Surgical access to a man's heart (or a woman's heart for that matter) is best achieved through the sternum, as lawnjart suggests. Direct access to the pericardium can be achieved with a needle aimed upwards from below the xiphisternum. Intravenous access to the right atrium of the heart is usually done through the jugular vein or one of the femoral veins whilst intra-arterial access to the left side of the heart via the aorta can be done through one of the femoral arteries (this is also how they do cardiac catherization for coronary angiograms).