Kazuo Yamanaka

Multislice Computed Tomography Accurately Quantifies Left Atrial Size and Function After the MAZE Procedure

Background— Although the MAZE procedure allows for the recovery of sinus rhythm and left atrial (LA) mechanical function in the great majority of patients with chronic atrial fibrillation (AF), the effects of MAZE on the precise LA geometry and wall motion remain to be elucidated. We hypothesized that LA size and mechanical function in patients with chronic AF and mitral valvular disease are well restored after MAZE. Methods and Results— We studied 14 patients (MAZE group: mean±SD age, 63.9±8.6 years; 8 men and 6 women) who underwent MAZE for chronic AF and mitral valve surgery and 10 patients with sinus rhythm (coronary artery bypass graft [CABG] group: age, 70.0±7.9 years; 5 men and 5 women) who underwent CABG at Takeda Hospital between February 2002 and September 2005. MAZE was conducted by the endocardial application of radiofrequency ablation with a temperature-controlled multipolar radiofrequency catheter. LA volume and booster function were quantitatively evaluated by multislice computed tomography at 17.9±10.0 months (MAZE group) and 15.3±13.6 months (CABG group) postoperatively. All patients with MAZE were free of AF and other atrial arrhythmias during the follow-up period. In the CABG group, LA maximal and minimal volumes and ejection fraction were 109±12 mL, 82±11 mL, and 26±10%, respectively. In the MAZE group, LA maximal volume was 139±17 mL (P=0.187 versus CABG), and LA minimal volume was 121±16 mL (P=0.082 versus CABG), with an ejection fraction of 15±7% (P=0.004 versus CABG). In both groups, all parts of the LA wall contracted toward the geometric center of the LA. The extent of wall motion was significantly worse in the MAZE group compared with the CABG group. In both groups, LA booster function was inversely correlated with LA maximal volume. Conclusions— MAZE with radiofrequency ablation is safe and effective for the restoration of sinus rhythm in patients with chronic AF and mitral valve disease. However, chronic AF associated with mitral valve disease deteriorates LA mechanical function diffusely throughout the LA wall. Further studies with the use of multislice computed tomography are needed to sequentially evaluate LA function after MAZE in patients with and without mitral valve surgery.

Bentall procedure in a patient with severely calcified "porcelain" aorta.

Abstractu2002 Patients with severe calcified “porcelain” aorta carry a high operative risk during cardiac surgery. We report the successful case of Bentall procedure in a patient with severe porcelain aorta. A 65‐year‐old woman was diagnosed with aortic prosthetic valve failure and enlargement of the ascending aorta. Preoperative chest X‐ray and computed tomography scan revealed heavy calcification throughout the aorta. At operation, cardiopulmonary bypass was established through the right axillary artery. The calcified aorta was transected by an oscillating saw under hypothermic circulatory arrest. Distal anastomosis was performed after endarterctomy of the calcified plate, which allowed us to complete the Bentall procedure without the postoperative bleeding.

Subacute aortic regurgitation due to traumatic tear in the aortic wall

A 37-year-old man presented with heart failure caused by severe aortic regurgitation (AR). He had a history of being involved in a traffic accident 3 months earlier. Imaging tests at admission detected no abnormalities in the aortic valve or aortic wall; however, the left coronary cusp prolapsed slightly on transthoracic echocardiography. He underwent aortic valve replacement because of uncontrolled heart failure and severe AR. Intraoperatively, the intima of the aortic wall just above the commissure of the left and right coronary cusps was torn to the short axial direction. Local aortic tear was the final diagnosis for the subacute AR. <Learning objective: Acute or subacute aortic regurgitation (AR) is comparatively rare, and it is sometimes difficult to clinically recognize. The tear in the aortic wall just above the commissure caused by a traffic accident led to the gradual progression of AR, and the diagnosis of the cause of AR was difficult despite using transesophageal echocardiography and contrast-enhanced computed tomography. We should recognize that the detection of subacute AR caused by a local aortic tear can be challenging.>.

Efficacy and Safety of Tolvaptan in Infants after Open Heart Surgery

Background: Reports on the efficacy of tolvaptan, which is a selective vasopressin V2 antagonist, in infants who undergo cardiac surgery are rare. We evaluated the efficacy and safety of tolvaptan to manage early fluid retention in infants following open heart surgery. nMethods: Pediatric patients under the age of 1 year who underwent biventricular repair with CPB were received conventional diuretics. Additionally, tolvaptan was administered in 18 patients two days after the administration of conventional diuretics when conventional diuretics did not effectively control fluid. For the evaluation of the effect of tolvaptan, the cumulative 24-h urine volume was measured. Changes in laboratory values, cardio hemodynamic factors, and all adverse events were also evaluated. nResults: The cumulative 24-h urine volume after 1st tolvaptan administration increased significantly compared with the urine volume before the administration (Day 3 vs. Day 4, 56.0 ± 15.0 vs. 84.2 ± 20.6 mL/kg; p=0.0002). Similarly, the cumulative 24-h urine volume after 2nd tovaptan administration were significantly larger than that before the tolvaptan administration (Day 5 vs. Day 3, 85.9 ± 32.2 vs 56.0 ± 15.0 mL/kg; p=0.003). There were no significant differences in hemodynamical factors and laboratory values on the tolvaptan administration. We also found that no adverse events were present. nConclusions: The addition of tolvaptan to conventional diuretics increases urine volume without major adverse events, and could be beneficial to control fluid in infants who underwent open heart surgery.

Case of prosthetic valve endocarditis with osteomyelitis associated with disregarded skin infection

Abstract nBackground: Prosthetic valve endocarditis (PVE) is a serious condition associated with high mortality rate. The causes of PVE vary from surgical procedure to superficial skin infection. Sometimes it is