Abstract: The invention relates to a method for treatment of Hypertrophic Obstructive Cardiomyopathy (HOCM) in a human heart, wherein a laser catheter means is introduced into a patient's body and advanced into a heart cavity and directed towards a hypertrophied region of the heart. Ventricular outflow tract obstructions may be substantially reduced or even abolished when laser light is applied to the hypertrophied tissue so as to produce a coagulation necrosis inside the hypertrophied septal wall.

Abstract: A method for puncture of the inter-atrial septum of a heart is performed by means of a laser catheter assembly comprising at least one longitudinal sheath and an optical fiber connectable to a laser energy source. The components of the laser catheter assembly are perveneously introduced and advanced into the right atrium until the sheath is in intimate contact with the septal wall and laser light is applied via said optical fiber and emitted on the tissue located in front of the distal end of the fiber so as to create a small hole in said inter-atrial septum.