They Say "It's the game of business". They're right.
Some business owners object when one refers to business as a "game". "What do you mean by a game? I take this very seriously, this is my livelihood". If you don't think of your business as a "game", with a clear winner or loser, you better get serious. Start by changing your vocabulary and ensure that everyone on your team is on-board. When you get a new customer, or a deal, say "We won a deal". Conversely, when you lose one say "We lost a deal". Yes, whether you call it a game or not, there are clear winners and losers in business and it may not be so apparent if you don't remind yourself of these consequences.
Some businesses have rituals to celebrate wins. Ringing a cowbell is common. There are no rituals for losing a deal or a customer except finger-pointing or CSI style analysis. Call me crazy, but I would add a loud ritual to losing as well. Maybe a siren? "Seriously, do you know how demoralizing it is for employees to know that we lost a deal"? Yes, I say, and that is why you should sound the alarm. Don't be defensive about this, be transparent. It IS OKAY to lose a deal, you're not going to win all of them. It is NOT OKAY to lose a customer. It will happen. But you have to make sure you learn from the experience, tell everyone about it (siren) and share the lessons that will hopefully prevent you from losing another one in the future.
I don't know where the term "sudden death" originated, a poor choice of words nonetheless. Losing isn't dying. However, losing frequently, especially in business, is a sign of ill health and requires a serious check-up. Think of losing as the stinging pain in your left arm coupled with shortness of breath and jaw pain. If you keep ignoring it, you are facing an uncertain future or worse.