the P wave was on the T wave, while diastolic mitral regurgitation (MR) was observed when the P wave emerged after the T wave (Figs. 1, 2). After treatment of complete AV block by pacemaker implantation, neither type of mitral flow was observed.

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