Shock-waves are applied using a combination lithotripsy probe/balloon system, comprising a needle and cannular balloon which can be inserted through the skin at a point between the ribs into the cavity beneath the chest wall and overlying the heart. Alternatively, the shock-wave can be administered extracorporally or via a catheter. A fluid injector is connected to the balloon, allowing it to be inflated with saline or other appropriate fluid to fill the space (for transmission of shock waves and/or to displace tissue—such as lung) and contact the surface of the heart. A shock-wave (acoustic) generator is used to generate shock-waves through the lithotripsy probe, through the fluid and into the myocardial tissue. The fluid provides a uniform medium for transmission of the acoustic energy, allowing precise focus and direction of the shock-wave to induce repeatable cavitation events, producing small fissures which are created by the cavitation bubbles. In this case, channels would not be ‘drilled’ into the heart muscle, minimizing trauma to the tissue while still creating conditions that will stimulate increased expression of angiogenic growth factors.