Despise the terms good and bad as it is not completely true. You NEED LDL to transport cholesterol throughout the body and so to call it "bad" is a gross overstatement (try surviving without it).
Total cholesterol is not indicative of heart disease per se, but those with a high carb diet may be at greater risk and high carb diets increase blood triglycerides which interact with LDL and make the particles small and dense and thus more likely to penetrate the endothelium of artery walls. Higher fat, lower carb diets tend to do the opposite and make the LDL particles large so they are unable to penetrate the endothelium.
Moral, eat less carbohydrates and try move from the mindset that LDL is "bad" as it is the carbs that make them harmful.
As trigs are transported in the blood by lipoproteins, large, triglyceride-rich VLDL1 results in the formation of small, dense LDL through triglyceride exchange and subsequent hydrolysis. Small, dense LDL are cleared from plasma relatively slowly and tend to accumulate in the circulation where they exert their atherogenic effects.
As an extra, smaller, denser LDL particles bind less to their receptors which increases plasma residence time and thus oxidation (which is bad). The same is true for HDL. Trigs can interact with these as well by reducing HDL plasma residence time and thus decrease reverse cholesterol transport
http://www.ncbi.nlm.nih.gov/pubmed/1420088
http://www.ncbi.nlm.nih.gov/pubmed/19657464
http://www.ncbi.nlm.nih.gov/pubmed/16685042
http://jn.nutrition.org/content/136/2/384.long
http://jn.nutrition.org/content/135/6/1339.abstract?ijkey=4b0ba9ad9aceda47a4f5156d1fa341b91b7eda6b&keytype2=tf_ipsecsha
http://www.ncbi.nlm.nih.gov/pubmed/9645501