Takashi Murashita

By Takashi Murashita

The number of patients who suffer from heart failure is rapidly increasing. In about one‐third of heart failure patients, conduction delays cause dyssynchronous left ventricular contractions, which leads to reduction in left ventricular function, adverse cardiac remodelling and finally increased mortality. Cardiac resynchronization involves simultaneous pacing of both ventricles, and improves left ventricular contractile function. Although resynchronization does not restore myocardial function, multiple studies have shown that cardiac resynchronization therapy improves quality of life, exercise capacity, symptoms of heart failure, left ventricular ejection fraction, morbidity and mortality. The use of cardiac resynchronization therapy has increased significantly, since its initial approval in 2001, in patients with advanced heart failure.

Part of the book: The Role of the Clinical Cardiac Electrophysiologist in the Management of Congestive Heart Failure

By Takashi Murashita

Along with the rapid evolution of transcatheter interventions, interventional cardiologists are playing more and more important role in the care of cardiovascular disease. The consequence of rapid change in the landscape has been fostering new and improved relationships between interventional cardiologists and cardiac surgeons and the formulation of Heart Team to facilitate patient management. A hybrid strategy is a combination of tools available only in the catheterization laboratory with those available only in the operative room in order to gain maximum profit from both of them. In the current era, the continuous development in transcatheter procedures along with the adoption of minimally invasive surgical approaches makes hybrid strategy an attractive alternative to conventional surgical or transcatheter techniques for any given set of cardiovascular diseases. In the areas of coronary revascularization, valve repair or replacement, and ablation for atrial fibrillation, hybrid approaches have shown great benefit especially in high-risk cases. With the technological evolutions in the treatment of cardiovascular disease, the Heart Team approach utilizing the expertise of all relevant specialties will be more and more invaluable in facilitating optimal patient selection, procedural planning, complication management, postprocedural care, and patient outcomes.

Part of the book: Interventional Cardiology

By Takashi Murashita

Since its introduction, deep hypothermic circulatory arrest has been widely used for cerebral protection during aortic arch surgery. The use of electroencephalogram plays an important role in intraoperative neurophysiologic monitoring. Systemic cooling to the point of electrocerebral inactivity has been thought to ensure optimal neuroprotection from the ischemic injury during circulatory arrest. Therefore, electroencephalogram can guide surgeons to induce deep hypothermic circulatory arrest at an optimal timing. In the meantime, along with the advent of adjunctive cerebral perfusion techniques, there is a certain trend that circulatory arrest is induced at higher degrees than traditional deep hypothermic approach, called moderate hypothermic circulatory arrest. The role of electroencephalogram in this approach has not been well established yet, but some studies suggested the importance of intraoperative electroencephalogram in this approach as well. Electroencephalogram is also utilized in emerging operative techniques called hybrid arch repair. To conclude, intraoperative use of electroencephalogram can greatly contribute to cerebral protection in the field of aortic arch surgery, and surgeons should be familiar with its mechanism, indication, and interpretation.

Part of the book: Electroencephalography

By Takashi Murashita

The use of the left internal mammary artery (IMA) has been shown to improve long-term survival and has been a gold standard in coronary artery bypass grafting (CABG). However, the choice of second or third graft conduit is still controversial. Multiple studies demonstrated the benefit of using multiple arterial grafts such as right IMA and radial artery in addition to left IMA in terms of long-term survival and graft patency. However, most of the centers still perform CABG with one IMA and vein grafts in a real world. The challenges for bilateral IMA utilization include longer operative time and concerns for higher rates of perioperative morbidity and mortality associated with increased sternal wound infection. Several studies reported that skeletonization technique can reduce the risk of sternal wound infection. Radial artery is another arterial conduit, which does not increase the risk of sternal wound infection and is easy to harvest. The superiority between radial artery and right IMA has been controversial. In the meantime, multiple trials have been made to improve the patency of vein grafts. The choice of graft conduits in CABG should be well considered preoperatively based on each patient’s backgrounds.

Part of the book: Coronary Artery Bypass Graft Surgery

By Takashi Murashita

The prevalence of atrial fibrillation and the likelihood of undergoing concomitant surgical ablation at the time of open heart surgery are increasing. Currently, the conventional cut-and-sew Maze procedure has been predominantly replaced by Cox-Maze IV procedure, in which new energy sources such as radiofrequency energy and/or cryoablation are applied. Cox-Maze IV procedure has been associated with lower rate of complications than a cut-and-sew procedure. However, some previous studies reported the lower success rate of Cox-Maze IV procedure, possibly because radiofrequency ablation or cryoablation cannot always achieve transmurality. For the success of surgical ablation, achieving transmurality, defined as complete atrial wall thickness of fibrotic changes, is of paramount importance. A review of previous articles regarding histopathological changes of the atrial tissue following surgical ablation is performed. The effectiveness of new energy sources such as radiofrequency and cryoablation in terms of histological transmurality is discussed.

Part of the book: Cardiac Arrhythmias

By Takashi Murashita

Isolated tricuspid valve infective endocarditis is relatively rare. However, the frequency of tricuspid valve infective endocarditis in the United States is rapidly increasing, mainly due to the epidemic of intravenous drug use. A medical treatment is the first choice for this disease; however, surgical intervention is required when the patients suffer from heart failure, large vegetation, or persistent bacteremia despite appropriate medical treatment. Several techniques for tricuspid valve reconstruction have been proposed, and their outcomes have been reported to be good. However, in the cases of severe valve destruction, tricuspid valve replacement is required. Post-surgical management of drug-induced infective endocarditis is challenging due to its poor compliance to medication and high rate of reinfection. There is an ethical controversy as to surgical indication for reinfection induced by relapse of drug use. In addition, because reoperation for tricuspid valve carries high risk, there is also a controversy regarding valve choice in drug users.

Part of the book: Advanced Concepts in Endocarditis

By Takashi Murashita

Hypertrophic cardiomyopathy is the most common cause of sudden death in young athletes. Surgical septal myectomy is highly effective for the patients with hypertrophic obstructive cardiomyopathy, which is refractory to medical treatment. The perioperative mortality rate for isolated septal myectomy is less than 1% in high volume centers. The long-term outcomes have been reported to be outstanding with >90% of patients being free of significant symptoms and most being able to return to a normal lifestyle. There is a documented survival benefit after surgical septal myectomy. There is a wide variation of pathophysiology in hypertrophic cardiomyopathy including diffuse midventricular obstruction or subvalvular abnormalities. Several surgical approaches have been applied in accordance with the pathophysiology, such as transaortic, transapical, and transmitral septal myectomy. There is a controversy how to manage concomitant mitral valve regurgitation. The most recent Society of Thoracic Surgeons database showed that operative mortality of concomitant septal myectomy and mitral valve operations was double compared with isolated septal myectomy.

Part of the book: Current Perspectives on Cardiomyopathies

By Takashi Murashita

Cardiogenic shock following cardiac surgery is rare, but a serious complication. Patients who suffer from severe valvular disease, low cardiac function, massive myocardial infarction, and acute aortic dissection have high risk of cardiogenic shock after surgery. Extracorporeal membrane oxygenation (ECMO) is a last resort treatment option for such patients. However, ethical concerns exist regarding whether ECMO is worthwhile for them, because it carries a huge financial burden, and the mortality of ECMO patients following cardiac surgery is reported to be as high as 60–80%. No guideline exists regarding optimal patient selection, duration of mechanical support, and management of ECMO. There are many unanswered questions in this field. This is a comprehensive review regarding the most recent available evidences in the field of ECMO support for post-cardiotomy cardiogenic shock.

Part of the book: Advances in Extra-corporeal Perfusion Therapies

By Takashi Murashita

Robotic mitral valve repair is now routinely and safely performed all over the world. There are many literatures which showed advantages of reduced blood loss, lower risk of infection, lower risk of atrial fibrillation, shorter length of hospital stay, quicker return to normal activities, and a superior cosmetic result, compared with a conventional sternotomy. However, the introduction of new technique requires a learning curve even for expert mitral valve surgeons. There are complications specifically related to robotic mitral valve surgery, such as major vascular complications, inadequate myocardial protection, and unilateral pulmonary edema. The purpose of this chapter is to characterize the tips and pitfalls of robotic mitral valve repair and to discuss the controversial issues in the contemporary practice.

Part of the book: Cardiac Surgery Procedures

By Takashi Murashita

Part of the book: Inflammatory Heart Diseases