[Assessment of blood flow of the internal thoracic artery in patients with aortic stenosis]

The number of patients undergoing combined aortic valve replacement (AVR) for aortic stenosis (AS) and coronary artery bypass grafting (CABG) has been increasing. In CABG, the internal thoracic artery (ITA) is the preferred conduit for its long-term patency. Although Doppler studies on ITA have been widely used, flow characteristics of the vessel in patients with AS have not been reported. To evaluate blood flow pattern of the ITA in AS, duplex scanning was performed in 10 patients before and after AVR. Peak systolic velocity was measured, and blood flow was calculated from mean velocity and cross-sectional area. The mean diameters of the vessels were approximately 1.8 mm on both sides. AVR caused an increase in systolic velocities from 61.2 cm/sec to 85.5 cm/sec in right ITA and from 58.4 cm/sec to 84.7 cm/sec in left ITA. The flow volumes increased from 32.2 ml/min to 46.7 ml/min in right and increased from 31.6 ml/min to 46.3 ml/min in left after AVR. In simultaneous AVR for AS and CABG, suitability of the ITA should be assessed before its use, and concomitant AVR may be quite important to provide adequate flow of the ITA as a conduit.

[Assessment of left internal thoracic artery grafts by atrial pacing]

The flow reactivity of a left internal thoracic artery graft (LITAG) in response to atrial pacing was evaluated in 14 patients who underwent coronary artery bypass grafting (CABG) with LITAG to left anterior descending artery (LAD). Systolic peak velocity and diastolic peak velocity were recorded using a duplex scanner of 7.5 MHz, and flow volumes in each phase and flow ratio were calculated. The external temporary atrial pacing was used to increase heart rates 25 and 50%. Diastolic peak velocity and flow volume increased predominantly on both pacing rates. In contrast, systolic peak velocity decreased when heart rate was raised 50%, and there was no significant difference between the pacing modes in systolic flow volumes. As a result, flow ratio increased predominantly on both pacing rates. Based on the present studies, there may be some advantages with atrial pacing to increase the LITAG flow in response to the myocardial oxygen demand.

[A surgical case of cardiac malignant lymphoma in right atrium]

We reported a case of malignant lymphoma originating from the right atrium. The patient was a 71-year-old man who had no symptoms associated with heart failure and arrhythmias. At the time of admission the patient was suggested the presence of a tumor in the right atrium by an echocardiogram accidentally. Coronary angiography revealed a feeding artery to a tumor. Although cytological confirmation was not obtained, diagnostic extirpation of tumor was performed under cardiopulmonary bypass. The histological diagnosis was malignant lymphoma of B-cell origin. His postoperative course was uneventful and no recurrence had been observed one year postoperatively without chemotherapy.