Therapeutic AV block has been preferred in drug-resistant cases, although concurrent pacemaker implantation is mandatory. If it is technically possible to control surgically produced AV block to the first or second degree, this would certainly make conjoined use of a demand pacemaker quite unnecessary. This concept prompted us to undertake an experimental study, in which we succeeded in producing first to third degree AV block in 30 mongrel dogs through ablation of the AV node by applying direct current from the epicardial side. From immediately after starting ablation a stepwise progressive prolongation of the PQ interval was noted, with eventual development of third degree AV block. Histopathologically, the lesion consisted of coagulation necrosis which involved an average of 95% of the AV node in animals developing third degree AV block and an average of 66% in those with first degree AV block. These results suggest that our surgical procedure, if technically refined to permit ablation of the AV node to the desired extent, will provide an acceptable means of treating supraventricular tachyarrhythmia without requiring permanent pacemaker implantation.

It has been widely recognized that the drinking of strongly acid hot spring water often causes gastrointestinal symptoms. However, the research in this subject has been distinctly sporadic.
Fundamental and clinical experiments were undertaken to ascertain the effect of the drinking of Tamagawa Spa on the gastrointestinal mucosa. The property of Tamagawa Spa, Akita prefecture, is acid vitriol spring whose pH value is 1.2, and it contains a large amount of hydrochloric acid and hydrogen sulfide.
1. Studies in Man
The changes of gastric mucosa in 36 subjects after the drinking of hot spring water were observed by gastrocamera or gastrofiberscope.
Varying degrees of hyperaemia were found in all subjects administered non-diluted hot spring water, whereas these change were markedly reduced in subjects administered two times and over diluted hot spring water.
No instances of erosion or ulceration were seen in any of the subjects.
2. Experiments in Animals
Twenty three healthy rabbits, orally administered non-diluted or diluted hot spring water for seven days were autopsied.
The changes of gastric mucosa were similar to those in man, and no significant influence on the jejunal mucosa was seen. Microscopically the affected mucosa revealed degeneration of the epithelial cells of gastric gland and edema of the submucosa.
Based on the critical review of former studies, several important factors were suggested to explain the occurrence of gastric impairment after the drinking of Tamagawa Spa water.

The purpose of this study was to clarify the effect of warm water bathing (40°C) of the hand on the psychologic sweating measured in the opposite palm. The subjects were 2 males and 4 females, aged 38±10 years (26-58 years). The psychologic sweating was estimated by the apparatus developed by Sakaguchi et al (Sakaguchi, M. et al BME 26: 213, 1988). The room temperature was 27 to 28°C and the relative humidity was 60 to 70%. The sensor was attached using adhesive tape on the right palm. Then the psychologic sweating was measured after deep respiration, mental arithmetic, hand grip, bathing in warm water of 40°C at the level of left wrist. The results showed that the mean values of palmar sweating were 15.6 for deep respiration, 16.8 for mental arithmetic, 15.5 for hand grip and 0 for warm water bathing.
Above results suggest that local water bathing of moderate temperature induces a decrease of psychologic sweating, probably due to relaxing effect of the cerebrum.

We reviewed our experience with 19mm size aortic valve prostheses for cases with small aortic annulus. Forty-six patients operated on between 1990 and Septembr 2002 were enrolled in this study. Clinical late assessment was performed to evaluate the incidence of valverelated complications, residual transprosthetic gradient, left ventricular mass index (LVMI), and NYHA functional class. Postoperative echocardiography was performed to evaluate hemodynamic performance of the prostheses. Follow up was 1 to 12.7 years (mean 5.3±3.6). There was no hospital mortality (0%). Actuarial survival rates at 10 years were 81.4±1.5%. The late postoperative peak gradient was 25±11mmHg. LVMI was significantly reduced in late phase. NYHA functional class significantly improved in the late period. Although 19mm size aortic valve prosthesis remains small transprosthetic pressure gradient, LVMI significantly reduced and patient activity was satisfactory maintained in the late period.

Dacron prostheses are the most widely used grafts in replacement procedures for abdominal aortic aneurysms, but they are not perfect grafts. We encountered a rare case of late graft complication. A 66-year-old man was admitted to our hospital with a pulsatile mass in an abdominal operation scar. He had received placement of a Y-shaped Cooley double velour knitted Dacron graft 18 years previously. Computed tomography and angiography demonstrated graft dilatation and an aneurysm. After resection of the graft aneurysms, the operative findings showed a non-anastomotic aneurysm formation due to longitudinal division near the graft guideline. In this case, this graft failure may have been due to the deterioration of the filter of the Dacron prosthesis itself. Therefore it is important to perform careful long-term follow-up in patients with implanted Dacron arterial prostheses.

We studied cardiac function and outcome long after aortic valve replacement using a 19mm bileaflet valve. The subjects consisted of 10 of 12 patients living 10 or more years after the operation and 7 of 8 living 5-9 years after the operation. We measured the left ventricular ejection fraction (LVEF), %fraction shortening (%FS), left ventricular diastolic dimension (LVDd), systolic dimension (LVDs), PWT, IVST, and LV-aortic pressure gradient (PG) of in 6 patients each in 10 more years after the operation (Group I) and 5-9 years after the operation (Group II) who underwent ultrasonography, and calculated the left ventricular mass index (LVMI). No statistically significant differences were seen in either parameter in either group. Prognosis was 1 cardiac 2 cancer deaths each in 10 or more years after the operation group. The cumulative survival rate was in 85.7% post operative 5-9 years and 72.7% in 10 years. Although cardiac function was maintained in both groups, more observation is needed from now on because the pressure difference or LVMI may increase.

Median sternotomy is commonly used for suture fixation of a myocardial lead. Instead of this conventional technique, we used the technique of resecting the 5th costal cartilage through a small horizontal skin incision at the left 5th sternocostal junction in 33 patients, between 1980 and 2001. Here we describe this procedure, as well as the outcome of patients who underwent this myocardial lead fixation procedure. A skin incision of about 6 to 8cm was made in the left 5th intercostal space. Approximately 5cm of the 5th costal cartilage was resected through the skin incision. Then, a myocardial lead was sutured on to the anterior wall of the right ventricle. The generator was generally placed in the upper subcutaneous space of abdomen. Additional costal cartilages were removed in 7 patients in whom a larger operating field could not be obtained initially. The electrode was sutured to the right ventricular wall in 28 patients, right atrial wall in 6 patients, and the left ventricular wall in 5 patients. The mean operation time was 150min and mean bleeding during operation was 82ml. Long-term results (258 months at the longest, at the time of writing) showed that all the patients did well, except for one adult who suffered cerebral infarction, and one child with pacing failure. Based on these findings, we believe that this procedure is minimally invasive method, and is good for fixation of a myocardial lead.

Abdominal aortic aneurysms (AAA) are frequently associated with clinically significant coexistent ischemic heart disease (IHD). Cardiac events are the most common cause of death after AAA repair. Preoperative coronary evaluation and revascularization have been recommended to reduce postoperative cardiac complications following AAA repair. In this study, we retrospectively reviewed all patients who underwent AAA repair and compared operative results in patients with and without IHD. Of 388 patients who underwent elective AAA repair, 382 (98.5%) had aortography and coronary angiography for preoperative evaluation. Significant coronary artery disease was seen in 124 patients (32.5%). As a result of the evaluation, 46 patients (12.0%) were considered candidates for medical therapy, 18 for percutaneous coronary intervention (PCI), and 60 for coronary artery bypass grafting (CABG). In 24 patients (6.3%) who needed CABG and had large sized AAAs (>60mm), simultaneous CABG and AAA repair were performed. In the remaining 36 patients (9.4%) who needed CABG and had medium sized AAAs (40mm<, <60mm), staged operation was performed. We performed retrospective review comparing postoperative cardiac events and operative mortality among these treatment groups. There were 5 operative deaths (5/388, 1.3%) in patients following AAA repair. There were 2 operative deaths (2/124, 1.6%) in patients with significant IHD and 3 deaths (3/258, 1.2%) without IHD. In patients with IHD, 1 patient who received medical therapy died of acute renal failure and another one who received PCI died of acute myocardial infarction. There were no operative deaths or cardiac-related events in patients who received CABG before or concomitant AAA repair. There was only 1 cardiac-related event in all patient groups following AAA repair. Coronary arteries were preoperatively evaluated in almost all patients with AAA. If IHD was significant, the treatment for the IHD preceded AAA repair. Our strategy succeeded in reducing operative mortality and cardiac-related events in patients with both AAA and IHD. If a patient with a large sized AAA (>60mm) needs CABG, one-stage operation is recommended.

A 40-year-old woman visited our emergency room (ER) with fever and shaking chills. Blood cultures for suspicion of urinary tract infection revealed bacteremia two days later. Since Streptococcus mitis was detected, infective endocarditis was strongly suspected. In addition to her history of dental calculus removal, careful cardiac auscultation revealed a continuous murmur, leading to the existence of patent ductus arteriosus (PDA). PDA was confirmed by echocardiography and 3D-CT angiography. The patient was successfully treated by antibiotics and then received transcatheter PDA closure. Careful auscultation after detection of bacteremia led to a diagnosis of PDA.