Advances in percutaneous cardioscopy for heart disease

Percutaneous endoscopy for direct visualization of the cardiac interior, i.e., percutaneous cardioscopy, was developed in Japan in 1980. Approved by Japanese Ministry of Health, Welfare and Labor, this imaging technique has been used for diagnosis and evaluation of interventional and surgical treatment of various categories of heart disease. This article reviews recent advances in percutaneous cardioscopy. Percutaneous cardioscopy has demonstrated that the endocardial surface exhibits various colors characteristic of different heart diseases. This imaging modality can now be used for evaluation of the severity of myocardial ischemia, and staging of myocarditis. Myocardial blood flow recovery induced by vasodilating agents or percutaneous coronary interventions can be clearly visualized. Subendocardial microvessels can be seen through the endocardium. Combined use of cardioscopy and intracardiac ultrasonography is useful for evaluation of morphological and functional changes in the cardiac chambers and valves. Cardioscope-guided endomyocardial biopsy enables pin-point biopsy of diseased myocardium. Dye-image and fluorescent cardioscopy were developed for evaluation of the subendocardial myocardial blood flow or tissue fluid flow. These imaging techniques have demonstrated that myocardial microcirculation disturbance remains frequently after angiographic successful PCI. Cardioscopy is also useful for evaluation of percutaneous transseptal mitral commissurotomy or open-heart surgery of various categories of heart disease. In near future, cardioscope would be used for guidance of myocardial ablation, valvuloplasty or transendocardial angiogenic or myogenic therapy. In conclusion, percutaneous cardioscopy has the potential to contribute to our understanding of heart disease, and to assist intracardiac therapies.