Masahiro Koh

Off-pump coronary bypass using interposed radial artery graft

We describe a patient with severely diseased ascending aorta and small internal mammary arteries, who underwent off-pump coronary artery bypass to the left anterior descending coronary artery and right coronary artery using composite arterial grafts consisting of the pedicled proximal internal mammary artery and interposed radial artery graft. The interposed radial artery graft provides advantages, such as making coronary anastomosis on the beating heart easier and to increasing the flow potentiality of the internal mammary artery.

Chronologic changes in P-wave characteristics after the Fontan procedure: The effect of surgical modification

OBJECTIVES The Fontan-type procedure has undergone 2 major modifications, including intra-atrial baffling and extracardiac conduit. To clarify the effect of these modifications on arrhythmia propensity, we analyzed chronologic changes in P-wave characteristics after atriopulmonary connection, intra-atrial baffling, or extracardiac conduit. METHODS A retrospective analysis was conducted on electrocardiographic data from 40 patients with tricuspid atresia who underwent the Fontan-type procedure and follow-up for greater than 5 years: 18 had atriopulmonary connection, 13 had intra-atrial baffling, and 9 had extracardiac conduit. The mean follow-up period in years was 19.8 for atriopulmonary connection, 13.3 for intra-atrial baffling, and 8.0 for extracardiac conduit. We analyzed chronologic changes in P-wave duration, dispersion, and amplitude and prevalence of sinus node dysfunction. RESULTS Atrial tachyarrhythmia was documented in 9 patients with atriopulmonary connection but not in any patients with extracardiac conduit or intra-atrial baffling. Both P-wave maximum duration and dispersion decreased slightly over time with extracardiac conduit but increased progressively in the intra-atrial baffling and atriopulmonary connection groups. Intra-atrial baffling resulted in significantly shorter P-wave duration than atriopulmonary connection, whereas extracardiac conduit had significantly shorter P-wave duration and smaller dispersion than atriopulmonary connection and intra-atrial baffling. P-wave amplitude decreased markedly immediately after surgical intervention with intra-atrial baffling and extracardiac conduit but remained unchanged in patients undergoing atriopulmonary connection. Sinus node dysfunction was found commonly in all 3 groups. CONCLUSION After intra-atrial baffling, patients increasingly had prolonged P-wave duration and larger dispersion associated with sinus node dysfunction, suggesting a propensity to arrhythmia, although less progressive than seen in those undergoing atriopulmonary connection. In contrast, despite an equal prevalence of sinus node dysfunction after extracardiac conduit, the lack of important changes in P-wave characteristics over time suggests that the extracardiac conduit procedure is the preferred option for optimal rhythm prognosis.

Is the Morphologic Mitral Valve in Discordant Atrioventricular Connections Always Normal

BACKGROUND The purpose of this study was to determine structural features and variations in the mitral valve guarding inflow of the morphologic left ventricle in hearts with discordant atrioventricular connections. METHODS Morphologic investigation was carried out on the inlet valve to the morphologic left ventricle in 48 autopsied specimens with this particular entity of malformation. RESULTS The tension apparatus was straddling to the morphologic right ventricle in 2. Another 34 hearts had a bifoliate valve and the papillary muscles abnormally oriented; a solitary papillary muscle in 3, two papillary muscles but deviated in 5, one of two papillary muscles being dysmorphic in 9, and three or more papillary muscles in 17. The origin of these papillary muscles was frequently deviated. In 5 hearts with a trifoliate or quadrifoliate valve, multiple papillary muscles were also the case. One of these had thick leaflets, a part of which was adherent to a membranous flap around the ventricular septal defect as well as to subpulmonary fibrous tissue tags. Eventually, the valve was comparable with the mitral valve seen in the normally structured heart in only 7 hearts (15%). There was no obvious correlation noted between the presence of abnormality in the mitral valve and that in the tricuspid valve. CONCLUSIONS Architectural abnormalities are not rare in the morphologic mitral valve in this setting. The valvar structure needs precise recognition.

The impact, and surgical implications, of isolated anomalous connection of one pulmonary vein.

Partially anomalous pulmonary venous connection of a solitary pulmonary vein in the setting of an intact atrial septum is often subclinical, and the indications for surgical repair are controversial. Here we describe a patient who developed a significant shunt over a period of 10-years. Flow through the anomalously connected pulmonary segment depends on the difference of pressure between the right and left atrium, and may increase with age.